It would make electric vehicles much more economical than oil. We could finally make a ship that could pack enough punch to make a trip to the asteroid belt and back. To bring back the unobtainium.
Nuclear cars would be cool, too, but I think we need to consider the weaponizable nature (both for governmental military forces and for terrorists) of these technologies.
I dare say this would take a briefcase bomb to a whole new level.
So, roughly speaking, a soda bottle of antimatter is a megaton of TNT[1]. Well, half a soda bottle if you ask the stewardess for a soda of non-antimatter once you get on the plane.
If you want to equal the largest of nuclear warheads tested, you will have to pay a small overage fee on your luggage.
[1] I'm ignoring containment overhead. Once you show me a gram of antimatter we can talk about containment.
So the problem is making it safe enough to not explode even if the electric-antimatter converter is shot, crushed, disintegrated in an explosion or superheated.
Bond the anti hydrogen with anti Oxygen, Bond it with an anti-matter noble gas (elements that refuse to react). Maybe there is a creative way to make it hard to unlock into it's explosive state. That way you can only dole out the energy with a complex process that an accident would not recreate.
Your airport scanner would thus have to infer the presence of antimatter rather than detecting it directly (by looking for high-energy photons), but if your containment vessel is leaking then you have bigger problems than law enforcement :-)
Scientists would LOVE to find a difference, it would explain so much about the universe.
And no, there is no "creative way to make it hard to unlock into it's [sic] explosive state". Such a thing is impossible. The only thing you can do is make some kind of really good containment.
And BTW a few thousand atoms is not much, even for anti-matter. It's about the energy of a flying mosquito.
If I've got a kilo of antimatter in a briefcase, I'm just going to set it off at the scanner then, killing the ~10k people in the airport... and half the city it's part of.
1Kg of antimatter is about the energy of the Tsar Bomba if you want to try it out: http://www.carloslabs.com/node/16
I can also buy any type of "missle" (read vehicle).
I can also buy fertilizer, cheaply.
Say I forego the fertilizer route, and fill my car full of gasoline. Now, all I need to is then put a rag in the gas intake and break off the tab. I have a molotov cartail, that, when steered does a lot of damage.
It's easy to kill people and cause terror. Moreso, if you are an engineer. But its decency and ethics that keep people from doing these sort of things.
Surely as scientists we could take some comfort in the statistics of the likelihood of any one of us actually experiencing "terrorism" first hand....
The closest comparison for endurance would be nuclear power. Its worst failure mode is meltdown, which while very bad is nothing like as destructive as an AM explosion.
And it gets worse! Suppose your AM containment fails in a carpark. The explosion will cause a chain reaction of car explosions.
Finally, there is the incredible inefficiency with which AM is manufactured. It takes gigawatts and many hours of accelerator time to create even minute quantities. Because the only way we know of to create AM is smashing things together in particle accelerators. There aren't many LHCs to go around.
But the "fail-dangerous" issue is more of a user responsibility, and I don't see that being solved anytime before the above technology is discovered (if ever).
Putting speculation aside, we know that AM is fail-dangerous. For all current purposes, we have better alternatives. For long-endurance power sources we have fission. For weapons we have fusion.
I cannot personally think of a common use where the statistical certainty of failure outweighs the risk.
My knowledge in this domain is quite limited, but maybe someday somebody will figure something out. Just the thought of antimatter existing is very cool.
http://en.wikipedia.org/wiki/Ivy_Mike
The Tsar Bomb test was restricted to 50Mt by missing out the 3rd stage - so it was primarily a fusion device. Had the depleted uranium tamper been in place it would have given the 100Mt the design was capable of - but with horrific fall-out.
When electricity was first being invented for human utility, I bet it took several orders of magnitude more energy to package it than to simply light a candle, for example.
Or when candles were first invented, it took several orders of magnitude more energy to create one than to keep a campfire going. Etc.
Right now we're at the "invent a candle" stage, and talking about the "hydroelectric dam" stage, so it's hard to imagine. But it's far from impossible.