Poll: Where is everyone?

[Amp34]

C'mon now...

I like the idea youre presenting, there's something about it, but it's just not plausible. If we can dig up dino fossils, then 150m year from now, our future civilisation will dig up ~ a billion cars. If there was a lost civilisation as advanced as ours, we would have markers for it. We don't see any though.

Would they?

Or would they be mining an iron ore rich area?

Not everything would be destroyed, but anything not metal would almost certainly end up back in its component parts, and depending on the pressure and heat the metal probably wouldn't show any kind of structure that even we would recognise as a car. You may just end up with an area high in iron, with some hydrocarbon remnants - if that hadn't already migrated away.

If you were really lucky there may still be some textures in the rock from the tyre tread.

 

[Amp34]

In quick and dirty layman's terms: A planet's relative position to its star and orbit are not the only things which influence temperature variation: the atmosphere, geological composition, size and mass matter also. Each key variable that affects temperature and seasons is also subject to several planetary cycles from gas exchange to continental crust renewal and drift that feed into the final result. And of course there are special cases that can miss one or more variables and cycles.

A prime example of this is the Earth and the Moon. Both different in size and atmosphere, but relatively similar distances from the Sun.

Also, just to clarify. I hope you don't mean continental drift...

 

[rubberduck]

http://spaceplace.nasa.gov/seasons/en/

Explains it better than I could.

 

[datalol-jack]

A prime example of this is the Earth and the Moon. Both different in size and atmosphere, but relatively similar distances from the Sun.

Also, just to clarify. I hope you don't mean continental drift...

Read the last part about special cases. As for continental drift, it gets around, see: "Albedo contrast and glaciation due to continental drift" and other work to this effect. If the body has oceans and an active core, then the relationship becomes more important still.

 

[Glaucus]

I've wanted to ask this question for a while but it doesn't warrant it's own thread, however the images above give a pretty good example of my question.

The habitable zone, as it's known. Is it taking into account things being able to live in -100c to +200c or something. I ask this because the "zone" seems rather large, i.e maybe hundreds of thousands of miles either side, right??
However if that is the case, why do we have such a massive temperature swing from summer to winter of 30c+ when we only move 5-10k miles (probably less) closer to the sun do to our angled spin..

Anyone?

Its where water can be liquid, so its large due to different planet sizes and atmospheric pressures.
But it also doesn't include all places that could be liquid, moons like Europa aren't in the habitable zone, but do have liquid water. Just generated by the gravitational effects of a gas gaint.

Its a very much an overly simplified concept and continue to evolveas we learn more.

 

[marl]

There has to be life elsewhere in the Universe/Galaxy. Just consider how diverse life on our world is. If it can happen in here then why not elsewhere?

 

[Zethor]

You hit the nail on the head with "current". Science is evolving too and we're always discovering new theories, modifying old ones etc. Was once a time when people believed the universe revolved around the earth and so on. We're only just beginning to get to grips with quantum physics and we've barely begun with understanding Dark Matter. Our knowledge is far from complete. So it's possible the Darwinian model, as applicable as it is on Earth, might not be the only way life can evolve elsewhere. That said, I do agree it's likely to be a model that's replicated elsewhere.

Science doesn't evolve, it's more like a pyramid with a foundation that mostly consists of mathematics. Scientific progress is like going up the pyramid which means it has diminishing returns. Even if our current knowledge is incomplete, our future scientific theories will still have sets of theories such as the Standard Model at the base so they won't be wildly different than what we know today. A huge leap such as the one that happened when physics went from a Newtonian model to a relativistic and then quantum one is unlikely to occur in the future.

As for the theory of evolution it is probably the most 'solid' theory in science, much more than say, relativity or even quantum mechanics, because it explains an observed phenomenon perfectly, without any contradictions, paradoxes or exceptions. It's a theory of everything for Biology so there can't be another model, at least not in this Universe.

I guess that's including flora as well as fauna, but never the less - I love the number, love the odds.

They're all related so the actual number is one. In that case, the odds don't look great, uh?

 

[Amp34]

Read the last part about special cases. As for continental drift, it gets around, see: "Albedo contrast and glaciation due to continental drift" and other work to this effect. If the body has oceans and an active core, then the relationship becomes more important still.

Haha, maybe, but it's still wrong.

Plate tectonics took its place in the 60's


My example was to show two bodies a similar distance from the sun showing marked difference in temperature due in part to the examples you gave.

 

[Zethor]

My issue with this is what you're basically saying is we are "special", in the sense that we are the only one and lucky to be where we are. What we see all around us in nature is that there is very rarely anything "special". Even things that we note as special and singular initially usually run out to be very common when we start looking for them, both in nature and geologically on this planet and astronomically in space.

As much as we as humans like to think of ourselves as special and important (be that as individuals, as nations, as species or as a planet the chance of being unique or special in that sense is arguably astronomically small.

Lofe may be rare, but with billions of galaxies, stars and planets rare is relative. With that many possible starting locations rare could still mean millions/billions of "rare" occurances.

Edit: re reading what you put I realize now you probably don't mean as rare as I initially thought you did... the post is mostly a commentary on the philosophy of many people, who don't appear to be able to accept that they (and humans) are not as important/special as they like to think (for example that we aren't just another animal that happens to have evolved to use tools).

Yes I'm not into the 'We're special' line of thought, there's not a shred of evidence to support it. All I'm saying is that current observations suggest life is extremely rare. I do hope that future observations will shift that to just rare or even common but that's fantasy at the moment.

 

[datalol-jack]

As for the theory of evolution it is probably the most 'solid' theory in science, much more than say, relativity or even quantum mechanics, because it explains an observed phenomenon perfectly, without any contradictions, paradoxes or exceptions. It's a theory of everything for Biology so there can't be another model, at least not in this Universe.

Are you a biologist by trade? Even Darwin wrote of "Difficulties of the Theory." I'm yet to meet a biologist who thinks the theory is complete and perfect, but would love to learn more.

Haha, maybe, but it's still wrong.

Plate tectonics took its place in the 60's


My example was to show two bodies a similar distance from the sun showing marked difference in temperature due in part to the examples you gave.

You must be a real hit with the ladies at geological conferences.

 

[Amp34]

Science doesn't evolve, it's more like a pyramid with a foundation that mostly consists of mathematics. Scientific progress is like going up the pyramid which means it has diminishing returns. Even if our current knowledge is incomplete, our future scientific theories will still have sets of theories such as the Standard Model at the base so they won't be wildly different than what we know today. A huge leap such as the one that happened when physics went from a Newtonian model to a relativistic and then quantum one is unlikely to occur in the future.

That's a very bold statement. And I'd like to think wrong as well. It would be very depressing if it's true, as it's basically saying we understand all the basics, we just need to clear up a few loose ends.

As for the theory of evolution it is probably the most 'solid' theory in science, much more than say, relativity or even quantum mechanics, because it explains an observed phenomenon perfectly, without any contradictions, paradoxes or exceptions. It's a theory of everything for Biology so there can't be another model, at least not in this Universe.

Darwins Theory of Evolution has evolved over time, along with many other theories. Wile the basics are the same there have been changes since he proposed it.

 

[Amp34]

Yes I'm not into the 'We're special' line of thought, there's not a shred of evidence to support it. All I'm saying is that current observations suggest life is extremely rare. I do hope that future observations will shift that to just rare or even common but that's fantasy at the moment.

Sounds good. This is certainly a topic where observation, evidence and conjecture is important to distinguish between.

The current observations do indeed point to us being an anomaly, but hopefully in the future our conjecture will be proven right with evidence.

As long as that doesn't involve the aliens wanting to destroy earth to build an intergalactic super highway.

EDIT: And Damn it! I blame you all. I was supposed to dig a hole today but got nowhere because of this topic.

 

[Zethor]

Are you a biologist by trade? Even Darwin wrote of "Difficulties of the Theory." I'm yet to meet a biologist who thinks the theory is complete and perfect, but would love to learn more.



You must be a real hit with the ladies at geological conferences.

Darwins Theory of Evolution has evolved over time, along with many other theories. Wile the basics are the same there have been changes since he proposed it.

I've studied economics so far from it lol.

Yes the theory has been tweaked since its inception and will continue to be improved but the basic explanation of the diversity of life will not change so in that sense, the theory can be considered perfect.

 

[Cern]

Science doesn't evolve, it's more like a pyramid with a foundation that mostly consists of mathematics. Scientific progress is like going up the pyramid which means it has diminishing returns. Even if our current knowledge is incomplete, our future scientific theories will still have sets of theories such as the Standard Model at the base so they won't be wildly different than what we know today. A huge leap such as the one that happened when physics went from a Newtonian model to a relativistic and then quantum one is unlikely to occur in the future.

As for the theory of evolution it is probably the most 'solid' theory in science, much more than say, relativity or even quantum mechanics, because it explains an observed phenomenon perfectly, without any contradictions, paradoxes or exceptions. It's a theory of everything for Biology so there can't be another model, at least not in this Universe.

But it's still taking what we observe on Earth and extrapolating that to the rest of the universe.

Let's assume that life exists in some form in a galaxy, so far away that the whole galaxy is just a smudge of light / radiation to us. We have only extremely limited methods for observing what conditions exist in that galaxy, let alone any individual star in it, let alone any individual planet orbiting such a star. We will likely never have much information about that system. So how can we assume that life there follows the pattern of evolution / natural selection, just because that's what we observe here?

I guess if life is defined by the same parameters that we have on earth then I can see how that extrapolation can be made. But is carbon-based life the only form of life? Can life exist in other forms?

 

[datalol-jack]

I've studied economics so far from it lol.

Yes the theory has been tweaked since its inception and will continue to be improved but the basic explanation of the diversity of life will not change so in that sense, the theory can be considered perfect.

To an economist it may well be.

 

[Zethor]

That's a very bold statement. And I'd like to think wrong as well. It would be very depressing if it's true, as it's basically saying we understand all the basics, we just need to clear up a few loose ends.

I could be wrong but I think that's unlikely. 500 years ago we were at the center of the Universe which is now a laughable conception but let's not forget that the idea was based on products of imagination(mostly religions) and very few observations, let alone using the scientific method.

Current ideas are much more solid, the amount of evidence behind them is immense. Discovering what Dark Matter and Dark Energy are won't magically invalidate relativity or quantum interference. There are more than just a few loose ends but their discoveries will simply be more precise theories of what we already have today, depressing as it may be.

 

[Chojin]

There may be intelligent life out there, but their concept of time could be completely different to ours. E.g. the time span of human existence might be the equivalent to a second of the alien's time, or vice versa.

 

[Zethor]

But it's still taking what we observe on Earth and extrapolating that to the rest of the universe.

Let's assume that life exists in some form in a galaxy, so far away that the whole galaxy is just a smudge of light / radiation to us. We have only extremely limited methods for observing what conditions exist in that galaxy, let alone any individual star in it, let alone any individual planet orbiting such a star. We will likely never have much information about that system. So how can we assume that life there follows the pattern of evolution / natural selection, just because that's what we observe here?

I guess if life is defined by the same parameters that we have on earth then I can see how that extrapolation can be made. But is carbon-based life the only form of life? Can life exist in other forms?

Yes but Physics and Chemistry are the same everywhere, including in that far away galaxy. Life is a self-sustaining, replicating entity, right? Evolution is a consequence of replication so there can't be another model as it's an inherent characteristic.

Galaxies have quite a few differences but their foundation is mavity so the model is the same for each and every one of them.

 

[v0n]

C'mon now...
If we can dig up dino fossils, then 150m year from now, our future civilisation will dig up ~ a billion cars. If there was a lost civilisation as advanced as ours, we would have markers for it. We don't see any though.

I doubt it. In the future, when humans are long gone, they are still going to find a metric **** ton of rubbish we've left behind - plastics, metals, radioactive material, you name it. So even if somehow all of our buildings and industry left no mark (unlikely) our waste would. It doesn't all "turn to dust", the footprint that humans have left on this earth is permanent.

But that's just the thing guys - nothing we make or throw away will last more than few million years. Not metal, not concrete, not rubbish. Even the thickest plastic water bottle will turn to dust in 800-1000 years. Glass bottle in 4000-5000 years at best. Radiation from Chernobyl - slightly over 1000 years. We all know what happens to unmaintained metals and brick houses exposed to the elements - we've all seen what happens to old cars, big artillery guns, boats and ruins merely tens or hundreds years old. The oldest human structures of "lost civilisations" - the most weather and time resistant stuff made by our own species - which usually amounts to a few oddly shaped stones on the same hill, too close together to be incidental, range from 5.5k years in case of Stonehenge all the way to Göbekli Tepe estimated at about 12k years ago. The oldest cave painting we discovered - approx 40,000 years old. The oldest stone tool ever found - arguably estimated to be 2.8 million years old. That's the best we can do. Sings of our DNA according to google could in optimal scenario last up to maybe 6.8 million years although it would most likely be mostly unreadable after 1.5 million years. In comparison mother nature's greatest hits - Grand Canyon - up to 70 million years old. White Cliffs of Dover, approx 85 million of years old. Now imagine 150 million years. 200 million years. Scale. Perspective

By contrast, there is absolutely ZERO trace of any other previous intelligent / technological life in the fossil records, geology or anywhere else. ZERO.

Again - firstly - because our sample range is extremely poor, secondly - our methodology of searching for intelligent life is extremely basic - we are always looking for signs of technology similar to ours, that's why we send radio waves and look for radio signals we can understand returning from outer space - we do so in timescales and among wavelengths logical to us. We can't listen or search for something we can't predict or don't understand. We can't expect others to listen and search for something they can't predict or don't understand. In that sense we are a bit like one of the uncontacted tribes, be it Kawahiva Indians or similar - every full moon the leader picks up a horn and blows a long, deafening signal as loud as he can, towards the hill where the sun sets, the river where the sun rises, and the two valleys inbetween. He waits a while and blows the horn again. Nobody answers. "My tribe" he says to the others "by Gods on earth and heaven, we are in this universe, completely alone... Maybe next time"

And what if technology of other intelligent species out there/back here in the past is/was purely organic or based on something we can't imagine yet?

 

[Zethor]

Kevlar, among quite a few other things, will last until the Sun destroys the planet.

The absence of the oil/coal we removed and burned will also be observable until the planet's destruction.

Radioactive sediments etc. etc. Tones of traces really.