Who says that there isn't life on other planets without water?

I have always thought that the statement that 'life can't exist without water' to be narrow minded and, most likely, highly in error. (not an insult to those who feel that way)

Sometimes people just can't think outside the box. Sometimes people have tunnel vision.

Just because we humans are water based creatures and just because Earth is water based, doesn't mean that every life form in eternity is.

The spirit world is energy based (IMHO). Who knows what life is going on around us that we can't see. Other dimensions ... other planes ...

water = life is earthbound thinking.



[edit on 12/13/2006 by FlyersFan]

From a biological standpoint, water has many distinct properties that are critical for the proliferation of life that set it apart from other substances. It carries out this role by allowing organic compounds to react in ways that ultimately allow replication. All known forms of life depend on water. Water is vital both as a solvent in which many of the body's solutes dissolve and as an essential part of many metabolic processes within the body. Metabolism is the sum total of anabolism and catabolism. In anabolism, water is removed from molecules (through energy requiring enzymatic chemical reactions)in order to grow larger molecules (e.g. starches, triglycerides and proteins for storage of fuels and information). In catabolism, water is used to break bonds in order to generate smaller molecules (e.g. glucose, fatty acids and amino acids to be used for fuels for energy use or other purposes). Water is thus essential and central to these metabolic processes.

From

Wikipedia

Which explains things kind of nicely from the water point of view.

It is possible, given the fact that other elements may exist elsewhere that we are unaware of, that Silicon based life could exist, however silicon does not bond as effectively as carbon does and therefore the conditions would have to be exteme. That having been said it may be possible for a silicon based creature to exist in surroundings rich in hydrocarbons that allow a solvent to form enabling biological actions.

There may be other forms of life we are completley unaware of. The laws of physics and chemistry we see only really apply to the observable universe, and may fluctuate elsewhere.

I agree also with the question.
IN Earth i don't be surprised at all if ALL the living things need water to survive, this is almoust a "water planet", so it's normal that creatures in it require it, due to be the moust abundant element here. but who knows if in a planet with only sand that creatures will not require just Silica?..humm?
i think it's possible to the creatures in each planet can adapt in diferent ways to the moust abundant element present in they'r planet.

[edit on 13-12-2006 by Umbra Sideralis]

Originally posted by FlyersFan
I have always thought that the statement that 'life can't exist without water' to be narrow minded and, most likely, highly in error. (not an insult to those who feel that way)

No one is saying life can't exist without water, just that it seems to be the best/easiest for life to form in and thus, likely more common. Check out the link I posted on the previous page.

Also something interesting to note from that link:

The Earth, as well as other terrestrial planets, is exceptionally silicon-rich and carbon-poor. However, terrestrial life is carbon-based. Rare carbon proved to be much more successful as a life base than abundant silicon.

So even though silicon is very abundant on Earth, carbon based life still formed here.

this is a bit out of context, but I read somewhere that they dug like a kilometer into the earth or sumthin and found silicon bacteria. the bacteria can only ive under extreme pressure, so I guess maybe it is possible, since water is sort of lacking down there amidst the rocks. I read this a while ago and have no idea where to find the article, just trying to give and idea that other life exists, not just carbon based.

Originally posted by racerzeke
I was just thinking, is it proven that there are no other living things that can live without water?

Pretty much.

What if there are other living things that can live without water[/quote
That'd be cool.

I just dont understand why the everyone is looking for specifically water

Because all known life requires water. And because the other planets are earth like, BUT, lack water, and are lifeless.

Its entirely possible that there are ways to have life without water. But, woudl we even recognize it as alive?
Best, I'd think, to focus the search on earth like planets with water, and see if life is there.

I just dont understand why a planet that cant sustain human life is automatically checked off like pluto,

Pluto can't sustain any life, not merely human life. Nothing that is know is alive AND doesn't require water. Thats why we obsess about water.

malganis
and no one can ever explain to me why planets specifically need water for any kind of life.

I'd think its obvious, all life that we know of requires water. Without it, there is no life, as far as we know. So it'd be irrational to say 'life exists without water', everything we know shows us that it doesn't. We could be wrong, but the mere fact that we could be wrong doesn't mean we shouldn't be focusing on the water issue.

radekus
and found silicon bacteria

No. What has happened is that when they've dug extremely deep, they still find bacteria, seemingly living within the rocks. They are interesting and unusual bacteria, but they are organic, they are not silicon based.

since water is sort of lacking down there amidst the rocks

These bacteia require water to survive. Water, the chemical h2o, can be present in solid rock. It can even be chemically released from otherwise dry rocks.

thanks for clarifying that, I like to be corrected when wrong, prevents me from spreading idiocies.

Originally posted by racerzeke
I was just thinking, is it proven that there are no other living things that can live without water?

The most common non-water solvent proposed as an alternative to water is Ammonia. Many chemical reactions are possible in an ammonia solution as liquid ammonia has some chemical similarities with water. It's also capable of dissolving most organic compounds as well as many elemental metals.

A biosphere based on Ammonia would be completely alien to us despite it's similarities with water. For one thing at normal pressure, the ammonias the melting and boiling points are extremely low: 195 K(-78 Celcius) and 240 K(-33 Celcius) respectively.

Ammonia can be liquid at normal temperatures but extremely high pressures .

Such a biosphere, if it exists, would be extremely rare methinks.

What if there are other living things that can live without water

I just dont understand why the everyone is looking for specifically water
[edit on 13/12/06 by masqua]

The reason why is simply because all our knowledge of Biochemistry and Chemistry in general points to the fact that life will form much more readily on a Liquid Water planet then a Ammonia planet.

Logically, with everything we know now about Chemistry, water based biospheres should be the most common.

Originally posted by sardion2000


Ammonia can be liquid at normal temperatures but extremely high pressures .

Such a biosphere, if it exists, would be extremely rare methinks.

...on the other hand, a pressure of 1 atmosphere might be rather unpleasant to certain aliens. Also, ammonia-based life doesn't necessarily have to be a very low-temperature one, if atmospheric pressure is high enough. since increases in pressure raise both boiling points and freezing points.

Life takes the path of least resistance.

Originally posted by neformore
The laws of physics and chemistry we see only really apply to the observable universe, and may fluctuate elsewhere.

...and on page 1 "thedangler" also has something to say concerning that :

"our planet formed around our sun, Unique reactions took place to form life on our planet. unique things happened over time for life to form on earth. correct?

"what if on a far a way planet while planets are being formed other elements that we don't have formed and are stable on that planet. maybe having 3 suns acting upon one planet shooting unique rays and forces that we don't understand. maybe these elements just Can't be formed on earth because of how it was made and is sustained."

Actually science assumes that natural laws are the same everywhere. What led them to that conclusion was the fact that the spectrums of all stars show absorption lines that identify exclusively KNOWN chemical elements, which logically suggests that the same laws have come up with the same things.

There are two cases in which science mentions the possibility of there being different sets of laws, though, but they involve extraordinary circumstances:

1) in our own universe, extreme conditions, like those that catastrophic gravitational collapse leads to in the evolution of stars with a mass above the Chandra limit (1.4 solar masses), seem to involve an end to physics as we know it, so we can't know what happens when there is infinite density and zero mass (black holes), and

2) in other universes, like the ones that the Oscillating Universe theory mentions, after every Big Crunch and the ensuing Big Bang, the new universe could evolve following a completely different kind of laws.

About "following the line of least resistance", in certain environments this could mean eventually a life based on elements other than carbon, like the ones mentioned above --ammonia, silicon-- and also one of the halogens, most probably chlorine.

(I'm trying to make up for carrying on so shamefully months ago, when I was convinced that the Cassiopaeans and their prophet, Laura Knight, were Holy Writ, but that was before I came across a topic about this at the Godlikeproductions discussion forum, where ex members of her group reveal a house raffle rip-off in Florida and more foul play. I still think Barbara Marciniack and "lizzardsamok" are being truthful, though. My apologies, anyway.)

Just because we need the sun, heat and water maybe other life forms dont. You cant base everyother life form on humans

reply to post by racerzeke


well

water is the thing that provides the best chemical reaction, but, yes, life could be formed by other means ... but searching for water you have more chance to find life

No one actually thinks that the only way life could possibly exist is with water so we should stop arguing about that. No one is saying that.

Lets say life does exist and its different from earth life and its on waterless planet. How the heck are we supposed to observe that with a telescope? If we send a probe how are we supposed to know what to have it look for? It would be pretty difficult, so we do the smart thing instead. We spend our time and money looking for what we know works and keep an eye out for anything else while we're at it. We are having a hard enough time finding places that support life as we know it.

Trying to find alternate forms of life is like trying to find a needle in a haystack only we don't know the difference between the hay and the needle.

Originally posted by racerzeke
Yea they are looking for signs of human life, whats the point? They're looking for signs of life on other planets and yet the bottom of our own ocean is still unknown about. Why dont they look for signs of living life, instead of past life?



I just think some priorities are messed up

As an anthropologist, i'm offended by your statement.

Anyway, we look for water because we KNOW water = life. You don't think hundreds of thousands of scientists have thought your same question (also the same question as many other ATSers in the past). If we just go by anything can create and sustain life, we'd be looking in depth at every single planet and exoplanet. Its just simplifying it. Same thing with the goldilocks zone. I'm sure someone can think of a clever analogy to illustrate my point, but it's 5:14am and I'm going to watch Keenan and Kel online now.

reply to post by FlyersFan


Sorry but I don't see it to be narrow minded at all!

We know of one planet that contains life & it's this one. In this planet, water is the criticial component that allowed life to begin & flourish. Start with what you know & expand outwards. It also helps that if we could ever manage to travel to said planet/moon in future, then it has water for our own needs.

Mars has water & we mind find evidence of past life. Enceladus, Titan, Europa all most likely will have water as well & I'd bet everything I have that at least 1 will contain some form of life under the oceans.

Personally, I think when we have FTL capabilities & are able to explore the galaxy, then we will find life that can use other substances other than water. Our telescopes have a lifepsan of 10/15/20 years & there are only a handful of them. I'd say it makes far more sense to spend that precious time & resources looking for planets that are as close to our own first & foremost. That means planets with water!