evidence against future nuclear winters

[sweetiepie]

is the fact that there hasn't already been a race of people on earth who wiped each other out using nuclear weapons evidence toward humans not wiping each other out using nuclear weapons?

that is..
suppose for example, 90% of all sentient races that ever come into existence wipe themselves out using nuclear weapons before leaving their home planet, leaving only non-sentient animals behind.
in cases where this happens the remaining species would likely evolve, as there's nothing to stop them, into a new sentient race.
such a sentient race would find evidence of the old ruined sentient race...
in such a universe 99% of the races would find evidence of former, ruined races.
to belong to such a universe, humans would have to be 1 in 100.
more likely, it is less unlikely that a random sentient race will wipe itself out.

[Boro Nut]

You've convinced me.

When do we leave?

Boro Nut

[walt6]

We only have 60 years of nuclear capability. What happens when somebody with nuclear weapons thinks its ok for mutual destruction, because his god is on their side.

[Loren Pechtel]

Except it's unlikely the Earth would ever give rise to another species with the ability to discover this.

Consider the hypothetical future Terrans. They're facing some *MAJOR* roadblocks--namely, almost no fossil fuel and little in the way of mineable ores. They're probably stuck at the early stone age as they can't find the materials to go farther.

That's assuming they even manage to evolve at all. If we take ourselves out we probably take most all the big animals with us. The world would be set back to a state like after the dinosaur killer hit. It took 65 million years from that state for intelligence to arise. What's going to happen in the next 65 million years? The Earth is going to be warming a bit. Not catastrophically but mammals are geared for a specific temperature--this would take a lot of evolution to overcome.

This warming will continue, there never will be a time free of it.

[RAFH]

is the fact that there hasn't already been a race of people on earth who wiped each other out using nuclear weapons evidence toward humans not wiping each other out using nuclear weapons?

I don't see how there would be any relationship between a previous sentient species committing nuclear suicide or not and any subsequent sentient species doing so or not.

There's no evidence of any previous sentient species on Earth.

For that matter, there's been no evidence of any other planet harboring life, much less sentient life. It would seem highly likely there would be life elsewhere in the universe, my personal opinion is life is rather ubiquitous and will occur wherever it can. But that's an opinion with little or no evidential support. Sentient life would also seem likely though certainly far less often.

There are other issues, whether development of nuclear technology is inevitable, whether a sentient species must inevitably be combative and whether a sentient species will inevitably develop nuclear weapons or any weapon of mass distruction.

that is..
suppose for example, 90% of all sentient races that ever come into existence wipe themselves out using nuclear weapons before leaving their home planet, leaving only non-sentient animals behind.

Do you have any support for that figure? Any at all?

I find it difficult to believe nuclear suicide is that inevitable.

In the event of a nuclear suicide it doesn't seem likely many other species survive it.


in cases where this happens the remaining species would likely evolve, as there's nothing to stop them, into a new sentient race.

Those species that would be likely to survive a nuclear suicide event, at least those we know of on Earth that might survive a nuclear suicide event, probably wouldn't be very likely to evolve sentience.

It should be noted sentience is not an inevitable result of evolution. Indeed, it may very well be a very rare result.


such a sentient race would find evidence of the old ruined sentient race...

Not necessarily, depends on how long it would take to evolve a new sentient species, if indeed, the remaining species were capable of such evolution. If there had been a sentient dinosaur, even one that was technically capable, its possible we would never find evidence of it. There are whole periods of time for which there are very limited fossils. Perhaps they had a technology based entirely on biology instead of machines and all evidence of such would have rotted away eons ago. How much of our civilization would still be recognizable 100 million years from now? Most metals would have oxidized, concretes would have crumbled, wood and textiles would have rotted. Maybe some ceramics would survive.


in such a universe 99% of the races would find evidence of former, ruined races.

Would they?


to belong to such a universe, humans would have to be 1 in 100.

I don't get where you get that ratio. Do you have any citation or calculations for such?


more likely, it is less unlikely that a random sentient race will wipe itself out.

This sentence makes no sense at all, perhaps you can reword it or explain what you mean.

[bilby]

There's no evidence of any previous sentient species on Earth.

But then, there wouldn't be. Assuming the human race died out today (and of course, assuming the human race counts as sentient:Cheeky: ), how long would it be before all evidence of our existence disappeared?

Most artificial structures have (if unattended and therefore unmaintained) lifespans measured in no more than tens or hundreds of thousands of years. (in fact most would be lucky to survive a few hundred years).

Amongst the most persistant artifacts would be such things as ceramics (as RAFH points out); high grade concrete structures (eg nuclear reactor containments, concrete highways etc.); and perhaps low-corrosion parts from ships and submarines which sank in favorable locations for preservation; either of which would perhaps be detectable by an archaeologist after several million years. Some less persistant artifiacts might survive through fosillisation, but they would be extremely rare and hard to find. Bones and even some softer tissues might be fosillised also, but these are likely to provide no evidence of sentience.

Take the pyramids of Egypt as an example of a pre-concrete artifact; given the deterioration they have suffered already since they were built, in just a scant few thousand years, how much will be left (if not artificially preserved) after another thousand times as long? That's still only a handful of millions of years - peanuts to the lifespan of the earth!

If the K/T boundary event, 64 million years ago, had wiped out a sentient race along with the dinosaurs, the probability of evidence both surviving and being found by paleontologists is pretty slim. Particularly if the species in question had not, at the time of extinction, developed concrete or high persistance steel alloys such as stainless steel. Concrete was invented about 2 - 3000 years ago, and corrosion resistant steel alloys much more recently. Compare this to the age of the species Homo Sapiens, (at least 15,000 years by even the most conservative estimate), and it seems quite plausible that we would see no evidence of past extinct sentient species, as long as they occur long enough ago.

Of course, this demolishes the argument in the OP very nicely too. If the dinosaurs had committed nuclear suicide, we would expect to find no evidence at all*, unless some lucky paleontologist was very very fortunate.

*[Lunatic fringe theory]Except perhaps a mysterious layer of iridium, perhaps used as a 'neutron initiator' or as a 'tamper/pusher' in their weapons ;) [/Lunatic fringe theory]

[RAFH]

But then, there wouldn't be. Assuming the human race died out today (and of course, assuming the human race counts as sentient:Cheeky: ), how long would it be before all evidence of our existence disappeared?

My guess is not much more than perhaps a million years. Indeed, if the flora and microscopic fauna were not seriously impacted, I'd say even much less than that. Look at the city of Pripyat near Chernobyl, while it looks fairly intact at a distance, most of the buildings are crumbling. Of course, some human artifacts such as large dams and canal systems as well a significant underground structures would last a very long time. There would at least be indications of their having been there.

Most artificial structures have (if unattended and therefore unmaintained) lifespans measured in no more than tens or hundreds of thousands of years. (in fact most would be lucky to survive a few hundred years).

I agree with the last comment, most buildings today wouldn't last more than a few hundred years without regular maintenance. A typical house that's left alone will deteriorate much faster than an occupied house. As above, the very large structures will persist for a very long time, at least in some form, maybe a heap or perhaps a big hole in the ground. The extremely large dams and canals like the Panama Canal will persist for a very long time, perhaps in the tens of millions of years. It would depend a lot on seismic and volcanic actions. Those could either destroy or preserve such constructions, perhaps both. Certainly structures near shorelines and adjacent to active rivers are going to suffer much more. I would expect the large open pit mines and some of the very deep mines like the Homestake in the Black Hills to persist for very long times.


Amongst the most persistant artifacts would be such things as ceramics (as RAFH points out); high grade concrete structures (eg nuclear reactor containments, concrete highways etc.); and perhaps low-corrosion parts from ships and submarines which sank in favorable locations for preservation; either of which would perhaps be detectable by an archaeologist after several million years. Some less persistant artifiacts might survive through fosillisation, but they would be extremely rare and hard to find. Bones and even some softer tissues might be fosillised also, but these are likely to provide no evidence of sentience.

I don't think any of the concretes would survive much more than a couple dozen thousand years. Metals that are subject to oxidation or other chemical action would disappear in a few dozens of thousands of years and as far as I know, other than gold, every metal is subject to corrosion.


Take the pyramids of Egypt as an example of a pre-concrete artifact; given the deterioration they have suffered already since they were built, in just a scant few thousand years, how much will be left (if not artificially preserved) after another thousand times as long? That's still only a handful of millions of years - peanuts to the lifespan of the earth!

Actually, most of the wear and tear on the pyramids have been the result of humans. If the casing hadn't been mined to build Cairo they would probably be in very good condition today. Natural stone is very resistant though some varieties are subject to corrosion by acids, particularly in rain and smogs. Even with the damage done, I would expect to find the pyramids around for a very long time. Maybe not so nice looking, perhaps just a huge mound, but I'd look to see something obviously made for well into the hundreds of thousands of years, unless the climate there changes radically. Dry desert air is good for preservation. Ifs biological forces that do most of the damage.

k
If the K/T boundary event, 64 million years ago, had wiped out a sentient race along with the dinosaurs, the probability of evidence both surviving and being found by paleontologists is pretty slim. Particularly if the species in question had not, at the time of extinction, developed concrete or high persistance steel alloys such as stainless steel.

My biologic culture hypothesis. There was a book about a race of reptiles that had such a culture, everything was grown, either as a plant or animal. Living coats that keep you warm. Houses that grow on you, literally. That sort of culture could be very advanced without leaving much evidence.

Concrete was invented about 2 - 3000 years ago, and corrosion resistant steel alloys much more recently. Compare this to the age of the species Homo Sapiens, (at least 15,000 years by even the most conservative estimate)

Make that about 75,000 to 200,000 years and we are in agreement.

, and it seems quite plausible that we would see no evidence of past extinct sentient species, as long as they occur long enough ago.

Yep, people generally have no concept of how long even 1000 years is, much less 1,000,000 years. If Kauai is any indication, where I live now will be buried under perhaps 2000 feet of volcanic output in the next 500,000 years, leaving no trace of anything currently on Windward Oahu.


Of course, this demolishes the argument in the OP very nicely too. If the dinosaurs had committed nuclear suicide, we would expect to find no evidence at all*, unless some lucky paleontologist was very very fortunate.

Hey, just the regular fossils are hard to find. To date, there are only 6 relatively complete T Rexs, and parts of 30. That's it. Not exactly a lot from a population that consisted of at least thousands of individuals over a couple dozen million years.


*[Lunatic fringe theory]Except perhaps a mysterious layer of iridium, perhaps used as a 'neutron initiator' or as a 'tamper/pusher' in their weapons ;) [/Lunatic fringe theory]


Shhhh! You must not reveal the technology before we are ready to strike and retake the world.

[Loren Pechtel]

My guess is not much more than perhaps a million years. Indeed, if the flora and microscopic fauna were not seriously impacted, I'd say even much less than that. Look at the city of Pripyat near Chernobyl, while it looks fairly intact at a distance, most of the buildings are crumbling. Of course, some human artifacts such as large dams and canal systems as well a significant underground structures would last a very long time. There would at least be indications of their having been there.

There would be evidence for a *LONG* time. If nothing else, look up. Some of the stuff in high orbits won't fall.

[Jaggers]

is the fact that there hasn't already been a race of people on earth who wiped each other out using nuclear weapons evidence toward humans not wiping each other out using nuclear weapons?But we also don't have evidence of any sentient life, on Earth or elsewhere, NOT wiping itself out either. Except ourselves. So far.

[Majestyk]

Unless I'm mistaken, sentient is not synonymous with technological. Elephants, in my opinion, appear to be sentient. Certainly other apes have demonstrated sentience.

So, besides sentience, what do we need for technology? Opposable thumbs, come to mind. Some ability to manipulate a wide range of the objects recognized in the environment. Apes have opposable thumbs, but not all apes have developed technology.

There must be something else needed, besides sentience and opposable thumbs. Maybe language? An inherent ability to associate abstract concepts with specific actions, which can be communicated to others, having the same ability.

Humans, are the only known species that possess sentience, opposable thumbs, and language. Was technological development inevitable with these three abilities? Does an environment that selects them, necessarily select a propensity for problem solving or tool usage?

Necessity, as the mother of invention, still needs materials before giving birth. In this way, technical development is similar to biologic speciation, there has to be need, resource, and existing platform from which adaptations can manifest. I'd say the premise of sentience leading inevitably toward nuclear fission, is questionable.