On the hunt for aliens...*UPDATED* Amazing news!!!

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Posted: Thu May 17, 2007 5:33 am

kleindoofy wrote:

Food for thought: with present technology, is it possible to shoot a rocket from the Earth into the Sun? Answer: no.

No problem KD. Years and years ago the USSR sent probes to Venus, one of the inside planets. And there have been probes to Mercury too, I'm sure there have.

The Venura probes just needed to generate a tremendous loss of energy (energy, not angular momentum - the Earth's orbital velocity does impart a huge amount of energy to anything launched from our position in the solar system). Just blast the rocket thrust against the Earth's direction of orbiting so the probe slows down and then it'll just drop into the sun. It should be going pretty fast by the it "lands"

Posted: Thu May 17, 2007 7:17 am

^^ I think it was Mariner 10 that flew past Mercury.

Baiting Guru Joined: 04 Jan 2006 Posts: 3193

KD's point was that to hit the Sun you need a delta-V of 18 miles per second. That's over twice what the Apollo Saturn V produced. It is not an easy job dumping that much velocity, but there are now means to do it, because you don't have to do it quickly. A solar sail would also do the job, but we haven't built one yet and it'd need complex control.

It is well known that SETI pre-selects for "Life As We Know It". There are no other viable options, since by definition we know nothing about "Life As We Don't Know It". The part of the radio spectrum monitored is known as the "water hole" - something to do with the emission spectra of hydrogen and oxygen and more clear than most frequencies from stellar noise and obscuration. Life as we know it would tend to find that particular band the ideal spot to contact others since it is not only free but also invokes the importance of water.

Any species can use radio to communicate so long as their language can be rendered as an ordered and bounded array of discrete symbols taken from a finite set. That is probably more likely than that they are similar to us.

There are only so many forms of "Radiation", and the others are nowhere near as useful, since they are massively harder to modulate. Always assuming, of course, that there isn't something new just around the corner, but Physics would be astounded if there were, and since we don't know about it, we have to go with what we have.

Posted: Thu May 17, 2007 9:03 am

How we will conquer the universe:

http://www.youtube.com/watch?v=OUbGkSfaKrs

Posted: Thu May 17, 2007 9:45 am

thud419 wrote:

KD's point was ...

KD's point was actually that supposedly simplistic principles can, in reality, be enormously difficult and that we should keep in mind that - figuratively speaking - if we aren't even sure how and where to put which strings on a violin, we shouldn't be worrying about how to play Paganini.

thud419 wrote:

... It is well known that SETI pre-selects for "Life As We Know It". ...

Yes, and that's the point. The probabilities of SETI finding something are normally equated with the probability of ET existing at all. Yet, SETI looks for "Life As We Know It." That reduces the quoted probabilities of making a positive discovery by 10^-14.

I really couldn't care less what people do, but I think the (tax and private) money put into parks of radio telescopes dedicated to SETI could be used for better things. Besides that, considering that the probability of humanity ever (i.e. within a span of a few hundred thousand years) finding that signal makes hitting the jackpot in the lottery six times in a row look like a sure thing, I think it's a bit, well, dishonest to convince hundreds of thousands of people to waste energy running a program on their home PC in the tingling hope of finding ET.

Sure, it all sounds so exciting. A wonderful dream. But it's entirely futile. Volksverdummung. I put it right up there with Uri Geller & Co.

However, regarding the form of a possible ET, I will gladly ostensibly, and purely ostensibly, contradict myself to say that our very existence is an argument for ET being something like us, resp. life on Earth. Physics repeats itself. A star in the Milky Way is exactly the same as a star on the far side of the universe. Our existence is a phenomenon of the universe, so it may very well be that we are what is to be expected, not a fluke. Who knows? I don't.

Posted: Thu May 17, 2007 10:27 am

kleindoofy wrote:

I put it right up there with Uri Geller & Co.

What's wrong with Uri? He used to work for the CIA.

Posted: Thu May 17, 2007 10:34 am

When I was doing the breakfast show in UK, I was driving into work one morning (about 4.15am) and I saw the wierdest thing in the sky. It was a bright light.
I got very excited and as I was single at the time, I was hoping for a little probing, but no. Sad

Just this light.

In all honesdty, to this day, I've wondered what it could've been.

Posted: Thu May 17, 2007 10:50 am

^^ The moon? Wink

Edit: Oooh, look at the link for my (this) post...
blah blah blah... viewtopic.php?p=890666#890666

Spooky... Twisted Evil

Posted: Thu May 17, 2007 10:57 am

thud419 wrote:

There are no other viable options, since by definition we know nothing about "Life As We Don't Know It".

... Otherwise known as the Anthropic Principle - the Universe is as it is because if it weren't, we couldn't exist.

However, that does not include parts of the Universe from where the light has yet to reach us. We don't know, and will never know, what happens or is happening there because information from these far flung reaches will never reach us.

I'd rather the masters poured more money into more worthwhile actions - like eradication of polio - than fanciful Sci-Fi stuff like SETI.

Baiting Guru Joined: 04 Jan 2006 Posts: 3193

^^^ No. All I am saying is that we can't find or talk to Life As We Don't Know It, because we know nothing about it. I don't deny it exists, in fact I tend to believe it does.

The Hubble Space Telescope has looked a long way back in time. The galaxies it has pictured were some of the first galaxies ever formed. Until the first stars exploded the universe only contained hydrogen, and therefore could not have contained life... All of course, according to our current understanding. However a long time before you get to that point it becomes impractical to search for signals. We would only expect to receive signals from our galaxy, and that is only 100,000 light years across. In fact we couldn't detect any signal that we could send, over a much shorter distance.

I certainly would not spend much money on SETI as it is currently formulated. However it does fire the imagination and that is a good thing. We cannot stay on Earth forever. Out there there is free energy, more mineral resources than we will ever need and zero environmental impact - with no life to harm, pollution is just another chemical.

Posted: Thu May 17, 2007 11:40 am

/\

What you say is true.

My point was that because of inflationary expansion of Space, we will never know if other parts of the Universe may have evolved in a completely different way. So there could well be life there which is not carbon based, not using electromagnetic radiation for everyday existence, not needing oxygen ....

And we'll never have any means of knowing. Not now, not ever. NEVER. And with time, more and more parts of the Universe will vanisg from our view.

Posted: Thu May 17, 2007 11:44 am

Zorro wrote:

... with time, more and more parts of the Universe will vanis[h] from our view.

Not really. The expansion of the universe is <C, therefore those distant parts will just appear to have a nice red glow, or so said Hubble.

Posted: Thu May 17, 2007 11:48 am

kleindoofy wrote:

Zorro wrote:

... with time, more and more parts of the Universe will vanis[h] from our view.

Not really. The expansion of the universe is <C, therefore those distant parts will just appear to have a nice red glow, or so said Hubble.

Believe it or not, the rate of inflatinary expansion = >c
It is proven and there is no violation of any law. More amazing is that the rate att which Space is expanding is increasing.

Posted: Thu May 17, 2007 12:04 pm

--> KD

For a far better explanation of what I said about inflationary expansion, you might like to go through UCLA's Ned Wright's Cosmology Tutorial

Posted: Thu May 17, 2007 1:40 pm

Err, you lot are brainy bastards. In a very nice way. I have a telescope, but I can see sod all 'cause of the big trees around my house.

Posted: Thu May 17, 2007 1:46 pm

Zorro wrote:

Believe it or not, the rate of inflatinary expansion = >c

By c, do you mean the speed of light? I didn't think that was allowed or did I miss the memo? Confused

Posted: Thu May 17, 2007 2:33 pm

My Toe Hurts wrote:

kleindoofy wrote:

I put it right up there with Uri Geller & Co.

What's wrong with Uri? He used to work for the CIA.

Uri doesn't bends spoons, the spoon stays still and the universe bends to his will.

Posted: Thu May 17, 2007 3:06 pm

@B.L.Z. Bubb: Relativity has not been revised, you didn't miss the memo.

UCLA wrote:

When talking about the distance of a moving object, we mean the spatial separation NOW, with the positions of both objects specified at the current time. In an expanding Universe this distance NOW is larger than the speed of light times the light travel time due to the increase of separations between objects as the Universe expands. This is not due to any change in the units of space and time, but just caused by things being farther apart now than they used to be.

Or in other words, it doesn't contradict relativity because light is traveling in an expanding universe, it is kind of growing as it travels. Relativity uses a different definition for distance than does a calculation for the speed of light in an expanding universe. If that makes sense. Confused

Posted: Thu May 17, 2007 3:10 pm

Kinda. I know what you mean, but I'll be buggered if I could explain it to someone else!

Posted: Thu May 17, 2007 3:19 pm

Imagine a car driving 60 mph on a (rather large) balloon that is being blown up. It never travels more than 60 mph, but after an hour, it has traveled more than 60 miles.

Posted: Thu May 17, 2007 3:22 pm

Thats a pretty good explanation. Very Happy

Posted: Thu May 17, 2007 3:32 pm

B.L.Z. Bubb wrote:

By c, do you mean the speed of light? I didn't think that was allowed or did I miss the memo? Confused

It's allowed on the German autobahn.

Posted: Sat May 19, 2007 3:55 am

luckey wrote:

Imagine a car driving 60 mph on a (rather large) balloon that is being blown up. It never travels more than 60 mph, but after an hour, it has traveled more than 60 miles.

Superbly put.

To expand on that a bit more, the objects are not moving away from each other - it is the space between them that is expanding, and that expansion is >c (c=velocity of light in vacuum). Put two (or more) marks on a baloon and then inflate it. The marks are really where they were to start with but since the baloon is being inflated, the marks are moving apart.

The next logical question is why then are the planets not moving away from ecah other, why is Alpha Centauri still 4 odd light years away.

For the answer, we look to Ned Wright again for the explanation

Posted: Sat May 19, 2007 7:32 am

thud419 wrote:

There has been life on this planet for something like three billion years. The earliest hominid fossil is around two million years old...

Sahelanthropus tchadensis is dated at between 6 and 7 millions years old. Or if you're in the camp who thinks he's too close to the common ancestor to be human, there's Australopithecus anamensis at 4 million years.

Edit: Sorry, every now and again my inner archaeologist takes over; she's back in her cupboard again now! Embarassed

Posted: Mon May 21, 2007 1:45 am

Aliens uh? sounds like a great baiting idea! Razz

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