PDA

View Full Version : Atom collision for propulsion?



2002-Jan-10, 05:10 PM
Can anyone proove / disproove that the the energy released by smashing together two atoms could be used as means of propulsion?

Azpod
2002-Jan-10, 07:24 PM
On 2002-01-10 12:10, RPN wrote:
Can anyone proove / disproove that the the energy released by smashing together two atoms could be used as means of propulsion?


It's a matter of efficiency. Yes, you get energy out of the collision, but that is (up until now) far less than the amount of energy that goes into accelerating the atoms in the first place. If someone could do this and get MORE energy out of the system, then they'd solve the world's energy problems, once and for all!

However, colliding atoms do create a whole lot of byproducts that can be useful. One of them is antimatter-- howbeit a really tiny amount of it! That could be used for propulsion, someday. However, we need to figure out a way to create the stuff a lot more cheaply than we know how today!

Here's an article on the subject: http://www.cnn.com/2002/TECH/space/01/10/antimatter.research/index.html

Simon
2002-Jan-10, 08:10 PM
Yeah, if you're going to accelerate particles that much, you might as well just shoot them out of the spacecraft and get your thrust from that.

...Hmm... Even if you only accelerated them to half light-speed, with a few milligrams of fuel, but could do that for a long time, and had a nuclear reactor to power the gig...

Can anyone say "interstellar probe"?

Azpod
2002-Jan-10, 09:56 PM
On 2002-01-10 15:10, Simon wrote:
Yeah, if you're going to accelerate particles that much, you might as well just shoot them out of the spacecraft and get your thrust from that.

...Hmm... Even if you only accelerated them to half light-speed, with a few milligrams of fuel, but could do that for a long time, and had a nuclear reactor to power the gig...

Can anyone say "interstellar probe"?


Barring something terribly cool like a warp drive or controllable macroscopic wormholes, that's pretty much what our first interstellar probes would likely be. DS1 essentially was powered by a mini-particle accelerator!

However, time would be the probe's greatest enemy. The faster we wanted to get it to the nearest star the more fuel it would need, and the fuel requirements go up pretty darn fast.

Getting a probe to the nearest star within a human lifetime would require a medium sized gas giant's worth of fuel! The problem is the more fuel you need to go faster, the more fuel you need to stop, and the more fuel you need to propel the extra mass of the extra fuel. It adds up really fast!

If we don't mind getting a probe to the nearest stars in hundreds if not thousands of years, we could probably do it without much of a problem. Of course, most humans aren't that patient. /phpBB/images/smiles/icon_smile.gif

Donnie B.
2002-Jan-10, 11:13 PM
I remember a Physics problem that required us to figure the amount of fuel required to get a 100-kg payload to the nearest star at 1/10 G acceleration/deceleration, assuming total conversion of mass to energy. I can't recall the number, but it was a vast amount of mass... comparable to a planet.

People just don't understand how difficult it is to get around the cosmos. I think belief in UFOs would plummet if this could be gotten across to the general public, in some visceral way.

Unfortunately, shows like Star Trek (much as I enjoy them) have made it impossible. Hey, we can just zip around from star to star, no problem! Engage!