OT - Physics Question on Anti-Matter
 

I am curious to know what an estimated force in kt that an ounce of Anti-Matter mixing with an ounce of Matter would be.

Lets compare that to say a standard 20kt nuclear weapon.

I realize this is hypothetical, as this has never been done before, but in theory I am just curious how much energy can be realized from an anti-matter/matter contact.

Re: OT - Physics Question on Anti-Matter
 

OK, let's see... You have 2 ounces of matter and antimatter, that's about 57 grams or 0.057kg, and the speed of light is 300 million meters per second... thus using E=m*c^2, the energy produced in the detonation is 5.7*10^-2kg * (3.00*10^8m/s)^2 = 5.1*10^15 kg*m^2/s^2, or 5.1 quadrillion (the American kind, a thousand million million) joules. What that is in kT I don't know, but I'll try looking it up...

edit: OK, a "ton of TNT", according to Wikipedia, is defined as 1 gigacalorie, which equals 4.184 billion (thousand million) joules (it also happens to equal a million dietary calories - think of THAT next time you sit down to dinner, since there are a million grams in a metric ton, you are eating the energy equivalent of hundreds of grams of TNT! http://forum.shrapnelgames.com/images/smilies/eek.gif Don't let your food a splode! http://forum.shrapnelgames.com/images/smilies/wink.gif)... anyway, since the antimatter explosion produces 5.1 quadrillion joules and a ton of TNT is 4.184 billion, that means that the antimatter explosion is equivalent to... 1.2 *billion* tons of TNT (1,200,000 kT) - which is about 10 times more powerful than any bomb mankind has ever devised! http://forum.shrapnelgames.com/images/smilies/eek.gif (The most powerful bomb was developed by the Russians during the Cold War and it had an estimated output of 100,000 to 150,000 kT...)
(SJ or some other mathematically inclined person, could you stop by and make sure I didn't horribly screw up the math? http://forum.shrapnelgames.com/images/smilies/wink.gif)

Re: OT - Physics Question on Anti-Matter
 

Assuming the matter and antimatter can be combined perfectly to cause total annihilation (which is actually a huge assumption), you just have to plug the numbers into Einstein's equation:

E=mc^2

=(1 ounce matter+1 ounce antimatter)(186000 miles/sec)^2

= 6.9192E10 ounce-miles/(sec^2)

Unfortunately, college physics was too long ago for me to remember the conversion factors to change that mess of units to kilotons. Converting ounces to tons gives an order of magnitude around two megaton-miles/sec^2.

Edit: and Ed posted while I was trying to look up the conversion factor before I submitted the post.

Re: OT - Physics Question on Anti-Matter
 

A ton of mass or weight is not the same as a ton of explosive force, so that conversion would have been misleading anyway http://forum.shrapnelgames.com/images/smilies/wink.gif

Re: OT - Physics Question on Anti-Matter
 

Well, there's got to be some conversion factor between the two. Whatever that number is, you've still got a big BOOM.

Re: OT - Physics Question on Anti-Matter
 

Wow, here we have the resources to figure out what it really takes to blow up a planet. The 'death star' beam is stoopid, of course. It takes enough energy to accelerate the planet's entire mass to its own escape velocity to make it explode. For an earth-sized planet this is equivalent to several months output by our sun. (!) A simple 'beam' cannot possibly deliver this much energy. And anyway, if it's delivered from outside, it just burns away one side of the planet, sending the rest spinning away somewhere. The only practical way to really explode a planet is to deliver enough anti-matter to the core to make an explosion big enough to shatter the planet.

So, if someone can figure out how much energy is needed to accelerate the earth's mass to it's own escape velocity, then back-convert that to matter/anti-matter reaction, we would then know how much anti-matter a super-high-tech ablative delivery device (the 'bunker buster' is a toy compared to this problem... http://forum.shrapnelgames.com/images/smilies/happy.gif ) has to deliver to the planet's core.

Re: OT - Physics Question on Anti-Matter
 

E = mass x C^2 is valid to give the energy for total conversion from matter to energy. But ya, assuming that's what you can get from an anti-matter bomb is an assumption.

Nuclear weapons kilotons are in terms of equivalent explosive force compared to a certain mass of T.N.T., which of course has its own conversion factor involved. I bet it's not too hard to google up.

There is of course another web page with lots of discussion about what it takes to destroy a planet in various ways.

Re: OT - Physics Question on Anti-Matter
 

Well, it's a bit more complicated than that. First, it's gonna be a nasty volume integral, since the gravity will be different along points from the surface to the core. Then, there isn't an easy way to tell how much of the energy from the annihilation will be converted to kinetic energy instead of heating up bits of former-earth. And it would probably not be the case that the annihilation happens all at once, or that the energy flux would be uniform across the unit sphere, so you cannot be certain where the center of gravity will be.

Anyway, with all that, I would say that it is safe to assume that the amount of anti-matter needed is bounded by the mass of the Earth. http://forum.shrapnelgames.com/images/smilies/laugh.gif

Re: OT - Physics Question on Anti-Matter
 

All my data is from Google, so ask it to back me up http://forum.shrapnelgames.com/images/smilies/happy.gif

Earth has a mass of 5.9742 x 10^24 kg.
Escape velocity is 11 km/s approx.
7.228782 × 10^32 (72,278,200,000,000,000,000,000,000,000,000) Joules are needed to blow the planet up.
Based on e = mc^2, 8.0431047 × 10^15 kilograms of a matter/anti-matter mix is needed to detonate the planet, so just inject 4.02155235 x 10^15 kg of anti-matter into the core.
That's 4,021,552,350 million kilograms of anti-matter... ouch.

Well, good luck on getting that http://forum.shrapnelgames.com/image...ies/tongue.gif

Re: OT - Physics Question on Anti-Matter
 

Well regardless of how close you are, that still paints a pretty picture. I guess if an Anti-Matter research center proposal comes up in your next city counsel meeting, it would be a safe bet to say no!

Whoops, the magnetic containment field surrounding the pebble sized bit of Anti-Matter failed and wham there goes the county.

Re: OT - Physics Question on Anti-Matter
 

Ok, so in the game perspective, some of the components that utilize Anti-Matter Warheads, we're probably talking about very finite amounts of AM, say less than a gram of the stuff? Other wise we would see one hit one kill damage types correct?

If an ounce of AM and an ounce of matter can produce and energy release something like 10 times that of the most powerful nuke or hydrogen bomb ever produced and we were to successefully hit say an aircraft carrier sized vessel, it would be a safe bet that the aircraft carrier would be nothing but ashes, maybe some mangled trushes and support beams here and there, on one hit.

Next question, how large of a device and energy requirement would it take to contain a gram or less of AM. Hypothetical guesses again are welcome, just trying to visualize this in my head.

Re: OT - Physics Question on Anti-Matter
 

Energy requirement is basically zero.
The device dosen't need to do any work on the antimatter, but simply provide a potential gradient (electromagnetic) to keep it away from the sides of the container.

The size depends on how good your materials science is... how strong/small/light of a magnet can you manufacture?

Re: OT - Physics Question on Anti-Matter
 

Jumping back to the Death Star beam, something of the sort might be possible, just maybe not on that scale.
Physicists have been able to get atoms to flow along a laser. If the laser is powerful enough to vaporise all the stray atoms in its path and allow anti-atoms to flow along the beam to its end you could have an anti-matter tunneling weapon.

Re: OT - Physics Question on Anti-Matter
 

While containment is difficult, making antimatter is much more of a challenge. Making a stable antimatter atom has been done. I'm not extremely current on it, but the last thing I read was that scientists were only able to make a few atoms of anti-hydrogen (antiproton combined with an "orbiting" positron). Capturing this antimatter atom in an electric field is hard enough; and making an ounce is completely beyond our current capabilities. Not to mention that it is a really bad idea because, as the math above shows, a problem with the containment vessel will release lots of energy.

Re: OT - Physics Question on Anti-Matter
 

I just ended up thinking about entropy.

I wondered how you could make a profit because to get the energy out you have to spend energy to make the AM. But then the Positive matter has already been made so you only need to make half of it. From there I started thinking about Fusion power where you get the energy out of sea water because the energy was placed into it at the beginning of time or whatever. From there I ended up considering mining sunlight from a star, but that's not infinite either. Eventually even the star will die. So clearly there is no such thing as an infinite energy source. It makes a clear argument for entropy. One day the universe will die. In about a billion years we might flee to another universe, but clearly even that will die. Which is more disturbing, that everything will die eventually or that I am getting depressed about soemthing that won't happen for maybe 14 billion years http://forum.shrapnelgames.com/images/smilies/fear.gif http://forum.shrapnelgames.com/images/smilies/smile.gif

Re: OT - Physics Question on Anti-Matter
 

This reminds me of a short story by Isaac Asimov, The Last Question.

Re: OT - Physics Question on Anti-Matter
 

hmm, a pretty obvious conclusion.

I can recall 2 stories such as that one. In one a man in a bar is asked how might a robot live forever and they talk about how it would have to upgrade every once in a while but yes it could last forever. The end of the story lingers over one mans young companion.

Another story that comes to mind is after a war where a computer ran everything some men ask its caretaker if it was unable to solve a problem. He answers that he would then flip a coin to decide.

Re: OT - Physics Question on Anti-Matter
 

That's not entirely true. Blackholes represent a massive amount of potential gravitational energy that I'm sure could (eventually) be harnessed by mankind. However, physicists believe that blackholes do "decay" slowly over time, losing mass, so it is possible that even blackholes would eventually all disappear, though that would take hundreds of billions or trillions of years.

Re: OT - Physics Question on Anti-Matter
 

Speaking of infinite energy.. you all should enjoy this if you haven't already.

http://infohost.nmt.edu/~mlindsey/asimov/question.htm

Re: OT - Physics Question on Anti-Matter
 

How is it not true?
How do you plan to get anything out of said hole without reducing the hole's mass-energy?

Just because there is a lot of mass there dosen't mean it is infinite in any way. Where "a lot" is only a handful of stellar masses in many cases.

Re: OT - Physics Question on Anti-Matter
 

That's like saying you'll surely die of old age in "about a microsecond." I.e., you are off by so many orders of magnitude that you're asking the wrong question, several times over.

It's also based on cosmological assumptions based on far too little evidence, which is the mistake modern science generally makes even when it gets its math right. Not to mention the misinterpretations of people reflecting upon the hypotheses and conjecture of cosmologists. Or the imaginitive leaps of science fiction and TV documentaries.

PvK

Re: OT - Physics Question on Anti-Matter
 

hmm, I thought a billion years was about right before we could actually traverse universal barriers. Well maybe not exactly but the intent was that it would be a very long time.

Re: OT - Physics Question on Anti-Matter
 

Entropy, cold death... if the universe keeps expanding everything will break down eventually.

http://www.physlink.com/Education/AskExperts/ae181.cfm

Re: OT - Physics Question on Anti-Matter
 

Assuming that there were no unknown factors( which there most certainly is ), wouldn't gravity keep the universe from maximum entropy? Is there anything to indicate the universe wont just do the whole big-bang thing over and over again?

I also thought I read somewhere that they'd discovered that light didn't actually travel infinitely, but somehow bended back towards us when it had travelled for some time?

Re: OT - Physics Question on Anti-Matter
 

That's one possibility, but as of the moment the Universe's expansion actually seems to be speeding up, not slowing down..

Re: OT - Physics Question on Anti-Matter
 

Last i heard it was speeding up too. Really, the 'Last Answer' story answers this well http://forum.shrapnelgames.com/images/smilies/wink.gif

So if everything we know now is true 9which is probably isn't), the universe will run out of 'energy' some day.

Re: OT - Physics Question on Anti-Matter
 

Yeah, but when that 'energy' is depleted and everything has 'stopped', gravity will still be there( as far as we know ). What is to stop it from pulling everything together again?

I read the Last Answer. It was a nice read, thanks.

Re: OT - Physics Question on Anti-Matter
 

Gravity would dissipate to pretty much nothing I suspect. Gravity is a force and spread over theoretical particles called gravitons. So as stars, planets, elements, atoms and particles break down, so does the gravitational force. All these things are held together by very strong forces compared to gravity, so if those are breaking, gravity probably isn't a big issue.

Of course, this is just based on my basic understanding and I could be wrong.

Re: OT - Physics Question on Anti-Matter
 

According to that theory, the universe seems to exceed the "escape velocity from the Big Bang".

However, this is all rather presumptuous speculative interpretation about the meaning of what we're seeing from our perspective.

A mere few hundred years ago, the general idea was you fell off the edge of the earth once you sailed past the Azores from Europe...

I'm not convinced that modern cosmologists have got it nearly as right as some people might assume.

PvK

Re: OT - Physics Question on Anti-Matter
 

Well, I wont claim to know any better, but I would have thought that if gravity was still there, however 'weak', the particles would slowly start to pull together again; unless something was actually exerting force on them( stronger than the gravity ), keeping them apart.

Anyway, if indeed the expansion is speeding up, that means energy is being continusly applied to the mass in the universe( thus providing the speed increase). Since energy = mass ( right? ), that means further that the amount of mass in the universe is increasing as well? And since all mass has gravity, as far as we know, that also means gravity increases? Thus eventually becoming strong enough to counter whatever other force is pulling the stuff apart...?

My non-existing education got cut short, so I'm a little out of the loop. Please correct me if something's wrong with my understanding.

Also, wont the whole 'expansion speeding up' thing also mean the entire mass of the universe will be traveling at light-speed in a 'few years'?

Re: OT - Physics Question on Anti-Matter
 

Its not the objects accelerating (IE Kinetic energy), but the underlying spacetime itself expanding.

BTW, if something is at escape velocity, it will never fall back (barring interference from other space objects)... that's because even though gravity is always there tugging on it, gravity is weakening faster than the speed is decreasing.
On a parabolic "orbit", the speed approaches zero as time approaches infinity... but it never quite manages to go negative and loop back. No matter how long you wait, you've always got just a little speed left, and gravity is *just* slightly too weak to stop you.

Re: OT - Physics Question on Anti-Matter
 

The Expanding Universe theory is that gravity is too weak to slow down something moving quickly away that is already an astronomical distance away. Gravity gets weaker and weaker the farther something is away. There is a limit to how much its force will ever add up to beyond a certain distance, so if the distance is increasing, and effect of gravity decreasing, things can escape gravity. The question then became exactly how massive is the universe, and how far is it apart, how fast does it seem to be expanding?

However, after many years of trying to figure that out based on all sorts of assumptions (which made sense, but are still just theories), cosmologists are starting to decide that some even more basic assumptions seem to likely be not correct, such as that the rules of the universe remain constant over time and distance...

The idea that we are seeing the universe all receding at increasing speeds at great distance is all based on assumptions about how to interpret the light we see based on a mountain of theories. It's an extremely sophisticated mountain of theories, but it's still an active volcano, so to speak.

PvK

Re: OT - Physics Question on Anti-Matter
 

As far as the accelerating expansion, sort of.

Consider the balloon analogy. You've got a superstretchy rubbery surface which is being inflated, at a rate such that two centimeters stretches to four centimeters every minute.

Lets add some starry anthills to the surface, such that most of them are emitting ants, all of whom crawl along the surface towards our hill. Ants crawling at the speed of light, which we will make a quite leisurely pace, say 8 centimeters a minute.

So the little photon ants crawling towards us are hustling along, but the space is expanding so their trips take longer and longer.

For the ants that start a centimeter away, no problem. They arrive before there is much noticable expansion.
For the ants that start 8 cm away, they suffer. The distance between them and their goal is expanding at 8cm/minute at the start, so although they move away from their starting point quickly, they never quite reach the destination.

The ants at 7.9 cm distant make a teensy bit of progress at each step, and as they slowly close the distance, things get easier. All the ants from that hill will eventually make it, although it will take a long time.

So, with this rate of expansion, we can see everything closer than 8cm. Ants that started just short of 8cm will have taken the lifetime of the universe to reach us.

Now, if the expansion accelerates, then the ants from the 7.9cm distant hills can no longer reach us.
As such, the observable part of the universe has shrunk from 8cm radius to 7.9cm or less.

For "small" things like superclusters of galaxies, gravity's pull is plenty strong enough to keep things snug for now. They pull apart a little, but at the same time, keep moving towards each other. If the expansion keeps accelerating then gravity starts losing at smaller and smaller scales... all the way down to star systems. And then eventually electromagnetic forces lose, and rocks get pulled apart... and then nuclear forces lose and atoms get pulled apart. But by then, nobody will care.

Re: OT - Physics Question on Anti-Matter
 

Thanks for the explanation, SJ.

They haven't figured out how the whole 'dark matter' and 'anti-stuff' fits in, have they? And let's say we had a super-fast spaceship and travelled to the edge of the spacetime, do they have any idea what would happen if we tried to move past it?

Re: OT - Physics Question on Anti-Matter
 

If one of the ants got into a drop of caffeine and started travelling in clear defiance of the speed limits imposed, it would go round and round... there is no edge.

And that's pretty much what we've probably got, in 3D.
As far as it is possible to see, in all directions... you have stuff, more stuff, older stuff, and eventually the microwave background.

Whether it is closed like a balloon shape, or flat or open (saddle-shaped), it is uniform in all directions to the edge of the visible universe. (7.999... cm on the balloon analogy)
So, no evidence for edges.

If it helps, you could think of a closed expanding universe as a game of asteroids... year by year, you keep increasing the resolution of the screen, but it is still a finite size (320x200 way back when, and 1280x1024 nowadays)... there are no edges to fall off of, since the left side is connected to the right side and the top to bottom.
Its not spherical, but rather doughnut shaped, but still finite with no edges, and a decent example.

Also, if your ship can only travel at 1 pixel per second, and you increase the screen rez fast enough, you won't be able to reach objects that happen to be too far away when you start.

Re: OT - Physics Question on Anti-Matter
 

If you're finding this discussion interesting, you might also enjoy the most recent Irregular Webcomic podcast (The word "podcast" is a second link.) You can download Episode #4, or read the transcript.

This is one of my favorite Webcomics. The author is a professional astrophysicist, and is quite good at explaining things in layman's terms. Podcast #4 explains why the night sky is black, which turns out to be relevant to this thread.

Re: OT - Physics Question on Anti-Matter
 

I was a tad dissapointed with the latest IWC podcast. It goes for about 9 minutes but after about 30 seconds when he started going on about giant red lights in the sky I thought "Do I really need to listen to this when he will obviously start explaining why the night sky is black". I mean ok he's got a Phd in Physics, what can you expect, but I already know that sort of stuff. When is he going to start explaining M-branes?

What do I know of brane cosmology?. Easy, I wrote half of one of the scenarios http://forum.shrapnelgames.com/image...es/biggrin.gif.

Edit: oh and capnq, just if you're interested, I am one of the writers for his new comic project.

Re: OT - Physics Question on Anti-Matter
 

Random thoughts:

I often find it funny how some scientists deride religion because it fails to meet scientific standards but will stand firm on accepted theories that truly can not be proven right or wrong. Hmmm, sounds like faith to me.

If the Big Bang Theory is correct then everything in the universe was created in that instant, albeit in different forms of energy and matter. Therefor, infinite energy is an impossibility because we live in a finite universe. However, if you throw in the infinite universes theory you could get infinite energy by tapping into other universes. Last I heard scientists think that they could accomplish this, but would need an infinite energy source to do so. http://forum.shrapnelgames.com/image...es/biggrin.gif

How much is our understanding of physics colored by our own perception? Our perception of "now" is an infinitely small slice of time and by the time our brain receives sensory input the data is already old because travel time for that signal is not instant. Looked at from this point of view we are actually out of step with our environment because we can only perceive the past.

Re: OT - Physics Question on Anti-Matter
 

Nope, they basically have no real idea what dark matter is. An interesting side point about antimatter is that "normal" (baryonic) matter and antimatter should have been created in equal quantity at the big-bang. However, we take a look around and we can't detect any antimatter out there, but there's lots of normal matter. They still haven't figured that one out http://forum.shrapnelgames.com/image...ies/tongue.gif

Re: OT - Physics Question on Anti-Matter
 

A handful of solar masses? The central blackhole of the central galaxy of a galactic cluster is estimated to have up to several hundred billion solar masses. It'd take a while to use up that amount of mass/energy.

Re: OT - Physics Question on Anti-Matter
 

Oh, you can do a lot of proving. Contriving large-scale experiments with astronomy is a *****, but in that respect its not that different from geology or any of the other sciences that involve large-scale processes.

So instead you make models, poke with them, use them to make predictions, and (important step religion leaves out) use them to make predictions. You can test THOSE against reality to see if they match. We can't really test if its possible to exceed C yet, but we can -and have- tested time dilation. Etc.

Re: OT - Physics Question on Anti-Matter
 

I consider the idea of dark matter on par with the Aether. I'm not saying it isn't true but on the one hand they couldn't find how light propogated through space so they invented some invisible substance that filled space, the Aether, and on the other hand they can't figure out where most of the universes weight is so likewise they guess it must be some invisible substance filling space, dark matter.

Re: OT - Physics Question on Anti-Matter
 

shinigami said:
"I often find it funny how some scientists deride religion because it fails to meet scientific standards but will stand firm on accepted theories that truly can not be proven right or wrong. Hmmm, sounds like faith to me."

Let's not derail this discussion...

Re: OT - Physics Question on Anti-Matter
 

I havn't read all of this, but all of you are silly, silly people for trying to figure out how to destroy the Earth.

All the information you need is right here: How to destroy the Earth

Silly people. You can find anything on the internet.

Re: OT - Physics Question on Anti-Matter
 

I'll be interested when the first comic appears. I don't really want to watch the creation process, though, so I've ignored that section of the forums.

Re: OT - Physics Question on Anti-Matter
 

They do have a theory about that, though. For example, see this lecture; scroll down to the section labeled "Matter versus Anti-Matter".

Re: OT - Physics Question on Anti-Matter
 

Hmmm, that's an interesting link, thanks Capnq! http://forum.shrapnelgames.com/images/smilies/happy.gif So there is a theory for the asymmetry between antimatter and matter, though unproven.

Re: OT - Physics Question on Anti-Matter
 

Those are pretty rare. And nowhere near infinite.
Lots of holes get formed from stellar deaths, with only 3-tens of stellar masses.

How so? Infinite density does not mean infinite energy.

Now, if the universe is infinite in extent and as homogenous as it looks from here, then indeed there would be infinite energy in it.
However you only have access to the observable universe, which is a finite volume of space, with a finite amount of stuff in it.

Re: OT - Physics Question on Anti-Matter
 

There's an idea. If I'm getting involved perhaps I should actually join the forums.

Re: OT - Physics Question on Anti-Matter
 

I think that was what I was saying, finite universe means finite energy.

For the universe to be infinite wouldn't that mean that somewhere in it energy and matter are being created or added to it? Seeing as physics, as we understand them, can only go back as far as a few milliseconds after the big bang and that time did not exist beforehand then it is possible that the BB is still happening and creating the additional energy for an infinite universe. Very esoteric theory that's hell to wrap my head around! http://forum.shrapnelgames.com/images/smilies/laugh.gif

I think that in man's quest for infinite energy we'll find that it truly doesn't exist (barring extra-dimensional sources) in the strictest sense. However, from our limited point of view (ie, short lifespan compared to the universe,) we'll find plenty of sources that seem to be infinite.
What would you call that, practical infiniteness? http://forum.shrapnelgames.com/images/smilies/wink.gif

Anybody remember the space shuttle tether experiment? Compare that with some of Tesla's work and we might have an outstanding source of renewable energy. As for harnessing it....