Antimatter question

[Hellbound]

Hmm, a 40 kiloton lightbulb. There must be some kind of world record there somewhere.



No, I don't think it would be useable, except through standard ways of harnessing the heat produced, such as steam turbines or thermocouples. I just mentioned particle detectors to point out that it is possible to capture virtually all particles, even if we can't necessarily do anything with them. The problem is that in order to stop high energy particles the detectors must be very large and dense, so it would be almost impossible to do anything with the energy collected before it just became dispersed as heat.

I was way out on a tangent thinking about a power system using antimatter, though...as in how much useable energy you could get out. I was thinking it'd likely be a thermal system: small amount of antimatter with matter (likely water) to produce very hot steam, which could then be run through a system to turn a turbine. I figure your efficiency wouldn't be very high because of the fact that about all you could use from it is the heat.

Course, in a rocket engine it's easier. Hydrogen reaction mass combined with antimatter fuel in a magnetic nozzle on the back = instant acceleration Because of the temperatures and, consequently, exhaust velocities you can produce in the hydrogen, you can get by with very little reaction mass (compared to current spacecraft where 90%+ of the weight is reaction mass).

But apparently I've wandered far afield of the original questions, so I'll just dotter over to the desert bar to get my free seniors prune yogurt

 

[Ziggurat]

As a power source, I think antimatter is well beyond our reach.

I guess there's a difference between power source and energy source, but the two can get mixed up so let me clarify something for those who might not have picked up the distinction as it relates here. As an energy source, antimater is an impossibility because we have no natural source for antimatter. As a form of energy storage (to be used later as a power source) we have the dual problem of generating power from antimatter (which you mention) plus the fantastic inefficiency in generating the stuff in the first place (which is why those figures for how long it would take CERN to make a gram are so ridiculously large).

 

[Cuddles]

(which is why those figures for how long it would take CERN to make a gram are so ridiculously large).

SLACkers.



Sorry, didn't someone say it was time for some really bad physics puns?

 

[Deetee]

All that was needed to destroy the WTC was some homeopathic antimatter. No need for CERN.
http://www.hominf.org/posi/posifr.htm

 

[RecoveringYuppy]

I figure your efficiency wouldn't be very high because of the fact that about all you could use from it is the heat.

Well, there's heat and then there's heat.

The gamma rays that you get from the annihilation of anti-protons (or even positrons) are very high frequency and very hot (billions? of degrees, I'm guessing). They are also "just" heat. But the second law of thermodynamics allows very high efficiency in the extraction of work from very hot heat sources. The efficiency of a heat engine is determined by the difference between your input temperature and your output temperature. On Earth your output temperature is practically never lower than about 300 Kelvins because those are the temperatures we experience on Earth.

If you could take those million/billion degree photons and convert them directly to the 300 degree microwave/infrared waste heat you could have extremely efficient energy conversion. Without some actual calculations I don't know how many decimal places it would go, but we're talking 99.999.. % type efficiencies.

But practically speaking who really needs all those decimal places? An input temperature of 5000 degrees gives a potential of 94% efficiency. Compared to what our coal fired generators do now that would be a miracle.

Five thousand degrees would be some kind of plasma, but it would be a plasma we are capable of handling now. Some MHD (Magnetohydrodynamics) technology has been experimented with that could make practical use of those temperaturs (or something similar) now.

 

[Ziggurat]

But practically speaking who really needs all those decimal places? An input temperature of 5000 degrees gives a potential of 94% efficiency. Compared to what our coal fired generators do now that would be a miracle.

The problem is that antimatter is not an energy source, and never will be. It would only ever be useful as energy storage. And the antimatter creation inefficiencies are so fantastically bad that efficiencies for extracting energy from antimatter-matter anihilation are essentially irrelevant.

 

[RecoveringYuppy]

@Ziggurat,

Yes, basically the same objections when someone identifies burning (as opposed to fusing) hydrogen as an energy source.

 

[Ziggurat]

@Ziggurat,

Yes, basically the same objections when someone identifies burning (as opposed to fusing) hydrogen as an energy source.

Quite true.

However, hydrogen can be generated with moderate efficiency, so using it as an energy storage system (for cars, for example) isn't out of the question (though there are still hurdles to be overcome). The basic idea there is that it may provide some of the efficiency advantages for mobile applications that electricity already provides to stationary power users (namely, decoupling the details of the use of energy from the particular mechanisms of the energy source, so that sources can be adapted or switched as needed).

 

[Timothy]

Interestingly, a lot more people have below average intelligence than above, because the distribution is not actually a Gaussian. Many people have slightly below average IQ, say around 90, but this is balanced by a few having much higher, say 130 (numbers made up by me). So for every three people below average, only one is needed above to keep the average the same. If you think about the extreme cases this is actually just common sense. It is impossible to have a negative IQ, so either 0 or 1 must be the lowest score possible, but it is possible to have over 200.

While you are correct that the distribution is not Gaussian, it is reasonably close to being Gaussian for casual discussion.

However, your understanding of the distribution is faulty. The distribution is of the number of people within a scoring percentile, not the numerical value of the score of that percentile. You do not average the scores to find that there are (for example) three people with IQ 50 to balance out one person with IQ 150. There are (appoximately) as many IQ 50 individuals as IQ 150 individuals.

It is *not* theoretically impossible to have a negative IQ. With a mean of 100 and a standard deviation of either 16 or 15 (depending on whether you use Stanford-Binet, Wechsler, or Cattell), someone with an IQ of 7 standard deviations below the average would have a negative IQ. In reality, the distibution is no longer Gaussian near the extremes, the ability to measure a miniscule but non-zero intelligence doesn't exist, and no one cares about being able to discriminate differences at that level. At the high end, it's similarly difficult to measure, but people have an interest in trying to determine the variations in the very highly intelligent. (Ask anyone versed in psychometrics about the validity of an IQ score of 200, and you'll see the problems that it involves. )

The values of mean=100 and SD=16 were chosen to provide a useful range that was positive, but they're completely arbitrary. Nothing *inherently* prevents a negative IQ. One could just as easily choose a mean IQ of 0 and a standard deviation of 1, and half the population would have negative IQs.

 

[FaisonMars]

That would mean an awfully large number of people near GZ with, like, major cancer or already dead!

Actually, I think an high dose of gamma-rays turns you into the Incredible Hulk.

 

[Timothy]

The way the towers collapsed sure looks like the tidal effect you'd get if you dropped a quantum black hole on the towers from above. A QBH wouldn't be slowed by air and so would fall at free fall. And it would suck the debris down *faster* than it normally would fall through the air. OMG, I've finally answered Christopher Brown's question! A realistice explanation for the free fall of the Towers! It would explain some of those mysterious holes as well.

Sheesh, antimatter?!? Don't these CTers know anything about physics? Yep, quantum black holes raining down from above, that's the answer. Yep, yep, yep. That's my story and I'm sticking to it.

 

[slyjoe]

...

Sheesh, antimatter?!? Don't these CTers know anything about physics? Yep, quantum black holes raining down from above, that's the answer. Yep, yep, yep. That's my story and I'm sticking to it.

In a word? No.

 

[Tanstaafl]

I thought everyone already knew this: You only have to capture enough energy to maintain the warp field.

Sheesh!

 

[bobdroege7]

There isn't nearly enough significant digits in Huntsman's calculations.

Starts with one and ends with one, don't be fooled by all the trash at the end!

 

[Cuddles]

The values of mean=100 and SD=16 were chosen to provide a useful range that was positive, but they're completely arbitrary. Nothing *inherently* prevents a negative IQ. One could just as easily choose a mean IQ of 0 and a standard deviation of 1, and half the population would have negative IQs.

I stand corrected. Do you have any links that show a more or less even distribution around the mean? I'm sure I read somewhere that more people have a slightly below average IQ which is balanced by a few having much higher ones, but I can't actually find anything about that now so I could be mistaken.

 

[Cuddles]

Well, there's heat and then there's heat.

The gamma rays that you get from the annihilation of anti-protons (or even positrons) are very high frequency and very hot (billions? of degrees, I'm guessing). They are also "just" heat. But the second law of thermodynamics allows very high efficiency in the extraction of work from very hot heat sources. The efficiency of a heat engine is determined by the difference between your input temperature and your output temperature. On Earth your output temperature is practically never lower than about 300 Kelvins because those are the temperatures we experience on Earth.

If you could take those million/billion degree photons and convert them directly to the 300 degree microwave/infrared waste heat you could have extremely efficient energy conversion. Without some actual calculations I don't know how many decimal places it would go, but we're talking 99.999.. % type efficiencies.

But practically speaking who really needs all those decimal places? An input temperature of 5000 degrees gives a potential of 94% efficiency. Compared to what our coal fired generators do now that would be a miracle.

Five thousand degrees would be some kind of plasma, but it would be a plasma we are capable of handling now. Some MHD (Magnetohydrodynamics) technology has been experimented with that could make practical use of those temperaturs (or something similar) now.

But there is also the problem of how you capture the energy. In order to stop most of the gamma rays you need a very large, very dense mass. In order to get any useful work out of this it is this mass that needs to be heated up, and if you heat it up to thousands of degrees there will be huge losses, never mind the problems of containment.

 

[Big Al]

The way the towers collapsed sure looks like the tidal effect you'd get if you dropped a quantum black hole on the towers from above. A QBH wouldn't be slowed by air and so would fall at free fall. And it would suck the debris down *faster* than it normally would fall through the air. OMG, I've finally answered Christopher Brown's question! A realistice explanation for the free fall of the Towers! It would explain some of those mysterious holes as well.

Don't talk such ARRANT NONSENSE, Timothy. You know PERFECTLY well that there's a SIMPLE, REASONABLE and RATIONAL EXPLANATION for the self-evident FREE FALL. The 3" REBAR ON 4' CENTERS in the CONCRETE CORE was put in place with a coating of C-4 around it. Chris has utterly and convincingly PROVED IT!

Haven't you learnt ANYTHING?

Dammit, I thought I'd got that damned thread out of my head! Must... find... pills!

What is it with the woosters and capitals, anyway? The shift keys on their keyboards must be practically worn away. And the exclamation mark.

 

[Big Al]

The gamma rays were contained by a coherent resonant tachyon field. Obvious, when you think about it.

Then again, maybe it's just a little too simple... must be a cover up for an even more fiendish plot.

Wait! Suppose some terrorists hijacked a couple of fully-laden passenger planes and crashed them into the towers?

Hmm???

Naah, that's just plain stupid. Antimatter gets my vote.

 

[Ocelot]

Wait! Suppose some terrorists hijacked a couple of fully-laden passenger planes and crashed them into the towers?

Surely someone would have seen something like that. Why haven't the families of the passengers come forward? If that'd happened there be so much evidence you couldn't possibly entertain any other theories. people accross the whole world would see it on the news.

 

[RecoveringYuppy]

But there is also the problem of how you capture the energy. In order to stop most of the gamma rays you need a very large, very dense mass. In order to get any useful work out of this it is this mass that needs to be heated up, and if you heat it up to thousands of degrees there will be huge losses, never mind the problems of containment.

Well, yeah, all true. I was addressing an earlier posters notion that extracting energy from "heat" was necessarily inefficient and that steam turbines were the limit in efficiency [don't remember exactly what the original poster said]

In the last couple of sentences of my post (after "but practically speaking ...") I wasn't thinking anti-matter at all. Five thousand degree temperatures don't require anti-matter. We don't need the 99.9999% efficiency we might be able to achieve with anti-matter (assuming we adressed the legitimate points you just made). 94% efficiency, even 80, would be just fine. Consequently, we don't need anti-matter. We can get those temperatures with fuels we have now. I think some MHD technology was even run on powdered coal (and MHD was just one technology I pulled off the top of my head).