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View Full Version : Gravity distorts space-time?


The_Absolute
Jun17-09, 12:33 PM
I've heard alot about how an extremely powerful gravitational force can distort space and time. I was wondering (hypothetically) if it is possible to distort space-time enough by focusing a somehow artificial gravitational field into a single tiny point to pop a hole in space-time and travel vast distances through the cosmos in very little time. Sort of like an artificial wormhole. I am not a physicist, but I'm guessing that would require generating a gravitational field powerfully equal to that of a black hole. Which is probably impossible.

But if it were actually possible, human beings could travel to other galaxies, solar systems, in search for habitable, extra-solar planets to colonize, or perhaps search for extraterrestrial life.

Fredrik
Jun17-09, 12:57 PM
There are solutions to Einsteins equation that are a lot like what you describe, but don't expect to be able to buy wormhole generators at IKEA anytime soon. There are lots of problems: You'd probably need more energy than the sun radiates in its lifetime. You need to produce large amounts of a type of matter that may not even exist. You need to be able to control said matter precisely. And maybe a wormhole would collapse immediately due to virtual particles going around it in a loop infinitely many times.

The_Absolute
Jun17-09, 01:04 PM
There are solutions to Einsteins equation that are a lot like what you describe, but don't expect to be able to buy wormhole generators at IKEA anytime soon. There are lots of problems: You'd probably need more energy than the sun radiates in its lifetime. You need to produce large amounts of a type of matter that may not even exist. You need to be able to control said matter precisely. And maybe a wormhole would collapse immediately due to virtual particles going around it in a loop infinitely many times.

Perhaps that energy can be produced using anti-matter or cold fusion? When anti-matter collides with matter, they annihilate each other and create pure energy. However, I don't know if there is any way to control that reaction and use it as energy, and not create an explosion equal to that of 500 megatons of TNT.

Although that will probably still not produce anywhere near enough energy to create a wormhole.

Here, look at this. :P

http://farm4.static.flickr.com/3013/2427438338_a6d762ee8e.jpg

Fredrik
Jun21-09, 10:57 AM
Perhaps that energy can be produced using anti-matter or cold fusion? When anti-matter collides with matter, they annihilate each other and create pure energy.

No. Both fusion and matter/anti-matter annihilation are insufficient to produce that kind of energy. There are some order of magnitude estimates in "The physics of Star Trek", by Lawrence Krauss. It's a good book, so you might want to check it out.

Matterwave
Jun25-09, 07:23 AM
I don't know how much energy is required, but I'll take Fredrik's word for it that it's on the order of the solar luminosity emited over the lifetime of the sun.

To show you a rough estimate of the vast energy that is:

So, the sun fuses over 610 tons of hydrogen every second into about 606 tons of helium.

That's 4 tons of mass converted into pure energy every second. Using matter-antimatter annihilation you can do this using just 4 tons of material, instead of the 610 tons required by fusion. But still, 4 tons is quite a lot.

So, if the energy radiated over the lifetime of the Sun, that's about 10 billion years, is the energy you need, you need to convert over 1.2 quintillion tons of matter into pure energy using annihilation to get it. (For a rough idea of how much matter that is, it's about 3.4 trillion empire state buildings)