Revisiting the Drake Equation

[Loren Pechtel]

Mankind will be lucky to be around in 1,000 years.


Sent from my iPhone using Tapatalk

True. That's one of the possible explanations for Fermi's Paradox--is L is quite low.

It certainly looks like life should be abundant. However, we don't see ETs. That means somewhere on the road between life and starfaring civilization there's fence that's very hard to cross. Realistically, we are left with:

1) Multi-cellular life is very hard within the available timespan.

2) Intelligence is very hard within the available timespan.

3) The destruction of life is common.

4) It's very hard for intelligent life to survive to become starfaring.

Some combination of these 4 almost certainly add up to a minimum of billions to one odds.

Either we are experiencing an observer effect--one of the first three is the hurdle, any planet that doesn't pass that hurdle doesn't have observers to note how unlikely survival is--or the hurdle is the last one.

 

[Loren Pechtel]

War won't do it - we probably had just barely enough nukes in the 1980s to engineer a total extinction event, but even then, it would have required a deliberate strategy of extinction by at least one of the two superpowers - and I suspect that both would tend to avoid nuking remote non-combatants (Why would the Soviets or the Americans have wanted to fire a warhead at a few hundred Aborigines on the fringes of the Great Sandy Desert, or the tribes of the upper Amazon, or the Tuareg villages on the edge of the Sahara, or the Kalahari bushmen?). I reckon even a worldwide, all-out thermonuclear exchange at the peak of the cold war would struggle to kill every last pocket of humans, and history shows that we can bounce back within a few tens of thousands of years.

Disagree--you're ignoring the secondary effects. Lets replace the existing bombs with magical versions that make just as big a boom but don't kill anyone. A full exchange with such bombs would still endanger the survival of the human race (and might actually make it even less likely!)

The problem isn't the bombs themselves. It's not realistically possible for them to kill everyone--as you say, there will be a lot of people that the bombs simply aren't aimed at. The problem is what follows.

1) You have a total grid-down situation. By itself this will kill most of the human race even if there were no other problems at all. You have a lot of people with no food and who know that there is no meaningful law enforcement. They'll take anything they can, kill anyone who gets in their way--and as things get dire they'll start killing each other.

2) Scavenge from the cities? Note something that's found in every appreciable city in the world: A fire department. We're talking a grid-down situation, there will be no fire department. Those cities will burn.

3) You will have months where the skies are too dark to grow anything. The world doesn't have a lot of food in storage anyway, this will run those stocks to zero.

4) The fallout from the bombs will kill just about every unprotected person in the northern hemisphere anyway--and even if the people have fallout shelters livestock doesn't. What little in the way of animals that survive will be eaten by the mobs--don't expect anything larger than a mouse to survive.

A 'dinosaur killer' style meteorite is something we are on the cusp of being able to detect and deflect; and within mere hundreds of years, we might have colonies elsewhere in the Solar System that could survive for long enough to re-populate the Earth once the dust settles.

We probably have already catalogued all dinosaur killers in ordinary orbits and it doesn't look like there are any serious threats. New comets show up all the time, though--and our chances of a successful deflection mission against one is a big, fat goose egg. The risk is low, not zero. Remember 4 years ago where the Martians got a serious case of pucker factor?

The Sun seems to be sufficiently stable as to give us a pretty good chance of at least many thousands, probably a few million, years before it eradicates us.

Tens of millions before it's a big deal.

Pandemic diseases might kill billions; But even the most deadly plagues in history only kill about 95 - 97% of the host population, which would leave over 200 million people alive to rebuild.

Disagree. Look at what happened to the New World--parts of it were depopulated by the plagues of the Old World. It doesn't take 100% to leave a population non-viable, nature will finish what the plague started. Also, we are far more tied together, the vast majority of those 200 million would die.

Kill 99% of humanity, and then have 90% of the survivors succumb over time due to lack of survival skills and/or resources in the post apocalyptic wasteland, and you still have 7 or 8 million surviving humans. 10,000 years is more than enough time for such numbers to recover to the current level of population and technology, particularly as they need not re-invent the wheel.

I would be shocked at only 90% of the survivors dying as they compete for what's left.

And they're not going to be rebuilding in 10,000 years. All the easy-to-get resources are used. You can't mine the cities very well because they burned. If you can manage to get to it there's a lot of buried copper to dig up but that's about it.

 

[bilby]

I dunno; It's going to be pretty hard to eradicate us.

What do you see as the extinction mechanism?

Likely mankind or mankind because of the Sun.

War won't do it - we probably had just barely enough nukes in the 1980s to engineer a total extinction event, but even then, it would have required a deliberate strategy of extinction by at least one of the two superpowers - and I suspect that both would tend to avoid nuking remote non-combatants (Why would the Soviets or the Americans have wanted to fire a warhead at a few hundred Aborigines on the fringes of the Great Sandy Desert, or the tribes of the upper Amazon, or the Tuareg villages on the edge of the Sahara, or the Kalahari bushmen?). I reckon even a worldwide, all-out thermonuclear exchange at the peak of the cold war would struggle to kill every last pocket of humans, and history shows that we can bounce back within a few tens of thousands of years.

You don't need extinction to bring progress to a halt.

Sure; But you said "Mankind will be lucky to be around in 1,000 years", not 'Mankind will be lucky to still be making progress in 1,000 years', and it is that to which I responded. I agree that we may be lucky to be as advanced as we are today in 1,000 years.

A 'dinosaur killer' style meteorite is something we are on the cusp of being able to detect and deflect; and within mere hundreds of years, we might have colonies elsewhere in the Solar System that could survive for long enough to re-populate the Earth once the dust settles.

I don't know if we are psychologically strong enough to handle space travel and space colonies. We are talking Joe Schmo who throws the remote control at the TV because of a bad call in a baseball game handling the depths of space?

For sure, MOST people don't have the 'right stuff'; but I doubt MOST people will go. Those who do will self-select for suitability (and natural selection will doubtless make a second pass)

Pandemic diseases might kill billions; But even the most deadly plagues in history only kill about 95 - 97% of the host population, which would leave over 200 million people alive to rebuild.

Humans are like cockroaches; Easy enough to kill in large numbers, but very hard to eradicate completely, because we are numerous, adaptable, and widespread.

Kill 99% of humanity, and then have 90% of the survivors succumb over time due to lack of survival skills and/or resources in the post apocalyptic wasteland, and you still have 7 or 8 million surviving humans. 10,000 years is more than enough time for such numbers to recover to the current level of population and technology, particularly as they need not re-invent the wheel.

Science and mankind are on a great track. Every time it discovers something that'll benefit mankind, it gets repurposed to try and destroy it.

And yet our population has been on an upward trajectory for 10,000 years, and not one of the small set-backs along the way has been due to too MUCH technology. So it's doing a pretty shit job of being repurposed to destroy mankind.

The only technology that has made a really serious dent in our population growth has been the contraceptive pill - which is specifically limiting population growth on a purely voluntary basis without anyone having to die, and which has successfully averted the dangers of excessive population growth - we are now on-track for a stable population within the (technologically enhanced) carrying capacity of the planet.

We have made a lot of poor decisions as a species, and have used technology in some truly awful ways; But the net result has always been strongly positive, and I see no good reason why this would change so drastically as to lead to extinction - as I outlined above, the worst case I can see as even vaguely plausible would be to reduce population by 99.99% through nuclear war, and even that threat is VASTLY lower today than it was 35 years ago. The recovery time from such a setback would likely be measured in millennia, rather than centuries; But recovery would be, I think, inevitable.

We might get bombed back to the stone age; But it only took us 4,000 odd years to get here from there, from a standing start.

 

[bilby]

Disagree--you're ignoring the secondary effects. Lets replace the existing bombs with magical versions that make just as big a boom but don't kill anyone. A full exchange with such bombs would still endanger the survival of the human race (and might actually make it even less likely!)

The problem isn't the bombs themselves. It's not realistically possible for them to kill everyone--as you say, there will be a lot of people that the bombs simply aren't aimed at. The problem is what follows.

1) You have a total grid-down situation. By itself this will kill most of the human race even if there were no other problems at all. You have a lot of people with no food and who know that there is no meaningful law enforcement. They'll take anything they can, kill anyone who gets in their way--and as things get dire they'll start killing each other.

Hence my guesstimate of 90% post-apocalyptic population loss. But maybe it would be 10x as bad; Even with 99% initial losses and then another 99% lost in the post-apocalyptic phase, that still leaves a LOT of people - almost all of whom are currently living 'off grid' in harsh environments.

2) Scavenge from the cities? Note something that's found in every appreciable city in the world: A fire department. We're talking a grid-down situation, there will be no fire department. Those cities will burn.

Not all useful resources are combustible. Iron and steel don't burn well.

3) You will have months where the skies are too dark to grow anything. The world doesn't have a lot of food in storage anyway, this will run those stocks to zero.

Food for 10,000 people for a day is equal to food for 10,000 days for a person. The non-perishables in just one surviving grocery store would feed a handful of people for months, maybe years. And anyway, most survivors are people who already know how to live off-grid in harsh environments - see above

4) The fallout from the bombs will kill just about every unprotected person in the northern hemisphere anyway--and even if the people have fallout shelters livestock doesn't. What little in the way of animals that survive will be eaten by the mobs--don't expect anything larger than a mouse to survive.

Note that all of my examples of places where I would expect people to survive are in the Southern Hemisphere.

A 'dinosaur killer' style meteorite is something we are on the cusp of being able to detect and deflect; and within mere hundreds of years, we might have colonies elsewhere in the Solar System that could survive for long enough to re-populate the Earth once the dust settles.

We probably have already catalogued all dinosaur killers in ordinary orbits and it doesn't look like there are any serious threats. New comets show up all the time, though--and our chances of a successful deflection mission against one is a big, fat goose egg. The risk is low, not zero. Remember 4 years ago where the Martians got a serious case of pucker factor?

Yes; I said 'on the cusp of' - we are not quite there, but we can see how to get there from here.

The Sun seems to be sufficiently stable as to give us a pretty good chance of at least many thousands, probably a few million, years before it eradicates us.

Tens of millions before it's a big deal.

Pandemic diseases might kill billions; But even the most deadly plagues in history only kill about 95 - 97% of the host population, which would leave over 200 million people alive to rebuild.

Disagree. Look at what happened to the New World--parts of it were depopulated by the plagues of the Old World.

Last time I checked, there were still populations of native Americans in various places on both the North and South American continents.

It doesn't take 100% to leave a population non-viable, nature will finish what the plague started. Also, we are far more tied together, the vast majority of those 200 million would die.

Maybe there would only be 10 million. or 1 million, or even as few as 10,000 people left. Those are STILL viable populations:

A 2005 study from Rutgers University theorized that the pre-1492 native population of the Americas are the descendants of only 70 individuals who crossed the land bridge between Asia and North America.

The controversial Toba catastrophe theory, presented in the late 1990s to early 2000s, suggested that a bottleneck of the human population occurred c. 70,000 years ago, proposing that the human population was reduced to perhaps 10,000–30,000 individuals

wikipedia

Kill 99% of humanity, and then have 90% of the survivors succumb over time due to lack of survival skills and/or resources in the post apocalyptic wasteland, and you still have 7 or 8 million surviving humans. 10,000 years is more than enough time for such numbers to recover to the current level of population and technology, particularly as they need not re-invent the wheel.

I would be shocked at only 90% of the survivors dying as they compete for what's left.

It's a guesstimate; But even if we pick a much larger number, there are plenty of people left (see above)

And they're not going to be rebuilding in 10,000 years. All the easy-to-get resources are used. You can't mine the cities very well because they burned. If you can manage to get to it there's a lot of buried copper to dig up but that's about it.

A burnt out city is not a harder to reach resource than the ores that were used in the early Bronze and Iron Ages.

The ENTIRE annual iron production of the Roman Empire at its peak was less iron than is found in one large modern container ship. You don't even need to go to a city - there will be VAST resources (by Iron Age standards) washed up on beaches all over the world.

 

[Kharakov]

The Earth Abides....

 

[lpetrich]

 Earth Abides:

Earth Abides is a 1949 post-apocalyptic science fiction novel by American writer George R. Stewart. It tells the story of the fall of civilization from deadly disease and its rebirth. The story was set in the United States in the 1940s in Berkeley, California and told by a character, Isherwood Williams, who emerges from isolation in the mountains to find almost everyone dead.

The title is from a translation of Ecclesiastes 1:4 -- "Men go and come, but earth abides." (not in any translation in Ecclesiastes 1:4 - Bible Gateway or Ecclesiastes 1:4 Generations come and generations go, but the earth remains forever.)

-

Our industrial civilization has been built with the help of fossil fuels, and with the easier deposits used up, it will be hard to rebuild it in its current form. That is why long-term sustainability requires industrial-scale renewable-energy production. We are gradually getting there, but we still have a long way to go. Cleantech News — Solar, Wind, EV News (#1 Source) | CleanTechnica is an enthusiast site, and it is revealing what it does not talk much about: synthetic fuels (synfuels). These are still too expensive to compete directly with fossil fuels, except in small niche markets like motor oil. Synfuel versions are often much better-behaved than petroleum-derived versions.

With enough energy, one will not need to look for good ores of desired materials -- one can instead extract them from garbage or ordinary rock or seawater.

 

[Don2 (Don1 Revised)]

There are also ideologies that may impact some of these variables: fc and L in particular. Aliens with a large percent of individualistic thinking who do not want to cooperate, though intelligent, on Big Projects of society may have less ability. Also, aliens who are imperialistic (and destroy/enslave/coopt other civilizations) may affect L.

 

[James Brown]

It's hard to imagine a post-apocalyptic society rebuilding itself on fossil fuels.

 

[bilby]

It's hard to imagine a post-apocalyptic society rebuilding itself on fossil fuels.

Our current society has only used fossil fuels in large quantities for about two centuries.

Almost everything up to the early 19th century was done using charcoal and wood for burning, and animals, water, and wind for motive power.

Fossil fuels are a big boost to industrialisation, but they are probably not essential; they certainly are not necessary in order to build a civilised society.

 

[Loren Pechtel]

Not all useful resources are combustible. Iron and steel don't burn well.

But a big fire will do a lot of damage and expose that iron to the weather--it will rust away. By the time civilization is recovering all that will be left is what's underground.

Food for 10,000 people for a day is equal to food for 10,000 days for a person. The non-perishables in just one surviving grocery store would feed a handful of people for months, maybe years. And anyway, most survivors are people who already know how to live off-grid in harsh environments - see above

No, because most of it won't last anything like 10,000 days.

Besides, you're looking at what would happen if the people were killed off first--in that case the survivors could do quite well by salvage. That would only be a likely scenario if the threat was biological. In that case I think we could rebuild.

However, in the war or impact scenarios you have more mouths than supplies--if that grocery store survives it's going to be stripped bare in hours.

And 10,000 survivors in one community is viable. 10,000 survivors in 1,000 scattered groups probably won't make it.

We probably have already catalogued all dinosaur killers in ordinary orbits and it doesn't look like there are any serious threats. New comets show up all the time, though--and our chances of a successful deflection mission against one is a big, fat goose egg. The risk is low, not zero. Remember 4 years ago where the Martians got a serious case of pucker factor?

Yes; I said 'on the cusp of' - we are not quite there, but we can see how to get there from here.

We are on the cusp of being able to deflect a rock with a lot of warning. If they find a dinosaur killer 10 years out I would think they would get it. You don't need much deflection that far out, if the rock is solid enough a single h-bomb will do it, if it's a gravel pile it will take several smaller bombs spaced out over time. (Against objects that lack strength you're limited to deflections well below it's escape velocity so it doesn't come apart when it's hit.)

Now, if it's something like the one that scared the Martians it's quite another matter--trying to deflect it would actually be a bad idea, the effort should be spent digging in instead.

Maybe there would only be 10 million. or 1 million, or even as few as 10,000 people left. Those are STILL viable populations:

10,000 is certainly non-viable--that's going to be a bunch of scattered individuals who don't know where others can be found.

A burnt out city is not a harder to reach resource than the ores that were used in the early Bronze and Iron Ages.

A burned out city will leave behind stuff that rusts. There won't be much metal left within a few generations.

The ENTIRE annual iron production of the Roman Empire at its peak was less iron than is found in one large modern container ship. You don't even need to go to a city - there will be VAST resources (by Iron Age standards) washed up on beaches all over the world.

Rust.

 

[beero1000]

Rust doesn't just vanish though, it'll spread a bit by wind and water but you'll still get huge regions of extremely heavily enriched soil. Much easier to mine than basically any naturally occurring deposits of iron. You could pretty much just drag a magnet through it to get enough iron oxides to convert.

 

[Angra Mainyu]

I dunno; It's going to be pretty hard to eradicate us.

What do you see as the extinction mechanism?

One potential mechanism is evolution - of sorts.
I'm not sure what the odds are (so, I'm not claiming it's going to happen, but I wouldn't affirm it won't, either), but I would say that things like genetic engineering and perhaps also integration between brains and machines has the potential to do it, and humanity would be replaced by one or more post-human species (or whatever one calls them, since the concept of species might be difficult to apply given the cyborg integration part).
Even if the cyborg part does not make much of a dent, genetic engineering has the potential to make a very big one. Of course, it might be that humans (or just moderately GM humans) also stick around, alongside different post-human entities. But it might not be so.
At any rate, if 1000 years is too little, if we think longer term - say, 10000 years -, the odds go up by a lot, I think.

Of course, this sort of scenario also results with an advanced civilization very likely colonizing the Solar System (and later, beyond). Just not humans, but something that evolves from humans.

 

[bilby]

But a big fire will do a lot of damage and expose that iron to the weather--it will rust away. By the time civilization is recovering all that will be left is what's underground.

Food for 10,000 people for a day is equal to food for 10,000 days for a person. The non-perishables in just one surviving grocery store would feed a handful of people for months, maybe years. And anyway, most survivors are people who already know how to live off-grid in harsh environments - see above

No, because most of it won't last anything like 10,000 days.

Besides, you're looking at what would happen if the people were killed off first--in that case the survivors could do quite well by salvage. That would only be a likely scenario if the threat was biological. In that case I think we could rebuild.

However, in the war or impact scenarios you have more mouths than supplies--if that grocery store survives it's going to be stripped bare in hours.

And 10,000 survivors in one community is viable. 10,000 survivors in 1,000 scattered groups probably won't make it.

We probably have already catalogued all dinosaur killers in ordinary orbits and it doesn't look like there are any serious threats. New comets show up all the time, though--and our chances of a successful deflection mission against one is a big, fat goose egg. The risk is low, not zero. Remember 4 years ago where the Martians got a serious case of pucker factor?

Yes; I said 'on the cusp of' - we are not quite there, but we can see how to get there from here.

We are on the cusp of being able to deflect a rock with a lot of warning. If they find a dinosaur killer 10 years out I would think they would get it. You don't need much deflection that far out, if the rock is solid enough a single h-bomb will do it, if it's a gravel pile it will take several smaller bombs spaced out over time. (Against objects that lack strength you're limited to deflections well below it's escape velocity so it doesn't come apart when it's hit.)

Now, if it's something like the one that scared the Martians it's quite another matter--trying to deflect it would actually be a bad idea, the effort should be spent digging in instead.

Maybe there would only be 10 million. or 1 million, or even as few as 10,000 people left. Those are STILL viable populations:

10,000 is certainly non-viable--that's going to be a bunch of scattered individuals who don't know where others can be found.

A burnt out city is not a harder to reach resource than the ores that were used in the early Bronze and Iron Ages.

A burned out city will leave behind stuff that rusts. There won't be much metal left within a few generations.

The ENTIRE annual iron production of the Roman Empire at its peak was less iron than is found in one large modern container ship. You don't even need to go to a city - there will be VAST resources (by Iron Age standards) washed up on beaches all over the world.

Rust.

Rust = iron ore.

 

[James Brown]

It's hard to imagine a post-apocalyptic society rebuilding itself on fossil fuels.

Our current society has only used fossil fuels in large quantities for about two centuries.

Almost everything up to the early 19th century was done using charcoal and wood for burning, and animals, water, and wind for motive power.

Fossil fuels are a big boost to industrialisation, but they are probably not essential; they certainly are not necessary in order to build a civilised society.

How will a society create a transistor from charcoal and a mule?

 

[bilby]

Our current society has only used fossil fuels in large quantities for about two centuries.

Almost everything up to the early 19th century was done using charcoal and wood for burning, and animals, water, and wind for motive power.

Fossil fuels are a big boost to industrialisation, but they are probably not essential; they certainly are not necessary in order to build a civilised society.

How will a society create a transistor from charcoal and a mule?

Why does society need a transistor? It did pretty well without one for over 10,000 years.

 

[beero1000]

Our current society has only used fossil fuels in large quantities for about two centuries.

Almost everything up to the early 19th century was done using charcoal and wood for burning, and animals, water, and wind for motive power.

Fossil fuels are a big boost to industrialisation, but they are probably not essential; they certainly are not necessary in order to build a civilised society.

How will a society create a transistor from charcoal and a mule?

It isn't that hard if you have the knowledge. The only real technological requirement is a furnace and access to relatively common chemicals. There are homemade transistor how-to videos on youtube.

 

[James Brown]

How will a society create a transistor from charcoal and a mule?

Why does society need a transistor? It did pretty well without one for over 10,000 years.

Ah, I guess I'm assuming a technological society that's decimated by asteroid, plague, whatever would work its way back to the starting point.

Does that mean that a habitable world only gets one Industrial Revolution? If that's true, and given the high number of random civilization-destroying events in our universe, that would indeed reduce the Drake figure by a large factor. Intelligent, pre-industrial life may be teeming throughout the universe, but those worlds only get one chance to build a radio telescope. If they blow it, then their probability of building another one is extremely low. They'll be perpetually stuck in the pre-industrial age.

 

[Don2 (Don1 Revised)]

How will a society create a transistor from charcoal and a mule?

Why does society need a transistor? It did pretty well without one for over 10,000 years.

Duh. Internet porn. Pretty much any civilization will eventually create it and following that advanced virtual sensation-based sex. As a mere coincidence, they will probably also by that time be able to communicate with other civilizations due to their technological improvements for sex.

 

[lpetrich]

Why does society need a transistor? It did pretty well without one for over 10,000 years.

That can be said of *any* technology that is now commonplace. Or even obsolete after being used a long time, like horse-drawn vehicles.

I find it hard to take that seriously for another reason: transistors have numerous advantages over their competition in electricity controlling electricity: vacuum tubes and electromechanical relays.

Transistors and vacuum tubes can easily be MUCH faster than electromechanical relays, and they don't have any mechanical parts to wear out.

Transistors don't have any components that tend to burn out, as vacuum tubes do. Vacuum tubes have filaments for emitting electrons, just like incandescent electric lightbulbs, and they burn out for the same reason.

Transistors can be made small and with low power consumption, since they don't have to heat a filament or move some mechanical part.

In fact, they can be made small enough for millions of them to fit onto a chip the size of a postage stamp. Try that with tubes or relays.

 

[James Brown]

Geez, did I ever pick the wrong example to make a point.