No, it's covered by earth and water.
Anyway, the reason such a planet isn't possible, is because the eco-system simply couldn't function properly. There would have to be variety, like some colder and some warmer spots.
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No, it's covered by earth and water.
Anyway, the reason such a planet isn't possible, is because the eco-system simply couldn't function properly. There would have to be variety, like some colder and some warmer spots.
Not really. Like I said before (that everyone ignored), in the Jurassic period the Earth had a very well regulated temperature over the whole planet.Quote:
Originally Posted by Marvo
also, there could be some sort of weird heat source. or rather a few orbiting the planet, so that the heat is even throghout the whole planet.
That was hardly a period that a regular human would recognize as a tropic paradise though.Quote:
Originally Posted by esfx
Also, I find it somewhat unlikely, that the entire earth at some point had a worldwide, fully working eco-system, that was completely the same everywhere, unless all continents were forged into one big super-continent.
How so?Quote:
Originally Posted by Marvo
First of all, I never said the temperatures were exactly the same; only that they varied less. And there was a super-continent called Pangaea. But even after that continent split apart, the temperatures were still highly regulated. Like I said, in the far south, I'm talking antarctic circle, there were temperate forests. Now, you can ignore the facts all you like, but that's just being ignorant.Quote:
Originally Posted by Marvo
Source:Quote:
All the reliable evidence that we can muster points strongly to the conclusion that the Jurassic climate was appreciably more equable than that of the present day, with tropical-subtropical conditions extending far into the present temperate belts and temperate conditions occurring in polar regions. There is no evidence of polar ice caps, and, at least partly for this reason, the ocean surface stood at a higher level with respect to the continents.
http://books.nap.edu/openbook.php?re...11798&page=159
I guess you're right then. I'm not exactly certain as to the nature of a jurassic climate though, and whether it is what we'd classify as paradise.
Why would you include water into your statement then? Is there not earth under the water? Sand makes up a great deal of the ocean shore, both above and immediately below the water for miles. Sand makes up 20% of the world's deserts, of which deserts make up roughly around 14% (not sure about that number, could be slightly more or less) of the earth's land surface. The Sahara covers the northern half of an entire continent.Quote:
Originally Posted by Marvo
I'm only saying that it's possible to an extent, primarily because I see a problem with beaches being everywhere.
There would be, if just ever so slightly. Tropical temperature isn't one set value, it can vary by around 25 degrees F. The temperature wouldn't have to be "perfect" in the middle of the oceans either, unless of course the OP suggests that we have no oceans at all, in which case there'd be more of a problem.Quote:
There would have to be variety, like some colder and some warmer spots.
Also: Greenhouse gases for a stable temperate landscape. OP never said anything about actually being able to survive there, har har.
I still don't understand this comment. What, specifically, about the Jurassic climate screams "not paradise" to you. I just want to know what the hell you're talking about.Quote:
Originally Posted by Marvo
I saw a show on the Learning Channel or History Channel and it stated that mosquitoes were likely the size of large birds. The oxygen content was much different than it is now. It's possible to have a uniform temperature world wide (look up "Canopy Theory"), but if the temp wasn't just right, a tropical paradise could easily be a "prehistoric" nightmare.
Marvo, Earth was once a one big super-continent, look up Pangea.Quote:
Originally Posted by Marvo
Actually there have been many supercontinents throughout Earths history, it's a cyclic which is around ~300 millions years.
http://upload.wikimedia.org/wikipedi...imation_03.gif
Fauna has NOTHING to do with climate. The oxygen content was higher than today, so we wouldn't suffocate. And the temperature was temperate worldwide, as already stated.Quote:
Originally Posted by Zhaylin
Assuming
- this type of planet is possible
- the universe is infinitely large
- there are an infinite number of planets
- the planets have differing and diverse, even "random" properties
this is guaranteed
Just seems unlikely to me, that we'd be able to enjoy it completely without some quirks, like a slightly different atmosphere.Quote:
Originally Posted by esfx
Also, stop telling me that there once was one big super-continent, I know that. According to the articles on Wikipedia, pangea started splitting out around 250 million years ago, the jurassic era ended 65 million years ago. Additionally, about the atmosphere deal, Wikipedia says that carbondioxide levels were up by twelve times, and oxygen levels were about 11% higher. It's likely that the temperature of the atmosphere was simply too hot for humans to enjoy properly.
edit: comment to Zhaylin's supposed stupidity; very trustworthy article about the canopy theory on CreationWiki.
Thanks for the link. Very nice info if not somewhat confusing because at the beginning it says the theory is now largely discredited but the explainations provided still makes sense to me. What discredits the theory?
It was an excellent point about the stars though- I had never thought of that...
Esfx, what do you mean fauna has nothing to do with the climate? I've never seen a tropical rainforest or the animals that live in them flourish naturally in, say, Arctic climates. If the oxygen/carbon dioxide levels were different then as they are now, the animals and plant life supported by them would be much different than they are now.
Then there would also be an infinite amount of exact copies of Earth...Quote:
Originally Posted by arby
That's a whole different thing, but urr durr.
Uhh, read it again. The Cretaceous ended 65 mya, hence the name "K/T event".Quote:
Originally Posted by Marvo
Well, since CO2 is non-poisonous* and is essentially a buffer gas, we really only need to look at O2. 11% higher means it's more than breathable. In fact, a human would be quite comfortable.Quote:
Originally Posted by Marvo
*Pre-empting the uninformed, CO2 only causes deaths when it replaces the O2 in the air, as is the case when combustion is taking place. By itself, it's not poisonous.
It was likely the same or lower than today's tropics. CO2 doesn't just increase temperature, it moderates it.Quote:
Originally Posted by Marvo
Fauna does not cause climate. If your point was that we should be worried about giant mosquitoes, then I say that the OP asked if completely temperate planets were possible, and I answered. The fauna that are produced in that climate are irrelevant to the discussion.Quote:
Originally Posted by Zhaylin
http://en.wikipedia.org/wiki/Carbon_dioxide#Toxicity
Carbon dioxide is toxic, however as mentioned earlier, the levels were only 12 times higher, so the difference would only be somewhat noticeable.
Higher oxygene levels are not necessarily a good thing. If the levels are 11% higher, that means things can more easily burn. Also, higher oxygene levels are not always beneficial for humans.
11% higher oxygen will lower ignition temperatures slightly, but you wouldn't expect trees to burst into flames on a hot day or anything. But sure, wet wood would burn more easily and that sort of thing. I don't see how that's an issue.Quote:
Originally Posted by Marvo
Also, higher oxygen doesn't hurt humans, unless you want to start talking about the borderline pseudoscientific theory of "free radicals", which has more to do with aging than immediate health.
And finally, the the hell are you arguing with me about this? If I had to go no further than OUR OWN PLANET to find an environment extremely close to what the OP wanted, then obviously these sorts of environments can and do happen.
actually esfx, if you were to live on very high levels of oxegen you would surely die. humans have adapted to the high level of nitrogen and low level of oxegen. infact, if there were much less oxegen it would be better because there would therefore be less carbod dioxide levels.
Ok, let's try an experiment. Put yourself in a sealed chamber, and replace half the oxygen with nitrogen. See what happens.Quote:
Originally Posted by slash112
What? :?Quote:
Originally Posted by esfx
That's impossible, unless Earth was covered entirely by water, there was still a variance in temperature across it, because of the different angles that light hit earth and the difference in heat and cooling times for land and water.
well i was just emphasising the fact that you dont want more oxegen. i realise human beings would need to evolve/adapt to breathing in different levels of oxegen/nitrogen/carbon dioxide etc.
Venus isn't covered by water, yet it has a perfectly constant temperature over its entire surface, down to a few degrees. Like I said, CO2 (and atmosphere in general) acts as a temperature buffer. The more CO2 any atmosphere has, the less variation there will be.Quote:
Originally Posted by A Roxxor
Also, what I said about past Earth is considered fact by most climatologists. I don't understand why you suddenly feel the need to argue with it.
http://en.wikipedia.org/wiki/Venus#A...re_and_climate
Yes, I understood the first time. But you were wrong. Less oxygen = dead human. More oxygen = human that ages slightly faster, MAYBE.Quote:
Originally Posted by slash112
Yes, Venus. Not earth.Quote:
Originally Posted by esfx
Earth didn't have such a thick atmosphere that the pressure and deflected radiation would cause it to have a constant temperature across it's surface. Earth has continenets and oceans. They heat and cool at different rates, so there is absolutely no way that the temperature was a constant across the whole planet. I have no idea where you're getting this from :|
ffs.Quote:
Originally Posted by A Roxxor
Not constant, NEAR constant. The poles were colder, but much warmer than today. For example, trees could grow at the south pole.
http://books.nap.edu/openbook.php?re...11798&page=159