Forum: Author Hangout

Maybe even more important than a number is the who.

The who is the most important aspect of it. The farce they call "essential jobs" is far from the reality. Electrical generation, emergency personnel, medical workers, food production/distribution, sanitation, water, all examples of personnel required to keep the minimum functionality of a society in the short term. With few exceptions, most of these people require extensive training to minimally function. A group of untrained people could not run a power plant, operate medical equipment, put out a building fire, grow/harvest food on an industrial scale, operate a sewage plant or water plant, ad nauseam.

Most lawyers, jewelry store workers, recreational facilities, and others along those lines are not short term needs for society to function. All of which were designated as 'essential' dependent upon the state.

The 'who' is definitely 1st in that race with shear numbers across the board being 2nd.

The 'who' is definitely 1st in that race with shear numbers across the board being 2nd.

Agree but there's a third very important issue: time. There's a massive difference between a million deaths in a week or in six months. What I've seen among a lot of countries about how the covid-19 problem is handled is that the lockdowns were not primarily to stop the decease but to spread it out over a longer period of time so the emergency services could cope with the numbers. In an apocalyptic scenario time will play a big role in handling both the ill and the deaths.

Sometimes, aiming small is better

The problem with an apocalyptic story with a localized disaster is that you lose any long term survival aspect to the plot conflicts as you eventually get rescue/re-supply from outside the disaster area.

Electrical generation, emergency personnel, medical workers, food production/distribution, sanitation, water, all examples of personnel required to keep the minimum functionality of a society in the short term.

I have do disagree slightly. Society existed before modern medicine, and it will not collapse short term from a lack of medical personnel absent some sort of pandemic.

Most major pandemics historically permanently alter women and other minorities role in society. Once the society realizes they can no longer dictate who works and who doesn't, they're forced to accept the inevitable, whether they support it or not.

The whole concept of 'romantic love' and marrying who you love basically arose following the European Bubonic Plague.

You missed the point I was hinting at: the impact of the number of males vs females in an apocalyptic situation. Few females: few births to rebuild population, few males: possibly more births. Either group in the "few" category risks being enslaved because they have become a necessary scarce resource. Social concepts like love and romance only reappear when a stable situation has been reestablished. Until then it's fighting for survival.

Social concepts like love and romance only reappear when a stable situation has been reestablished. Until then it's fighting for survival.

I would be very curious to know where, or from whom, you learned that? Not disagreeing with it, far fom that actually. But the places I've witnessed it, and other people I've learned from, we're not what any sane person would call pleasant.

I would be very curious to know where, or from whom, you learned that? Not disagreeing with it, far fom that actually. But the places I've witnessed it, and other people I've learned from, we're not what any sane person would call pleasant.

It's a sad fact but humans aren't generally pleasant. We're little more than smart animals who are lucky to have an opposable thumb which allows us to handle tools effectively. Just looking at our history and the current state of our world should be enough to see what I mean.

You missed the point I was hinting at: the impact of the number of males vs females in an apocalyptic situation. Few females: few births to rebuild population, few males: possibly more births. Either group in the "few" category risks being enslaved because they have become a necessary scarce resource. Social concepts like love and romance only reappear when a stable situation has been reestablished. Until then it's fighting for survival.

That would be a bit more of a mixed bag and depends on some other variables as well. Few women to many men is not likely to be a pleasant situation for the women, I'd certainly agree. but that also going to depend on the nature of the men they "fall in" with over time.

Few men to many women is a more varied scenario, and actually fodder for a lot of harem fics.

This also ignores the matter that creepy as some may find it. Most of the men can wait 18-ish years for a chance to reproduce. The women wouldn't necessarily have that option, as humanity in general may not be able to afford that wait.

Women are the bottleneck on repopulating an area, not men.

This also ignores the matter that creepy as some may find it. Most of the men can wait 18-ish years for a chance to reproduce. The women wouldn't necessarily have that option, as humanity in general may not be able to afford that wait.

Women are the bottleneck on repopulating an area, not men.

Just to comment on this with what I have already mentioned elsewhere (probably repeatedly): the maximum possible growth rate of human population is actually mind-blowing if you put extreme values into simulation. In theory, arbitrary small group could rebuild current population numbers in under three centuries if procreation is put as primary goal. Between age of 15 and 45 a woman can have 20 kids and the youngest daughter be the same age as oldest granddaughter, so the actual maximum rate is above exponential.

It is also interesting that in somewhat randomized simulation I got results that differed by several orders of magnitude just by changing the minimum procreation age for women from 15 to 18. I strongly suspect current age of consent trends are actually very much about population control, intentionally or not.

so the actual maximum rate is above exponential.

No. Exponential growth allows for any exponent from 2 to just shy of inifinity.

No. Exponential growth allows for any exponent from 2 to just shy of inifinity.

Yes, it was mathematically inappropriate statement from me.

I just wanted to emphasize that one has to take those generation overlap effects into consideration or the result will be significantly underestimated, talking about theoretically maximizing population growth.

Just to comment on this with what I have already mentioned elsewhere (probably repeatedly): the maximum possible growth rate of human population is actually mind-blowing if you put extreme values into simulation. In theory, arbitrary small group could rebuild current population numbers in under three centuries if procreation is put as primary goal. Between age of 15 and 45 a woman can have 20 kids and the youngest daughter be the same age as oldest granddaughter, so the actual maximum rate is above exponential.

Except we run into some other technical hurdles here.

They have to care for and feed the children that are created for at least the first 6 years, and really the first 12 at a minimum.

While women can be reproductively capable at the age of 15, many are not particularly viable until they're in their 20's.

Also having children is hard on the body, and often carries a number of risks as well. Although some of them could likely be tested for and efforts take to avoid some at least initially. (No RH+ men impregnating RH- women for example, the second and subsequent RH+ positive baby is at high risk of miscarriage without specific precautions being made)

Also, the older the woman becomes the higher the risk factor becomes of congenital birth defects and other abnormalities happening. So your prime "breeding window" runs from early 20's up into the 30's. And realistically, you'd probably want them to wait a year or more between pregnancies for better outcomes for the mother.

Of course, if you want to go a little more dystopian, and presume that they have some more advanced medical capabilities still present. They could also go for artificial insemination for most women and pre-screen the sperm to increase the odds of the child being female. In order to further maintain the gender disparity while in "repopulation mode" although that would open the door to some other potential (mildly) dystopian impacts from there. Depending on exactly what kind of ratio we're talking about. It may not be too bad for the men. But for the women it would be another matter entirely.

It is also interesting that in somewhat randomized simulation I got results that differed by several orders of magnitude just by changing the minimum procreation age for women from 15 to 18. I strongly suspect current age of consent trends are actually very much about population control, intentionally or not.

I think it's more to do with time for educational attainment in order to function independently in society and the increased importance that is being placed on women being able to do so as well as men.

It is also seeing further backing based on medical evidence which further supports the idea of waiting until later.

But yes, the human race is very capable of creating quite the runaway population if it was inclined to do so. Thankfully it seems we're on the verge of having the discussion shift towards concerns about depopulation rather than over-population. Which is probably a good thing as our increasingly technical world keeps destroying jobs almost as quickly as it created them.

While women can be reproductively capable at the age of 15

They are reproductively capable at puberty (average onset around 9). Though, the minimum for safe, non-surgical, birth is probably 18 years.

The record for youngest mother is around 5 1/2 years.

This happened somewhere in South America in the mid 20th century. While a c-section was required for delivery the child (male) was born healthy and lived a normal lifespan for the time and country of his birth.

Based on medical observation of the condition of the mother's reproductive tract by the team that did the c-section, they estimated she started puberty somewhere between 6 months and 2 years.

Except we run into some other technical hurdles here.

Oh yes, very much.

I watched the population age structure, and it very soon became extreme, with very few adults. In the scenario I was interested for the absolute naturally attainable max I could safely ignore any practical difficulties because it was about alien hive integrating humans as one of the species of the collective. (My actual question was, "If the hive's observed human sub-population is X billion, what's the minimum time since humans were introduced?" assuming they don't do mass cloning in artificial wombs, for unspecified reasons.)

For any post- or even pre- apocalyptic human only societies that maximum at large is likely unattainable for all the practical hurdles mentioned. While indeed, small groups for limited timeframes possibly could replicate something close, forced or otherwise, the excercise was just that, assessing the potential. Still, I find it informative in understanding why human populations barely register mass death events in long run instead being predicted, apparently, more by purely ecological factors even if how isn't understood.

Thankfully it seems we're on the verge of having the discussion shift towards concerns about depopulation rather than over-population. Which is probably a good thing as our increasingly technical world keeps destroying jobs almost as quickly as it created them.

Currently, the most effective tool for global population control appears to be a smartphone in Africa.

It is somewhat counterintuitive that in modern society the most procreative group always is the poor and undereducated, botch locally and globally. Informed independent women tend to average to a child count that is actually under replacement level. And that is why global population is now predicted to bounce against something around nine billion and start to decline afterwards. While I have seen eleven billion as a number for ecological max of humans on Earth.

While I have seen eleven billion as a number for ecological max of humans on Earth.

This is actually very dependent on climate (warmer=better) and technology.

I would recommend taking any estimate on the ecological limit for human population with a metric ton of salt.

ETA: At 6 square feet per person, you could squeeze more than 5.5 Billion people into Rhode Island.

I think that assessment was more likely limited by freshwater availability. (We already use potentially unsustainable percentage of easily available freshwater.)

Sure, technology and -- even more -- life style expectations may alter that at least somewhat (e.g. water use of cotton industry; being both of highly varied efficiency and somewhat optimal in total volume -- since we could live with far fewer clothes). Also, it is not said there couldn't be more people at least temporarily, just at what point population would likely cause irrecoverable damage resulting in significant, forceful and at least semi-permanent drop of maximum population.

I think that assessment was more likely limited by freshwater availability. (We already use potentially unsustainable percentage of easily available freshwater.)

The problem with that is in terms of biological use, we don't actually use it up. It's almost infinitely recyclable.

we don't actually use it up

Like beer in a tavern. We don't buy it, we just lease it and return it to the tavern when we use the urinal.

The problem with that is in terms of biological use, we don't actually use it up. It's almost infinitely recyclable.

Sure. But while available reserves is a problem on itself (melting mountain glaciers etc.) it's a different problem. The main problem is that something like upwards of 70% of currently available water cycle we could possibly use we are already using. And wildlife has to fit in somewhere too, well, the tiny enclaves of it remaining in the human world.

The main problem is that something like upwards of 70% of currently available water cycle we could possibly use we are already using.

"something like upwards of 70%" Sounds like a WAG, you have a source for that..?

I think that assessment was more likely limited by freshwater availability. (We already use potentially unsustainable percentage of easily available freshwater.)

Humans don't use water, they recycle it. After it's discarded from use, it makes it's way back to the large bodies via discarded water --> lakes/rivers --> oceans --> atmosphere --> rain and the whole cycle starts again.

Insufficient water is an engineering problem, not a supply problem.

And that is why global population is now predicted to bounce against something around nine billion and start to decline afterwards. While I have seen eleven billion as a number for ecological max of humans on Earth.

There are numerous assumptions in those numbers. Just to list a few:

1. The average total solar irradiance stays above 1362 W/m^2. That doesn't appear to be happening.

http://lasp.colorado.edu/data/sorce/total_solar_irradiance_plots/tim_level3_tsi_24hour_640x480.png

https://climate.nasa.gov/news/2659/four-decades-and-counting-new-nasa-instrument-continues-measuring-solar-energy-input-to-earth/

2. The spectral output of the sun doesn't change. It's a forgone conclusion that it has given other changes which brings us to three.

3. https://www.cnn.com/2010/US/07/16/nasa.upper.atmosphere.shrinking/index.html

Oddly, media and NASA mostly shut up about it after 2013. That didn't change anything though. The normal heating/expansion cooling/contraction cycles as the overall solar cycles transit from min to max to min again didn't happen. The atmosphere did not fully recover to its normal as the sun's output wasn't strong enough, which brings us to four.

4. Weakening Magnetosphere.

http://www.esa.int/Applications/Observing_the_Earth/Swarm/Earth_s_magnetic_heartbeat

Most people view that in abstract, not really understanding the significance of it. Among the many changes that plays a role in is Earth's Albedo, amount of cosmic particles and radiation into lower atmosphere, and cosmic spallation of atmospheric gases which feeds into both particle levels and Albedo changes. The increased radiation levels have been confirmed btw.

https://spaceweather.com/images2018/30jul18/stratosphere_california.png

That's just one graph. There are thousands to choose from if you dive in far enough.

So what's the point you might ask? The point is, any of those population numbers assume no change or increases in food production. A deep dive into agricultural output over the last ten years will show a steadily decreasing level of output. Simply put, the sun is on the ebbing side of one of its natural cycles. That has decreased both quantity and quality of energy from it. Those changes have a direct input on crops. Plants need light to grow, changes in that light change the growth.

Fortunately, technology has overcome most of the negatives, but it hasn't made them go away.

Another assumption in those numbers were that no significant pandemic would occur. We all know how that assumption has worked out.

I can go on for a month of Sundays regarding those assumptions, but what it all boils down to is, it's effectively a wild ass guess/WAG by people with too much time on their hands.

I can go on for a month of Sundays regarding those assumptions, but what it all boils down to is, it's effectively a wild ass guess/WAG by people with too much time on their hands.

Sure. It may be based on decades old data and may be less, and it may be double, with allowance for future technology and severely limited lifestyle, but the exact number doesn't matter. I mentioned it just as that, an educated guess as an aid for assessing trend, particularly, that global overpopulation seems to be taken off the list of pressing problems, given current predictions holding, by comparing 9 < 11 (wherein both numbers are "wild guessing" as in, we can't directly test neither beforehand).

Another assumption in those numbers were that no significant pandemic would occur.

With may be less significant than you make it or not at all. Historically, even very bad events had provided only short term dents in steady population trends, likely controlled by other factors (one notable example I do remember charted was Japan's recovery from WW2 loses, and it was positively compared to European plague events (with caveat that it concentrated on city populations and admitted limited data)). Short term in the particular case, the current pandemic is so mild it may not even show up on the total population trendline. It's fully possible marginal gains like traffic accident deaths prevented by stay-at-home orders may even outweigh direct deaths. While it is believed pandemics aren't the type of disaster particularly lending for immediate baby booms, it's to be seen next year was there one.

4. Weakening Magnetosphere.

Yup, the pending reversal of Earth's magnetic field is interesting venue for potentially apocalyptic scenarios.

We know from geological records it is somewhat regular, relatively sudden event (and likely overdue, with is concerning), but it's rare enough for any direct short term effects to be unknown. There's a couple lava flows implying rapidly (like within days or hours) changing directions of magnetic poles, suggesting intermittent phase of chaos and not a full shutdown/restart, but we don't know does the full process take months or millennia, nor what the effects on lifeforms will be. There's even suggestions that multiple weak magnetic poles rapidly roaming around may do quite interesting things to sanity of animals, including humans.

Yup, the pending reversal of Earth's magnetic field is interesting venue for potentially apocalyptic scenarios.

We know from geological records it is somewhat regular, relatively sudden event (and likely overdue, with is concerning), but it's rare enough for any direct short term effects to be unknown. There's a couple lava flows implying rapidly (like within days or hours) changing directions of magnetic poles, suggesting intermittent phase of chaos and not a full shutdown/restart, but we don't know does the full process take months or millennia, nor what the effects on lifeforms will be. There's even suggestions that multiple weak magnetic poles rapidly roaming around may do quite interesting things to sanity of animals, including humans.

The pole switch is coming. However, the people running around with their hair on fire claiming it will happen in months, have not reviewed the data available.
The geology you refer to is primarily from the Mid-Atlantic Ridge. There are other areas, but that location is the most tested location and considered the baseline for other areas.
The MAR is a divergent/constructive zone in that the tectonic plates push away from each other. Volcanic activity is what fills in the gap and why it's considered a constructive zone.

In the process of eruptions, magma rises above the materials curie point. Curie point to be defined as the temperature at which below it, the magnetic dipole of the material is fixed into position. Above that temperature, the magnetic domains are unaligned/random.
When the temperature drops below that point, the dipoles snap into alignment with the polarity of the earth's magnetic field at that time. That phenomenon btw, is how specialized rare earth magnets are formed. Heat up, shape, apply preferred magnetic orientation, then snap cool it locking in that orientation.

Geological cores are cut in the solidified volcanic materials, radiometric dated, then the magnetic orientation measured.

Now that we've established the how and why, we get to where and when.
The rapid change flows you speak of where highly contested. It takes time for the lava to cool below the magnetic curie temperature. Days to a month dependent upon subsea or ocean. The hours part has been thoroughly debunked, the days nearly so since those locations were above ground. That's before we get to the error factor in radiometric dating. The range for long half-life isotopes is years to thousands of years depending on the isotope. It's definitely in the thousands of years for isotopes that cover 3/4 million years or more. I use that number because the last pole shift occured ~780,000 years ago. If you can't fix a start and finish date within a thousand years, how do they explain days and hours?

As for localized areas of change, there are currently two areas on the globe that are doing that as we speak. One is the South Atlantic Anomaly, and a much newer one forming up off the coast of South Africa.

All of which is on top of the generalized weakening that has been occurring the last 160 years. In the last ten years, that weakening has accelerated, but at its current pace, will still be a while before any pole shift occurs.

The two anomalies mentioned above give more credence to the idea that the earth's fields will devolve into a chaotic mishmash before the poles switch completely.

Based on those mentioned cores, and the geological record they represent for previous pole shifts, none of those previous shifts occured in terms of months, more like a few thousand years.

the bottleneck on repopulating

Its not the neck that babies come out from.

Pure from logical thinking the number would have to be huge, so huge that not enough people are left to produce basic needs. Maybe even more important than a number is the who. There's a big difference in impact between all elderly dying or a whole younger generation. Even a huge discrepancy between the number of males and females will have a huge impact. There are so many scenario's that it would be impossible to put a fixed number to it.

Pure logic would suggest that, but reality is people aren't rational, so they're likely to respond irrationally to what they perceive the threat to be.

So it would need to be more deadly than Covid, obviously, but I don't know that it would need to be more than a multiple of covid's own lethality to make a lot of social systems collapse under the strain.

People like winners over appointed commanders, and if the winners can also provide for everyone else, they'll rise in power quickly, regardless of the formalized opposition to them.

Maybe you should explain what that has to do with the OP?

Just not as much as basic immunity does, which is often dictated by purely random DNA aborations, so having a small core community rise up, as the main surviving group, quickly changes the other factors.

Just a reminder of part of the OP question;

How many Americans would have to die for our society to completely break down

The small core of surviving people you speak of, would mean the collapse had long since happened. The idea is to prevent that and if not, define the break point.

You're really stretching the fabric of reality with that post.

So, no one is allowed to address specific responses, instead always having to start an entirely new discussion about the initial post? Is this the first forum you've ever visited? Separate threads develop over a protracted discussion.

Umm no, it's not the first by a long shot. Condecend much?

The OP asked a question, your post was out in left field with no apparent connection to that question. There was no part of your reply that explicitly, or indirectly, addressed the number of dead.

How many Americans would have to die for our society to completely break down

The small core of surviving people you speak of, would mean the collapse had long since happened. The idea is to prevent that and if not, define the break point.

You're really stretching the fabric of reality with that post.

Well, we could get into games about "define 'our society' for the purpose of this exercise?"

Because there probably are a few "near collapse" scenarios that could happen which would radically alter the cultural outlook of the society in short order.

Because there are sub-communities within the larger society that are likely to be more robust than the society as a whole is. So when it comes SHTF time, those communities are going to be the ones that pull-through and likely bring a lot others along with them. And once you're "on the other side" those groups are going to be the ones holding a lot of the political and actual power. Even if things didn't completely collapse.

t pretty much must be some kind of "zombie virus" where the fear of the disease far exceeds the direct impact, triggering violent tribalism.

So, COVID19...

where the fear of the disease far exceeds the direct impact, triggering violent tribalism.

So, COVID19...

Yes, but much worse.

But if COVID-19 had something like 10% overall mortality (instead of 2% with heavy bias to 65+ age group (where it does reach 15-30% for known cases)) it all would actually made sense to almost anyone and therefore there would probably be less discord.

Also, looking in from the outside, it's fun to mention it is mostly conservative "sceptics" who ever mention fear as driving narrative. Not only in this either. Watching discussion on some other forums, I initially assumed it to be pure trolling when people I perceive as rational and constructive were described as fearful by Trump's cult wackos, but gradually I'm growing to understand those people indeed seem to see the world through such a prism, that fear might be a significant factor in people's motivation. And then I once again come across the self description of "God fearing" (a completely alien concept to me, but that's me) meaning it like that would be a virtue, and I had to think, doesn't it resonate.

And indeed, probably for a disease to disrupt society it must amplify existing systems of superstitions and prejudices in contrary to actual necessity.

Fun aside, reading the bible Old Testament I couldn't help but think, the original intent of the book was actually quarantine rules, retold multiple times by people who didn't understand the teachings.

Yes, but much worse.

I'm not sure that's true. The government over response to COVID has done an awful lot of damage, and it could get worse yet.

Rarely a catastrophe has a singular cause even if a specific trigger event can be identified. That's true even for engineering failures, further more for sociopolitical disasters.

Trump probably wouldn't become prominent in politics without his anti Obama rhetoric, COVID-19 itself, or at least mitigation measures in particular, might be less of a problem in calmer political environment with actual, early engaged strategy in place. Would current riots be triggered by a random episode of police brutality without the background of already elevated tensions about COVID-19 and possibly the free time people have at hand because of it?

It's actually easy to imagine continuous chain of escalating overreactions out from this. Let Trump involve army, declare martial law, or worse, encourage counter violence by certain (well armed) civilian groups. Etc, down into chaotic civil war without set goals, just lots of hate.

Would the resulting collapse be attributed to COVID-19 after the dust settles? Probably, because people like to have flashy singular excuses instead of analyzing vague long going trends and deeply ingrained problems with many contradictory nuances. However, actual death counts of the disease would be incidental to the overall resulting situation.

Fun aside, reading the bible Old Testament I couldn't help but think, the original intent of the book was actually quarantine rules, retold multiple times by people who didn't understand the teachings.

Who or what were these rules meant to protect them from...???

Oh wait.

In Genesis alone;

When Adam and Eve disobey God, he curses them and banishes them from the Garden of Eden.

Cain, the first born man, murders his brother Abel. God curses Cain for this, and also grants him protection from danger.

God sees that "wickedness of man was great" and decides to exterminate mankind and all animals, saving only Noah and those he brought with him on the Ark. After the Flood, God promises to never again destroy all life by a flood.

God resolves to destroy the cities Sodom and Gomorrah, "because their sin is very grievous".

It would seem that "God fearing" was entirely justified, not due to faith or belief but just for survival.

It would seem that "God fearing" was entirely justified, not due to faith or belief but just for survival.

Yeah, but it is exactly the more active involvement of Jehovah in the historical events -- as opposite to the creation stories (with are retellings of earlier legends anyway) -- that I found interesting. A fun read of Moses story is to imagine Jehovah as a resourceful fellow in a rocket ship who grabbed a bunch of slaves in Egypt as his expendable ground force.

((Although the rocket aspects much probably refer to the eruption of Santorini. Although, said eruption did destroy outpost of the most advanced civilization in the Mediterranean at the time, and as everyone knows, Tutankhamun died from injuries of an airplane crash, so one don't necessarily exclude the other.))

Ok, based on your last post, you either need more, or should start taking, or have overdosed on something...

Enjoy the ride, some of us will be around when you land...

:)

Ok, based on your last post, you either need more, or should start taking, or have overdosed on something...

The only thing overdosed in that post is alternative history "theories" and I didn't indicate I'm actually buying any of that. However, it isn't unnoticeable that christianity have signs of a cargo cult.

hijacked

Hi, Jack.

I was going to reply to the thread earlier, but by the time I could, it was well off the rails - let's try now.

I think the proportion will be a lot lower with modern civilisation than in the past because modern technology is so specialised and interdependent, and most people don't even have the conception that some jobs exist, let alone the absolute requirement for them. Also, modern resource extraction is also more specialised and more fragile than in the past; we don't wander around and spot an interesting rock then start digging it out of the ground, rather there are teams of scientists who identify a possible site, more teams to drill boreholes to test, then a major construction effort to dig a kilometre-deep shaft to get to where it's possible to finally start digging out useful bits - which are often now a lower grade ore than the stuff that used to lay around on the surface.

So long as we still have communications and transport, local problems can be solved with input from the whole country (or wider), but isolate us and there's bound to be problems that can't be solved and cause the community to wither and die. So, the tipping point depends on the circumstances of the apocalypse, IMHO.

This was your question.

How many Americans would have to die for our society to completely break down into the typical post-apocalypse scenario?

The question was poorly stated as there were too many underlying assumptions. One such assumption was defined early, in that it was more who rather than how many. That has some historical precedence if you care to look it up.

Broad spectrum deaths, as in simple shear numbers across all walks of life has few if any recorded total collapses of a society. The closest version of that would take us back to the black death early to mid 1300's.

Command and control I.E. leadership deaths have collapsed more than one society as the aftermath civil wars, border wars, etc, attempted to fill the power vacuum, effectively destroyed the societies involved.

Remember you stated "to completely break down" as modifications of a society were far more frequent. The aftermath of the world wars being prime examples.

That gets us back to who. Taking out enough people from specific segments of society would cause a complete breakdown. Medical personnel would definitely do it among others.

Modification of society is another story. Covid19 has already done that.
Then again with the death of one man (George Floyd) looks to have permanent repercussions on US society.

Bottom line is, your question was too broad to give specific answers without addressing the underlying causes and assumptions necessary to answer it.

Broad spectrum deaths, as in simple shear numbers across all walks of life has few if any recorded total collapses of a society. The closest version of that would take us back to the black death early to mid 1300's.

At issue here is "broad spectrum death" only has the 1918 influenza outbreak to compare against, and as bad as it was, it wasn't that bad as a percent of population.

You get a Black Death scale event to happen in our even more specialized society than what existed in 1918, and it becomes a roll of the dice as to who the 10 to 30% of the population is that dies. If you get lucky enough people with the right skills survive.

If you get unlucky, enough people in a certain segment of the specialized society succumb to it that it sets a domino effect in motion that crashed the entire system for entire regions if not (small) nations as a whole.

All you'd need is one major city to be rendered inhospitable because they lacked the skilled trades needed to keep it operating, and the resulting exodus of people in turn overwhelms and swamps to surrounding area, which then triggers another "wave" refugees which then overwhelms the next set of communities, and so on. (Which isn't to mention what the refugee movements could do for spread of the outbreak itself)

Visited the Zombie Hut in Sacremento in the mid 80's, and the reincarnation of it in Brooklyn in 2004. Should the tipping have been different there?