# Tag Info

## Hot answers tagged antimatter

17

The total antimatter in the van Allen belts is estimated to be 160 nanograms. Annihilating that with matter would produce a whopping 8 kW-hr of energy. A quarter of a gallon of gasoline has that much energy. The star ship would be better off getting a quick spurt from a gas station pump before heading out.

11

No. Accelerating mass to the speed of light requires infinite energy. A matter-antimatter reaction releases a huge amount of energy, but $huge \neq \infty$, not even close. On the other hand, if you want to accelerate something without mass to the speed of light, you don't need anything fancy such as antimatter. Just turn on a flashlight.

9

It's a "beam core" engine, described in some further detail on Project Rho's Big List O' Engines: Microscopic amounts of antimatter are reacted with equal amounts of matter. Remember: unless you are using only electron-positron antimatter annihilation, mixing matter and antimatter does NOT turn them into pure energy. Instead you get some energy, some ...

7

The wavelength you mention corresponds to about 510 KeV. As hdhondt says, conventional optics, such as a parabolic mirror, don't work at this range. Wolter telescopes use grazing incidence reflectors and can work up to about 100 KeV. The NuSTAR X-ray telescope is a Wolter with a maximum energy of 79 KeV. The BAT (Burst Alert Telescope) on Swift uses a ...

5

It's difficult to say exactly what type of engine this is as Anti-matter engines are solely conceptual. Mainly due to the highest production available for Anti-Hydrogen seems to be about 1 gram per 100 billions years (see comments). That aside we can still analyse the engine in question. You have a storage tank containing Anti-Matter Hydrogen atoms (A-H2) ...

5

Electromagnetic radiation with frequencies above $10^{19}Hz$ are conventionally called Gamma Rays. Gamma rays will penetrate instead of reflect of most materials. Reflection is only possible at very shallow angles of incidence, and even then it works best for lower energies like X-rays, below $10^{19}Hz$. This method is used in the European X-Ray satellite ...

5

They are on to something... else than they try to claim on their site. The paper on the actual science explains the concepts. This is not intended to be the "holy grail", genuine antimatter drive (a photon drive utilizing gamma rays from annihilation of positron and electon; specific impulse of the maximal ${c}\over{g_0}$ and 100% mass to energy conversion)...

4

As written, this question is far too broad. "Are they on to something?" is a nearly meaningless question. Is antimatter propulsion theoretically feasible? Yes. Does it make interstellar travel possible? Not by itself. Does Positron Dynamics know how to make an antimatter-powered thruster useful for interstellar travel? No. Will Positron Dynamics ...

3

The Enterprise uses Bussard-Collectors to harvest hydrogen from interstellar space. While the Enterprise is science fiction, the Bussard-Collector - or more the Bussard ramjet1 - is a theoretical concept from a physicist named Bussard from 1960. In this concept, the spacecraft uses very strong EM fields to deflect and focus the hydrogen it's flying through ...

3

Yes, antimatter can be used to propel a spacecraft. The concept of an antimatter rocket is what we're after. Just a concept drawing, but it gives us an idea of what we're talking about. Another article discusses such a rocket (highlights here): Smash a lump of matter into antimatter and it will release a thousand times more energy than the same mass of ...

2

It's bad when matter and anti-matter come in direct contact[reference needed]. Currently, the only way to store antimatter is to trap it inside some very strong magnetic fields. In short, the size of the containment system would greatly exceed the savings in volume gained by using anti-matter. Those magnetic fields have to be very strong, which ...

2

There are proposed thermal antimatter rocket designs which could work with positrons. I am focusing on these to answer your questions (in reverse order): The amount of energy generated is (more or less) an engineering problem. Assuming that asteroid mining is feasible, there is no principle limit to scale these operations. Since antimatter is the fuel for a ...

2

There are a number of terrestrial uses for plasma, which could be adapted for space purposes; these could theoretically harvest the required plasma from the Van Allen belts. There are even a few terrestrial uses for plasma that have been suggested as future space technologies if some further development is made. Have a look into plasma windows (used in ...

1

This is essentially an engineering question. Dangers, or risks as you'd typically call them in engineering, have two aspects: probability and outcome. Something can be a high risk because of a high probability, or because of a serious outcome. In the case of anti-matter, any significant containment failure would result in a catastrophic loss, so it's an ...

1

The major reason why modern rockets have not implemented a matter-antimatter propulsion system is because of the dangers that antimatter and its annihilation with matter pose. Some of the antimatter problems are: Storage: As we know the storage of antimatter is very difficult and cumbersome. Its storage is energy consuming which will make the rocket more ...

1

An anti-matter engine could potentially be very efficient, as you have mentioned it is extremely energy efficient for its mass. The tradeoff, however, is that you need a lot larger engine to contain the antimatter fuel. The only theory for trapping the fuel is to use careful magnetic fuel. That requires a significant size of a field typically, and thus ...

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