Follow Slashdot stories on Twitter

 


Forgot your password?
Close
typodupeerror
×
Space Science

Antimatter Space Drive 383

Posted by michael from the eee-equals-emm-cee-squared dept.
sckienle writes "Space.com has an article on using anti-matter for propulsion in space. It isn't true Star Trek warp stuff, in fact it is a variation on an fusion based pellet design I saw in the late 70's, but interesting concept. The concept is still somewhat of a dream, as stated in the article: 'The real hub is the storage [of antimatter]. There's a lot of technology between here and there.' Later on it also mentions that we can't produce a lot of antimatter efficiently yet. Still it might be worth the effort if the theoretical acceleration proves out." The BBC has a story about studying antimatter in a lab.
This discussion has been archived. No new comments can be posted.

Antimatter Space Drive More

Antimatter Space Drive

Comments Filter:

  • Interesting (Score:4, Funny)

    by drhairston ( 611491 ) on Wednesday October 30, 2002 @04:42PM (#4568311) Homepage
    However, any advanced design like this is not without its hurdles. "The real hub is the storage," Howe says. "There's a lot of technology between here and there."

    That is quite possibly the most circuitous way I have ever seen someone admit that something is impossible. Fascinating.

    • Re:Interesting (Score:5, Insightful)

      by KeatonMill ( 566621 ) on Wednesday October 30, 2002 @04:44PM (#4568328)
      It isn't impossible. By using a strong magnetic field, you could store antimatter in a vaccum without contact with the walls of the container. However, if the field were to fail at all, anhiliation would come pretty quick.

      • Re:Interesting (Score:5, Interesting)

        by man_ls ( 248470 ) on Wednesday October 30, 2002 @04:48PM (#4568383)
        This is the basis for the "containment field" of Star Trek fame.

        In a DS9 novel, they talk about transferring antimatter between holding tanks by using tightly confined magnetic field beams and piping the antimatter through their magnetic pipes from one place to the other.
        • "In a DS9 novel, they talk about transferring antimatter between holding tanks by using tightly confined magnetic field beams and piping the antimatter through their magnetic pipes from one place to the other."

          Isn't that sort of how plasma is handled today?

          I think the holy grail technology will be a forcefieled that is powered by the anti-matter that it contains. As long as it's not powered by an external field, it should be safe. (That is provided the field itself is generated by components that don't wear down easily.)

          Okay, maybe that suggestion wasn't that helpful heh.

        • Re:Interesting (Score:4, Funny)

          by geekoid ( 135745 ) <{moc.oohay} {ta} {dnaltropnidad}> on Wednesday October 30, 2002 @07:33PM (#4569740) Homepage Journal
          leave it to a DS9 book to use the stupidest way possible to transfer something in a world with teleporters.

      • Re:Interesting (Score:5, Insightful)

        by Ralph Wiggam ( 22354 ) on Wednesday October 30, 2002 @06:01PM (#4569091) Homepage
        The magnetic containment doesn't have to be electromagnetic. Natural permanent magnets have nearly 0 chance of failure. The little plastic fruits have been sticking to my grandmother's fridge for 50 years now.

        -B
        • "No! Don't bang on that magne..." BOOOOOOMMM

        • Re:Interesting (Score:3, Informative)

          by merlin_jim ( 302773 )
          The magnetic containment doesn't have to be electromagnetic. Natural permanent magnets have nearly 0 chance of failure. The little plastic fruits have been sticking to my grandmother's fridge for 50 years now.

          Depends on how the magnetic containment works. Faraday proved that no static assemblage of magnetic, gravitic, and electric fields can be stable; in other words, a non-dynamic system that depends on only the above three fields will fall apart.

          Faraday did not know about two things, though, and that's diamagnetics and antimatter. All materials are either ferro-magnetic, meaning they can take and hold a magnetic field, paramagnetic, meaning they attract magnets, or diamagnetic, meaning they repel magnets. A google search will tell you more.

          Faraday's proof doesn't work for diamagnetic materials. However, most materials are only very slightly diamagnetic. Water, bismuth, and a certain kind of graphite are the most diamagnetic. I have succesfully levitated a very small slice of graphite using permanent magnets.

          Someone once levitated a frog. That magnet was a 10 Tesla magnet, though; there are no permanent magnet technologies that can get anywhere close to that magnetic strength.

          The only way you could do it with permanent magnets is if antimatter happens to be diamagnetic. This would be the case if, for instance, we find that antimatter's magnetic fields respond oppositely to that of normal matter; anti-steel, for instance, would not be paramagnetic but strongly diamagnetic.

          If that's not the case, then you HAVE to use big honking electromagnets.

    • Re:Interesting (Score:5, Insightful)

      by Anonvmous Coward ( 589068 ) on Wednesday October 30, 2002 @04:47PM (#4568375)
      "That is quite possibly the most circuitous way I have ever seen someone admit that something is impossible. Fascinating."

      Sorry Mr. Spock, think you missed the point of what he was saying.

      "The real hub is the storage," Howe says. "There's a lot of technology between here and there."

      What he means is that it's not as simple as a gas tank.

      • Re:Interesting (Score:5, Insightful)

        by anzha ( 138288 ) on Wednesday October 30, 2002 @04:52PM (#4568411) Homepage Journal

        Indeed. It's like saying that an exoflop (or op) supercomputer is impossible.

        It is. Right now.

        However, give us 20 years, then easily you'll have it.

        After all, it's just technology between here and there.

        • Re:Interesting (Score:5, Funny)

          by HeghmoH ( 13204 ) on Wednesday October 30, 2002 @05:02PM (#4568550) Homepage Journal
          By that definition, it is impossible for me to have a burrito. That's true, right now. However, in ten minutes, I can go to the burrito place, and I'll easily have it.

          When people say things are impossible, without qualifiers, they mean it's impossible forever.

          • Re:Interesting (Score:5, Funny)

            by Anonymous Coward on Wednesday October 30, 2002 @05:08PM (#4568601)
            But I think you'll need to concede my basic point, which is that it is impossible for you to have an antimatter burrito. Especially with current technology.
            • Would eating an anti-burrito make you constipated? 'Cuz a regular burrito certainly coes the opposite....
            • "But I think you'll need to concede my basic point, which is that it is impossible for you to have an antimatter burrito."

              The technology to do that cannot be that far off. Today it's possible for the human body to convert a burrito from one state of matter into another. If the human body can turn a solid into a gas, then it's possible to have an anti-matter burrito one day.

          • Re:Interesting (Score:4, Funny)

            by Skyshadow ( 508 ) on Wednesday October 30, 2002 @05:41PM (#4568910) Homepage
            Weirdly, I am actually having a burrito right now (surfing during a seriously late lunch). I feel very metaphysical right now.
        • I think a better example would be "it's impossible to build a space station capable for the average person to spend a month on." They know what they need to do to contain anti-matter just as well as they know how to make a livable space station, unforunately there are a lot of components to it that need to be well thought out and tested before faith can be put into it.

    • Re:Interesting (Score:5, Funny)

      by L. VeGas ( 580015 ) on Wednesday October 30, 2002 @04:50PM (#4568401) Homepage Journal
      There's a lot of technology between here and there

      This is like saying that the only impediment to being rich is all the money you don't have yet.

    • Re:Interesting (Score:3, Insightful)

      by Daniel Dvorkin ( 106857 )
      That is quite possibly the most circuitous way I have ever seen someone admit that something is impossible. Fascinating.
      No, that's not "admit[ting] that something is impossible" at all. That's saying that the barrier between what we have now and what we want to have is one of engineering, not science. We understand the scientific principles; we just haven't developed the technology. Yet.

      If the guys who built the foundations of the Net back in the Sixties and Seventies had said, "there's a lot of technology between here and there" -- which would have been a perfectly accurate statement at the time -- would you have told them that they were admitting that what they were trying to do was impossible?

    • Re:Interesting (Score:3, Interesting)

      by sakeneko ( 447402 )
      However, any advanced design like this is not without its hurdles. "The real hub is the storage," Howe says. "There's a lot of technology between here and there."
      That is quite possibly the most circuitous way I have ever seen someone admit that something is impossible. Fascinating.

      Nothing so interesting, IMHO -- it's just a garden case of someone not reading what someone else said very carefully, or possibly not understanding it well. <wry grin>

      A scientist or engineer who claims that there is a "lot of technology" between here and there is merely saying that we can't do it now, with today's technology. Given the rate of change in technology over the past hundred years, saying that something can't be done today is hardly the same as saying it can't be done at all.

      While no physicist expects Star Trek-like warp drive any time soon (or at all), we've known that anti-matter exists since the late 1920s, when Paul Dirac developed the equations that showed that it had to exist. We first "saw" real anti-matter in the mid-1930s, when Carl Anderson observed a positron, or anti-electron. Both of these men won Nobel prizes for their work -- this is not exactly news to anyone who keeps up with science and especially physics.

      Antimatter isn't the brainchild of some writer with lots of imagination and little grasp of science. It exists. It is real. Further, its properties are widely understood -- we know how it behaves.

      More to the point, we know that, to produce and keep large quantities of it, we must determine how to isolate it from regular matter. We know that, to use it in an engine, we must expose it to regular matter in a controlled fashion, and harness the energy released when it and the regular matter annhilate each other.

      In other words, we already have the basic science in hand. What we haven't figured out yet is how to do what needs to be done economically and reliably -- we don't have the technology in hand.

      This doesn't sound impossible to me. It sounds like it will take time and effort, probably quite a bit of time and effort, but as technology goes it isn't sufficiently advanced to be indistinguishable from magic. (Five mod points to anyone who identifies that reference.) ;>

  • Hm (Score:5, Funny)

    by Anonymous Coward on Wednesday October 30, 2002 @04:42PM (#4568313)
    It isn't true Star Trek warp stuff, in fact it is a variation on an fusion based pellet design I saw in the late 70's, but interesting concept.

    Are you sure those aren't tracers from the bad acid you took back in the late 70's?
    • It isn't true Star Trek warp stuff


      (in voice that gets more and more mouse like as we keep speeding up towards the speed of light)

      Capt'n Kirk, she's flying appart ... I do'not know how much longer I can hold her together ... She's com'in appart ...

      -- Scotty

      That is what we'd be saying once this thing was traveling faster than the speed of light!

      C'mon people, some simple physics here!! We can not travel that fast! Also, consider that with the nuclear blasts they are talking about, which would blow the sail right off of our little space craft!

      Damn kids and their buzz words!

  • The cost of antimatter... (Score:5, Interesting)

    by hpa ( 7948 ) on Wednesday October 30, 2002 @04:43PM (#4568321) Homepage
    I don't think anyone is arguing that antimatter would be just unbelievably useful to spacecraft, but the cost needs to be taken down by something like nine orders of magnitude -- the currently going rate for antiprotons is something like a million dollars per nanogram.

    The cooling ring only helps you once you have antiprotons to cool down to antihydrogen. Right now the production of antiprotons itself is just too expensive.

    • Re:The cost of antimatter... (Score:5, Funny)

      by phud ( 539476 ) <philip.elliott@g ... G.com minus poet> on Wednesday October 30, 2002 @04:46PM (#4568355) Homepage
      Yeah but look how much vcr's have come down in the last few years!
    • "...but the cost needs to be taken down by something like nine orders of magnitude"

      I know that's an issue, but I'm not convinced that's the biggest issue. The biggest issue is safety. Anti-matter is hard to contain. Imagine if gasoline violent explodeded when exposed to air. Nobody'd wanna put that into their cars.

      However, if Anti-matter were capable of powering ships capable of say... travelling to one of Mars or Jupiter's moons for the sake of bringing back large quantities of valuable minerals, then you'd find a great deal of effort going into anti-matter generation.

      When safety goes up and demand goes up, the price will magically fall as a bunch of places jump on board to start extracting it. (or converting a better word? I can't remember how anti-matter is generated.)

    • Social justice would reduce the cost considerably. (Score:5, Funny)

      by theonomist ( 442009 ) on Wednesday October 30, 2002 @05:09PM (#4568603) Homepage

      In a just society, where the wants of the underprivileged are not left unattended-to, in a truly accepting and broad-minded multicultural community where spiritual values and emotional resonance are cherished and rewarded, it's clear that the hierarchically-constrained "male physics" which enforces today's high antimatter prices would cease to obtain.

      I invite you all to contemplate the joys and rewards of a non-judgemental, people-centered physics, which takes emotional and spiritual considerations are factored into every equation. With such a "physics of the heart" taught as a scientifically acceptable and morally rewarding alternate truth -- for there are always many mutually exclusive and identically valid truths, especially in matters of radiation -- adequate supplies of antimatter would be within the reach of all! Imagine every child having enough antimatter to dream and to grow, to achieve his or her full creative potential as an individual, regardless of his or her astrological sign!

      Is it truly so radical, to contemplate making science the servant of humanistic values, rather than their enemy? Is it really necessary for antimatter, like the so-called "Western literary canon", to be the exclusive province of dead white males? I think not.

    • What about teleportation? The technology is fairly new.

      I remember reading about it several times here on slashdot and it sounds very star trekish. Could someone with a physics background tell me if its possible to have one anti-proton and a regular proton that can change to an anti-proton through quantum entagglement?



      Perhaps we could replicate anti-protons and anti-electrons using this technology on standard particles.



      I believe this was already demonstrated in 2000.

    • Lets assume that in the next 1000 years we havent wiped ourself out.

      Let us also assume that the human race will continue to expand.

      With a population of 10billion+, we'll need to spread out from earth. Space colonies in orbit, on mars, the moon, and jupiter's moons should all be possible by 2500, no problem. Given my 2 assumptions it's inevitable.

      With that size civilisation, it's not a far strech to belive we could build as many orbiting solar satelites that we want. On board each station, convert solar energy into anyimatter. OK, you might get a 0.001% efficency rate, however with a large enough surface area, at a similar height of Mercury's orbit, you would produce 9E21W of energy, wirh 0.001% efficeny we could produce 1kg of antimatter a second. Thats a lot of antimatter.

      Of course what would we use antimatter for? Answer: Convert to energy.

      All antimatter is, in the long run, is an energy source. If we have a very effiecent battery, which can pack an enourmous punch for its mass, then theres no need for anti matter for general power production. For the times we specifically need antimatter, produce it in situ. Wont be as efficent (solar -> "battery" -> antimatter), however it will be a lot easier then hauling even a minute amount of antimatter arround the solar system.

  • And in 20 years.... (Score:3, Insightful)

    by cyberise ( 621539 ) on Wednesday October 30, 2002 @04:43PM (#4568324)
    We'll see antimatter missles :(

    • Re:And in 20 years.... (Score:5, Funny)

      by Loki_1929 ( 550940 ) on Wednesday October 30, 2002 @05:14PM (#4568653) Journal
      " We'll see antimatter missles :(

      Sorry, I think you typed a '(' where you meant to type a ')' .

      " We'll see antimatter missles :)"

      I'm excited to! :P

  • What are the mods thinking??? (Score:5, Funny)

    by glwtta ( 532858 ) on Wednesday October 30, 2002 @04:44PM (#4568331) Homepage
    A story relating to religion and then a story with the word "antimatter" in it right after? Do you realize how many insane rantings by people who consider themselves to be experts in such matters (no pun intended) will be the result of this?

    I mean, come on - why not post Linux vx. MacOS X and Emacs vs. vi stories while you are at it.

  • Grrr.. (Score:5, Funny)

    by Loki_1929 ( 550940 ) on Wednesday October 30, 2002 @04:44PM (#4568333) Journal
    "Later on it also mentions that we can't produce a lot of antimatter efficiently yet."

    We'd be able to produce tons of it by now if the frickin' Vulcans didn't hold us back!

  • "It isn't true Star Trek warp stuff, in fact it is a variation on an fusion based pellet design I saw in the late 70's, but interesting concept."

    so are they feeding those hamsters special pellets to make them run faster on the little wheel pushing the craft or are the waste pellets used for powering and propelling the ship?

  • Antimatter costs far more than it's worth... (Score:4, Informative)

    by Bonker ( 243350 ) on Wednesday October 30, 2002 @04:45PM (#4568338)
    ...At least to provide thrust for a vessel of any kind since it costs more energy (incredibly more, with current technology) to produce than it actually stores. The only advantage to using an antimatter/matter reaction as a propellant is the sheer efficiency of the reaction. You get a lot more push out of a lot less 'fuel'. If you can get away with carrying less total mass, then you don't have to accellerate or decelerate as much.

  • Better than what? (Score:5, Funny)

    by shrikel ( 535309 ) <hlagfarj&gmail,com> on Wednesday October 30, 2002 @04:45PM (#4568347)
    From the article: Howe is laying the groundwork for a faster, better, cheaper antimatter drive.

    Faster, better, and cheaper than all the other antimatter drives we have already produced?

  • Insterstellar travel is still centuries away (Score:5, Insightful)

    by SexyKellyOsbourne ( 606860 ) on Wednesday October 30, 2002 @04:46PM (#4568351) Journal
    Thanks to movies and television series such as Star Trek and especially Star Wars, most people have no idea just exactly how far another star system is.

    The closest star is Tau Ceti, which is 4.7 Light years away, would still take a decade to reach and a decade to return even with a very, very, very advanced anti-matter engine -- a space shuttle with chemical engines, in comparsion, would take 100,000 years to reach there.

    Anti-matter still costs approximately 40 quadrillion dollars per gram to make, and storing it and dealing with the gamma rays is quite another thing.

    Sorry, sci-fi fans: we will never visit another star system in our lifetimes, and probably not even Mars with the amount of funding that goes to space.

    • Re:closest star (Score:5, Insightful)

      by Bill Currie ( 487 ) on Wednesday October 30, 2002 @04:53PM (#4568430) Homepage
      Actually, it's Alpha Centauri at about 4.2 light years.

    • Re:Insterstellar travel is still centuries away (Score:2, Informative)

      by Anonymous Coward
      The closest star is Tau Ceti, which is 4.7 Light years away

      This is incorrect; the closest star is Proxima Centauri; 4.24 LY. Tau Ceti is 11.35 LY away (Source [216.239.51.100])

      • This is incorrect; the closest star is Proxima Centauri; 4.24 LY.

        Alpha Centauri C (to use a more official designation) is indeed marginally closer to us than Alpha Centauri A and B. But at absolute magnitude 15 you would have to be just about standing on it to see it.

        I can't see much exitement in going all that way just to see a red dwarf...

        ...laura

    • Actually I asked a question [slashdot.org] similar to your statement a while back in a discussion about Voyager [slashdot.org] and I like the answer [slashdot.org] I got.

      Here's what he said so you don't have to click the links

      Voyager is not travelling all that fast, and we could go faster with sufficient time and engineering effort.

      First cab off the rank is probably the Orion drive. Build a really big plate, attach it with really big springs and dampers to a heavily radiation-shielded spacecraft, and detonate atom bombs behind the plate. The basic technology exists right now, all you need is a pile of cash and be prepared to violate the space weapons treaty. Maximum speed is about 1-2% of the speed of light, so you're still taking a couple of centuries to Proxima Centauri.

      Next option is a fusion engine. We can't generate power with controlled fusion yet, but ITER probably will if and when it gets built. ITER is, er, rather large and heavy, and doesn't really produce much net power, so a practical space fusion power plant is a fair bit of engineering development down the road. Anyway, the idea is quite simple. Release the "exhaust" of the reaction out the back of the engine, just like a normal rocket except the exhuast is a hell of a lot hotter and travelling a lot faster. Maximum speed maybe 10-12% of the speed of light.

      Alternatively, use a light sail powered by a really big laser. All you need is to scale up laser and telescope technology a crapload (so, again, considerable engineering development required). Maximum speed? Somewhere between 10 and maybe 30% of the speed of light, depending on just how big you can make your mirror (and consequently how far you can keep accelerating).

      The other big issue with interstellar spacecraft is the question of how much debris is out there. If there's a lot, as you go faster you'll need one hell of a shield to protect you.

      Finally, there's there's also the possibility of using antimatter-matter reactions to power a ship. Antimatter is kinda powerful stuff to have around, and you could theoretically use it to power a ship to near the speed of light. However, there is no known natural source, and manufacturing it requires milllions of times more energy put in than you get back when you "burn" it. It, therefore, is a really long-term option from when humanity has such astounding energy generation capacity it can afford to use it to power antimatter-powered spaceships.

      All in all, there are some possibilities, but most are still a fair bit of technological development away. Let's get to the rest of the solar system first :)

  • ...would make a great name for the Microsoft Insider, or what ever that publication is called. :) (required karma leecher)

    This work is important because it will enable us to understand why there is any matter at all in the Universe. This is one of the great mysteries.

    Yes indeed, the antimatter-matter is interesting also because - it makes use remember that a big part of our current understand of science is based on just assumptions. Rules, that exist because they have made sense (so far). One day, when we learn more, many of these rules might get obsolete.

  • Accelerating this way, Howe's vessel could reach a speed of 260,000 mph
    Faster than light!

  • Space.com math (Score:5, Interesting)

    by Rupert ( 28001 ) on Wednesday October 30, 2002 @04:47PM (#4568377) Homepage Journal
    About 40 times about 5 equals about 250.

    Would it kill them to be a little more precise on:
    • the distance from the Sun to the Oort cloud (about 250AU)
    • the distance from the Sun to Pluto (about 40AU)
    • the ratio of those two distances (apparently about 5)
    ?
    • "Would it kill them to be a little more precise"

      You're looking at average distances between objects moving faster than you (or I) can imagine, being pushed/pulled by 4 different forces eminating from an unimaginable number of masses.

      In other words, give them a break.

      (For those wondering - and this is off the top of my head... Nuclear strong, Nuclear weak, electromagnetic, and gravitational)

    • Re:Space.com math (Score:5, Funny)

      by JonnyElvis42 ( 609632 ) on Wednesday October 30, 2002 @05:36PM (#4568854)
      About 40 times about 5 equals about 250.

      It comes out a little closer for extremely large values of 5.

  • Antimatter Space Drive (Score:5, Insightful)

    by Dunark ( 621237 ) on Wednesday October 30, 2002 @04:52PM (#4568416)
    Storage of antimatter is just one problem. Another is that antimatter annihilations yeild a rather inconvenient form of energy: Gamma rays, which come out in pairs of photons headed in opposite directions. We don't know any way to reflect such photons, and absorbing them would require a huge shielding mass that would rapidly get vaporized.
  • <humour>

    People keep talking about this like cost is an issue. As we all know from Star trek, in 100 years, after the end of WOrld War 3, when around a quarter of the world is killed a nulclear war, people realize that money *isn't* really there, and that it means jack squat. Then people just start being all lovey dovey and feeding the world and doing things for the advancement of knowledge, not for money. Thus we eliminate hunger, eliminate war, and eliminate cost of making antimiatter!!! Of course all this free antimatter comes in handy when Cochrane invants the warp drive in the same time period, thus allowing us to meet the Vulcans.

    So if Star trek is right (as it HAS TO BE!!!), no interstellar travel in our life times, but in our kids maybe.

    </humout>
  • ...the last line in the article reads: "Conceptually if we found the funding, we could do it in a year," Howe laments. "We're on that border, that fringe."

  • Doesn't the Enterprise use Dilithium crystals for it's warp drive, not anti-matter?
    • No. This site [lcarscom.net] has some relevant technobabble.

      Basically, warp drives are run off antimatter -- but dilithium is the only known substance that doesn't react to antimatter, when subjected to an EM field. So the dilithium just processes the antimatter.

    • the dilithium crystals stabalize the warp matrix, the whole rig is powered by a reaction of deuterium and antideuterium that takes place in the warp core and that power is then sent to the warp coils through the em relays, thats at least close to how it 'works', someone wanna tell me if thas SB or not, man, i'm a nerd

  • Bonus! (Score:2, Funny)

    by paulfwilliams ( 410508 )
    One side-effect of anti-matter drives is making self-destruct much, much easier.

  • This is for REAL! (Score:4, Funny)

    by NutMan ( 614868 ) on Wednesday October 30, 2002 @05:10PM (#4568618)
    Just a coincidence I am sure, but over on anti-slashdot.org they have an article about some guy who actually built one of these babies...

    It topped out at 3,492,901 MPH, and then the impact of space dust turned their little umbrella thingy inside out. Now they're trying to figure out how to stop the damn thing, by firing a cold fusion cannon out the front...

  • Production?? (Score:4, Interesting)

    by olethrosdc ( 584207 ) on Wednesday October 30, 2002 @05:11PM (#4568630) Homepage Journal
    Any physicists out there? Why is antimatter so hard to produce? What I know about the matter is limited to the following - (please correct me if you have the appropriate knowledge)

    1. The amount of antimatter currently visible in the known universe is negligible compared to the amount of matter.

    2. However, in the big bang, antimatter and matter are supposed to have been created in equal amounts. So where did antimatter go?

    3. QED equations for antiparticles are exactly the same as those for normal ones if you reverse the direction of time.

    The only conclusion that *I* can draw from this is that there is no antimatter left nowadays because it is travelling in the opposite direction in time, whatever that means.

    That in turn gives a simplistic explanation of why it is hard to create antimatter - there is no causal relationship normally. According to my weird intuition, you can only create antimatter in a material universe by violating 'normal' causality.

    PS. I am *not* a physicist.

    • Re:Production?? (Score:2, Insightful)

      by olethrosdc ( 584207 )
      Oh, I just thought that possibly you can't get a lot of output in a collider because antimatter tends to re-combine with matter and gets lost again. Hm.
      Silly me.

    • Re:Production?? (Score:2, Insightful)

      by scorp1us ( 235526 )
      I think I read that matter and antimatter, while being equal, are not. In our universe, it takes more animatter to destroy matter. See the other atricle titled "One of Many"

    • Re:Production?? (Score:4, Informative)

      by chenzhen ( 532755 ) on Wednesday October 30, 2002 @05:32PM (#4568825) Homepage
      My focus isn't particle physics, but maybe I can offer a correction for your approach. In #2 you presuppose that antimatter and matter are produced in equal amounts; actually, nature seems to favor production of matter over the anti counterpart. Look up CP violation for more on this. So at the Big Bang, all the antimatter annihilated with much of the matter, but since there was an imbalance in the initial production, there was still some matter left over. This is the stuff you and I are made of.

      As far as difficulty in production, it happens that most of the particle-pair interactions that decay into antimatter particles only occur at very high energies compared to what our accelerators can achieve, and even then at low probabilities. Then there is the matter of containment. Current methods involve redirection with magnetic fields or trapping with lasers, both of which are extremely difficult and therefore expensive.

      As usual, the big problem with this bit of physics is the funding. Going out on a limb, particularly in longterm scientifics, is not promoted as a safe or particularly clever business strategy. This leads to what is not exactly the most logical method of pursuing progress, but I digress in my bias.
    1. Accumulate a large amount of antimatter in some place
    2. ...
    3. Profit!
  • Last time i checked, it took megawatt-hours of electricity and an expensive atom-smasher to make one microwatt-hour worth of antimatter. Without a fantastic advance in antimatter production technology, talking about *any* use for non-microscopic quantities of antimatter is just blowin' smoke.

    It would be workable to pump the megawatts into a bank of lasers and let the lasers push on the probe's small light sail. (And you could tap the military budget for a good hunk of the cost of those space-based laser batteries.)

  • Political difficulties (Score:3, Insightful)

    by f97tosc ( 578893 ) on Wednesday October 30, 2002 @05:26PM (#4568781)
    There are already numerous propulsion ideas that are not only feasible but much better than anything that is used today.

    The issue is that anything inolving nuclear power is a political impossibility, at least for another generation. Antimatter drives have exactly the same issues (hum... or maybe this is not widely understood... 'antimatter' sounds much better than 'nuclear'...)

    Tor
  • .. gee.. i started to go all WTF after seeing the title. and then the word storage..

    i guess one shouldn't be staying up too long after donating blood.

  • Sorry for yet another Star Trek reference, but... (Score:4, Interesting)

    by arkain ( 198918 ) on Wednesday October 30, 2002 @05:30PM (#4568810)
    ...it would seem to me that they have the right idea. They used a crystal of sorts(dilithium) to regulate the matter/antimatter reaction. Here's the reality check:

    Since matter/antimatter reactions cause 2 gamma-frequency photons to be thrown off at right predictable angles to the impact vectors of the original matter and antimatter particles, an engine could be designed that ensured that one of the 2 photons always exited from the engine exhaust port to propel the ship. What of the other one? Position a crystal in the appropriate location to catch the second photon. Depending on the structure of the crystal, the result would either be mechanical (heat or vibration) or electrical energy which could be converted and/or stored as needed.

  • how do you stop the damn thing... (Score:3, Interesting)

    by ianjk ( 604032 ) on Wednesday October 30, 2002 @05:41PM (#4568907)
    wouldn't it take just as much force to bring one of these babies to a stop? At the type of speeds they are talking about, wouldn't deceleration be a couple of month process?

    • I think the idea is this: for short journeys, you accelerate until you're half way there, then you turn the ship around and decelerate. This has the added advantage of providing you with some sort of gravity (how much depends on your acceleration) for the duration of trip (aside from when you're flipping over). For longer trips, you'll accelerate until you're cruising along nicely, then turn the engines off. You'll have to flip over and decelerate for the same amount of time you spent accelerating tho...

      You very quickly pile up speed too. If you accelerate at 1g for a year, you get rather close to c. If you ever want to return home tho, you'll have to be careful: at 0.99999999996c, you can cross the galaxy in 12 years of your own time, but 113 000 years will pass for us back here.

    • Re:how do you stop the damn thing... (Score:4, Informative)

      by Idarubicin ( 579475 ) on Wednesday October 30, 2002 @07:59PM (#4569880) Journal
      Don't bother decelerating. You want to stop a probe? Put a planet in the way. Just make sure you gather (and transmit) lots of data--really fast--on the way down. Or do a flyby. Or aim really carefully and put yourself into an orbit about some object of interest.

      Some of the Russian Venera and Luna probes took the first approach--deliberately crashing into Venus or the Moon, respectively. NASA's Voyager craft did a tremendous amount of good science with just flybys. Galileo (the spacecraft, not the Italian scientist) dropped a probe into Jupiter's atmosphere and then settled into two years of orbiting the planet.

Slashdot Top Deals

To be awake is to be alive. -- Henry David Thoreau, in "Walden"

Close