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ET'S

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have aliens visted earth
yes
44%
 44%  [ 8 ]
no
33%
 33%  [ 6 ]
uncertain
22%
 22%  [ 4 ]
Total Votes : 18

did you know....
105730.  Mon Oct 23, 2006 11:44 am Reply with quote

thanks for making this again jenny

 
smiley_face
105737.  Mon Oct 23, 2006 12:01 pm Reply with quote

It is also believed by some scientists that we are in fact alien life forms in a sense. The theory goes that life was brought onto this planet by an asteroid, and then evolved. Although this is dubious.

The "primeval soup" theory suggests that molecules were the first thing to form on the way to life. For example, micelles are a very basic form of cell, as they provide an area within them which is protected by a membrane impermeable to many substances.



Other examples are proteins, and small strips of RNA (the more basic form of DNA, found in prokaryotic cells such as bacteria).

To test this theory, scientists created a "primeval soup" with the same chemical constituents as would have been on Earth shortly before life developed. The results of the experiment showed that the molecules required for life to begin to develop did form.

With regards to the "What is life?" question, I wrote a blog on it a few months ago...

Quote:
Is there life elsewhere in the universe?

A fairly scientific question you might think. Until you actually think about it. What do we define as life? You could say its something that respires, but really, thats just reacting oxygen and sugar to produce energy. There are other things that could be reacted together to produce energy. What if we found another form of being that looked like human, but had another chemical reaction to produce energy to survive, would we call that life? In which case, is life something that can convert different types of energy. We might say that, but then what about the sun? That converts nuclear energy to heat and light energy, but we wouldn't call it a life form?

So you might say that life is something aware of its existence. As far as we know, the sun does not know it exists, therefore is not life. But equally, an orange tree does not know it exists, yet we would call it life.

You might say that life is something that can reproduce itself. After all, all living organisms on earth reproduce by some means, be it by budding, pollenation or sex. And the sun certainly doesnt have the capability to produce another one of itself. Neither does a rock. So it seems we have reached a conclusion here. It certainly seems a criteria that all "life" as we know it fulfils. But then, what if there's a computer program capable of replicating itself? Computer viruses invade your computer and replicate themselves, so are they a form of life?

Okay, well that's enough thinking for the time being.


It's a direct quote from a MySpace blog, hence the colloquialism.

 
did you know....
105740.  Mon Oct 23, 2006 12:06 pm Reply with quote

surely there is another form of life in the universe, that is, if the universe really is infinate. where that life is intelligant or not is another matter. also wot are the chances of humans being able to progress far enough to find these life forms. it take us this long to get to jupitur and planets just in our solar system so why should we be able to go further in however long we have left before the earth's destoryed

 
smiley_face
105743.  Mon Oct 23, 2006 12:11 pm Reply with quote

The universe isn't infinite though. We've established that it is expanding, therefore it must be getting bigger, and therefore has to be finite (as you cannot get a number larger than infinity).

It is a problem that even if there was to be other forms of life in the universe we would never reach them. It is impossible by the laws of physics to travel faster than the speed of light, and given that the universe is expanding faster than this, there will be parts of the universe that it will theoretically be impossible for us to reach. The only way around this would be for us to pass through hyperspace using a wormhole. However, many physicists have recently decided that wormholes do not exist, since they would collapse in on themselves, even with these things called "cosmic strings" to hold them open.

Oh well, I think we know none of this is going to happen in our lifetimes, so why get worried about it!

 
did you know....
105750.  Mon Oct 23, 2006 12:36 pm Reply with quote

damn, this stuff can really make your head hurt after a while

 
Twopints
105819.  Mon Oct 23, 2006 2:35 pm Reply with quote

dr.bob wrote:


Tas wrote:
Who says they are not already talking with world leaders?


If they were, we'd know about it. I mean, just take a look at the bunch of stupid, in-bred freaks that currently are our world leaders. You really think they're capable of keeping anything a secret? :)


Conversely, you could argue that with the cretinous, sly, dishonest bunch of crooks we have as world leaders, are they really capable of telling the truth?

 
smiley_face
105919.  Mon Oct 23, 2006 4:31 pm Reply with quote

Look guys, we all know we're being watched over by a secret police. We may as well just go on leading our lives the way we are. There's no point thinking outside the box because they are all corrupt thoughts.

 
Gray
106154.  Tue Oct 24, 2006 3:53 am Reply with quote

*dreams of becoming hopelessly corrupt*

 
dr.bob
106181.  Tue Oct 24, 2006 4:44 am Reply with quote

did you know.... wrote:
what are the chances of humans being able to progress far enough to find these life forms. it took us this long to get to jupiter and the planets just in our solar system so why should we be able to go further in however long we have left before the earth's destroyed


Bear in mind that it was only about 90 years ago that the first controlled, powered flight was made. 50 years after that, a man stood on the moon. Unfortunately, about 10 years after that the space programme hit budget problems. Still, the potential is there :)

smiley_face wrote:
The only way around this would be for us to pass through hyperspace using a wormhole. However, many physicists have recently decided that wormholes do not exist


They could simply be wrong. Or someone might find some other technology which makes travel to distant stars possible. Life usually turns out much more strangely than we could have possibly imagined.

 
Tas
106199.  Tue Oct 24, 2006 5:22 am Reply with quote

Quote:
We've established that it is expanding, therefore it must be getting bigger, and therefore has to be finite (as you cannot get a number larger than infinity).


Well, we have a theory that seems to have a few holes in. Doesn't the estimated age of the Universe keep changing? I seem to recall reading an article about a new galaxy that's been found that is further away than thought possible...making our estimated age of The Universe change (yet again).

Just as a matter of interest, what proof do we have that The Universe is actually expanding? Is it not possible that our Universe that we can observe is one of a number that are rotating around one another, in much the same way that stars revolve around in a galaxy?

If that is the case, space is far, far bigger than we first thought.

:-)

Tas

 
dr.bob
106222.  Tue Oct 24, 2006 6:05 am Reply with quote

Tas wrote:
Just as a matter of interest, what proof do we have that The Universe is actually expanding?


Stuff is rushing away from us in every direction for as far as we can see.

True, that might just mean it's piling up somewhere very far away, but.....

 
Long Haired Hippy
106231.  Tue Oct 24, 2006 6:29 am Reply with quote

dr.bob wrote:
Tas wrote:
Just as a matter of interest, what proof do we have that The Universe is actually expanding?


Stuff is rushing away from us in every direction for as far as we can see.

True, that might just mean it's piling up somewhere very far away, but.....


Redshift:-

Light is a wave as is sound. When you hear a car rushing toward you it sounds higher pitched than when the same car rushing away from you.

This is called the doppler effect. Something very similar happens to lightwaves.

If a star is rushing towards you distinctive spectral lines will be shifted to a higher frequency (blueshift) and if it is rushing away from you the spectrum will be shifted to a lower frequency (redshift)

We have a number of ways of measuring the distance of stars. For close stars there is parallax. For slightly further stars in the "Main Sequence" we can tell their temperature from spectral analysis and therefore their absolute luminosity and then by comparing their apparent luminosity can calculate (approximate) their distance. From the stars that we observe using these methods we find a correlation between distance and redshift. The further away the star the greater the redshift. So by extrapolating we find the distance of much further stellar objects from their redshift.

Whilst I have suggested that redshift is attributed to the star rushing away from us alternative explanations have been proffered. "Tired light" suggests that light loses wavelength as a natural consequence of travelling for long distances. Either by interaction with particles, the "ether" or by virtue of changing velocity (direction) in a curved universe.

So to answer the original question - we have no proof just conjecture and evidence.

 
Tas
106267.  Tue Oct 24, 2006 7:54 am Reply with quote

Perhaps the swirl of the Universe is so large that we can't see it? I mean the Universe is awfully big, and we seem to be seeing further and further, the harder we look. I bet that if another super-duper telescope gets built, that surpasses Hubble, we'll see something else that is another 'x' light years away, making the Universe even older...

:-)

Tas

(My query about a galaxy-like universe was prompted by the fact that nature tends to spiral bodies around one another, due to gravity etc)

 
dr.bob
106283.  Tue Oct 24, 2006 8:20 am Reply with quote

Long Haired Hippy wrote:
So to answer the original question - we have no proof just conjecture and evidence.


That sums up all science pretty neatly.

 
Long Haired Hippy
106317.  Tue Oct 24, 2006 9:26 am Reply with quote

dr.bob wrote:
Long Haired Hippy wrote:
So to answer the original question - we have no proof just conjecture and evidence.


That sums up all science pretty neatly.


Some things are more esoteric than others. Much of astrophysics and cosmology is based upon some pretty shakey assumptions. They are used because th
dr.bob wrote:
Long Haired Hippy wrote:
So to answer the original question - we have no proof just conjecture and evidence.


That sums up all science pretty neatly.


Nearly all science Id say, but not all

Some aspects of science are more esoteric than others. Much of astrophysics and cosmology is based upon some pretty shaky assumptions. They are used because they're the best assumptions we have but there are a few where there is no evidence whatsoever. Personally I don't think the cosmological constant looks like anything other than a fudge factor. I suspect that the universal gravitational constant might be no such thing and in years to come we could see how presumptuous we wee measuring this variable at one location and assuming that it is the same across all of space time. Still you make do with what you have and without a better model for gravitation we just have to assume that it's the same everywhere.

On the other hand, statistical physics is pretty much built from the ground up based upon axioms that are fundamentally true by definition. Even if one were filled with Cartesian doubt: conjecturing that we might in fact be many tentacled blobs trapped in a matrix style illusion; there is more that we can say with absolute certainty than just "cogito ergo sum." We can say that 2+2=4 and be certain of other mathematical proofs that exist independent of any sensory perception. Amongst these mathematical proofs are the results of statistical physics including the laws of thermodynamics.

 

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