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How does it work?

  1. Jul 12, 2004 #1
    Recently, I heard something very interesting from a friend who spoke with a NASA scientist. He stated that NASA has devised a way to use anti-matter in actual spacecraft reactors, and that combining this new source of propulsion with other recent advances in technology could yield a speed that would bring the arrival time to Mars down from its current 18 month period, to seven minutes! I know very little about the reality of antimatter and how it can be used in our "solid material" world. Kyle (my friend) didn't know very much either about the specific functions of antimatter. If one of you could enlighten me on a few antimatter topics, i.e. the principles behind it, how it can be used for propulsion, and the possible danger(s) it could pose, I would be grateful. So basically, what, how, and why?
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  3. Jul 12, 2004 #2


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    I'll leave the details of what anti-matter is to someone more knowledgeable than myself (just about anyone)

    However, what I will say, is that if NASA had developed:
    a) A cost-effective technique to produce/extract large quantities of anti-matter.
    b) A safe way of storing anti-matter
    c) A device for exploiting the energy release following the merging of matter/anti-matter for mechanical purposes (i.e, a propulsion system)

    then not only Kyle would have talked about it; it would have signaled the greatest revolution in applied science (everyone would have talked about it!)

    What is probably the issue here, is that some scientist at NASA has found a partial answer to a single one of these issues (I would suspect it to be c))
  4. Jul 12, 2004 #3
    can someone tell me how anything can travel to mars in this short time?
  5. Jul 12, 2004 #4
    Alrite, I think i know enough about antimatter to answer your question. First of all, antimatter is actually very much like matter, but it has a different charge. What i mean by that is...antiprotons have a negavity charge, positrons(antielectrons) have a positive charge, antineutrons are still neutral but the quarks that make up the antineutron have oppsite charge to the ones making up normal neutrons. The key factor in the ability to use antimatter as a prepelant is that when antimatter and matter touch, they completely annihilate each other. In other words they completely get comverted into energy. In which case...well, lets just say u can get a lot of energy from very small amouts of antimatter. But the thing is that what your friend said probably isnt true because its very hard and expensive to make antimatter in particle accelerators. Antimatter is the most expencive substance in the universe pretty much, i think 1 g of antimatter is in the trillions of dollars. Also, its not possible at this time to make enough antimatter to power a spaceship to Mars. If you combined all the antimatter made in the world, i think it can power a light bulb for 3 seconds. In other words, there's not sufficiant way of geting antimatter at this point, and so its impossible to use it as a source of energy for anything. BUT IF people would make a spaceship run on antimatter, it would be much more powerful than say, a spaceship running on nuclear fusion. The reason is because in nuclear fusion, only a fraction of the mass is converted into energy, while in antimatter engines, all would be.
  6. Jul 13, 2004 #5

    It would have to be traveling AT light speed (or a good percentage of it) for this too happen. Depending on where Mars is in relation to Earth light takes anywhere from 3 to 22 minutes, 12 minutes being the average. Plus remember that light is already at c velocity whereas a spacecraft needs to accelerate and decelerate over the course of a trip adding even more time to the trip.

    I guess at some point way down the line that antimatter engines could push a craft to a large percentage of light speed....
  7. Jul 13, 2004 #6
    thank you for your answers.
    I do understand antimatter.
    neutroncount kind of touched on the answer.
    The problem with traveling at fractions of the speed of light is the fastest you go the more your mass increases, this means that if your mass increases then you need more energy to go faster still up to the point where you need infinite energy because the mass of the object increases the more energy supplied to accelerate it.
    now as you no this is in violation of the conservation of energy
  8. Jul 13, 2004 #7
    Yea, he's right about everything. Besides, we're just not going to anytime soon have engines powerful enough to go anywhere close to the speed of light, not even a quarter. Nuclear fusion engines are being worked on right now i believe, but that wont be enough to make space travel that short. Although it would decrease the time to mars dramatically. But what I wonder is, since in nuclear fusion reactions, some percentage of mass is converted into energy, if you would have a nuclear fusion engine on a spaceship, and made it go faster and faster, and therefore increase in mass, then more energy would be released because there's more mass to be converted into energy. And as the spaceship speeds up more, the mass still keeps increasing, basicly towards infinity, therefore, the energy released also increases, towards infinity, giving the spaceship enough boost to keep accelerating. I wonder if that would be enough to make the spaceship reach the speed of light. Anyways, its just a though. :D
    Last edited: Jul 13, 2004
  9. Jul 13, 2004 #8
    according to the mass energy equivalence energy and mass are interchangable comodoties( i dont fink i spelt that right). The problem would be that mass/energy could only be created accordibg to e=mc^2. this implies that you would not have enough mass/energy to go that fast
    what are your thoughts armoskater

  10. Jul 14, 2004 #9
    Even if it were theoretically possible, no human or materials used in the spacecraft could survive such rapid acceleration and deceleration. Plus, it isn't cost effective to do. The few labs that can create antimatter do it at extreme costs, and very little quantity is produced that can be stored. While positrons can be created "relatively easily" it is harder to then remove them from the particle accelerators and then store them.
  11. Jul 14, 2004 #10
    Last edited: Jul 14, 2004
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