Just a thought

[Wiccan_Child]

As of right now, we have no reason to believe that many planets exists. We're simply being optimistic.

Actually, we do. Statistically speaking, there are billions of stars per galaxy, and billions of galaxies per universe (we'll assume there's only one universe). Any one of those stars could have any number of planets, and any of those could be suitable for abiogenesis. Indeed, using the rather rough technique of looking at a star's 'wobble', we've already found hundreds of extrasolar planets. Most are Jupiter-like, but some are deliciously small and rocky.

Isn't just a pure assumption that life can evolve anywhere? Earth is TEEMING (sp?) with life. Yet we can't find even one indication of life elsewhere?

That's because we haven't been anywhere else. If life can form on Earth, it's a safe bet that it'll form on Earth-like planets too. And the conditions on Earth weren't that unique. Hydrogen, Nitrogen, Oxygen, Carbon, etc, are all common elements, and, surprise surprise, are all used in life on Earth. All that's really required is the stage: a planet of the correct conditions for these things to chemically react in the right way (and, given the right conditions, they will react in the right way).

The most extreme conditions on earth are still no where as extreme as any other planet.

I agree, but that wasn't my point (well, kinda ). First, life on Earth exists at all the extremes Earth has to offer; there's no reason why those extremes represent the absolute limit of life's versatility. For example, just because we haven't found life that lives at 500°C isn't because it can't, but rather because it doesn't need to (on Earth).
Second, we can expose various organisms to rather unnatural conditions, and they do survive them. High levels of radiation, near-vacuum pressures, etc, do not occur naturally on Earth, but there are organisms that survive them. So, if life can survive in conditions it never evolved to, imagine what life could do if it did evolve to fit those conditions. Imagine the dosage of radiation an organisms could withstand if its species evolved near, say, a natural nuclear reactor!

Again, Earth teeming (sp?) with life. We are packed full of life everywhere. Yet we've found nothing elsewhere. This is good evidence that life needs pretty specific requirements.

Well, life needs to get a foothold first. Life began in the ocean, because it couldn't begin on land. But it thereafter evolved to fill all the niches Earth offers. So life doesn't exist on the Moon because it couldn't get there to begin with. But I believe that, if there was a tiny place on the Moon where abiogenesis could occur, the Moon today would be teeming with Moon Critters.

And for the record, it's not that I don't believe life may exist elsewhere; it's that there seems to be no reason to believe so.

I'm of the opposite view: there's no reason to believe it doesn't. The universe is vast, and if it happened once (as we can see it did), it almost certainly happened again. It's incredibly unlikely that the Earth is the only place in the universe that harbours life. Statistically speaking, at least.

 

[Wiccan_Child]

What proportion of all planets have we examined in enough detail to find life?

I'm curious. How do you define side effects and intentional changes in this context?

Plants changed the atmosphere, but not because it was beneficial for them to do so. There was no selection pressure, they didn't evolve to change the local (or global) atmosphere, etc. Earthworms revitalise the soil, but not because they evolved to do so.
Ants, on the other hand, do intentionally change their environment: they build elaborate nests, churning up tons of dirt to make way for their nests. They don't find a convenient place in the environment and live there, they alter the environment to suit them.

 

[Chesterton]

I present this as a nice example of someone who cannot comprehend that a group of atheists might have different opinions, while totally ignoring the fact that theists have thousands of conflicting beliefs.

I've mentioned this elsewhere - atheists may not have official groups, but that does not mean that they don't exist. Atheists are just as alike as theists are, and it would do you good to remember that. Atheism is not a group like Christianity is.

Okay, well, you guys need to get organized. You look kinda silly attacking Christianity with contradictory ideas. (One of the reasons I'm not one of you. )

 

[Wiccan_Child]

Just more atheist doublethink. Some atheists believe the universe must be teeming with life, therefore the claim that "man is special" (which is not really a Christian claim) must be false. Other atheists believe the universe is a vast wasteland, therefore also, man is not special, because man is so insignificant in terms of space occupied (weird idea in itself). Both schools of belief can't be right.

It's more to do with how you view the word 'teeming': it teems inasmuch as we'd expect it to teem, given that life probably isn't that hard to come by. But it doesn't teem inasmuch as there are vast swaths of space which are completely inhospitable to life.

Besides, it's not doublethink if one atheist thinks one thing, and another thinks another. We're not an organised entity with a single, gestalt mind, y'know!

If only they gave Olympic medals for mental gymnastics.

If they did, you'd win for your pièce de résistance: the Trinity .

 

[SithDoughnut]

Okay, well, you guys need to get organized. You look kinda silly attacking Christianity with contradictory ideas. (One of the reasons I'm not one of you. )

You say that as if Christians don't contradict each other all the time. The Bible is literally true vs. the Bible is metaphorical, Theistic Evolution vs. Creationism, Global Flood vs Local Flood, Pro-choice vs Pro-life, and everything any denomination has ever disagreed with any other denomination on (which is a lot). You look kinda silly attacking atheism with contradictory ideas.

 

[Chesterton]

It's more to do with how you view the word 'teeming': it teems inasmuch as we'd expect it to teem, given that life probably isn't that hard to come by. But it doesn't teem inasmuch as there are vast swaths of space which are completely inhospitable to life.

What's the probability, Kenneth? (I respect you too much to think that you'd make a scientific/mathematical statement without a scientific/mathematical basis for it. )

Besides, it's not doublethink if one atheist thinks one thing, and another thinks another. We're not an organised entity with a single, gestalt mind, y'know!

Okay, but the more important point is that both are bad arguments. One attacks a strawman (that Christians say Earth is the only place with life), and the other (that physical space is somehow related to existential "significance") is an emotional appeal that really just doesn't make any sense.

If they did, you'd win for your pièce de résistance: the Trinity .

Your quantum mechanics would give us a tie for first place.

 

[sandwiches]

That doesn't answer the question. If life simply needs to adapt to an environment, than life, for the most part, should have an equal chance of developing everywhere. If life can truly evolve anywhere, shouldn't there be life everywhere? If life can truly evolve anywhere, why haven't we found life on the moon? Why haven't any unmanned vehicles sent to Mars found anything? In light of the fact that earth is PACKED with life, shouldn't we have found something by now, if all life needs to do to exist, is adapt to the planet?

It seems that life can't just evolve anywhere, but that life needs specific conditions, so far only found on earth.

What does life evolving in very adverse conditions have to do with life ARISING everywhere? Cars can drive on dirt but how come we don't see cars driving on Mars?

 

[sandwiches]

Just more atheist doublethink. Some atheists believe the universe must be teeming with life, therefore the claim that "man is special" (which is not really a Christian claim) must be false. Other atheists believe the universe is a vast wasteland, therefore also, man is not special, because man is so insignificant in terms of space occupied (weird idea in itself). Both schools of belief can't be right.

If only they gave Olympic medals for mental gymnastics.

The gold medalists would be Bible literalists, without a doubt. God is good even when he kills thousands of babies, amirite?

 

[shinbits]

Actually, we do. Statistically speaking, there are billions of stars per galaxy, and billions of galaxies per universe (we'll assume there's only one universe). Any one of those stars could have any number of planets, and any of those could be suitable for abiogenesis. Indeed, using the rather rough technique of looking at a star's 'wobble', we've already found hundreds of extrasolar planets. Most are Jupiter-like, but some are deliciously small and rocky.

You make a good point.

That's because we haven't been anywhere else. If life can form on Earth, it's a safe bet that it'll form on Earth-like planets too. And the conditions on Earth weren't that unique. Hydrogen, Nitrogen, Oxygen, Carbon, etc, are all common elements, and, surprise surprise, are all used in life on Earth. All that's really required is the stage: a planet of the correct conditions for these things to chemically react in the right way (and, given the right conditions, they will react in the right way).

We've been to the moon, and we've sent vehicles to the surface of Mars. Yes, that's only just a small start in an unimaginably vast universe, but we've been elsewhere. Not one sign that life exists. That the moon isn't far from Earth at all (which is brimming with life everywhere), and still has no life, lends evidence to the notion that life needs specific requirements.

I agree, but that wasn't my point (well, kinda ). First, life on Earth exists at all the extremes Earth has to offer; there's no reason why those extremes represent the absolute limit of life's versatility. For example, just because we haven't found life that lives at 500°C isn't because it can't, but rather because it doesn't need to (on Earth).

Since when is "need to" a requirement for life to exist? Life doesn't "need" to exist anywhere.

Second, we can expose various organisms to rather unnatural conditions, and they do survive them. High levels of radiation, near-vacuum pressures, etc, do not occur naturally on Earth, but there are organisms that survive them. So, if life can survive in conditions it never evolved to, imagine what life could do if it did evolve to fit those conditions. Imagine the dosage of radiation an organisms could withstand if its species evolved near, say, a natural nuclear reactor!

Another good point. But as you say later in your post, life needs a foothold to begin; the example you used, was that it began in the sea because it couldn't begin on land. Just because certain life forms can bear extremes right now, it doesn't mean that life could've began under those extremes, which is the condition of all the planets we've studied thus far.

Well, life needs to get a foothold first. Life began in the ocean, because it couldn't begin on land. But it thereafter evolved to fill all the niches Earth offers. So life doesn't exist on the Moon because it couldn't get there to begin with. But I believe that, if there was a tiny place on the Moon where abiogenesis could occur, the Moon today would be teeming with Moon Critters.

As discussed above, life probably can't occur on the Moon.

I'm of the opposite view: there's no reason to believe it doesn't. The universe is vast, and if it happened once (as we can see it did), it almost certainly happened again. It's incredibly unlikely that the Earth is the only place in the universe that harbours life. Statistically speaking, at least.

True. Hopefully we'll find something. And hopefully, they wont want to vaporize all humans.

 

[BrianOnEarth]

I'm of the opposite view: there's no reason to believe it doesn't. The universe is vast, and if it happened once (as we can see it did), it almost certainly happened again. It's incredibly unlikely that the Earth is the only place in the universe that harbours life. Statistically speaking, at least.

I agree with you. I also think it is the ultimate arrogance for Earthings to believe that Earth is uniquely capable of life among such an impossible to conceive number of solar systems. It doesn't even seem plausible from a religious stance either - God makes this vast creation and only puts life on one planet?

One thing that would improve our chances of being the only life would be if we were one of the oldest suitable planets. I read that some 14 billion years have passed since the bang and that the Earth is some 4.5 billion years old. Is it likely that other suitable planets formed in the 9.5 billion years prior to Earth? Given the inconceivably vast number of stars that are older than Sol this is as certain as can be.

I reckon bacterial type life is very common. Life seems to pop up where there is liquid water. Evidence seems strong that liquid water existed on Mars and that it exists today on Europa.

 

[shinbits]

What does life evolving in very adverse conditions have to do with life ARISING everywhere? Cars can drive on dirt but how come we don't see cars driving on Mars?

If live "can" arise anywhere, then there should be a lot more life to be found; finding it shouldn't be rare, but more common than not. It should at least exist in the areas near the Earth that we've explored, like the Moon or Mars.

As far your car example, cars don't supposedly have a fairly equal chance of arising anywhere, like some people claim life does. That's why we don't see cars on Mars.

 

[Wiccan_Child]

We've been to the moon, and we've sent vehicles to the surface of Mars. Yes, that's only just a small start in an unimaginably vast universe, but we've been elsewhere. Not one sign that life exists. That the moon isn't far from Earth at all (which is brimming with life everywhere), and still has no life, lends evidence to the notion that life needs specific requirements.

To start, perhaps. But thereafter it can adapt to pretty much any environment (I say that tentatively, because I know someone will catch me out!).

Since when is "need to" a requirement for life to exist? Life doesn't "need" to exist anywhere.

I meant that we don't see life that can live at very extreme temperatures because nowhere on Earth exhibits those temperatures: we only see life evolving to cope with the highest and lowest temperatures as found on Earth. The hottest places on Earth are about 200°C (deep sea vents and the like), which is why life on Earth has only evolved to cope with temperatures up to around that point (this doesn't include volcanoes, since, while hotter than 200°C, aren't around long enough to allow species to evolve to cope in molten lava!).

Anyway, point is, that we've only found life that can survive to around 200°C doesn't mean that that's the absolute upper temperature at which life can possibly survive: it just means that those particular extremophiles have no incentive to evolve adaptations for even hotter temperatures. If such temperatures did exist on Earth (say, deep sea vents at 500°C), I daresay we would find life that could survive at higher temperatures.

This was in reply to your comment that "The most extreme conditions on earth are still no where as extreme as any other planet". While this is true, it isn't an argument against the versatility of life, since we don't expect extremophiles to exist on Earth that could survive (say) the harsh pressures of a Jovian atmosphere: those conditions don't exist on Earth, and no organism would evolve to suit it.

On the other hand, there are organisms that can, for whatever reason, survive in extraordinary conditions, such as high levels of radiation, or complete vacuum.

Another good point. But as you say later in your post, life needs a foothold to begin; the example you used, was that it began in the sea because it couldn't begin on land. Just because certain life forms can bear extremes right now, it doesn't mean that life could've began under those extremes, which is the condition of all the planets we've studied thus far.

True, but that begs the question as to under what conditions life could form. Which, in turns, begs the question as to what constitutes 'life'. But those questions aside for one moment, can we both agree that, if life gets a foothold, it will flourish thereafter?

As discussed above, life probably can't occur on the Moon.

Indeed, which is why we don't see it teeming with life. If conditions for abiogenesis are stable, life would have taken over the entire Moon by now. So I reckon most planets will be either void of life entirely, or completely overwhelmed with life. It's just a question of getting that foothold.

True. Hopefully we'll find something. And hopefully, they wont want to vaporize all humans.

I, for one, welcome our new insect overlords.

 

[Wiccan_Child]

I reckon bacterial type life is very common. Life seems to pop up where there is liquid water. Evidence seems strong that liquid water existed on Mars and that it exists today on Europa.

I read recently that there appears to be water on the Moon. Strange times.

 

[Wiccan_Child]

What's the probability, Kenneth? (I respect you too much to think that you'd make a scientific/mathematical statement without a scientific/mathematical basis for it. )

I'll copy-and-paste what I said to shinbits, since I'm a lazy bugger:

"Actually, we do. Statistically speaking, there are billions of stars per galaxy, and billions of galaxies per universe (we'll assume there's only one universe). Any one of those stars could have any number of planets, and any of those could be suitable for abiogenesis. Indeed, using the rather rough technique of looking at a star's 'wobble', we've already found hundreds of extrasolar planets. Most are Jupiter-like, but some are deliciously small and rocky."

That is, life is relatively common from planet to planet: a substantial number of rocky planets and moons harbour life. In that regard, life is common.

But interstellar and intergalactic space overwhelmingly outweighs that: there is far more empty space than 'living' space, if you will. If God wanted to make a universe full of life, why all the spare room?

Okay, but the more important point is that both are bad arguments. One attacks a strawman (that Christians say Earth is the only place with life), and the other (that physical space is somehow related to existential "significance") is an emotional appeal that really just doesn't make any sense.

I agree. It doesn't work as an argument in and of itself, though I think it just about passes as a counter-argument. Christians say the Earth is special because it has life, but we say it probably isn't the only place to have life. Christians say the universe is built for life, but we say vast swathes of the universe are distinctly lacking, so we aren't that significant. What 'we say' isn't an argument in itself, but a refutation of one of 'your' arguments.

Your quantum mechanics would give us a tie for first place.

Hah, got me there .

 

[BrianOnEarth]

I read recently that there appears to be water on the Moon. Strange times.

Yes, weird. All those lunar landings and astronauts too busy driving cars and playing golf to notice the water. Typical humans! They would have had something to put in their gin & tonics had they had their eyes open. Ok, so maybe their landing site wasn't within range of the ice deposits.

I've read that water is probably very common in the universe in various states. I understand that life here requires liquid water. I suppose the moon may or may not ever have had liquid water. I don't know what the experts think about this. It looks as if Mars did once.

I am inclined to consider Earth an average sample. The thing is we have no other info so all we have is a single sample from some unknown population of planets with liquid water. Statistically, it seems logical to me to start with the assumption that a single sample is average rather than being some extreme of the bell curve. Egotistically it may make sense to consider the Earth unique. But I think it is logical to consider the Earth average in the absence of better information.

So its seems to have taken less than a billion years for basic bacterial life to form on Earth. Then it took another 3.5 billion to get to this forum. So intelligent life may take, on average, a third of the lifetime of the universe to evolve. That's a hell of a long time. And all that time, as a minimum, it requires liquid water to exist on the planet. Pretty tough requirements but then again there are just so many planets out there - more than I can conceive of - that even intelligent life has got to be nearly certain.

 

[Chesterton]

I'll copy-and-paste what I said to shinbits, since I'm a lazy bugger:

"Actually, we do. Statistically speaking, there are billions of stars per galaxy, and billions of galaxies per universe (we'll assume there's only one universe). Any one of those stars could have any number of planets, and any of those could be suitable for abiogenesis. Indeed, using the rather rough technique of looking at a star's 'wobble', we've already found hundreds of extrasolar planets. Most are Jupiter-like, but some are deliciously small and rocky."

That is, life is relatively common from planet to planet: a substantial number of rocky planets and moons harbour life. In that regard, life is common.

You'd have to show that abiogenesis happened even once, and show that it wasn't intelligent abiogenesis, before you could attempt any statement of the probability of it accidentally happening more than once.

But interstellar and intergalactic space overwhelmingly outweighs that: there is far more empty space than 'living' space, if you will. If God wanted to make a universe full of life, why all the spare room?

Why all the spare room in every atom? You ask that as if you assume there is no good answer just because neither of us knows the answer.

 

[shinbits]

To start, perhaps. But thereafter it can adapt to pretty much any environment (I say that tentatively, because I know someone will catch me out!).


I meant that we don't see life that can live at very extreme temperatures because nowhere on Earth exhibits those temperatures: we only see life evolving to cope with the highest and lowest temperatures as found on Earth. The hottest places on Earth are about 200°C (deep sea vents and the like), which is why life on Earth has only evolved to cope with temperatures up to around that point (this doesn't include volcanoes, since, while hotter than 200°C, aren't around long enough to allow species to evolve to cope in molten lava!).

Anyway, point is, that we've only found life that can survive to around 200°C doesn't mean that that's the absolute upper temperature at which life can possibly survive: it just means that those particular extremophiles have no incentive to evolve adaptations for even hotter temperatures. If such temperatures did exist on Earth (say, deep sea vents at 500°C), I daresay we would find life that could survive at higher temperatures.

This was in reply to your comment that "The most extreme conditions on earth are still no where as extreme as any other planet". While this is true, it isn't an argument against the versatility of life, since we don't expect extremophiles to exist on Earth that could survive (say) the harsh pressures of a Jovian atmosphere: those conditions don't exist on Earth, and no organism would evolve to suit it.

On the other hand, there are organisms that can, for whatever reason, survive in extraordinary conditions, such as high levels of radiation, or complete vacuum.


True, but that begs the question as to under what conditions life could form. Which, in turns, begs the question as to what constitutes 'life'. But those questions aside for one moment, can we both agree that, if life gets a foothold, it will flourish thereafter?


Indeed, which is why we don't see it teeming with life. If conditions for abiogenesis are stable, life would have taken over the entire Moon by now. So I reckon most planets will be either void of life entirely, or completely overwhelmed with life. It's just a question of getting that foothold.


I, for one, welcome our new insect overlords.

Well, this is just another darn good post. I pretty much agree with everything said. It's kinda scary, though. You were pretty intelligent when I first met u on these forums, and now u seem even more so.

Donate your brain to science.

 

[MolecularGenetics]

I present this as a nice example of someone who cannot comprehend that a group of atheists might have different opinions, while totally ignoring the fact that theists have thousands of conflicting beliefs.

I've mentioned this elsewhere - atheists may not have official groups, but that does not mean that they don't exist. Atheists are just as alike as theists are, and it would do you good to remember that. Atheism is not a group like Christianity is.

Okay, well, you guys need to get organized. You look kinda silly attacking Christianity with contradictory ideas. (One of the reasons I'm not one of you. )

That is an interesting insight into your thought process, Chesterton. You see contradictory differences of opinion regarding perceived reasons not to believe in your worldview in people that don’t share it with you; but rather than accept that diversity, you perceive it as a point of ridicule, and criticize them for it.

That is to say; you imply that you believe atheists and agnostics are ideally a cohesive group, and that you view their differences of opinion as an obstacle to cohesiveness for them to overcome.

Even more interestingly, you perceive the contradiction in some of these differences of opinion so negatively, that you seem to think that they effectively negate the validity of any of them (otherwise, the differences wouldn’t be a reason to continue believing in your worldview).

And finally (as SithDoughnut already pointed out), you don’t perceive the same contradictory differences of opinion among believers in your worldview to negate their validity, or as a reason to stop believing—you didn’t even acknowledge those differences.

It seems to me that you are applying an unreasonable standard to non-believers that you don’t apply to believers.

 

[shinbits]

the first picture is the earth. the second picture is the solar system. but is what the third and fourth pic of? the fifth pic is our galaxy. I'm guessing the sixth pic is our galaxy cluster. so is the 7th pic a wider view of our galaxy cluster? and what are the last two pics of? is the last pic supposed be where we are in the universe?

any help would be apreciated.

 

[BrianOnEarth]

any help would be apreciated.

I assume the 5th pic is the Milky Way galaxy. According to Wikipedia, the diameter of the Milky Way is 100,000 light years. The diameter of the universe is at least 93,000,000,000 light years.