I'll do my best to form my questions within my limited knowledge of particle accelerator, and not to make fool out of myself.

As far as I understand, a particle accelerator speeds particles up close to the speed of light and collide with particle that is coming opposite direction. It seems that longer the accelerator higher energy (?) we get. However, since we can accelerate particle up to 99.99...% of c (or am I wrong?), there must be a theoretical limit to how long a particle accelerator needs to be (note: needs to be & not could be) to get highest energy possible from a circular or a liner accelerator. Or, maybe there is no such limit and we can build thousand light years long accelerator and still be able to discover something new?

Of corse, providing we have technology to build such a thing...

Hope it was clear enough...

Thanks!

You may have a misunderstanding about relativity.

The longest a linear accelerator can be depends on the average mass of each length of the accelerator. If it is light enough, it can be as long as you have material to make it. If it is two massive, it will collapse under its own self gravitation.

__________________
Forming opinions as we speak

In theory, you could keep accelerating particles, getting them closer and closer to the speed of light. Look at this, for example:

http://www.fourmilab.ch/documents/OhMyGodParticle/

A natural event caused this, but it was thought to be moving at about 99.99999999999999999999951% of c.

However, we don't know if there comes a point where there isn't anything more useful to be discovered, even with more and more acceleration. On the other hand, you might reach a point where you really would put more energy in a small volume than nature does (unlike the LHC), in which case you might run into something new - and you might not like what you find.

__________________
I say there is an invisible elf in my backyard. How do you prove that I am wrong?

Disclaimer: Avatar is not an official NASA image and does not imply any specific interplanetary or interstellar capability.

The Leif Ericson Cruiser

You are probably right. I only have basic knowledge of relativity. However, it is more likely that I'm not forming a question right.

I have read in a sci-fi book where they are building a massive circular accelerator hundreds of light years in diameter. Of course, it will not be possible to build such a thing with technology at hand. I was wondering if it would be nessesary to build such a long accelerator since we can only speed particle up to 99.99...% of c.

Hope that made clear-er...

Thanks!

Your shorthand of 99.99...% does not tell us how many 9's you mean here.

The more force you can apply to a particle, and the more distance over which you apply it, the closer you will get to c.

No, I didn't think about that. I think Van Rijn and Hornblower answered my question. So, Here's another question: say we build a particle accelerator light years long and particle is accelerated close to light speed as say "the oh-my-god" particle. What can we hope to find out beyond what we are already experimenting with accelerators that exist.

Thanks!

We don't know. If it turns out that there are various levels of supersymmetry, there is probably no energy we could produce that wouldn't potentially have something new to teach us.

__________________
Forming opinions as we speak

say we did build an accelerator a thousand light years long- just think of how long the waiting list would be to get you experiment to run on it, since each experiment would take thousands of years to complete.. and i'd hate to be the guy that accidentally turns the thing off by spilling my Pepsi on a console right as some particles were about to collide.

__________________
"blacker than the blackest black... times infinity."- Nathan Explosion
The.. Best.. Thread..Ever...

Is it possible to find out the existence of multiverse? or proof of string or M theory with that?

Thanks!

No. You don't prove things in science.

__________________
Forming opinions as we speak

There's no way to know what would come of such experiments. Perhaps a lot, perhaps little or nothing.

__________________
I say there is an invisible elf in my backyard. How do you prove that I am wrong?

Disclaimer: Avatar is not an official NASA image and does not imply any specific interplanetary or interstellar capability.

The Leif Ericson Cruiser

Thank you so much everybody! Satisfied my curiosity.

You're welcome. Stick around, and take a look around the board. You might find other things of interest or think of more questions.

__________________
I say there is an invisible elf in my backyard. How do you prove that I am wrong?

Disclaimer: Avatar is not an official NASA image and does not imply any specific interplanetary or interstellar capability.

The Leif Ericson Cruiser

About 40,000 kilometers.


(What do I win?)

As I understand your question has 2 parts.

1.) Is their an upper limit of energy (lets call it El where we can say: "Ok, nothing new will be found if we go even to higher energy as El"
I guess Antonsieb and VanRijn gave the answer to that.

2.) And implicitly you ask about the correlation between accelerator ring diameter and the maximum energy that can be achieved in the accelerator. This is correlated, but not as easy as you would think at the first glance.

The maximum energy is not only depending on the ring diameter, but also on the technology available to accelerate forward and - very important - to move the particles around the curves.

So with the same diameter you can go to higher energies if you have new technology for both the acceleration types. This is exactly what was done at CERN.
So before someone would invest in a 1000 light year long accelrator, he would look into the possibilities to upgrade existing facilities with new technology.

__________________
Andre

"They did not know it was impossible, so they did it!"
Mark Twain

The LTBL accelerator is so incredibly huge that only guesstimates exist about its size, and it's so advanced that not all of its inner workings are understood. Not even its shape is known! It is, however, a likely source for the OhMyGod particle.

Let there be light! ;-)

__________________
"Ignorance more frequently begets confidence than does knowledge" -- Charles Darwin
"Ignorance convinces" -- slang's dad
"Your right to hold an opinion is not being contested. Your expectation that it be taken seriously is." -- Jason Thompson

Perfect reason to go out and start mining the asteroids:

Find a 50-100mile/diameter asteroid and start hollowing out the interior for living space; use the iron to start building a circular accelerator around the outside of the asteroid.

If you could tug it into an orbit between Earth and Venus you could probably use solar power to run the whole operation.

And it would safely put the research off Earth, so no one could claim that you'll suck up the planet in a black hole

Win, win, win.

Why make such a small one. If you want to have a ring accelerator, why not girdle the Moon?

__________________
Forming opinions as we speak

Pfft. Why make such a small one and incur the cost of getting all those materials up in space?

40,000 km, yo!

Saturn. The ring is already there!

__________________
"Ignorance more frequently begets confidence than does knowledge" -- Charles Darwin
"Ignorance convinces" -- slang's dad
"Your right to hold an opinion is not being contested. Your expectation that it be taken seriously is." -- Jason Thompson