[gecko]

Given that antimatter explodes violently when put into contact with regular matter, I kind of hope that's not how they go about achieving this. A kid who forgets to recharge his board, allowing the magnetic fields to collapse, could do a considerable amount of damage.

[enko]

> I kind of hope that's not how they go about achieving this

Don't worry. The design is impractical anyway - regulating the "anti-mass" would be extremely difficult. Just when you got it balanced, the kid would drink a glass of water and the board would sink into the ground.

Due caution would indeed be advisable when selling these gadgets, though. A matter-antimatter collision of 50kg would be equivalent to about 2.1 gigatons of TNT, or about 400 times more powerful than the most powerful hydogen bomb ever developed, so it would indeed caused a "considerable amount of damage".

[pavel_lishin]

> The design is impractical anyway

Nah, you just need a miniature collider inside the board, manufacturing more anti-matter as necessary.

And obviously, it would be powered by annihilating matter/antimatter together, via a small Mr. Fusion at the back.

[amalcon]

They could just use a compressed-air ballast tank. That would certainly be simpler than a miniature collider, and the explosion risk isn't that bad compared to the rest of the device.

[enko]

That is a good solution. You should patent it! METHOD FOR DYNAMICALLY REGULATING BALLAST MASS ON ANTI-GRAVITY FLOATATION TRANSPORT DEVICE

[StavrosK]

So you're saying that this has fantastic military applications? Interesting...

[jacques_chester]

The military don't like antimatter weapons because they are fail-dangerous. They require active stabilisation.

If a nuke fails, nothing happens. If antimatter containment fails, your entire arsenal of antimatter weapons go up at once.

For a similar reason, nitroglycerin is strangely unpopular for both civilian and military purposes.

[StavrosK]

Interesting, so you are suggesting some sort of gun that creates antimatter in a remote location. That's a great idea!

[jacques_chester]

A weapon that could create antimatter at a remote location would be a particle accelerator. One that could create non-trivial amounts of antimatter would cause far more damage from its direct consequences than from antimatter. By factors of millions or billions.

It would be heinously expensive and would require the kind of energy input that only gigawatt-grade nuclear power plants could provide. Rather than using a complicated, failure prone and inefficient way to transform nuclear fission into destruction, it would be simpler and more effective to lob a nuke with the same amount of uranium or plutonium.

Hence, for your day-to-day megadeath needs, thermonuclear weapons will remain the tool of choice for the foreseeable future.

[StavrosK]

Unless we could convince the enemy to use that weapon!

I guess thermonuclear weapons are cheaper, though...

[enko]

So .. you don't read much sci-fi, do you?

[goalieca]

Not to mention that it would take a LOT of mass to balance out the weight of the board and the person riding it.

[viraptor]

Not saying that it's as feasible as normal engine, but when you ride a bike you pretty much fill it with matter that explodes violently when ignited. Then you ignite small parts of it to make the bike move...

We may still see some normal devices which use antimatter in one way or another.

[simpleTruth]

Meaningful amounts of Mater + antimatter produces extreme amounts of radiation, and takes ridiculous amounts of energy to produce.

To put things into perspective, 1kg (~2.2lb) of antimater + 1kg of matter = 2* (9×10^16 J/kg) of energy, TNT = 4.2×10^6 J/kg so that works out to 42,000,000,000 kg of TNT or a 100 mega ton bomb which is larger than the largest H bomb ever tested.

PS: The other issue is unlike gas which is fairly stable, any sort of containment failure = detonation.