h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Yes there can be planets and life around Alpha Centauri.

Think of the moons of Jupiter, and Jupiter is pretty close to the Sun. Jupiter's moons do not smack into any of the other planets, and in fact could support life. In the same way, Alpha Centauri and the rest of the stars in the system could have their own solar systems without disrupting each other's systems.

I wholeheartedly agree with SetupWeasel.

The guide has got to do better fact checking.

Guess they just cannot get the staff anymore.
Anyhow, what is all the fuss about The Clips, what clips?
Off to play with my digital watch.

you mean the eclipse?

What Eclipse?
Er, I've been counting the office paper clips.....
Andy.

You guys have obviously been reading too much Arthur C. Clarke.

Jupiter is fine now because it's just a gaseous giant. It's a sleeping star. If it became a star (as proposed in Clarke's 2010), it would aquire a much greater gravity well around it. Multiplied several times over what it is now. It's density would increase. Jupiter would also have to have more density and matter to it to turn into a star in the first place. The only reason why it cooled into what it is now instead of turning into a star was because it's not big enough. Had Saturn and Jupiter combined, then you might have enough hydrogen and other elements to make a star.

The orbits of most of the planets would suddenly become more erratic than Uranus is now, and odds are within a year's time our planet would fly out into space like a stone cradled in a slingshot, being approximately dead center between Sol and Jupiter. Most life on Earth would be dead by then from internal techtonic disturbances and massive tidal waves. By the time it actually left the solar system flying like a bat out of hell, our planet would be little more than a very large comet.

The original entry was accurate. You guys have no concept of Newtonian physics.

Try this. Put a bunch of metal filings on a piece of paper and set it over a glass table. Take one strong magnet and put it under the glass table directly beneath the paper. Watch what the metal filings do.

Then take a second magnet, and without moving the first one, place the second magnet under the paper also, a few inches away from the first magnet. Notice how the metal filings move. Some of them turn away from the first magnet.

Now imagine each metal filing is something circling around our sun, and introducing the second magnet is like Jupiter going nuclear. Imagine these metal filings as MOVING bodies, and then you will see precisely why it's absurd to think anything could circle between stars safely for millions of years.

Planet Earth wouldn't survive one orbit.

Oh God could you please sort this out!

I'm very confused, not up on all my physics and don't know which was to turn...

The one thing I will add to the discussion that isn't in any way helpful is the thought:

Newtonian physics? I thought we were past all that nonsense!

Zach, I'll list the sources that I gave Mark and Yoz.

http://monet.physik.unibas.ch/~schatzer/Alpha-Centauri.html

http://www.aip.org/enews/physnews/1991/split/pnu033-4.htm

The clever thing to do is, film it all, and then play the film backwards.

Pah. You shouldn't have quoted sources at them you should have quoted them at me. Hmph.

Are you sure you meant to say that here? If so, what on Earth does it mean?

Are you sure you meant to say that here? If so, what on Earth does it mean?

(sorry, missed the reply button first time...)

Sorry smiley, you had said you were going to be gone for the week that I found this, that's why I didn't come to you first.

I did get too jumpy, and I apologize for that. I just hate misconceptions about my field.

Don't worry. I probably was away. Didn't mean to be critical, it's just confusing and I could do with evidence either way

Taken to extremes then, a marble in Australia will to some extent influence a similar marble AND all other objects in the universe to some extent. After all, they will all have their own gravitational fields. Tricky..........

What does it mean? What are you doing on this site?
Quoting a little banter between Ford Prefect and Arthur Dent from the original BBC radio series "The Hithch-Hikers Guide to the Universe" whilst they were dining at the Restaurant at the End of the Universe of course!

Point one: Newtonian Physics was dismissed by Einstein only in the fact that such actions are relative to other things happening in the universe. Gravity still works on this planet and the basic concepts of inertia and how bodies of matter interact with one another are still consistent with Newton's original "laws." Einstein's theory of relativity only points out that if things don't happen the way you expected them to by just looking at Newton's rules, it's because there's other factors at work too, like an expanding universe for example.

Point two: In order for any planet to have life (as we know it) on it, a number of things must be in place. One thing in particular is something Issac Asimov called an "ecosphere." From Venus to the asteroid belt just outside of Mars, this solar system has an ecosphere. It's an area of space circling the sun in which sentient life can feasibly evolve if there is a planet revolving in that space which has other factors like water and amino acids and eventually a McDonalds. This ecosphere must be untouched by external forces, like say ANOTHER SUN, and it must remain relatively untouched for thousands of years to allow sentient life to evolve on it. The three stars that make up Alpha Centauri are too close together to allow a decent ecosphere. Nothing revolving around one star within that space could properly develop life on it because when the planet got closer to another star it would dramatically affect its ecosystem. And when it pulled farther away it would be affected by the lack of that other star's effect on it. And two stars revolving around one another would further complicate the orbit of any given planet trying to survive between them, because there would be no distinctive ecosphere.

Point three: IF I'm wrong, and I'm not but if I'm wrong and there IS a planet revolving around one (or more) of those three stars, it's proof that there is a sentience of some sort that controls this universe, because the odds of a planet successfully revolving around more than one star over a course of thousands of years without its ecosphere being disrupted is far too impossible to calculate. Something would have had to have made it work on purpose. I mean it's too much of a stretch for me to believe THIS planet happened by the mere whims of probability. If we find aliens around Alpha Centauri, I'm going back to church!

I'm sorry Zach, this is MY field not yours. I gave you sources of respectable astrophysicists. If you choose not to believe them, that is your choice. Remember that these people have spent their lives studying mechanics. The truth is that no one knows what can cause life, and that certainly includes Asimov.

I'm done arguing this point

Ecosphere as WE know it, what about an ecosphere from another view point..... As for example "Life in a single star solar system is impossible because......."
I have to agree with SetupWeasel.