coke

matter source? well you're going to get antimatter anyways because positrons are antimatter!

light photons can be split up into positrons and electrons by a thin gold sheet, then positrons and electrons can be seperated by magnetic coils, see the link i gave above...natural radioactive decay is another option, but really its both less effective and requires exotic radioactive isotopes that have to be synthesized..

Here's how a computer would create any random number generator from a 2 number generator (and the 2 number generator is mechanical in the processor, i guess)

Because I'm sure most of you know thats how numbers are written in binary in the first place... i.e. 7 is 111. or 00000111, same thing.

0,0,0 -> try again
0,0,1 -> return 1
0,1,0 -> return 2
0,1,1 -> return 3
1,0,0 -> return 4
1,0,1 -> return 5
1,1,0 -> return 6
1,1,1 -> return 7

That would have efficiency of 8/125, or 6.4%.... after 3 runs.

I guess the tree's method is the best possible efficiency, it gets 84% chance, as he said, after 2 runs.

And 2 runs is the minimum, seeing as 7 > 5^1, but 7 < 5^2

Sisyphus... if you are going to try to hide a failed mechanism, at least make it appear functional! say sum of first attempt + second attempt, throw out 8-10.

did you see a little devil jumping on top of you? that sleep paralysis link is not the first place i've seen that idea... (i also saw it in 'a thousand ways to die')

Well making fun of someone who's gay is like making fun of someont who's fat or uncool... It's not in essence racism or anything like that, but still it's not very good.

Although idk, where I live, I really don't see people who are obviously gay get made fun of... maybe it's cause I live in California, lol.

And ok, I'm sure there are a lot of manly gay people, in the sense that they are agressive or strong or whatever....

I meant it more in a masculine sort of way. And this applies more not to the 'bears' if im guessing what you mean correctly, but the other ones.

lakmilis are you ever going to tell me and jake what pun was not intended?

come on, we're dying to know what pun was not intended...

LOL... 'NO'I don't think facebook iq tests are likely to be 'accurate'

 

(no pun intended)

what pun not intended?

 

come on... soemone tell me what pun was not intended...

I don't understand either.

Was this the pun you didn't intend?

I don't know a lot about IQ testing but I do know about puns.

http://xkcd.com/559/

And John' date=' I don't get what pun was not intended in that comic either!

Here's a bad pun from one of the threads...

I'm dating a chemist, something something what do I do?

You'll just have to wait and see if there's chemistry between you.

Hahaha hilarious. Let's make this thread about puns.

You know what i think is very probable?

Say you create an account at some site...i.e. here where they ask for an email and you need to login with a password...

I'm sure a large percentage of people would have the same password for the site as theire email. Say a person from the site can find out that password, and check your emails.

I think most people have like 2 or 3 passwords, and they just use different ones, undoubtedly repeating... I reccomend always never using the same password as your email, though, as I described above it will be very easy single step...

Ah, how upsetting...

Not that its not a perpetual motion machine, but how I missed the first few words of the article...

"Powered by sunlight..."

That's acutally a very good idea, there aren't really any good ways to convert CO2 into hydrocarbons...

Set up a couple factories for this processing, and you've got things going! Just use a nitrous oxide fridge to condense CO2 and then run it over these nanotubes... efficient? profitable? probably not, but maybe someday...

I think the poll results are fair- no smoking in public streets but in any building, it is the propery owner's right to decide...

Sorry for my outburst, Inow, I really did get the impression you're an anti-smoking nazi... should have read the post before where you said you used to smoke...

I smoke very little, no more than a couple cigarettes a day... but if you are only allowed to smoke in your house, you won't be able to show off how cool you are when you have a smoke in a public place... (lol, no just kidding)

It does bother me how it really shortens your respiratory endurance while running, but come on at this age who runs anyways?

I think really smoking bans are just so you don't like stand there and blow smoke in people's faces, or everybody having to smell your smoke at a restaurant...

Well the only reason why smoking wouldn't be allowed is the pollution- however pollution outside is much larger from cars and their exhaust- gasoline doesn't exactly burn very clean either and can make just as bad second hand smoke.

So, I disagree iNow. The pollution from cars is much larger and the combustion occurs at high temperature and creates several nitrogen oxides which are much more poisionous.

There is really nothing from secondhand smoke that's not in that type of pollution. What are you afraid of, 0.001 mg nicotine you accidently inhale when walking by a smoker? Is it going to get you addicted?

Yeah thats an interesting idea in itself...

Very good laser, would ionize any matter by contact into a plasma

I'll probably have to try that someday- strong laser making positrons, organized by several coils, and burning through anything...

I think in that context, the positrons would be even better at burning through things than the original laser...

This I don't get about antimatter- its clear how electrons and positrons annhilate each other, and say an atom of matter would annhilate an atom of antimatter.

But say you just have a positron ray (thank cap'n for this idea) and you fire it at say a block of metal, what will happen?

Would the positrons annhilate the electrons and leave a bunch of protons, that with no chemical bonds would just seperate into plasma?

That's a good idea for a lightsaber!

Magnet poles are North and South, and the force on a charge is ^{[math]q\vec{v} \times \vec{B}[/math]}. The cross product means the force is perpendicular to the field and to the motion.

So does that mean that picture in post 18 is how a magnet works or not? Or only an electromagnet works that way? It would be nice if a simple field could confirm that electrons are repeled from pole, without having to take lorentz or other forces into account...

Forget about the motion. The particles in first two sketches have motion is suppose (i'm aware they travel at 99% speed of light), but not in any organized direction, as they would with perhaps a cyclotron or like in the CRT picture.

the arrangement is also pants, you'll fint that there are just as many +(north?) magnetic poles on the inside of that container so if one repels it then the other will attract it.

Well see, the magnets are in different orientation such that all the + poles face the center... They should all repel positrons, only thing is maybe the field will somehow get screwed up, because as swansont said there's no place for the poles to meet up or something...

I found a quote on another thread that sounds similar to my sketch:

The way we hold our anti-matter at Fermilab is after the anti-matter is created it we separate it with a strong magnetic field that then 'pushes' it into a large tank where a strong magnetic field all around it keeps it in the middle of the best vacuum money can buy until we need it for something.

 

Like colliding with some protons.

That large tank sounds very similar to this idea...except it uses solenoids, of course... but its less interesting with coils because there are a lot of ways you could do it with them- for one keep spinning around in a cyclotron indefinitely.

Plus they require quite a bit of electricity

Well from what I understand, magnets and electromagnets work have a field like I drew in the picture below...

The coils in particle accelerators work this way, there are a series of coils, precisely timed to attract the positrons or electrons or whatever with the poles being on the axis that the particles are traveling...and not having to be perpendicular.

And from what I understand, solenoids make a field that behaves the same way as permanent magnets, no?

wait a sec... so these laser diodes work like leds without requiring a lens? by using some similar pump mechanism (simulated emission)?

that system won't work. a magnetic pole will not repel a charged particle.

Sure it will, why not?

Look at the picture below: it's a cathode ray tube (source) and those are electrons running through it, in a near vacuum.

You can see the small black permanent magnet in the right upper corner, its repeling the electron stream, causing it to curve downwards...

So, there's one example where a magnetic pole does repel a charged particle.

I don't see how it's any different with positrons.

I think like bignose said, the friction is independent of are for a certain weight (i.e. 20 pounds). The more area, the more surface area touching, but the less force pushing down per square inch.

But friction is also directly proportional to weight/area.

So if you decrease the area, you'd be increasing the pressure on that area for a constant weight, thus friction would remain the same.

Ok, Sfnfan,

He decided to use the first scale, which is not a good idea, but I didn't bother correcting him...

Use the second scale which gives you an exact weight (i.e. 5.8 grams)

You have 10 stacks with 10 coins each. 9 of the stacks are real, and contain coins that weigh 1 gram each. 1 of the stacks is fake and contains coins that weigh 1.1 grams.

So, what you do is, put 10 coins from the first stack, 9 coins from the second stack, 8 coins from the third stack...etc. etc. etc. 2 coins from the ninth stack ad 1 coin from the tenth stack onto the scale.

If all the stacks were real, you have 55 coins on there, so the scale should read 55 grams. But say if the first stack was fake, it would be offset by .1 grams for every coin, and you have 10 coins from the first stack, thus it would read 56 grams. If the tenth stack was fake, you only have 1 coin from the tenth stack, so it would read 55.1 grams. Depending on how much the weight is offset by, you can tell which stack was fake.

subscribed?

I'm pretty sure you mean perscribed.

wasn't there some honeybee disappeearing phenomena?

see colony collapse disorder

if this keeps happening, we might get a humanity collapse disorder

I wonder if there are like mirrors that reflect gamma. This might be difficult since gamma penetrates almost anything. Or maybe lenses that curve gamma rays. Then you can definitely make the flash of light into a uniform beam...

But if not, you actually have an interesting idea: make gamma rays excite some fluorescent or phosphorescent material that emits gamma rays. I have to wonder at the efficiency of this, but pumping would definitely make more uniform rays than the flash, which obviously diffracts in every direction...

Is this and radioactive decay seriously the only ways to make gamma rays? Of course, I would prefer annhilation to decay anyday- only electricity needed, no expensive synthetic isotopes.

Ok, ok, skeptic point is that it can be made very purely now, not that positron emission natural decay... all you need is a laser and some gold foil that you never have to replace...

Ok so its not insanely efficient. Still I think that's a great achievement.

Well, lets see. 10 billion positrons == 0.000818710414 joules worth of antimatter.

To my surprise your calculations are correct...

But still, it has the highest energy density next to pure energy itself... and that is something to prize...

Wow lol. I edited the post and calculated using google calculator plus had to find out a bunch of constants , and when I posted I find you already showed it...

I'm not sure what you and swansont mean by conserving momentum...

Perhaps the 1mm gold sheet they put in front of the laser here?

I know you can already make electrons and positrons from high energy photons,

Its clearly described in that link... which i think is a very cool link by the way...

I wonder if the gold even gets ruined in that experiment, or if antimatter can be created indefinitely without replacing the gold...

"The California researchers estimate that with every shot of their laser, which fires every 30 minutes, they create about 10 billion positrons, also called anti-electrons." (source)

The description of that image claims it's a 5mW laser. I'm guessing it's a relatively long exposure time to show up that well. My 50mW laser will do that for the naked eye at night.

Ah, that's interesting... I went to an electronics store and there were a bunch of red laser pointers (you know the ones you play with as a kid) and an expensive supposedly very powerful green laser... (of course, prob. not real lasers, just a led + lens)

But all said max. output is 5mW, so it surprises me how much the frequency difference or whatever has an effect...

Wait a sec!

Just wikipedia'd laser pointer and guess what picture came up?

Idk, cap'n if positrons do annhilate the air right in front of you, what would you get, protons flying around?

That is a nice idea to simply send a positron beam (accelerate the positrons like you do electrons in a crt television)

But I don't think the reaction between positron + an atom is as energetic as positron + electron, though...

In any case, it can surely be done to create a flash in a vaccum:

And surely that flash can be focused into a laser...

"A split second later the positrons and electrons annihilate each other on contact in a flash of pure energy, called a gamma ray." (source)

Question is, the original laser already has high energy photons, possibly gamma....so doing this would simply lose efficiency...

So I suppose the only sense would be if you wanted to say run the laser for 10 minutes at 1,000 volts, then get a 1 second jolt of 600,000 volts worth of gamma rays...

I suppose the laser jolt would look something like this:

http://www.youtube.com/watch?v=hDwgsZTQSyM

thank antimatter for finding the video

nice one cap'n, how many mw is that?

that's an interesting idea, stereologist, in fact i think they're making a hologram dvd disc on a similar concept... maybe not, idk

but that would work wouldn't it? say a 10-layered hologram disc with these dyes replacing the simply reflective coating: first two lasers focuse on the bottom layer, and after each read, focus on the layer above it... so 10 times storage of a dvd... or 10 times storage of a blu-ray for that matter...