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Science Fiction space combat

Dominions Son ๐Ÿšซ

On a prior thread, we got into an argument over realistic ranges for ship to ship space combat with lasers.

I had thought a couple of light seconds (a light second is 299792458 meters)

Someone else argued that lasers would be limited to point blank range due to dispersion.

Dispersion of a laser is measured by the Rayleigh length which is the distance over which the beam diameter will double and is calculated as(PI*(initial beam diameter^2))/wavelength. https://en.wikipedia.org/wiki/Rayleigh_length

I decided to calculate Rayleigh length for a few options. I found a list of naval cannon sizes here: https://en.wikipedia.org/wiki/List_of_naval_guns_by_caliber

The smallest naval gun in the US arsenal (WWII) is 28mm.
The largest is 406mm (WWII 16 inch gun)
The most modern US naval gun listed is 155 mm

So I will use those three options for beam diameter.

I also decided to check three wave length options, since Rayleigh length is inversely proportional to wavelength.

I went with Hard X ray (10^-10 meters), extreme UV (10^-8 meters)
Visible light (10^-6 meters)

28mm beam
xray = 24,630 kilometers
UV = 246 kilometers
VL = 2.46 kilometers

155mm
xray 2.52 light seconds
UV 7547 Kilometers
VL 75.5 Kilometers

406mm
xray 17.27 Light seconds
UV 51,785 Kilometers
VL 517 Kiliometers

Any of those size beams is still going to be able to put all the initial output energy into a Ship sized target at the Rayleigh length.

Replies:   Dominions Son  Not_a_ID
Dominions Son ๐Ÿšซ

@Dominions Son

Note: even for FTL capable starships, only a visible light laser is limited to what I would consider point blank range.

Ernest Bywater ๐Ÿšซ

Dispersion of a light beam is also a factor of the medium it's travelling through. The less dense the medium, the less dispersion. Then you have other technical factors to take into account, such as the system used to align the light beam and how the light is generated. Way too technical for this little birdie to think about too much.

Replies:   Dominions Son
Dominions Son ๐Ÿšซ
Updated:

@Ernest Bywater

Dispersion of a light beam is also a factor of the medium it's travelling through. The less dense the medium, the less dispersion.

We are talking about ship to ship space combat, so the medium is vacuum and refraction effects need not be considered.

Then you have other technical factors to take into account, such as the system used to align the light beam and how the light is generated.

We are talking about lasers, not regular light beams. Even with modern lasers, optics, beyond the laser emitter itself are much less of a factor.

Also, ship to ship space combat in a science fiction setting. Safe to assume that available optics are drastically better than the real world.

Ernest Bywater ๐Ÿšซ

Last I heard from the scientific circles was space wasn't a perfect vacuum and there were dust particles about, well spread out but there. However, you mention 'dispersion' and that requires something to disperse it. If the beam is in some sort of polarised emission so the rays go out parallel in a tight beam, there shouldn't be any natural dispersion.

Of course, we can then move onto gravity lenses and gravity beams, but my name isn't Webber.

Replies:   Dominions Son  pangor
Dominions Son ๐Ÿšซ
Updated:

@Ernest Bywater

Last I heard from the scientific circles was space wasn't a perfect vacuum and there were dust particles about, well spread out but there. However, you mention 'dispersion' and that requires something to disperse it.

Actually no.

1. Lasers will spread over distance even in perfect vacuum. https://en.wikipedia.org/wiki/Beam_divergence

2. The density of the interplanetary medium is very low, about 5 particles per cubic centimeter in the vicinity of the Earth. https://en.wikipedia.org/wiki/Interplanetary_medium

It might have some effect, but probably not significant at the beam sizes/energies we are talking about.

3. The point here is to define something plausible for space laser combat ranges not create a definitive calculation for all possible conditions.

Replies:   Not_a_ID  REP
Not_a_ID ๐Ÿšซ

@Dominions Son

1. Lasers will spread over distance even in perfect vacuum. https://en.wikipedia.org/wiki/Beam_divergence

Not just LASERS, but anything on the electromagnetic spectrum will "spread" over distance without regard to the medium. Although the medium can make it happen sooner rather than later.

That said, you then end up contending with focal lengths, how adjustable that focal length may be(think telephoto lenses on cameras as a close comparison), and how quickly it can be adjusted. Which then brings in the matter of how imperfect the focusing medium may or may not be.

In this case, I'd presume Dominion's Son is presuming a nearly 100% efficient focusing means, presumably with variable focal lengths out to a presumed maximum range with that 100% efficiency number.

REP ๐Ÿšซ

@Dominions Son

The point here is to define something plausible for space laser combat ranges

If I understand your intent correctly (i.e. a plausible rationale for space combat), it seems to me that you are approaching development of your rationale the wrong way. This thread seems to be focused on the amount of dispersion of the beam. Regardless of improvements in current technology, dispersion will occur over distance. Accept that and move on. To me, the more important factors are:

1) The ability and tactics used by the target to avoid an energy beam before the attacker fires and to break contact once a beam hits the target.

Lots of factors to consider here. Does your future technology allow the target to make small micro-jumps? If not, how long does it take to make a significant change to the target's direction of travel? Can the target move sideways or just in the direction of force created by its main engines?

2) The ability of the attacker to predict the movements of the target spacecraft.

Humans tend to be predictable over a period of time, and computers are more likely to control the target's evasive actions, but computers are programed devices so there is a pattern. The attacker's computer need to detect that pattern and synchronize the aiming and firing of its weapon so the beam reaches the proper point in space at the same time that the spacecraft shifts to that place.

3) Duration the beam is focused on a target that is taking evasive action.

The attacker can't shift the beam to track movement of the target. The beam needs to be fired as a short burst, not a continuous output.

4) The amount of energy the attacker must provide in order to damage the target (dispersion does affect the amount of energy that reaches the target).

5) The target's ability to shield itself from an energy beam (i.e. absorb or disperse the beam's energy before the beam reaches the outer surface of the spaceship).

Replies:   Dominions Son  pangor
Dominions Son ๐Ÿšซ
Updated:

@REP

If I understand your intent correctly (i.e. a plausible rationale for space combat)

You don't. It's not a plausible rational for space combat, but a plausible rational for long range combat.

1)

A) If you allow combat at FTL speeds, neither beam weapons nor ballistic ordinance weapons make sense. Only missiles make sense in that situation and even then the missiles themselves need to be FTL capable.

B) Allowing Micro FTL jumps by itself is not enough to make a tactical difference against laser weapons.

Once you discount FTL combat, most combat will occur inside a star system. With other large objects about, micro jumps inside a start system will be particularly dangerous.

Assume combat at 2 light seconds. You have to detect that the enemy has fired, calculate and execute a micro jump in under 2 seconds. I don't see that as particularly plausible.

You might use a micro jump to flee, but using it to dodge attacks with laser weapons is not practical.

C) Again, I'm mainly talking about ship to ship combat, not fighter to fighter or ship vs fighter.

It's not just changing the velocity of the ship, to dodge laser weapons, you have to change the velocity by enough to alter where the ship will be by hundreds or even thousands of meters in just seconds ( milliseconds). And, you have to do so without turning the crew into goo. Heavily armed warships, no matter how fast, are not going to turn on a dime.

ETA:
1G equals acceleration of 1 meter per second per second. For a large warship to effectively dodge laser weapons even at several light seconds of range, it has to execute maneuvers at hundreds or thousands of Gs. Even with inertial dampening technology, that could be risky to the crew.
End ETA

3) I don't see that as a particularly plausible assumption.

4) that's what the thread is about. A 155mm xray laser will reach a distance of 2.5 light seconds before the beam doubles in diameter to 310mm. Against a target with a silhouette of thousands of square meters, that's not going to result any loss of energy delivered to the target.

5) This is more a factor in how long combat will last than it is for the range at which combat will occur.

Replies:   Not_a_ID  garymrssn  REP
Not_a_ID ๐Ÿšซ

@Dominions Son

Assume combat at 2 light seconds. You have to detect that the enemy has fired, calculate and execute a micro jump in under 2 seconds. I don't see that as particularly plausible.

Keep in mind also that with light speed sensors & weapons, engagement at 2 light seconds away means a 4 second time lag between the "most recent data" and when you have "rounds on target" as it were. Which is why I was comparing it to an old school dogfight, even with advanced targeting systems, you're still essentially firing blind in many respects. Not so much of an issue with large non-maneuverable craft, but for anything capable of moving when the pilot/Captain wants it to, 4 seconds is enough time to potentially defeat the targeting prediction systems. They may not be able to shoot back effectively, but they could avoid being shot.

Replies:   Dominions Son
Dominions Son ๐Ÿšซ

@Not_a_ID

Not so much of an issue with large non-maneuverable craft, but for anything capable of moving when the pilot/Captain wants it to, 4 seconds is enough time to potentially defeat the targeting prediction systems. They may not be able to shoot back effectively, but they could avoid being shot.

Again, even jut defeating predictive targeting is about more than being able to change course every x seconds. The larger your ship is the more energy it will take to affect a given change in velocity. However, the bigger the ship is, the greater the change in velocity you need for evasive maneuvers.

garymrssn ๐Ÿšซ

@Dominions Son

Assume combat at 2 light seconds. You have to detect that the enemy has fired, calculate and execute a micro jump in under 2 seconds. I don't see that as particularly plausible.

With a light based weapon at a range of 2 light seconds, not only does it take 2 seconds to reach the target but the target can't see it until it gets there. That is unless the target can see faster than the speed of light.

Replies:   Not_a_ID
Not_a_ID ๐Ÿšซ

@garymrssn

With a light based weapon at a range of 2 light seconds, not only does it take 2 seconds to reach the target but the target can't see it until it gets there. That is unless the target can see faster than the speed of light.

Which is why my initial comment said it would only truly be viable in an ambush scenario. After that they know someone is shooting at them, they don't necessarily need to know where the shot is actually going.

They just know they don't want to be anywhere that shot may be headed for--in other words, evasive maneuvering will begin in earnest. They may not need to defeat the weapon itself, simply thwarting the targeting computer should do.

Replies:   Dominions Son
Dominions Son ๐Ÿšซ

@Not_a_ID

They just know they don't want to be anywhere that shot may be headed for--in other words, evasive maneuvering will begin in earnest.

For anything bigger than the equivalent of a corvette ( https://en.wikipedia.org/wiki/Corvette ) evasive maneuvers aren't going to be all that effective unless you are close to the effective range limit of the enemy firing at you.

Replies:   Not_a_ID
Not_a_ID ๐Ÿšซ
Updated:

@Dominions Son

For anything bigger than the equivalent of a corvette ( https://en.wikipedia.org/wiki/Corvette ) evasive maneuvers aren't going to be all that effective unless you are close to the effective range limit of the enemy firing at you.

But that is a relative thing, the technology available to a given power will change what their calculus is as to what they define as being "a corvette." So if the technology disparity is great enough, you can end up with a space-faring civilization fielding "battleships" from the perspective of another civilization, while they view them as little more than "corvettes." (and may be as nimble as, or even more so, than the corvettes of the other less advanced civilization)

So once more, it comes back to how maneuverable the craft are. Size IS a factor, as that would change the amount of thrust they need in order to change course, but if the technical capability is present, they'll be able to generate that thrust for however massive the craft is. (Which then takes us back to inertial damping)

Replies:   Dominions Son
Dominions Son ๐Ÿšซ
Updated:

@Not_a_ID

Size IS a factor, as that would change the amount of thrust they need in order to change cours

It's not just how much thrust they need to change course, The bigger the ship, the bigger the course change has to be for effective evasive maneuvers.

Sorry, I'm not buying that evasive maneuvers will be even half as effective as you suggest for anything bigger than around 100 Meters.

Replies:   Not_a_ID
Not_a_ID ๐Ÿšซ
Updated:

@Dominions Son

Sorry, I'm not buying that evasive maneuvers will be even half as effective as you suggest for anything bigger than around 100 Meters.

Bigger ships, in particular bigger war ships, are likely to be heavily protected as well. So even with the additional hurdle of needing to move further to move clear of the "window" because their "window" is so much larger. You still come back to the issue that REP already brought up.

Power density of the beam vs energy dissipation ability of armor/shields of the ship being hit. Where even for that super-massive ship, they may not be able to move clear of the beam, but they have a pretty good chance of being able to ensure a different part of the ship gets hit.

Which then moves us into the kind of protective systems a ship may be employing. If shields are being used, how "discrete" are the various segments of the system? (IE, are different "cells" being hit on each shot--reducing the risk of a breach?)

If armor is being employed, is the energy input from the hostile fire sufficient to overwhelm the ablation/dissipation capacity of the armor in a single shot/burst? Or would they need to hit the same spot in multiple successive shots over a brief period of time? (Where "rolling away" or simply shifting those hits to other areas gives the previously hit region a chance to dissipate the energy and "recover" without any active measures needing to be taken)

This also ignores things like a ship that may have a semi-organic/self-repairing hull, with or without robotic/nano-tech assistance being there even before "regular crew" get involved.

Replies:   Dominions Son
Dominions Son ๐Ÿšซ

@Not_a_ID

Bigger ships, in particular bigger war ships, are likely to be heavily protected as well.

Again, I fundamentally disagree that ship protection factors affect combat range in any significant way.

Power density of the beam vs energy dissipation ability of armor/shields of the ship being hit.

Actually, for energy shields, there can be a finite limit to the amount of energy they can dissipate regardless of the density. A low energy density attack against a large percentage of the shield surface could actually be more effective in bringing the shields down.

If armor is being employed, is the energy input from the hostile fire sufficient to overwhelm the ablation/dissipation capacity of the armor in a single shot/burst? Or would they need to hit the same spot in multiple successive shots over a brief period of time? (Where "rolling away" or simply shifting those hits to other areas gives the previously hit region a chance to dissipate the energy and "recover" without any active measures needing to be taken)

Again, this affect how long a battle might last, it has no fundamental effect on the rage limit at which combat can occur.

Replies:   REP  Not_a_ID
REP ๐Ÿšซ
Updated:

@Dominions Son

Again, I fundamentally disagree that ship protection factors affect combat range in any significant way.

DS, hypothetically speaking - you put on a bullet proof vest and give me a Glock. Let me shoot you at 50' and then at 10'. Then, we can talk about the effect range has on protection factors.

Replies:   Dominions Son
Dominions Son ๐Ÿšซ
Updated:

@REP

you put on a bullet proof vest and give me a Glock. Let me shoot you at 50' and then at 10'. Then, we can talk about the effect range has on protection factors.

OR you can put on the vest and I'll shoot you with a Barret .50 at 1500 meters.

If you could make that work with naval cannons and surface ship armor, I might decide you have a point.

Not_a_ID ๐Ÿšซ

@Dominions Son

Again, this affect how long a battle might last, it has no fundamental effect on the rage limit at which combat can occur.

Length of battle can tend to be a very decisive factor in the outcome of the battle. That and generally speaking, "max range engagement" in the era before smart-weapons didn't have a very good track record. Generally speaking, the preferred tactic was to get as "up close and personal" as practical, even for the ranged weaponry.

It wasn't until electronically guided munitions came around that "standoff weaponry" really became decisive. Sure, those 16 inch battleship guns could throw out a lot of hurt, but they didn't do much for capturing land until/unless you had boots on the ground(/ready to land).

Otherwise, perhaps another historical battle could be used to compare against in your max range combat where nobody is able to do any kind kind of meaningful damage on the other craft: USS Monitor vs CSS Virginia.

https://en.wikipedia.org/wiki/Battle_of_Hampton_Roads

of course, while the 3 hour gun fight between the two ships was deemed "indecisive" the fighting that happened the day before the Monitor arrived DID change Naval Warfare for the rest of the century, as that marked the end of the age of sail for both the UK and France among others.

(CSS Virginia had sunk 2 ships, and run another one aground before night fell. USS Monitor arrived to defend the grounded ship over night, which set the stage for the two ships to fire canon balls at each other that were incapable of breaching one another's armor when Virginia returned to finish off the third)

Replies:   Dominions Son
Dominions Son ๐Ÿšซ

@Not_a_ID

Length of battle can tend to be a very decisive factor in the outcome of the battle. That and generally speaking, "max range engagement" in the era before smart-weapons didn't have a very good track record. Generally speaking, the preferred tactic was to get as "up close and personal" as practical, even for the ranged weaponry.

That was more a matter of the effective reach of weapons of the day exceeding the the capability to determine the enemy's position and the precision with which the weapons could be moved.

Naval surface warfare also has to deal with another factor that wouldn't apply to space combat but which affects precision aiming of ballistic weapons. The sea surface itself moves. This will cause even a stationary ship to rise and fall and pitch and yaw.

It wasn't until electronically guided munitions came around that "standoff weaponry" really became decisive. Sure, those 16 inch battleship guns could throw out a lot of hurt, but they didn't do much for capturing land until/unless you had boots on the ground(/ready to land).

I'm talking about ship to ship combat, not capturing land.

Even at maximum range, one hit from a 16 inch shell could sink a battleship. The problem during WWII was the difficulty of getting that hit.

Otherwise, perhaps another historical battle could be used to compare against in your max range combat where nobody is able to do any kind kind of meaningful damage on the other craft: USS Monitor vs CSS Virginia.

No, not really comparable.

1. I am talking about a range for lasers where energy density may have dropped by 75%, but total energy is the same. At maximum range, a black powder cannon shell in atmosphere has lost more than 90% of it's total energy. I don't think that is a comparable at all.

2. Those first iron clad ships were designed for combat against wooden ships. The guns of both the Monitor and the Virginia were horribly under-powered for combat against another iron clad ship. Evidence is lacking that their weapons would have been any more effective against each other even at closer range.

In general I agree, the majority of combat will take place well under even half the maximum range at which it can happen. But to understand the rage at which most combat will take place, you still have to define the maximum range at which it can take place.

REP ๐Ÿšซ

@Dominions Son

Your reply seemed to say "a plausible rational for long range combat" with the intent of defining a reasonable range. So far the thread addressed dispersion with only a loose tie-in to range. Before you can define a reasonable range, you must define the capabilities of the attacking and target spacecraft.

For the attacking vehicle, there is the capability to detect the target vehicle and determine its heading and speed. Let us also assume the attacker has a 155mm laser and the attack range is 2.52 light seconds.

For the target vehicle, we need to know its capability to withstand a laser beam using some form of shield and/or the resistance of its hull material to heating. We also need to know if the target vehicle has the capability to make micro-jumps of say 5 KM. Short jumps should not be dangerous within a solar system if there are no large bits of debris in the immediate neighborhood. If you were shooting at me, I would not sit there until you fired at me. I would jump before the beam had a chance to reach me.

1) Evasion Capability vs Attack Range. The attacker detects the location, speed, and heading of the target, and then aims and fires its laser. Meanwhile the target with a micro-jump capability is taking evasive action.
The target has just finished a 5 KM micro-jump. The time between the attacker detecting the target's new location and a laser beam, fired at the new location, reaching that location is a little over 5 seconds. If the target's computer is programed to automatically make micro-jumps at say 4-second intervals, then the beam will never hit the target. The jump rate is one factor needed to define the maximum attack range.

2) Duration of Beam Contact with Target. If we assume the target cannot make micro-jumps, then the duration of beam contact is important if the beam power at the target cannot destroy or seriously damage the target with a single short contact. That means the beam will have to overcome the shield or hull characteristics over a period of time and that means the beam must maintain contact with the same spot on the target vehicle to produce a cumulative heating effect. That may be very difficult to do with a moving target at a 2.52 light minute range. If the target is also making constant variations in its speed and heading, then the 2.5-second delay will also make that difficult to do. Those factors need to be taken under consideration in determining maximum attack range.

3) Power on Target. The deciding factor in whether a laser beam can damage the target is the energy in joules per square mm at the time the beam leaves the laser. At the 2.52 light second attack range, dispersion will result in the beam energy per square mm at the target being only 25% of the beam energy per square mm at the laser. If the beam energy per square mm is not adequate to damage or destroy the target, then there are 2 solutions: increase the laser's output power or reduce the range. Since lasers would be fired a full power in a combat situation, then the only variable would be range. Cutting the range by half would increase the power at target to 44% of the beam energy per square mm at the laser.

Replies:   Dominions Son
Dominions Son ๐Ÿšซ

@REP

We also need to know if the target vehicle has the capability to make micro-jumps of say 5 KM.

Sorry, I don't consider anything under 1 light second plausible for an FTL micro jump. 5 KM is absurd.

1)
A) A micro jump that short is implausible on it's own. Suggesting it could be done repeatedly every few seconds is an order of magnitude less plausible. Most Science fiction universes where FTL is done in "jumps" a jump requires enormous energy build up and would require several seconds to execute after all the necessary navigational calculations have been completed which itself would take a significant amount of time.

B) A lot of science fiction with that style of FTL, you have to be near the edge of a star system to initiate a jump because the gravity well interferes with the operation of the FTL drive, often in ways that separate from the increased chance of collision can cause catastrophic failure. Again, one micro jump of several light seconds to escape from combat might be plausible. Repeated micro jumps of a few KM as a form of evasive maneuvers is not.

C) In universes with that style of FTL where FTL combat is not possible, interdiction systems that can pull a ship out of FTL or prevent it from entering FTL are developed.

2) It does make a difference, but you insist on talking about what is possible only for the smallest ships. For a large ship (1000+ meters) it isn't enough to constantly vary speed an heading. The ship's actual position has to change by hundreds of meters every few seconds for evasive maneuvers to be even half as effective as you are suggesting. The basic laws of motion are going to make that very rough on the crew, even with some degree of inertial damping.

3) A increase in power can be done on a ship engineering level (construction), it doesn't need to be done on the fly.

Replies:   REP
REP ๐Ÿšซ

@Dominions Son

Sorry, I don't consider anything under 1 light second plausible for an FTL micro jump.

DS, you can shoot my observations down all day if you want to base your goal coming up with a reasonable range for long-range combat on what other fiction stories use as their premise for combat within a solar system. Are you bound by what they used in their stories, or are you flexible enough to say "Their premise is fiction and when our fictional assumptions meet the real world, these Authors may be wrong."

As Docholladay said,

In Jules Verne's stories the theory was sound, but the technology sure was very different than current knowledge of science and technology has proven to be.

The current theory may not be accurate, and future technology may permit things that current Authors don't have in their stories. A 5 KM jump may be possible using technology not currently envisioned, and the technology have absolutely nothing to do with FTL.

Replies:   Dominions Son
Dominions Son ๐Ÿšซ

@REP

"Their premise is fiction and when our fictional assumptions meet the real world, these Authors may be wrong."

I'm not a big fan of hard science fiction, so I don't give a rat's ass what happens when their fictional assumptions meet the real world.

I'm talking about stories with FTL travel. Real world is already out the fucking window.

If you allow continuous "micro jumps" for evasive maneuvers, you might as well go full bore and allow full FTL combat. At which point, the ONLY plausible weapons are FTL capable missiles. Which likely stretches combat ranges to several light hours.

Replies:   REP
REP ๐Ÿšซ

@Dominions Son

I'm talking about stories with FTL travel

But you are talking about long-range combat and excluded FTL. Why do you keep pulling FTL into the discussion if you want to exclude it.

Replies:   Dominions Son
Dominions Son ๐Ÿšซ

@REP

But you are talking about long-range combat and excluded FTL. Why do you keep pulling FTL into the discussion if you want to exclude it.

1) I didn't exactly bring it into the conversation. Not a ID brought it up by trying to add in FTL micro jumps for evasive maneuvers.

2) I'm not excluding it from existence, only from combat. Star Trek is the ONLY science fiction universe that allows combat while using FTL drives.

3) Combat in FTL is an entirely different ball game. At that point, both lasers and ballistic ordinance weapons are pointless. Only FTL capable missiles work as plausible weapons.

The situation I am focused on is FTL travel exists, but combat is limited to sub-light speeds and generally takes place in a stellar gravity well.

Range might make a significant difference in the effectiveness of armor against ballistic weapons in the Earth's atmosphere. However, that is because the atmosphere is constantly reducing the projectile's energy.

You have not made any case that that effect will translate in any way to space combat. Real world or not.

Replies:   REP
REP ๐Ÿšซ

@Dominions Son

It seems evident to me that you are only considering factors that fit into your preconceived concept of long-range combat and the things that might affect range. So I'll just drop out of this conversation.

pangor ๐Ÿšซ

@REP

but computers are programed devices so there is a pattern.

Not necessarily. Imagine a long-range laser fight - *really* long range as in several light seconds. Depending on the distance, it makes a lot of sense for the attacked to make totally unpredictable moves. E.g. if the ships are 20 light seconds apart, sensory information on the targets' course takes 20 seconds to reach the attacker, and the laser beam needs another 20 seconds to reach the target. On top of those, add some seconds to actually calculate/predict the course and aim the laser. The attacked ship, though, has exactly this time to change its course in a way that it is exactly *not* where a predicted shot would pass through.

A human might make predictable moves here, but a computer could take a really random course, as in quantum event based randomness. And this is no futuristic Sci-Fi, this can be done with a handful of electronic devices and a bit of software to an extend that total ramdomness can be achieved with a high grade of quality.

pangor ๐Ÿšซ

@Ernest Bywater

space wasn't a perfect vacuum and there were dust particles about, well spread out but there.

While this is true, I'd say that a floating speck of dust is not really an issue (for long) if it happens to be in the path of an arm-thick gazillion Watt laser beam.

Not_a_ID ๐Ÿšซ

@Dominions Son

On a prior thread, we got into an argument over realistic ranges for ship to ship space combat with lasers.

Ultimately the range consideration that factors in after focal length/focusing capabilities is a matter of:
1) what sensor technology is employed in conjunction with targeting systems.
2) How maneuverable the spacecraft are.

If you're dealing with light-speed sensors, then engagement from several light seconds out may not be a good choice if you're dealing with a target you have reason to expect will be highly agile even if the shot lands where expected(presuming an ambush scenario).

Basically, the further away the two combatants are from each other, a fight with light-speed weapons(and light-speed sensors) will begin to start resembling a dog fight between aircraft with auto-canons/machine guns. By the time the round gets there, the target is gone, even if the "round" is faster than the craft.

Replies:   Dominions Son
Dominions Son ๐Ÿšซ
Updated:

@Not_a_ID

If you're dealing with light-speed sensors, then engagement from several light seconds out may not be a good choice if you're dealing with a target you have reason to expect will be highly agile even if the shot lands where expected(presuming an ambush scenario).

True, you aren't going to be engaging fighters at that range.

On the other hand, how agile is a battle-cruiser going to be?

These numbers are intended for ship to ship combat.

Battle cruisers engaging each other with the big guns at long range while smaller point defense lasers in fast tracking turrets protect against faster and more agile light attack craft at much shorter ranges.

ETA:

To relate this to real world naval warfare, the 16 inch guns on a battle ship had a range of 10s of miles, in a fleet battle, A battle ship would use the big guns against enemy battle ships at ranges of over a mile while they are also bristling with smaller guns that would engage lighter faster torpedo boats and aircraft at at much shorter range.

The story Three Meals a Day talks about Battle cruisers in the size range of 1500 to 2000 meters long and dreadnoughts up to 4000 meters long. At a range of 2 light seconds, a laser will hit 2 seconds after firing.

A terrestrial surface battle ship is around 130 meters long and 17-19 thousand tons. Scale that up by over and order of magnitude, How much do you expect a 2000 meter, 200,000 metric ton ship to be able to change it's velocity by in 2 seconds?

Replies:   Not_a_ID
Not_a_ID ๐Ÿšซ

@Dominions Son

On the other hand, how agile is a battle-cruiser going to be?

Depend on the technologies the battle-cruiser has on board?

Are we talking an Imperial Star Destroyer, or are we talking about the USS Defiant? Or something else entirely? Maybe the White Star or the Firefly?

Depending on the mechanics of movement you're allowing that particular craft to employ, other variables come into play.

Dominions Son ๐Ÿšซ

@Not_a_ID

USS Defiant and White Star are not battle cruiser class vessels. In their respective universes they would be destroyer class.

Replies:   Not_a_ID
Not_a_ID ๐Ÿšซ

@Dominions Son

USS Defiant and White Star are not battle cruiser class vessels. In their respective universes they would be destroyer class.

The main thing about the Defiant and White Star wasn't their size. It was their having inertial dampers and being able to practically stop and change directions on a dime. where obviously, their smaller size helps considerably as that means even less inertia to overcome. :)

But the example could have just as easily been a Minbari Cruiser or the NCC-1701-E for that matter. Still highly agile and fast ships despite their size.

Replies:   Dominions Son
Dominions Son ๐Ÿšซ

@Not_a_ID

It was their having inertial dampers and being able to practically stop and change directions on a dime.

Nope, that's not what inertial dampers do, at least not in Star Trek.

The inertial dampers don't lower the inertia of the ship, they counteract the effects of inertia on the contents (crew) of the ship, so the ship can make 100+G maneuvers in an emergency without turning the crew into blood smears on the bulkheads.

The ship still has to have enough thrust to make those kinds of maneuvers. And they aren't perfect, so sudden unplanned changes in velocity can still throw the crew around.

Replies:   Not_a_ID
Not_a_ID ๐Ÿšซ
Updated:

@Dominions Son

Nope, that's not what inertial dampers do, at least not in Star Trek.

The inertial dampers don't lower the inertia of the ship, they counteract the effects of inertia on the contents (crew) of the ship, so the ship can make 100+G maneuvers in an emergency without turning the crew into blood smears on the bulkheads.

The ship still has to have enough thrust to make those kinds of maneuvers.

Typing on a tablet and being lazy. :p

Yes, the dampers "only" prevent the crew from being turned into mush. Of course, it would also follow that it would also lower the structural forces/stressors being exerted as a result of inertia. Meaning a lighter structure than would be needed in order to handle that much acceleration otherwise, which means potentially less energy needed in turn to generate that much acceleration.

Some of this stuff would feed back in on itself depending on the energy requirements for each step in the chain. (It's possible, and even probable that inertial dampening is more energy intensive than just simply adding more thrust)

Replies:   Dominions Son
Dominions Son ๐Ÿšซ

@Not_a_ID

Yes, the dampers "only" prevent the crew from being turned into mush. Of course, it would also follow that it would also lower the structural forces/stressors being exerted as a result of inertia. Meaning a lighter structure than would be needed in order to handle that much acceleration otherwise, which means potentially less energy needed in turn to generate that much acceleration.

In Star Trek on top of the inertial dampers, the ship's superstructure is reinforced with force fields, referred to as the structural integrity field, so Star Trek universe starships are going to be particularly light relative to their volume.

Dominions Son ๐Ÿšซ

@Not_a_ID

Are we talking an Imperial Star Destroyer, or are we talking about the USS Defiant?

For Star Trek Starships, Laser/phaser weapons are largely useless at warp speeds. On the other hand, they have photon torpedoes which are warp capable cruise missiles.

I'm thinking more towards Star Wars tech where combat at FTL speeds is flat out impossible, everyone has to slow to sub light speeds to engage in combat.

ChiMi ๐Ÿšซ

For weaponry and other hard-scifi Shiptech, I would take a look at the indie game "Aurora4X" You have to research up to 20 different fields to complete and use a laser weapon.

Here are some tutorials from the game regarding beam weapons
http://aurorawiki.pentarch.org/index.php?title=Beam_Overview

and the correct input into Ships
http://aurorawiki.pentarch.org/index.php?title=Basic_Beam_Warship_Tutorial

I think it is a good overview how to include something like this into a novel.

Vincent Berg ๐Ÿšซ

Despite how many 'hard' science-fiction stories I've written, I've yet to write a single 'combat in space' scene in any of them. I'm working on one now, though I'm mainly planning on avoiding the situation entirely by taking a different tact (using diplomacy rather than 'shooting it out') but this is still fodder for my mill.

docholladay ๐Ÿšซ

Hard core you have to have some kind of logical explanation. If its just theoretically possible now, have some scientist or inventor make some thing. The scientist or inventor doesn't have to be real, just name them as the creators of the technology. You can mention the theory but the tech will probably be very different from what is imagined today.

In Jules Verne's stories the theory was sound, but the technology sure was very different than current knowledge of science and technology has proven to be. In his stories the science and tech was not really explained that much, just enough to spark the reader's imagination.

To many precise details can create huge amounts of problems for fiction writers. Precise details work nice for scientific research and technology development but in science fiction. It can create major problems depending on how its presented.

Most science fiction will only mention scientific and technology discoveries as needed and then its the discovery and or invention of some one not directly involved in the story.

Replies:   Dominions Son
Dominions Son ๐Ÿšซ

@docholladay

Hard core you have to have some kind of logical explanation.

That's not the purpose of this thread.

On another thread, someone argued that divergence alone made laser weapons useless for ship to ship combat any anything more than point blank range. I just wanted to demonstrate that that isn't the case, that long range combat with laser weapons is plausible. For hard science fiction, or science fantasy.

ChiMi ๐Ÿšซ

Doing hard Scifi is tricky and you can make an ass out of yourself if it is obviously wrong.

In one of my stories I am planning a weaponized Supernova. The enemy does something to a star and the star goes supernova.

There are 3 main issues that have to be answered:
1. How does the supernova gets initiated? That is probably the most soft scifi answer in the plot because hard scifi doesnt really play ball with a quick initiation of a supernova.
2. When are the people getting killed? That's easy, the neutrinos would kill everything in the system in lightspeed. So something like earth would be dead after 8 ยดminutes.
3. When does the physical supernova shockwave hit? I checked that several times and got a little bit of different answers, but the median answer seems like 1/20th of lightspeed.

Harold Wilson ๐Ÿšซ

The "final" battle of the naval-gunnery era was Leyte Gulf. Battleships shooting at other battleships, torpedoes, destroyers, the whole shebang. In that battle, US forces equipped with radar gun directors engaged at a range of 12+ miles, which would require a time-of-flight between 20 and 30 seconds. This was a "surprise" attack, so should be considered at the high end of engagement range.

It's reasonable to consider evasive maneuvers. From a 0-velocity start, a 5g acceleration (uncomfortable, but bearable for present-day pilots) will produce a displacement of 625 meters after 5 seconds, and 2500 meters after 10 seconds.

Assuming that you are in a vessel 1000 meters long and 150 meters high/wide (proportionally slightly fatter than an American aircraft carrier), 1.75 seconds is enough time to "evade" - that is, to displace half the width of the craft, while 4.5 seconds is enough time to evade on the anterior/posterior axis.

Thus, evasive maneuvers can work if the crew is shielded or braced against them. (For example: sitting in a snazzy acceleration couch.) An unshielded/unbraced crew would probably require lower thrust, and thus could support less evasion.

So I would conclude that full-up naval combat (not cargo interdiction or whatever), with all parties aware that they were engaged, might be possible at 10 light seconds (LS), provided there were multiple shot sources so as to produce some sort of cross fire effect. But it's more likely to be effective at closer ranges. Expect the "first shot" to occur at 10-30 LS in an ambush scenario, but then expect some time and energy spent closing.

In scenarios where one side is constrained - they're stuck with low velocity orbiting a planet, or they're coming out of a hyper jump along a known vector, or threading their way through a Star Wars-density asteroid field, it makes sense for the opponent to shoot from farther away.

If you add in inertial compensators or whatever, to allow greater delta-V, then the range has to close. At 10g acceleration, lateral displacement time changes to 1.25 seconds (from 1.75 at 5g). At 100g acceleration, it's about 0.4 seconds. (Sadly, those first few tenths of a second are all very similar. The tยฒ component doesn't kick in for a bit.

Naturally, you try to factor this in to your salvos. If firing at 5 LS, you spread your shots across a wide swath and probably miss. Firing from 2 LS, a moderately tight grouping might hit against a target with an acceleration limit of 10g or less - take the shot!

Replies:   Not_a_ID
Not_a_ID ๐Ÿšซ
Updated:

@Harold Wilson

Assuming that you are in a vessel 1000 meters long and 150 meters high/wide (proportionally slightly fatter than an American aircraft carrier), 1.75 seconds is enough time to "evade" - that is, to displace half the width of the craft, while 4.5 seconds is enough time to evade on the anterior/posterior axis.

Which brings us back to the "sensor lag" side of things. If an enemy craft can maneuver clear of the trajectory your (time lagged) targeting systems locked in on, you're likely outside "effective engagement" range.

Now I guess you could extrapolate potential trajectories and put rounds on as many of them as practical, but you're diluting your firepower by doing so. Depending on the weapon (and target) involved, that may be a non-issue, but in other cases, it will be a big deal. As you're going from one or two "big space guns" to multitudes of them.

So we're back to the attacking craft at 2 light seconds distance contending with a craft that can accelerate at 5G's and potentially have cleared most of the targeted area before shots arrive about 4 seconds after the light-speed targeting data occurred. (How exactly do you describe that scenario? That's part of the problem in Sci-Fi at this time. While the concepts exist, they're rather esoteric at present, to the point no "jargon" has solidified around it yet to my knowledge.)

Replies:   Dominions Son
Dominions Son ๐Ÿšซ
Updated:

@Not_a_ID

Which brings us back to the "sensor lag" side of things. If an enemy craft can maneuver clear of the trajectory your (time lagged) targeting systems locked in on, you're likely outside "effective engagement" range.

Sure, if you are limited to electromagnetic sensors.

I would expect an FTL drive to emit tachyons or some other exotic particle / radiation that moves faster than light. It would even be plausible to develop a radar equivalent based on the above.

Another possibility is to use quantum entanglement to set up instantaneous (at any distance) communication with a remote sensor probe, which can be sent ahead of the ship.

How exactly do you describe that scenario?

Why describe that scenario at all? How plausible is it that a star spanning culture with FTL travel would be limited to light speed sensors?

Replies:   Not_a_ID
Not_a_ID ๐Ÿšซ
Updated:

@Dominions Son

Why describe that scenario at all? How plausible is it that a star spanning culture with FTL travel would be limited to light speed sensors?

Depends on how they're going FTL, doesn't it?

Some methods of doing so, do so using relativistic speeds, so they're still limited to the speed of light.(Hyperspace and Wormhole travel being the most common examples, although some authors will allow communications through hyperspace and/or wormholes, not all do)

Edit to add: Which isn't to mention a non-FTL society could pursue space battles over distances spanning light seconds, or even minutes for that matter.

Replies:   Dominions Son
Dominions Son ๐Ÿšซ

@Not_a_ID

Depends on how they're going FTL, doesn't it?

Generally no.

There might be a few rare exceptions, such as a society that is dependent on a network of natural but stable wormholes.

As for hyperspace, if you can push a physical object through hyperspace, how hard can it be to push a signal through hyperspace? A hyper drive likely leaks some energy into hyperspace constantly, why shouldn't another ship be able to detect that? What about pushing a probe ahead a few light seconds through hyperspace and using hyperspace for instant communication with the probe?

Replies:   Not_a_ID
Not_a_ID ๐Ÿšซ

@Dominions Son

As for hyperspace, if you can push a physical object through hyperspace, how hard can it be to push a signal through hyperspace? A hyper drive likely leaks some energy into hyperspace constantly, why shouldn't another ship be able to detect that? What about pushing a probe ahead a few light seconds through hyperspace and using hyperspace for instant communication with the probe?

Depends on the "hyperspace" we're talking about. For some authors, it's basically just a wormhole through space, just with a "tunnel" that may have no length, resulting in instant transit. As such, no real means for fancy "hyperspace senors" to develop to detect "leakage" of "hyperspace energies" nearby specific to a drive that is not actively interacting with it. (I'll grant that they should be able to detect the "window" itself and possibly at ftl speeds at that)

As to comms, "it varies" once more. Sure, some go the Babylon5 route. Others don't, some have hyperspace as inherently hostile to everything(including signals) to it just basically being a proverbial blender for comms. In such cases, you want something sent FTL, you hire a courier to physically transport it, or hope that some kind of pod or drone hardened against such issues is available.The

Even for the settings that do allow FTL comms, range is typically poor, and requires use of relays to get very far. Although obviously less of an issue when we're talking light minutes of distance rather than light years.

But we can then approach from the other side. You don't like short distance FTL movements? How about FTL comms are possible, just not easy, or cheap. That FTL combat sensor you wanted to use? It's the size of a Winnebago that sleeps 5 adults, puts out energy like you wouldn't believe(easily detected, because hey it opened a hyperspace window for comms), and is God-awful expensive. Also it doesn't work so good at close range, either due to a "transmission lobe" or inference with itself that is only significant at "close range." (Both are issues that have been experienced in RF comms and sensors)

Replies:   Dominions Son
Dominions Son ๐Ÿšซ

@Not_a_ID

But we can then approach from the other side. You don't like short distance FTL movements?

It's not a matter of not liking short distance FTL movement. Once you go there, you are in a completely different ball park tactically from what I am trying to discuss here or what was being discussed on the other thread.

Once you allow the tactical use of FTL movement on the battle field, you eliminate the viability of both beam weapons and ballistic ordinance based weapons. Only missiles, and FTL capable missiles at that, are viable weapons. At that point, you can start talking about battles conducted at ranges of light hours or even light days.

How about FTL comms are possible, just not easy, or cheap. That FTL combat sensor you wanted to use? It's the size of a Winnebago that sleeps 5 adults, puts out energy like you wouldn't believe(easily detected, because hey it opened a hyperspace window for comms), and is God-awful expensive.

No, I think that's absurd when you are talking about comms over just a few light seconds.

Look at the wormhole/tunnel view of hyperspace. To push a ship through, you need a tunnel that is tens to hundreds of meters wide. You only need a wormhole/tunnel a few mm wide to push an EM signal through. I can see huge power requirements for pushing a signal across interstellar distances, but for a few light seconds, the power requirements should be negligible against the Power draw of the ship's FTL drive. And why can't that be done from the ship rather than from the probe?

Replies:   Not_a_ID
Not_a_ID ๐Ÿšซ

@Dominions Son

No, I think that's absurd when you are talking about comms over just a few light seconds.

I think this is an item that is borderline "holy war" territory for you. Which is your prerogative when discussing things within the context of whatever setting you are writing in. Just bear in mind that others probably will have slightly different takes on things.

It just leaves open the question as to why you asked for outside input when you're just going to dispute everything anybody brings forward. (not to say there aren't merits to that, as that can be a valid test to check if their position is "well reasoned" and maintains internal consistency. Consistency between XYZ setting and ABC setting however, need not be maintained.

Look at the wormhole/tunnel view of hyperspace. To push a ship through, you need a tunnel that is tens to hundreds of meters wide. You only need a wormhole/tunnel a few mm wide to push an EM signal through. I can see huge power requirements for pushing a signal across interstellar distances, but for a few light seconds, the power requirements should be negligible against the Power draw of the ship's FTL drive. And why can't that be done from the ship rather than from the probe?

Alternately, the argument could be made(and is made in some SciFi cases) that simply opening the hole in space to allow passage is the biggest part of the energy expenditure, and from there size is just a variable. (Which usually translates into jump gates being employed by all but the largest of space craft)

Replies:   Dominions Son
Dominions Son ๐Ÿšซ

@Not_a_ID

I think this is an item that is borderline "holy war" territory for you.

You may be right, I'm not a big fan of hyper realistic science fiction.

It just leaves open the question as to why you asked for outside input

Where did I ask for outside input?

You have completely missed the point of this thread.
I certainly wasn't trying to discuss tactical constraints.

On the original thread where space battle ranges came up, someone (I don't remember who and I don't feel like looking it up) claimed that because of divergence, even if vacuum, lasers would be useless as weapons beyond a few hundred meters no mater how high the input energy was.

I didn't think this could be right, so I looked up the relevant formulas and low and behold, the claim was only even close to being true if you limit yourself to visible light lasers.

pangor ๐Ÿšซ

Whatever you do in the end, PLEASE don't make the lasers do "pew! pew!" sounds, and the passing ships "swooosh!" ;-)

JohnBobMead ๐Ÿšซ

@pangor

Whatever you do in the end, PLEASE don't make the lasers do "pew! pew!" sounds, and the passing ships "swooosh!" ;-)

Remember, in space no one can hear ice cream.

AmigaClone ๐Ÿšซ

@pangor

PLEASE don't make the lasers do "pew! pew!" sounds

I think lasers having those sound effects would be interesting. Granted, the sound effects would be heard only in certain locations within the ship .

Replies:   pangor
pangor ๐Ÿšซ

@AmigaClone

Granted, the sound effects would be heard only in certain locations within the ship

Well, you would probably hear some solenoids humming in the charging/discharging cycle. But not those terminally stupid "pew! pew!" sounds like in Star Wars and similar junk fiction movies. And definitely not outside the ship. Next you'll see is someone who heard the laser being shot and evades just in time! ;-)

Replies:   Not_a_ID  AmigaClone
Not_a_ID ๐Ÿšซ

@pangor

Next you'll see is someone who heard the laser being shot and evades just in time! ;-)

Well, IF the first shot missed, they possibly could have heard the shot "interacting" with the air it was passing through. What that would sound like I'm not entirely sure. I'd probably expect either a crackling noise(kind of like near miss lightning strikes) or a vague "sizzle" as it flash cooks/boils everything airborne in its path. If it hits something other than air, then the impact sound would likely vary wildly due to various factors.

Decent odds it won't sound like "pew" though. :(

Now that high pitched whine from charging circuits that Hollywood sometimes uses may be another matter. (Go Ghostbusters)

Replies:   pangor
pangor ๐Ÿšซ

@Not_a_ID

Well, IF the first shot missed, they possibly could have heard the shot "interacting" with the air it was passing through.

Considering the topic is about "Space Combat", the amount of air might be a bit ... thin.

Replies:   Not_a_ID
Not_a_ID ๐Ÿšซ

@pangor

Considering the topic is about "Space Combat", the amount of air might be a bit ... thin.

Well, I was thinking more of the lasers used in atmosphere in such Sci-Fi settings.

Replies:   Dominions Son  pangor
Dominions Son ๐Ÿšซ

@Not_a_ID

Well, I was thinking more of the lasers used in atmosphere in such Sci-Fi settings.

Well, the topic is not just space combat generally, but ship to ship combat in space.

I would expect that the firing of ship grade weaponry in an atmosphere would be fairly rare.

Replies:   StarFleet Carl  pangor
StarFleet Carl ๐Ÿšซ

@Dominions Son

I would expect that the firing of ship grade weaponry in an atmosphere would be fairly rare.

There typically would be no reason to fire in or through an atmosphere unless the two vessels were in different orbits. And while you MIGHT be able to fire at the planetary surface (such as when the Enterprise stunned a civilian population) - realistically, kinetic energy weapons are unstoppable.

And that's why the Honorverse has the Eridani Edict - because if you DO control the orbitals, you control the planet.

pangor ๐Ÿšซ

@Dominions Son

I would expect that the firing of ship grade weaponry in an atmosphere would be fairly rare.

Yep. The more energy the beam has, the more is lost in interaction with the atmosphere, and it would primarily have side effects on the shooters side, over effects near or on the target.

pangor ๐Ÿšซ

@Not_a_ID

Well, I was thinking more of the lasers used in atmosphere in such Sci-Fi settings.

I would definitely avoid powerful laser beams in atmospheric settings, especially if I was shooting in direction of my flight. The bigger the laser, the bigger the interaction with the air, and the bigger the losses before it reaches the target - if at all. Flying through expanding clouds of plasma is a guarantee for a bumpy ride.

AmigaClone ๐Ÿšซ

@pangor

Well, you would probably hear some solenoids humming in the charging/discharging cycle.

Depending on the size of the ship, you might hear those sounds near the solenoids. I was actually thinking of the "pew pew" sounds heard when firing the lasers to be a short MP3 file played on the bridge when the trigger is pressed .

awnlee jawking ๐Ÿšซ

@pangor

Whatever you do in the end, PLEASE don't make the lasers do "pew! pew!" sounds, and the passing ships "swooosh!" ;-)

Or perhaps only for European Union spaceships. They're allegedly in the process of forcing electric cars to emit sound to alert pedestrians that they're coming :(

AJ

Replies:   pangor
pangor ๐Ÿšซ

@awnlee jawking

Or perhaps only for European Union spaceships. They're allegedly in the process of forcing electric cars to emit sound to alert pedestrians that they're coming :(

Which is way better than getting run over. Our postal service has electrical delivery cars, and they are spooky as hell! You really cannot hear them approaching.

Replies:   awnlee jawking  Not_a_ID
awnlee jawking ๐Ÿšซ

@pangor

Which is way better than getting run over.

I drive an elderly pollution-emitting global-warming-preventing clattery diesel. Doesn't seem to stop pedestrians stepping out in front of it, especially if they're listening to their iPod or concentrating on their iPhone. You can't legislate for stupid :(

AJ

Not_a_ID ๐Ÿšซ

@pangor

Which is way better than getting run over. Our postal service has electrical delivery cars, and they are spooky as hell! You really cannot hear them approaching.

Ah memories, making me recall the YouTube video where some jokers replaced the horn on a small EV with a train horn and then went around sneaking up on people and "honking"(with the train horn) at them.

Or personally driving through a tunnel on the (US) Interstate Highway system when a trucker with a train horn decided to use it while in the tunnel.

Dominions Son ๐Ÿšซ

@Not_a_ID

Ah memories, making me recall the YouTube video where some jokers replaced the horn on a small EV with a train horn

Are you sure it was a train horn and not the air horn off a semi.

Or personally driving through a tunnel on the (US) Interstate Highway system when a trucker with a train horn decided to use it while in the tunnel.

Semi tractors in the US come with air horns as standard equipment.

Replies:   Not_a_ID
Not_a_ID ๐Ÿšซ
Updated:

@Dominions Son

Semi tractors in the US come with air horns as standard equipment.

As a truck driver, I know full well what the air horn of a semi sounds like. The standard air horn on a semi sounds nothing like a train horn. Which isn't to say a multitude of truck stops don't sell after market kits which can make a semi's air horn sound like the air horn of a train. (So it is entirely possible to encounter one with a train horn)

https://www.iowa80.com/pd/chrome-train-horn/06758/

Dominions Son ๐Ÿšซ

@Not_a_ID

So it is entirely possible to encounter one with a train horn

Just because an after-market parts dealer sells something that they call a train horn, that doesn't make it a train horn.

In my opinion, if it wasn't manufactured for use on a diesel electric locomotive, it's not a train horn.

Replies:   Not_a_ID
Not_a_ID ๐Ÿšซ
Updated:

@Dominions Son

In my opinion, if it wasn't manufactured for use on a diesel electric locomotive, it's not a train horn.

No love for the steam engines. :(

Many of them, in particular ones still in service, have a air horn rather than a whistle. (Although some may have both) ;)

Big difference is the "standard air horn" on a big rig only has a single horn, and thus only presents a single tone(depending on air pressure supplied). While the train sets will often have multiple horns, of differing size, this giving a multi-toned sound when it is used.

Which isn't to mention the train horn is designed to be heard from further away(mile+) than the semi is, so it is simply louder.

Replies:   Dominions Son
Dominions Son ๐Ÿšซ

@Not_a_ID

No love for the steam engines. :(

Steam locomotives had steam whistles, not air horns. Plenty of love for the steam engines.

Replies:   Dominions Son  Not_a_ID
Dominions Son ๐Ÿšซ

@Dominions Son

Big difference is the "standard air horn" on a big rig only has a single horn

I've never seen a semi tractor with only one air horn. There's always at least two, even if they are both the same note, one on either side of the cab roof.

Replies:   awnlee jawking  Not_a_ID
awnlee jawking ๐Ÿšซ

@Dominions Son

I've never seen a semi tractor with only one air horn. There's always at least two, even if they are both the same note, one on either side of the cab roof.

With an air guitar in the middle ;)

AJ

Not_a_ID ๐Ÿšซ
Updated:

@Dominions Son

I've never seen a semi tractor with only one air horn. There's always at least two, even if they are both the same note, one on either side of the cab roof.

The one I'm driving has one, but it isn't visible. So if you're seeing two, you're seeing things. You're thinking of older style trucks that didn't care about MPG.

Not_a_ID ๐Ÿšซ

@Dominions Son

Steam locomotives had steam whistles, not air horns. Plenty of love for the steam engines.

The steam locomotives that UPRR still retains in (limited) service, have air horns equipped.

Ross at Play ๐Ÿšซ

@Not_a_ID

Which isn't to say a multitude of truck stops don't sell after market kits which can make a semi's air horn sound like the air horn of a train.

It ain't necessarily so-ooo
It ain't necessarily so-ooo
The things that you proffer
That you think are kosher
Dominions Son says they ain't soooo

Dominions Son ๐Ÿšซ

@Not_a_ID

Ah memories, making me recall the YouTube video

https://www.youtube.com/watch?v=jLfD1AFsb1I

Having watched it, I am pretty sure those air horns are off a semi-tractor, not a locomotive.

Replies:   pangor
pangor ๐Ÿšซ

@Dominions Son

Having watched it, I am pretty sure those air horns are off a semi-tractor, not a locomotive.

There was one video with a trucks air horn, and later another one with the air horn of a locomotive. I've seen both.

Dominions Son ๐Ÿšซ

For all those arguing about lasers and the "pew pew" sound used in Star Wars. It should be fairly obvious that Star Wars blasters are not lasers, they are never described as lasers in the movies.

More than likely Star Wars blasters are some form of plasma weapon.

Replies:   ChiMi  pangor
ChiMi ๐Ÿšซ

@Dominions Son

Star Wars isn't SciFi, it is Fantasy. Ergo, those Lasers are magicbased and "pewpew" is the sound of the discharged magic.

And really, magic is just physics divided through "want".

Replies:   pangor
pangor ๐Ÿšซ

@ChiMi

Star Wars isn't SciFi, it is Fantasy. Ergo, those Lasers are magicbased and "pewpew" is the sound of the discharged magic.

That is probably the best explanation.

pangor ๐Ÿšซ

@Dominions Son

For all those arguing about lasers and the "pew pew" sound used in Star Wars. It should be fairly obvious that Star Wars blasters are not lasers, they are never described as lasers in the movies.

... which still would not make any kind of sound in the vacuum of space. Which is why I consider this Star Wars stuff as some of the worst SciFi ever.

Replies:   Capt. Zapp
Capt. Zapp ๐Ÿšซ

@pangor

Which is why I consider this Star Wars stuff as some of the worst SciFi ever.

It's not just Star Wars. I have yet to see a movie or TV show depict a battle in space without some hokey sound effects.

Replies:   Dominions Son
Dominions Son ๐Ÿšซ

@Capt. Zapp

It's not just Star Wars. I have yet to see a movie or TV show depict a battle in space without some hokey sound effects.

Yes, but other than the planet destroying main weapon on the Death Star, Star Wars space battle sound effects are hokier than most.

Replies:   Jim S
Jim S ๐Ÿšซ

@Dominions Son

Yes, but other than the planet destroying main weapon on the Death Star, Star Wars space battle sound effects are hokier than most.

I'd postulate that any sound effects in a space battle are hokey as they're physically impossible.

Dominions Son ๐Ÿšซ

@Jim S

I'd postulate that any sound effects in a space battle are hokey as they're physically impossible.

But that doesn't mean that some can't be hokier than others. And Star Wars has the worst space battle sound effects among big budget science fiction films.

Not_a_ID ๐Ÿšซ
Updated:

@Jim S

I'd postulate that any sound effects in a space battle are hokey as they're physically impossible.

Not necessarily true. Loud explosion sounds can happen in space, it just requires the thing exploding to have contained an atmosphere, and for you to be in it(the atmosphere) if you to hear the explosion.

Replies:   madnige
madnige ๐Ÿšซ

@Not_a_ID

requires the thing exploding to have contained an atmosphere

- or created its own atmosphere by vaporising (portions of) itself

helmut_meukel ๐Ÿšซ
Updated:

@Jim S

I'd postulate that any sound effects in a space battle are hokey as they're physically impossible.

Not true.

Sound is transmitted through gases, plasma, and liquids as longitudinal waves, also called compression waves. It requires a medium to propagate. Through solids, however, it can be transmitted as both longitudinal waves and transverse waves. Longitudinal sound waves are waves of alternating pressure deviations from the equilibrium pressure, causing local regions of compression and rarefaction, while transverse waves (in solids) are waves of alternating shear stress at right angle to the direction of propagation.

The impact of any weapon on the target will create sound waves, even if the internal structures are without air to avoid pressure waves created by the impact. Those sound waves will be transfered to the people in the target through contact with the target's structures. The space suits may even work like the vibrating diaphragm of a speaker.

Even laser, microwave or similar weapons transfering hull material from solid to gaseous will produce some sound in the hull.

HM.

Replies:   pangor
pangor ๐Ÿšซ

@helmut_meukel

Those sound waves will be transfered to the people in the target

There is no question that both the shooter and the target might have (or, when the target explodes, will have) local Sound effects.

But just take the first scene from "A New Hope" - big bad ship on the right shoots at small heroes ship on the left, and the observer, neither shooter or target, hears this stupid kindergarten "pew! pew!" sound. On board of the shooting vessel, charging weapons and control sounds on the bridge might be heard, or cooling systems running. On the target, exploding parts of the ship, or charging changes in the shields can make any sound they want. But for anyone else - silence.

Replies:   BlacKnight
BlacKnight ๐Ÿšซ

@pangor

But just take the first scene from "A New Hope" - big bad ship on the right shoots at small heroes ship on the left, and the observer, neither shooter or target, hears this stupid kindergarten "pew! pew!" sound.

It explains a lot of stuff if you just assume that, in the Star Wars universe, there's air in space.

Replies:   pangor
pangor ๐Ÿšซ

@BlacKnight

It explains a lot of stuff if you just assume that, in the Star Wars universe, there's air in space.

It also explains a lot of stuff if one assumes that in the Star Wars universe creator, there's air in the head.

Sorry, may sound harsh to Star Wars fans, but IMHO this is one of the worst things that could happen to SciFi.

Geek of Ages

My recollection is that the Mass Effect series did space combat (or rather, descriptions of what it's like) fairly well.

Wheezer ๐Ÿšซ

While there is no sound in a vacuum, thus there would be no sound from real weapons firing in space, it also makes for a boring as fuck movie to sit there in total silence for 5-10 minutes at a time. The background music alone wouldn't cut it. It would be as painful as watching a French film. Albeit, the silences would be briefer in the space battle scenes. I'll take a little ignoring of science facts in such matters. WTH? We're suspending disbelief for the whole fucking movie anyway. Why quibble over whether or not the weapons make noise in space?

richardshagrin ๐Ÿšซ

@Wheezer

It would be as painful as watching a French film.

I liked the Brigitte Bardot French films. Of course I was much younger then (she retired from films in 1973.)

Replies:   awnlee jawking
awnlee jawking ๐Ÿšซ

@richardshagrin

When I was young, UK TV had a spell of showing subtitled French movies and, despite not showing explicit sex, some of them were very hot. My favourite actress was Isabelle Adjani.

AJ

Replies:   richardshagrin
richardshagrin ๐Ÿšซ

@awnlee jawking

Isabelle Adjani

Isabelle Adjani nudity facts:
she was last seen naked 21 years ago at the age of 40. Nude pictures are from movie Diabolique (1996).
her first nude pictures are from a movie La gifle (1974) when she was 19 years old.
we list more than four different sets of nude pictures in her nudography. This usually means she has done a lot of nudity so you won't have any trouble finding her naked

Ross at Play ๐Ÿšซ

@Wheezer

no sound from weapons fired in space ... makes for a boring as fuck movie ... We're suspending disbelief for the whole fucking movie anyway.

Exactly!
Discussions like this one become moot once writers consider whether being condescending towards viewers/readers may prompt them to hit the kill switch.

awnlee jawking ๐Ÿšซ

@Wheezer

I'll take a little ignoring of science facts in such matters.

'Write what's interesting rather than accurate' is common writing advice and something I often try to do myself.

AJ

pangor ๐Ÿšซ

@Wheezer

it also makes for a boring as fuck movie to sit there in total silence for 5-10 minutes

That is a given. Not everyone can do a Kubrik, and have ships float to "The Blue Danube".

And a space battle can last way longer, if it was just a tad reality-based.

AmigaClone ๐Ÿšซ

Realistically the only sounds produced in a space battle would be some heard on some locations of the ship that is firing, and parts of the ship receiving the hits.

A ship that is observing the action would not hear any sound from the weapons fire itself. That could be simulated if the ship had sensors that detected weapons fire and produced an audible feedback for those on the bridge.

As a side comment, laser beams would likely also be invisible for most observers even if they could see the frequency being used.

Replies:   helmut_meukel  pangor
helmut_meukel ๐Ÿšซ

@AmigaClone

As a side comment, laser beams would likely also be invisible for most observers even if they could see the frequency being used.

Right in most cases. It depends on the location however.
Within an asteroid belt etc. there should be enough debris and dust in the way of the laser beam to be partially visible for observers.

HM.

pangor ๐Ÿšซ

@AmigaClone

As a side comment, laser beams would likely also be invisible for most observers even if they could see the frequency being used.

Yes and no. If I was in a universe with laser-based space combat, I would used sensors looking out for hydrogen atoms interacting with energy beams. Space is not a total vacuum, and whatever beam is going to interact with the one or other hydrogen atom. So while the beam would be invisible to the naked eye (except when we were dealing with a death-star-annihilating-a-planet-beam, which would rip the fabric of space with its energy density), the sensors could detect such interaction events and overly the tactical display screen with the virtual beams.

pangor ๐Ÿšซ

Just to enter a new direction about space combat: Has anyone read the "To The Stars" trilogy by Harry Harrison? I remember the battle for earth in the last part. Earth was very powerful, had lots of ships in earth orbit to protect the home planet, and they expected only little from the rebels, as earth had a tight control over all ship-to-ship missiles, so attacking earth with the missiles from the captured ships would be useless - they had remotely destroyed the missile control chips. Still, they were looking out for maybe the one or other missile the rebels might have re-engineered, but there were none.

Meanwhile, the rebel forces in the asteroid belt had been busy as fuck melting asteroids into iron balls and sending them on precalculated courses to earth via rail guns (so they basically all arrive in earths orbit at the same time). They were too small to be noticed astronomically/optically, and the defending forces found out about the iron hail just seconds before they were blown to pieces.

I admit that HH is not exactly high literature, but at least this is a twist I had seen nowhere else, and it might even work.

Dominions Son ๐Ÿšซ

@pangor

Has anyone read the "To The Stars" trilogy by Harry Harrison?

I haven't read that one. However I remember one book, I think it was one of David Brin's Uplift books, where an Earth colony was wiped out by an alien race. In retaliation, The Earth declared total war on the alien race, A human attack force showed up at the attacking specie's home world with a fusion ram jet.

The fusion ram jet was headed in system on a collision course with the alien home planet and was loaded with a dozen dense iron asteroids. At .9 C, they uncoupled from the asteroids and reversed thrust on the ram jet.

helmut_meukel ๐Ÿšซ

@pangor

I admit that HH is not exactly high literature, but at least this is a twist I had seen nowhere else, and it might even work.

As StarFleet Carl already wrote:

And that's why the Honorverse has the Eridani Edict - because if you DO control the orbitals, you control the planet.

And you don't need energy beams (laser or others) or explosives or fusion or fission bombs, simple kinetic will do. Some tons of rock or metal dropped down onto the target will destroy it and all things around it.
You have to calculate when and where to drop it so it meets the planet dead center and the target is then exactly there, but hey, a city, spaceport or so can't move away, the planet's turn will put it right there for the impact.

HM.

StarFleet Carl ๐Ÿšซ

@pangor

I admit that HH is not exactly high literature, but at least this is a twist I had seen nowhere else, and it might even work.

The Moon is a Harsh Mistress, by Robert A Heinlein, written 14 years prior to the books by Harry Harrison.

Oh, and regarding Star Wars ... "A long time ago, in a galaxy far, far away" is pretty much semantically equal to 'Once upon a time, in a far away kingdom' ... just like every OTHER fairy tale. (Doesn't mean I don't watch the Star Wars movies - just means Star Trek is better as science fiction rather than the pure fantasy that Lucas made.)

Replies:   JohnBobMead  pangor
JohnBobMead ๐Ÿšซ

@StarFleet Carl

The Moon is a Harsh Mistress, by Robert A Heinlein

That's where I first encountered the concept. I've come across it a number of times since...

Wait a minute, E.E "Doc" Smith in his Lensman Series used hyperspace engines mounted on rogue planets _way_ earlier than that. Hmm. Smith's had engines mounted on them, so they could be transported to another stellar system and let loose on an unsuspecting planet, but the basic concept is the same; planets are vulnerable to having big rocks thrown at them, the gravity well works in the attacker's favor in this case. It's been too long since I've read his stories, but it may have been in Second Stage Lensman (1953). Since RAH was a very good friend of Smith's, I have no doubts about his having been familier with Smith's use of this idea. HH was definitely a fan of Smith's, it's widely recognized that Star Smashers of the Galaxy Rangers is a sendup of his work. Can't speak in regard to whether Smith was read by Weber, although it would have been difficult to avoid his writings; I first read Smith in the mid-1970s; Pyramid Books kept most all of his novels in print between 1965 and 1976, with at the most 14 months between printings; Weber is eight years older than I am, he _has_ to have been familiar with Smith's opus; he has acknowledged RAH as an influence.

Replies:   StarFleet Carl
StarFleet Carl ๐Ÿšซ

@JohnBobMead

Wait a minute, E.E "Doc" Smith in his Lensman Series used hyperspace engines mounted on rogue planets _way_ earlier than that.

It's truly been so long since I read the Lensmen Series that I can say I have no memories of specific plot points. Nor do I have those books any longer. At various points in time, I've had to thin the bookshelves, if for no other reason than there were just too many of them. (Seriously, the basement in my house in Indiana had 400 linear feet of bookshelves - all full. Had to cut thin them out when I moved to Oklahoma, simply from the sheer weight and volume.)

Replies:   JohnBobMead
JohnBobMead ๐Ÿšซ

@StarFleet Carl

(Seriously, the basement in my house in Indiana had 400 linear feet of bookshelves - all full. Had to cut thin them out when I moved to Oklahoma, simply from the sheer weight and volume.)

Something similer in my near future. Planning to move into my sister & sister-in-laws spare bedroom (once it becomes the spare bedroom), so something like 98% of my belongings need to find new homes. I've switched my purchasing entirely to eBooks unless an item is only available as hardcopy, and as I obtain eBooks for what I've determined I _really_ want to retain, the hardcopy goes into the "find a new home" stack. But once the move is accomplished, we sell my place, use the proceeds to pay off their mortgage, I chip in $400.00 a month toward household expenses, my net expenses go down and their net money available each month goes up by $1000.00; none of which would matter if we couldn't get along, but my sister and I have been best friends all my life, and Karen is a sweetie. So after i suggested it, they thought about it, and decided that it made sense. And this way we get rid of my junk _before_ I go into a care home, and my heirs don't have to mess with it.

Anyway, the following eBook has the complete Lensmen series, the first three Skylark novels, and a bunch of others, for $2.99 https://www.barnesandnoble.com/w/e-e-doc-smith-collection-16-works-ee-doc-smith/1122948403?ean=2940148834564 Barnes & Noble has Skylark DuQuesne as a seperate item for $3.99 https://www.barnesandnoble.com/w/skylark-duquesne-ee-doc-smith/1016046952?ean=9780575122703 Which is how I now have them in my collection.

Replies:   awnlee jawking
awnlee jawking ๐Ÿšซ

@JohnBobMead

as I obtain eBooks for what I've determined I _really_ want to retain

Beware, there's a possibility you don't actually own them. And if your eBook reader dies, so might your ownership :(

AJ

pangor ๐Ÿšซ

@StarFleet Carl

The Moon is a Harsh Mistress, by Robert A Heinlein, written 14 years prior to the books by Harry Harrison.

Actually, this is the book I'm currently reading ;-)

just means Star Trek is better as science fiction rather than the pure fantasy that Lucas made.)

Actually, Star Trek does not really rate much better than Star Wars in my opinion.

Replies:   Not_a_ID
Not_a_ID ๐Ÿšซ

@pangor

Actually, Star Trek does not really rate much better than Star Wars in my opinion.

Star Trek actually does target a slightly older demographic. Jar Jar Binks alone is a demonstration of that. (Of course, then there is Wesley Crusher and Make Sisko)

That said, TOS was initially billed as "Wagon Train, to the stars." (And according to Roddenberry years later, to also give people a positive view towards the future--most strongly reflected in TNG productions prior to his death)

While Star Wars was an attempt by Lucas at creating a (modern day) heroic epic, it being in a SciFi setting was probably more a matter of convenience and scale than anything else.

Replies:   pangor
pangor ๐Ÿšซ

@Not_a_ID

Star Trek actually does target a slightly older demographic. Jar Jar Binks alone is a demonstration of that. (Of course, then there is Wesley Crusher and Make Sisko)

I don't dislike Star Trek because I'd be "too young to appreciate it" or something like that - I've seen it on TV back in the 70s and was not really impressed, having been a reader of SciFi for years back then. Yes, that was TOS, but IMHO, even the newer variants did not derive fundamentally from the mistakes of the original story design (for fear of losing their fans, which I can understand).

I could argue that Star Wars is actually worse, because they were so much later and could have learned so much from the mistakes of others, and still decided to ignore everything and make it worse.

But yes, while Star Trek is SciFi without a clue, Star Wars is a fairy tale dressed in SciFi garbs. I dislike them about equally, and that's why I would not got to a SciFi con - people would probably lynch me ;-)

Replies:   JohnBobMead  Joe Long
JohnBobMead ๐Ÿšซ

@pangor

But yes, while Star Trek is SciFi without a clue, Star Wars is a fairy tale dressed in SciFi garbs. I dislike them about equally, and that's why I would not got to a SciFi con - people would probably lynch me ;-)

If you attended a SciFi con, yes. The diehard media fans would do that. If you attended an SF con, on the other hand, you would find that many who focus on written SF agree with you. But I'd be careful using the term SciFi if you associate with the written SF crowd; Forry Ackerman coined that term to rhyme with Hi-Fi (short for High Fidelity, a keyword in stereo sales at the time) to help popularize the genre and there are still those who have never forgiven him for it. It's use by the SciFi (now SyFy) Network didn't help their feelings toward it any. And for Ghod's sake don't ever pronounce it "skiffy" near _any_ active SF or SciFi fan, of any media type. Skiffy is a term of derision reserved for the uttermost dreck and drivel masquerading as SF. The Day After Tomorrow is skiffy at it's worst, it set back rational discussion of the realities of Climate Change by twenty years, at least, by its misrepresentations of science; but it did correctly portray the reactions of politicians to reports from scientists at odds with what they want to hear, that part wasn't skiffy at all, unfortunately.

Joe Long ๐Ÿšซ

@pangor

But yes, while Star Trek is SciFi without a clue, Star Wars is a fairy tale dressed in SciFi garbs. I dislike them about equally, and that's why I would not got to a SciFi con - people would probably lynch me ;-)

I confess I've never missed a Star Trek - I was in front of the TV when the very first episode of TOS aired.

However, the point of good fiction is not just to entertain but to have the audience ask questions of themselves and others. The space faring science fiction that I've enjoyed the most are the low tech series, such as Space: Above and Beyond and the new Battlestar Galactica. They are war stories set in space, but making a choice not to rely on technology.

Ron Moore was a veteran Trek writer and producer when he re-imagined BSG, also drawing heavily on the World War II movie In Harm's Way and the sci-fi Blade Runner. Edward James Olmos, who starred in BSG as Admiral Adama and was also in BR, said that the first time the writers introduced an alien monster he was out of there. Deep Space 9's highest rated episodes were multi-part war stories that dealt with the moral choices of the characters.

Replies:   JohnBobMead
JohnBobMead ๐Ÿšซ

@Joe Long

I confess I've never missed a Star Trek - I was in front of the TV when the very first episode of TOS aired.

Having previously watched My Favorite Martian and Lost in Space, Star Trek was an eye-opener. I don't actually remember watching My Favorite Martian, but I've been reliably informed that I did. Anyway. I watched Star Trek religiously all three seasons, even such utter drek as And The Children Shall Lead; the third season they knew they weren't coming back, no matter what the fans did, and let some really bad scripts get accepted. I watched a number of episodes of Next Generation when it first came out, but somehow fell out of watching it part way through. I've seen scattered episodes of Voyager, Deep Space 9, and Enterprise, but not complete runs of them; I do own the complete series of Voyager (in what unfortunately turned out to be a Chinese bootleg), but haven't actually sat down and watched it; mom was enjoying seeing it in syndication, so I got it to watch with her, same as my purchase of Andromeda, but then her dementia became too great a deterent to living at home and was in a nursing home. I haven't seen any of the current incarnation, but I've also heard some bad reports about it.

I only saw scattered episodes of the BSG reboot, but was impressed by the gritty realism, and it wasn't anywhere near as blatantly "Mormons in Space" as the original; they couldn't avoid all of it without gutting the entire original premise. I quite approved of the gender changes in some of the key Colonial Warriors, as my experience is that outside of sheer physical strength, women can be just as effective as men in any of the activities I've been involved with, and their methods of warfare rarely if ever involved direct physical conflict.

richardshagrin ๐Ÿšซ

I agree, Sci-Fi is an abomination, when used to describe written science fiction. I can go with SF, which is how libraries distinguish it on the spines of SF novels so you can see it when books are shelved. The only time to use -Fi is when marines are saying Semper-Fi. In that case Fi is an abbreviation of fidelis, Latin for faithful, the motto is "Always Faithful" but somewhat more impressive because it is in Latin.

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