Forum: Author Hangout

However, reader's always accuse me of pushing an agenda which never even occurred to me.

Everyone thinks that the Bettles' "Lucy in the Sky with Diamonds" is about LSD even though Paul McCartney insists to this day that the song had nothing to do with drugs.

Considering the site, Hard science fiction would involve heroes with erections.

I'd have said "Erectly", but I'll save that for when they make a LEGO version of the movie.

Wouldn't "erectly" require an Erector Set version of the movie? Does anyone remeber Erector Set?

Down here erector sets were put out by a company called Mechano and were know as Mechano sets.

Ah, Mechano.
I didn't have one- they were very expensive. But a friend did & it was awesome. I've heard the current ones use thinner metal than the older ones did. We certainly built some very strong things with the old sets. Cars, trucks, cranes etc.

Does anyone remeber Erector Set?

I had an erector set as a young child. It was pretty flimsy, I believe they used to be much sturdier. The one Ryan Clark had in Forgotten Killer (by Wes Boyd) was clearly much sturdier than the one I had.

By the way, if no one's looked recently, the modern erector sets are very sophisticated with the kids building mechanical robots.

Some of the Lego Technical set my Nephews have are just incredible what can be done with them.

Declaring that the galaxy is only 200 light years in diameter - not so much.

As a reader and not a scientist it would depend on the method that the presentation uses.

Take the story "Lost Empire" by "Pars001" it is done as follows: "this galaxy is 200 light years across"

The implication is that there are more than one galaxy in the universe. Not all the sizes would have to be the same then.

Okay I never claimed to be a scientist. But its possible to worry too much about the scientific and technical details to either enjoy or write a story.

As a reader I want to enjoy it although its nice to pick up a few facts along the way in a good story, but I don't worry too much about those if the story is enjoyable in itself.

A bit of basic research will show that 200 light years is only the diameter of a medium to large sized globular cluster within a galaxy (20-100 parsecs). Even the smallest galaxies are a few thousand light years across. Any collection of stars only a couple of hundred light years in diameter is not a galaxy.

What is the target audience? a crowd of PhD astronomers or "the man in the street"? As one of the latter I have no idea how many AUs a parsec is (and can't be bothered to look it up) but I know a light year is one h*** of a long way.

I agree with docholladay who wrote "But its possible to worry too much about the scientific and technical details to either enjoy or write a story. "

As ["the man in the street"] I have no idea how many AUs a parsec is (and can't be bothered to look it up) but I know a light year is one h*** of a long way.

OK, I'm an engineer, not a scientist. I think a parsec is about 3-and-a-half light years (not quite to Proxima Centauri) (3+quater - I looked it up), and I know that a light year is as much bigger than an AU, as a year is to eight minutes (the time it tkaes light to get to the Earth fron the sun). Since light travels at nearly 300million m/s (in space) it's simple arithmatic to calculate a meaningly large number for a light year. I knew a galaxy, even a small one, was way bigger than 200ly though I didn't/don't know how big, just that ours is a lerge one. A really interesting thing I worked out a while back, to give a good sense of scale as to the size of the Earth/moon/sun, based on the scale of a kid's 6-inch globe (1:84million) the moon is about the size of a small apple on the other side of the room, and the sun's the size of a supermarket about a mile away. On that scale, a light year is nearly a quater the distance to the moon, a parsec is about the distance of the moon (and an AU is the mile to the supermarket mentioned earlier). Big numbers are usually pretty meaningless - give them some scale and they take on meaning. I was recently reading onne of the 'Lensman' books where this was put to use - one of the characters explained that flitting around the galaxy in a slow or fast spaceship was about the same timescales as flitting about America in a car or a plane.

Edit: that's a fictional, FTL spaceship. I'll leave the fat finger typing errors though.

OK, I'm an engineer, not a scientist. I think a parsec is about 3-and-a-half light years

A parsec is 3.26 light years. It's a unit of distance that is based on apparent motion of distant objects caused by the movement of the Earth around the Sun. As such, it's ultimately based on measurements of angles, not distance.

Parsecs are used in Astronomy because it's easier to calculate parsecs from the observational data than it is to calculate light years.

Personally I think parsecs are silly to use in Sci-Fi, because parsecs are based on a singular fixed point of reference (for astronomical purposes) and once you leave the earth, calculating some kind of standard parsec actually get's harder than using light years.

It's a unit of distance that is based on apparent motion of distant objects caused by the movement of the Earth around the Sun.

I knew that - Paralax error of one second of arc. I remember as a teenager reading another E.E.'Doc'Smith story (might have been one of the 'Skylark') where the hero tries to claim it's not an Earth-based measurement - shows that even the PhD's can get it wrong. I suspect the thought process goes something like 'it needs to sound spacey - can't use light year, 'cos the alien can't know what the Earth's year is - astronomers use parsec - let's use them too'. On the other hand, it should have been realised that it's fairly easy to get across the concept of Hydrogen atoms, their emission spectrum, the line we're interested in, and the number of wavelengths of that light that make up a light year (or other distance).

An interesting picture is on xkcd, from which it's easy to see that the Oort cloud is as much further away than Saturn, as Saturn is than the moon, and Everest is higher than a person. (they're all about the same vertical distance on the picture). Also, the 'next' picture is relevant

An interesting picture is on xkcd,

I'm glad to see they included the Romulan Neutral zone & Ford Prefect's home.

I suspect the thought process goes something like 'it needs to sound spacey - can't use light year, 'cos the alien can't know what the Earth's year is - astronomers use parsec - let's use them too'. On the other hand, it should have been realised that it's fairly easy to get across the concept of Hydrogen atoms, their emission spectrum, the line we're interested in, and the number of wavelengths of that light that make up a light year (or other distance).

The other way to approach that is to take the scientific definition of a second

"The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom."

http://physics.nist.gov/cuu/Units/second.html

Define a light second as the distance light travels in one second and a light year is x light seconds.

Another way to go is to drop light years and simply use higher order prefixes with meters. A light year is around 9.4607 peta meters (short scale, use the long scale if your intended audience is more familiar with the short scale than the long scale).

A light year is around 9.4607 peta meters (short scale, use the long scale if your intended audience is more familiar with the short scale than the long scale).

The beauty of SI prefixes is that there is no short/long scale ambiguity - except for a few special common-use prefixes (like centi- and deka-, not mentioned in the above reference) they are all 1e3 apart (1000 for those who don't read engineering notation) - that's equivalent to the short scale.

My route to the light year was intended to minimise the number of concepts to be transferred: yours, using the standard definitions requires defining Caesium (which requires defining the periodic table), the correct isotope, what the ground state is, what hyperfine levels are, the total count required (to make a year - there's no point in defining the second if we're only interested in distance), and the speed of light, for a total of six concepts. Defining the numbering system and specifying the big number required is the most complex of the four concepts my route requires, but the simplest when going through our standard definitions (which are chosen for ease of use for measurement purposes), and indeed my concepts are a subset of those required for the standard definitions route. However, the hyperfine transition of Hydrogen (at 21cm) was considered sufficiently universal to be included on the Pioneer plaque.

yours, using the standard definitions requires defining Caesium (which requires defining the periodic table), the correct isotope

Nope that is completely unnecessary, just provide a sample of the relevant isotope.

As to the number and complexity of the concepts involved:

1. In a first contact scenario, time is at least as important (if not more so) as distance as a base concept for dealing with other issues likely to come up. So delaying defining time units helps is not likely to gain you much.
2. If they can handle FTL travel, they have someone who can handle the needed concepts.

just provide a sample of the relevant isotope.

A little difficult from the other end of a comms maser - and. to provide an element sample, you've first got to ensure they know what to do with it ('For me? How sweet'. Nomnomnom) which is a whole consruction and operation manual.

I introduced this to show how EESmith's character should have defined an Earth-independant length scale, but it's been hijacked into a first-contact scenario. However, Caesium clocks didn't exist at the time the novel was written (time was defined in terms of the rotation of the Earth). Even now, because both sides would understand the concepts and would be able to translate between scales, it would be defined in terms of Hydrogen because that atom is simple enough to be modelled mathematically, rather than forcing them to build one of our atomic clocks just to establish a scale equivalency. We choose Caesium because it's fairly easy to get an isotopically pure sample and the technology involved is within our capabilities; other elements could easily be used (Rubidium is also used, Sodium AFAIK isn't but could be, Berylium has a single stable isotope but we wouldn't use it) However, our atomic clocks require a prior knowledge of the time scale to provide a precise time reference; a timescale based on Hydrogen emissions wouldn't.

I introduced this to show how EESmith's character should have defined an Earth-independant length scale, but it's been hijacked into a first-contact scenario.

My route to the light year was intended to minimise the number of concepts to be transferred:

No, you introduced the first contact scenario. Absent first-contact there is no need to transfer concepts at all. Meters and/or light years are not particularly Earth dependent.

I never made it past the 9th grade. Thanks to that goddamned Atlanta Police Detective who got off on raping kids. They put my ass in a mental Hospital for over 4 years to keep me from Killing him for revenge. They released me after he was caught in the act of raping a young girl. He loved pre-teenage kids of both genders. All my knowledge and skills are self-taught and my respect for the LAW is non-existent.

edited to add: If I was to see a cop shot or wounded I would just stand and laugh as they suffered. I do carry a grudge big time.

OH that cop was really punished after he was caught. His fellow cops gave him Early fucking Retirement with full benefits.

If your aliens are oxygen breathers from earth-like planets, then their years are not going to be significantly different than Earth years.

I make their year anything from our three months to three years, depending on star luminosity (factor of /*2) and planet position in habitable zone (/2 to *1.5)

I can't speak on broadcast standards, but while most countries are now on the metric and decimal scale there is still one major holdout, so it may be dangerous to assume that aliens don't have similar problems.
Though for practical writing purposes I think the assumption would be necessary and not even need to be stated. The alternative would be explanations to satisfy one or two argumentative and nitpicking readers while sacrificing the majority who were able to use their imagination.

You just lost all the animal rights SF audience!
:0)
Poor Gerbils....

@WheezerYou just lost all the animal rights SF audience!

:0)

Poor Gerbils....

Poor marmots as well

Do you have a thing about small mammals?

I plead innocent of any thought, word or action relating to marmots. I never went there! That was other people with guilty secrets hiding in a different thread.
Since I am presently in the states, I will plead the 5th on the rest of your question.

I can't speak on broadcast standards, but while most countries are now on the metric and decimal scale there is still one major holdout, so it may be dangerous to assume that aliens don't have similar problems.

As I understand it, even that holdout uses metric in most medical & scientific work (except for those times where some of those involved don't...)

except for those times where some of those involved don't

Without bothering to tell the rest of the project team that they didn't.

Hmm, that sounds vaguely familiar. Wasn't there some kind of incident involving a space probe?

Hmm, that sounds vaguely familiar. Wasn't there some kind of incident involving a space probe?

Yep.

NASA used metric, a contractor used imperial.

The probe was meant to orbit Mars to study the weather. It was determined later that the probe hit the atmosphere, and within a few seconds ceased to exist. The initial orbit should have been considerably further from the planet.

Another good one- a bridge involving Sweden & Germany. Engineering projects generally use sea level as their base reference point. However Germany & Sweden get their sea level reference points from different locations. The result is a difference of 27 feet, which was known about. Unfortunately instead negating the 27 foot difference, it got doubled, so when the bridge being built from either side of the river came together, there was a 54 foot difference in heights.

And one more- French railways gave the wrong measurements to a rail car manufacturer. 100s of new carriages were a couple of cm too wide to be able to pass a platform without hitting it...
Like the old saying says "Measure twice, cut once"

Besides, they are based on the meter, which is earth-centric.

Not by it's current official definition. Nearly all the base metric units have be re-defined based on basic physics and physics constants.

"the fundamental unit of length in the metric system, equivalent to 39.37 U.S. inches, originally intended to be, and being very nearly, equal to one ten-millionth of the distance from the equator to the pole measured on a meridian: defined from 1889 to 1960 as the distance between two lines on a platinum-iridium bar (the "International Prototype Meter") preserved at the International Bureau of Weights and Measures near Paris; from 1960 to 1983 defined as 1,650,763.73 wavelengths of the orange-red radiation of krypton 86 under specified conditions; and now defined as 1/299,792,458 of the distance light travels in a vacuum in one second. "

http://dictionary.reference.com/browse/meter

The second is a very earth-centric measurement.

It started out that way, but the current official definition is not Earth centric.

"The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom."

http://physics.nist.gov/cuu/Units/second.html

All of the measurements using numbers have to be earth centric by definition.
Assuming that aliens use a decimal system is rather egotistical of the human race since they may have an odd number of useable digits on which their system was based. Their system of mathematics could be constructed on totally different concepts that we have not researched. Mathematics as used is a human creation, not a universal occurrence.

All of the measurements using numbers have to be earth centric by definition.

Not at all. Converting numbers from one base system to another is actually fairly simple.

Using numbers is the crux of the problem, which is why it is earth centric.
Feet, hands, inches were not numerical concepts, they were physical ones and subsequently almost standardized, but were a practical and accepted form of measurement and calculation for centuries along with chains, furlongs, rods, poles and perches. Converting from one base system to another requires understanding the other base system first.
Certainly it is possible to write a program to convert, but even taking the simple concept of farthings, groats, crowns and guineas, which was in minor variations used for centuries by the major nation at that time, it is not that obvious where the relationships lie.
16 farthings to a groat, 15 groats to a crown, 63 groats to a guinea. All legal currency.

I totally agree, and being human I understand the terms used, but find that the assumption that aliens will have readily understandable concepts and measurements to be bordering on science fantasy and extremely arrogant.
The various earth nations find it almost impossible to agree on standard meanings and definitions, and there is no reason to believe alien cultures would be any different.

I totally agree, and being human I understand the terms used, but find that the assumption that aliens will have readily understandable concepts and measurements to be bordering on science fantasy and extremely arrogant.

Which is why almost everyone who has written anything detailed on first contact talks about starting with math and physics.

There are things that any alien race we encounter must necessarily have in common with us.

The same physics that apply to us must necessarily apply to them, and mathematics is the closest thing there is to a universal concept.

Feet, hands, inches were not numerical concepts

You are correct, they are unit concepts to which numbers are applied.

All metric units are now defined in non-earth-centric physics based ways. Talking about non-metric units in this context is meaningless.

it is not that obvious where the relationships lie.

16 farthings to a groat, 15 groats to a crown, 63 groats to a guinea. All legal currency.

I wasn't talking about converting between different units (which are independent of the numbers they apply to) I was talking about number systems themselves (decimal, binary(base2), octal(base8) hexadecimal (base 16)).

Any alien race that has mastered interstellar travel and/or communications must understand the same physics we do and the same mathematical rules, even if they describe them in different terms.

Explaining our units and number systems so they can convert will be about the easiest part of communicating with an alien race. Relatively speaking, not that any of it will be easy.

"The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom."

See my previous comment on the meter, in this case make it ten billion times for a universal unit. And why the cesium 133 atom particularly, why not say the hydrogen 1 atom?

See my previous comment on the meter, in this case make it ten billion times for a universal unit.

Again, so what, why is that a problem?

And why the cesium 133 atom particularly, why not say the hydrogen 1 atom?

I have no idea, you would have to ask the scientific body that created the current definition.

Why does it particularly matter?

1,650,763.73 wavelengths of the orange-red radiation of krypton 86 under specified conditions; and now defined as 1/299,792,458 of the distance light travels in a vacuum in one second. "

If either of those were the actual bases of the unit, they would be round numbers, e.g. 1,000,000 wavelength of (fitb) or 1/300,000,000 of a light second. (Though a 300 millionth is kind of an arbitrary unit. Make it a 500 millionth and you might have something.)

As it is you have a preexisting unit, a meter, and are trying to find a more accurate way to define it, without changing it.

As it is you have a preexisting unit, a meter, and are trying to find a more accurate way to define it, without changing it.

So what? If that produces a non-earth-centric definition that is useful. Why is that a problem?

Somewhere up there someone wanted to get away from Earth centric measurements. Those definitions are using non Earth centric units (wavelengths of the orange-red radiation of krypton 86 under specified conditions) to define Earth centric units (meters). So to make it universal drop the meters and just use the wavelengths. And to make it even more universal use Hydrogen (which we know absolutely is everywhere) rather than any other arbitrary element.

Make your basic unit for both time (the time it takes light to travel that distance in a vacuum) and length 100 million wavelengths of activated hydrogen.

Somewhere up there someone wanted to get away from Earth centric measurements. Those definitions are using non Earth centric units (wavelengths of the orange-red radiation of krypton 86 under specified conditions) to define Earth centric units (meters).

Sorry, I have to disagree here. A non-earth-centric definition makes the unit non-earth-centric.

You have said absolutely nothing to convince me otherwise.

you're wrong a meter is one ten-millionth of the distance from the equator to the pole measured on a meridian, redefined in wavelengths of some random element, and later redefined again as the distance light travels in a light meter. The basic unit hasn't changed, just the accuracy of the definition.

For instance defining a foot as 503,158.903,316,264,3 wavelengths of the orange-red radiation of krypton 86 under specified conditions doesn't make the foot a universal unit.

For instance defining a foot as 503,158.903,316,264,3 wavelengths of the orange-red radiation of krypton 86 under specified conditions doesn't make the foot a universal unit.

Edited:

Universal is not the same thing as non-earth-centric.

A lot depends on what you are looking for a non-earth-centric unit for. The original request for non-earth-centric units did not even specify that aliens would be involved.

For a human interstellar civilization, the standard metric units work just fine, because by their modern definitions measures can be verified/calibrated without any reference to the earth itself.

A human who has grown up on a colony world and has no knowledge of earth would be able to derive all the base metric units from their current definitions just fine. That is non-earth-centric enough for nearly all purposes.

Further more, in any plausible first contact scenario involving technologically advanced aliens, those unit definitions can be communicated just fine without having to make up units that have no history of earth-centrism.

All of your objections matter only if you are trying to create units that are from some alien civilization. And even then, unless you are describing a very old multi-species interstellar civilization, the use of "universal units" created the way you describe is highly implausible.

The U.S. is the major holdout on using the metric system, but France remains the major holdout on using English as the standard language for air traffic communications (there's always someone who refuses to get with the program).

A bit more than that, CW. Going back to the 1800s there were many meridians used for navigation so there was a conference to try to standardise. It was acknowledged that Britain had already done all the mathematics so every country bar one agreed to use a point at the Greenwich (East of London, UK) astronomical observatory. To be worthwhile agreement had to be unanimous but France was the ni***r on the woodpile, demanding that Paris be the centre. Eventually France agreed to the Greenwich meridian on the condition that Britain eventually converted to metric. That was nearly 150 years ago and UK regs still state that road signs must show distances in miles or yards etc.

France still has a meridian through Paris called the Green Meridian

edits; previously uploaded before completion

what's a general light year in Angstrom

9.461e+25, according to Google

(just as English is the universal language for air traffic control worldwide today)

Reminds me of a funny I saw on Nick Scipio's site:

A Pan Am 727 flight waiting for start clearance in Munich overheard the following:

Lufthansa (in German): "Ground, what is our start clearance time?"

Ground (in English): "If you want an answer, you must speak in English."

Lufthansa (in English): "I am a German, flying a German airplane, in Germany. Why must I speak English?"

Unknown voice from another plane (in a beautiful British accent): "Because you lost the bloody war."

It was mentioned that aliens would not use a light year as a measure of distance. I think it is very possible that they would, only their light year would be based on the orbital periods of their own home planet and be a bit different than ours.

There is a part of this thread about using an isotope of caesium for time so why not Angstrom units for length because they should be standard everywhere. (increases the numbers but is more accurate LOL)

In Europe the Germans are renowned for getting up early at hotels and resorts and placing their towels on the loungers by the pool so that they get the best seats.
Since the English are civilized and respect the Germans made the claim on the loungers first, they persistently complain about it but do nothing.
(The Germans also complain that the English do the same thing).

Thank you, it's the small cultural things that trip you up.

Yes; and that is what school teachers fail to teach you. As my friend Tachi showed me when he learned English you need a "pillow dictionary" (resident girlfriend)

Please explain, I'm an Aussie, and I don't get it!

I got it.
As ustourist posted, the Germans are renound for grabbing all the lounges (loungers in US- took me a while to figure out what they were the first couple of times I saw that spelling) that are available, well before most people are up.
It has been suggested they put them out the night before.

If you would walk a mile for a Camel, the opposite would be how far a Camel would walk for you.

Seems like a silly thing to be arguing about.

Really? Is it any sillier than anything else people argue about on the internet?

(God, only another year to go with electioneering!)

Unfortunately, the next round begins not long afterwards for the next election.

I am surprised the kilogram is being defined. I would have thought the gram would be the primary measure of weight, or is that of mass. A kilogram is just 1000 grams. For the same reason they define a meter, not a kilometer.

Ancient politics, what was supposed to be the baseline unit - the mass equivalent of a litre

Liter itself is falling out of favor.

Litering is against the law.

That doesn't make sense. A kilogram is 1000 grams, end of definition. The base unit that needs to be defined, either by mathematical/physical constants or by an exemplar (the cylinder in the vault outside Paris) is the gram (originally the mass of one cubic centimeter of pure water at three degrees Celsius).

originally the mass of one cubic centimeter of pure water at three degrees Celsius

IIRC, originally intended to be the mass of one cubic centimeter of pure water at maximum density (about four degrees Celsius), but they were out by about 28ppm - even then, defined by cubic decimeter and kilogram.

The unit system is meter-kilogram-second, even though (as you say) kilogram is not a base measurement (although it is the reference standard). Prior to that, it was centimeter-gram-second, again with a non-base unit - and with two of the units not matching the reference standards (meter and kilogram). Before that, in a lot of the world, foot-pound-second. But then, the meter is now and a second was defined as an arbitrary number of wavelengths/oscillations of given light - and not even the same light!

The standards are chosen for relative ease of laboratory reproduction, to match historic prototype standards which had limited accessibility, and those standards were chosen to be a useful size - a standard of one gram would require a much more precise balance than for 1kg, and most real-world uses would require multiplying up to kg-scale anyway.

BTW, degrees centigrade are defined from the temperature in Kelvin, which is set from the triple point of water (0.01 deg.C), again chosen to make the new definition match the historical units. Even the historical freezing-and-boiling water temperatures, subject to small variances due to air pressure as they were, were quite a bit more sensible than defining 'zero' as the lowest temperature found by adding various salts to ice, and 100 as body temperature. {add] Though, that's just like defining 'inch' as the width of a thumb, foot likewise, etc.

That doesn't make sense. A kilogram is 1000 grams, end of definition. The base unit that needs to be defined, either by mathematical/physical constants or by an exemplar (the cylinder in the vault outside Paris) is the gram (originally the mass of one cubic centimeter of pure water at three degrees Celsius).

Actually, no, for some reason the kilogram is the base unit for mass and a gram is defined as the thousandth part of a kilogram.

"The kilogram is the SI base unit of mass and is equal to the mass of the international prototype of the kilogram, a platinum-iridium standard that is kept at the International Bureau of Weights and Measures (BIPM). The primary standard of mass for this country is United States Prototype Kilogram 20, which is a platinum-iridium cylinder kept at NIST.

The kilogram, originally defined as the mass of one cubic decimeter of water at the temperature of maximum density, was known as the Kilogram of the Archives. It was replaced after the International Metric Convention in 1875 by the International Prototype Kilogram which became the unit of mass without reference to the mass of a cubic decimeter of water or to the Kilogram of the Archives. Each country that subscribed to the International Metric Convention was assigned one or more copies of the international standards; these are known as National Prototype Meters and Kilograms. Learn more about the history and current definition of the kilogram."

http://www.nist.gov/pml/wmd/metric/mass.cfm