Antimatter and Antistars? 156
payndz asks: "I'm currently writing an SF novel, and came up with a weird thought for a piece of background flavour that, if there's any scientific basis for it, might get expanded into a larger element. The most up-to-date theories for the creation of the universe 13.7 billion years ago (give or take...) suggest that at the Big Bang, matter *and* antimatter were created. Over time, the fact that there was slightly more matter than antimatter means that mutual annihilation has left a universe of matter. (I'm not going to open up the whole can of 'dark matter' worms, unless somebody wants to...). I have a 'what if' question, which since Hubert Farnsworth isn't around I thought would get some good responses here: what if, rather than antimatter being annihilated by matter in the universe at large, there are 'clumps' of both matter and antimatter making up the universe? Since our clump is almost entirely matter, billions of LY away could there be galaxies made up of antimatter?More to the point, what physical properties would these galaxies have? Would a star made of antimatter function in the same way as a matter star, and would its emissions be made of antiparticles? Can you have anti-photons, and if you could, what impact would they have on any matter they illuminated? Could life evolve in an antimatter environment?"
silly constraints (Score:1, Interesting)
Re:silly constraints (Score:4, Insightful)
Re:silly constraints (Score:1)
Fortunately I don't see Terry Pratchett as SF either
But there are scifi (Bladerunner, some Iain Banks books, Neuromancer. Matrix) which directly contradicts true "facts" or known science, yet are still called scifi. My point is rather that one shouldn't try to make something fit inside some "genre". Write what fascinates and compells you.
Re:silly constraints (Score:2)
Re:silly constraints (Score:1)
Fortunately I don't see Terry Pratchett as SF either
I recommend Terry Pratchett's Strata, which is science fiction and deals rather scientifically with a flat Earth.
Re:silly constraints (Score:5, Insightful)
Actually, the thing that matters in scifi is consistency. You can make up the rules, but once you have you have to stick to them, otherwise your stories disintegrate into deus ex machina handwaving. That is why Star Trek is bad scifi* - the capabilities of all its technological artifacts change from episode to episode, and they can always "technobabble" their way out of any situation. In Star Trek, technology is indistinguishable from magic. Far, far better is the work of Alastair Reynolds - he does use technologies which don't yet exist, but his characters are forced to work within fixed limitations (i.e. humans colonize the nearby stars relying on relativistic time dilation and suspended animation - there is no FTL, and anyone who tries it fails, no matter how useful it might be for the story).
--
* However it can be good drama, it's not scifi even tho' it's in space.
Re:silly constraints (Score:2)
I don't think Star Trek was ever intended to be great Sci Fi. The original series pushed the then-modern social envelope more than anything. It really wasn't until the 1990's that it decomposed into a politically-correct serial.
Re: (Score:1)
Re:silly constraints (Score:3, Funny)
You're Dubya's speech writer, aren't you???
Don't land on one :-) (Score:5, Informative)
Luckily for him his pilot is a coward, so they don't land
Seriously, the existrance of large amount of anti matter (whole galaxies of it) isn't _that_ far fetched. Consider that the original big-bang universe is made out of hot plasma. A blob of matter pressed against a blob of anti matter will create a terribly violent reaction in the interface zone; this would act as a "wall" repelling both matter and anti-matter away from it, preserving them as seperate regions. Also, any electrical current flowing through the plasma will tend to separate matter and anti-matter. Given the whole universe is expanding madly in the duration it is possible that ant-matter "islands" survived.
AFAIK (IANAP) anti-matter galaxies/stars would be indistinguishible from normal-matter ones. Photons don;t care whether they are created by matter fusion or anti-matter fusion, etc.
Re:Don't land on one :-) (Score:1)
After (Score:2)
Nothing like losing your air supply to get your attention.
Re:Don't land on one :-) (Score:2)
Re:Don't land on one :-) (Score:2)
Here's one you've seen before: A diamond.
Any diamond - a pure one - is a crystalline structure of carbon atoms, and hence any diamond, no matter how large is a single molecule.
Doesn't seem so freaky anymore, does it?
Re:Don't land on one :-) (Score:2)
Don't go there (Score:3, Funny)
Larry Niven thinks so... (Score:4, Interesting)
Also, wander up to your nearest university and look up the astro-physics department. Chances are there'll be a couple of knowledgable types in there who could point you in the right direction.
Physical properties of antimatter galaxies (Score:5, Funny)
One thing is for sure. There would be a person identical to you except they would have a goatee and no sleeves on their uniform.
Re: Physical properties of antimatter galaxies (Score:5, Funny)
> One thing is for sure. There would be a person identical to you except they would have a goatee and no sleeves on their uniform.
That's how everyone looks here. Where the heck are you posting from?
Re: Physical properties of antimatter galaxies (Score:2)
Re:Physical properties of antimatter galaxies (Score:2)
Like, from the NEGAVERSE
Re:Physical properties of antimatter galaxies (Score:2)
Some info as i remember (Score:5, Informative)
Secondly, according to the theories you mentioned, there's basically very little chance that large lumps of antimatter were formed during the big bang, since most of the annihilation would have taken place at a stage when all the matter was condended in a very small place, and therefore the distribution of antimatter would be quite uniform (so you wouldn't have a galaxy of am here and one of normal matter there).
Thirdly, there are no antiphotons. Photons are the antiparticles of themselves!
Hope it helps!
Re:Some info as i remember (Score:2)
Oh ghod, what have I become
M
Re:Some info as i remember (Score:5, Insightful)
Not only that, but it would seem that any clump of A-M of less than galactic size would have a hard time existing in a harsh, matter-filled region. A-M objects in an M galaxy would have to contend with the fact that interstellar space isn't empty, but has a faint hydrogen "wind" blowing thorugh it. For an inert body like an asteroid or rogue planet, this would mean gradual but inevitable erosion. For a star system, things might get interesting, since the star's own solar wind would sweep the interstellar medium out to its heliopause, which would presumably show up as a gamma-ray "halo" surrounding the system.
I wouldn't even want to speculate on the conditions necessary for the formation of such a system, since I'm simply talking out of my rear-end here (I Am Not An Astrophysicist).
Re:Some info as i remember (Score:2, Interesting)
Could be fun designing a starship to cross this boudry.
Re:Some info as i remember (Score:2)
I mean, you're sure as heck not going to land anywhere.
Re:Some info as i remember (Score:1, Funny)
Congratulations, you've crossed the matter/antimatter boundary with a starship. Now what do you do?
I'm going to Anti-Disney World!!
Re:Some info as i remember (Score:1)
You know how scientists have lots of trouble producing even tiny amounts of anti-matter. Where better to get copious amounts of the stuff? Could be used for such things as alternative energy source, or removing planets to make way for hyperspace bypasses.
Re:Some info as i remember (Score:1)
Re:Some info as i remember (Score:1)
I have no idea why they might want to, and very little conception of where they'd get the energy to do it, but these silly thoughts occur to me sometimes.
Re:Some info as i remember (Score:2)
There is ONE way to tell! (Score:1)
Re:Some info as i remember (Score:2)
ah, but annihilation releases energy, and the energy would
also have been extremely condensed, leading to the
formation of new matter, in equal proportions of charge.
this is during the period of rapid inflation, at the end of
which, i speculate, equilibrium between matter creation
and destruction existed. by that time, clumping had
already occurred, corresponding to galatic superclusters.
hey, it's plausible.
Shameless Plagiarism (Score:5, Insightful)
In this fundamental physics book, Feynman describes all of the states of physical matter and the laws of symmetry that go along with them. When discussing the right and left-handed rules, he asks the obvious question of whether they are arbitrarily chosen; whether right-handed means anything other than in opposition to left-handed. He asks this to spur our interest in discovering the basis for the symmetry of physical laws.
To illustrate, he imagines a conversation between a human and a distant alien, the purpose of which is for the human to communicate to the alien, after describing the human body and anything else of import, which hand is the left and which is the right, in order to know on which side to place the human heart. After dismissing a few possible physical phenomena by which this information could be conveyed, Feynman describes an instance (during a weak decay of a cobalt nucleus) in which the emitted electron always has a left angular momentum. This, he says, can be used to indicate to our alien friend which is left and which is right. Hold onto that for a second...
In the next section, he describes antimatter. He first theorizes that, other than annhilating each other on contact, objects made entirely of antimatter would not be noticeably different from those made of matter: It is one of the principles of the symmetry of physics, the equations seem to show, that if a clock, say, were made of matter on one hand, and then we made the same clock of antimatter, it would run in this (exact same) way. He then adds the example of the left-handed beta decay above by constructing a theoretical antimatter clock made of cobalt nuclei. He speculates that since left and right-handed matter clocks could be constructed to behave differently, thus violating the law of mirror symmetry, that antimatter clocks would also behave dissimilarly depending upon their handedness.
He goes through all of that to simply tell us that a left-handed matter clock is equivalent in every way to a right-handed antimatter clock. Unfortunately for sci-fi novelists, changing matter to antimatter merely alters the handedness of the particles, rather than actually violating symmetry or having any other noticeable effect. Of course, his lectures are no longer cutting-edge and the book only gives a laymans description of the underlying physics, but it doesn't look too good.
Feynman ends up concluding:
Re:Shameless Plagiarism (Score:1)
Re:Shameless Plagiarism (Score:1, Informative)
Re:Shameless Plagiarism (Score:3, Funny)
He is having difficulty getting his updates past the Editor.
actually... (Score:1, Informative)
CP (charge & parity) is violated.
Re:Shameless Plagiarism (Score:2)
Hmmm. I was going to s
Heyyyy (Score:1, Funny)
photons (Score:2, Informative)
Matter in Reverse (Score:1)
WTF? Do your own research! And protect yourself! (Score:5, Insightful)
This one takes the biscuit though. You're a writer (or want to be) - at the very least you should be able to do your own research for your work!
Posting an Ask Slashdot is a very bad idea, for at least two reasons:
1. There's no way you can easily distinguish between accurate and inaccurate statements.
Just because something quotes a scientist or it's been modded up it doesn't make it any more reliable then anything else.
2. You leave yourself open to litigation.
George Lucas makes a point of not looking at Star Wars fan fiction because he doesn't want to leave himself vulnerable to the guy who'll scream "Hey, you stole that scene/character/whatever in Episode III from my story!". You might not have billions to lose but by canvassing for information and ideas so publicly you're still leaving yourself wide open to that sort of allegation.
You might think that Slashdot is an open forum, populated by open source advocates who would all be opposed to intellectual property litigation and would do nothing more than help out and wish you luck but it'll only take one asshole to prove you wrong.
Someone's bound to mod this down as flamebait or as a troll but if you're going to be an author then you can't afford to ignore this stuff.
Re:WTF? Do your own research! And protect yourself (Score:3, Interesting)
Seems like you're the only one around here crufty enough to think it isn't. Most people have been giving lucid, well-thought out responses. Then there's the "I don't like this question, so I'll bitch" troll. Come on, whine a little more about ask slashdot! You can do it!
Wow are there a lot of whiney people on slashdot.
Re:WTF? Do your own research! And protect yourself (Score:2)
You say this knowing what the responses are. 20/20 hindsight and all. But even a few good responses may be worth the relatively little effort of posting the question to /. Free feedback, and all the questioner has to do is sort out the good from the useless (like our conversation).
I still can't unde
Re:WTF? Do your own research! And protect yourself (Score:2, Informative)
As for Point Two ... unless 1) somebody posts detailed plot, story, or character information here, 2) you are dumb enough to include it in your book, and 3) your book is lucky enough to make it into print after you include unsolicited fan fiction in it, you should be fine. The SF writing community trades research all the time; you can see it in action over on the SFF.net [sff.net] or
Re:WTF? Do your own research! And protect yourself (Score:1)
As much as I hate fan fiction, somehow I feel like that would make for a much better Episode III.
Respectfully disagree (Score:3, Insightful)
I wish more people would do so. I don't look forward to a society where everyone is afraid to ask questions in public for fear of being sued.
Re:Respectfully disagree (Score:3, Interesting)
How many people on Slashdot do you think would help someone else code a closed-source (possibly non-free) application? How is it any different because it's a book? That's partially where I'm coming from but I'm trying to be pragmatic, hence I responded with caveats rathe
differences (Score:1)
[this is an effect of the weak interaction]
note also: a poton is it's own antiparticle, this the stars would shine just like ours do.
gravity wise you wouldn't be able to tell the difference either. paricles and anti-particles have the same gravitational mass...
I'm sorry but I don't t
Yum (Score:5, Funny)
just do it, worry more about the plot.. (Score:4, Insightful)
most great scifi books/ short novels could have been just as easily setted in non typical scifi setting(heinleins starship troopers could be set without much fuss into ancient greek), bad scifi is where the 'scifi' is used just to cover up something else, like the lack of plot or bad writing. though, one can use the story to tell of a world to come and it can work pretty well, and predict possibilities of technology, but without good storytelling these are just academical papers on possible future.
and most things that apply to scifi apply to fantasy too, mostly because underneath they are pretty much the same for most authors, it doesn't really matter if the lockpick is a complicated electronic hacker gadget or a spell, or if you use a robot instead of a demigod as an ageless being watching over humanity for thousands of years.
Re:just do it, worry more about the plot.. (Score:1)
An antihyperjump moves you a very short distance?
Or it moves you a very great distance in a time longer than it would take to travel there in real space?
Re:just do it, worry more about the plot.. (Score:2)
Some differences (Score:5, Funny)
Mony Mony (Score:2)
So you're saying Billy Idol, to say nothing of Tommy James and the Shondells, were just a bunch of greedy aliens from this other galaxy?
Oh, right. Roswell 1947, shortly before the popularity of rock 'n' roll... and the rise of RIAA to world dominance. It a
Re:Some differences (Score:2)
"Be careful with that [matter inversion gizmo]... we could end up undoing unthings untogether!
-- Doctor Who, John Pertwee
Strong constraints exist from gamma rays (Score:5, Interesting)
IIRC, the smallest scale at which antimatter can dominate is galactic superclusters, but even that may now be ruled out.
Re:Strong constraints exist from gamma rays (Score:2)
IIRC, the smallest scale at which antimatter can dominate is galactic superclusters, but even that may now be ruled out.
I just wanted to respond to back this up; at least as of the mid-90's, you'd have to go out beyond the Local Supercluster. I haven't followed this since then, unfortunately, so I don't know what the implication of the current (GRO?) data is.
Could work though, if... (Score:2)
If instead of one big bang, in this universe, there were several, 100 billion light years apart. The universes would each cease to exist before they could detect each other...
couple of things (Score:4, Interesting)
See, empty space isn't really empty. There's Hydrogen out there. There would be an amazing light show at the border. The constant meeting of matter and anti-matter (space dust, if you will, emitted by both galaxies) would most likely be very visible. Matter/anti-matter reactions are very energetic, far more so than fusion, even.
The only way to have anti-matter galaxies in your universe is if they were more than 13.7 billion light years distant, so the light from the interface hasn't reached us yet. Or maybe there could be a single anti-matter galaxy somewhere out there, discovered by the weird light reaching us from that corner of the universe. I doubt our telescopes have looked everywhere, yet.
Aside from all that, science is just a hook. As long as you're internally consistent, it doesn't matter if your science is far-fetched. Plot, characters, story. Interesting things happening to interesting people will be what sell books. I probably didn't need to tell you that. I still read a lot of old sci-fi that has bad science in it. 'Lensmen', Heinlein juveniles like 'Tunnel in the Sky', 'Citizen of the Galaxy', and 'Starman Jones', Campbell's 'Arcot, Morey, and Wade' stories. Love that stuff.
Re:couple of things (Score:2)
Just an idea...
Nobody here reads Greg Bear? (Score:4, Interesting)
Not that this represents anything based in reality or the laws of physics. Just "prior art" from a respected hard sci-fi writer.
Re:Nobody here reads Greg Bear? (Score:2)
I am quite curious as to how this would alter their perception. Would everything look backwards to them?
Mad Max 4 (Score:2)
So, (Score:2)
Re:So, (Score:1)
My thoughts on the physics. (Score:1)
So... what is antimatter? It's matter whose particles have an opposite charge from the particles we know as matter. A matter proton has a positive charge. An antimatter proton (negaton?) has a negative charge. A matter electron has a negative charge. An antimatter positron has a positive charge.
What would antimatter be like?
The first thing I can think of is that antimatter electricity (positricity?) will flow in the oppos
Re:My thoughts on the physics. (Score:3, Informative)
Here's something to think about that follows: light emitted by antimatter, because the electric and magnetic fields are generated in reverse, would be inverted in frequency/wavelength.
I have no idea what you mean by "inverted in frequency/wavelength." However, the truth is that light would be perceptibly unaffected. As correctly noted by several people here, the photon is its own antiparticle. Or, if you wish to think in terms of E-M waves, changing the sign of the E- and B-fields in an electromagne
Re:My thoughts on the physics. (Score:2)
Remember, I qualified my post that I was brainstorming. Clearly my storm fizzled out.
Of course... it would be fun sci-fi to conjecture that the light would be reversed.........
Re:My thoughts on the physics. (Score:2)
Also, electromagnetism would be reversed. With matter, magnetic fields generated by an electric current follow the left-hand rule. Magnetic fields generated by a positric current would follow the r
From their point of view (Score:1)
According to... (Score:1)
Answer... (Score:1)
Astrophysicists had seriously toyed with the question of wether other galaxies were anti-matter. Indeed, based off of EM radiation (light), there would be no way to tell, since matter and anti-matter both emit light.
Also, if the matter between them never interacted, there would be no way to tell, as matter and anti-matter are indistinguishable when complet
Anti-Photons (Score:1)
Antistars (Score:1)
Check out Nobel Laureate Hannes Alfvén (Score:1)
To quote http://www.agu.org/sci_soc/alfven.htm
"Some of Hannes Alfvén's ideas are still controversia
Anti-matter is cool, but... (Score:1)
Re:Anti-matter is cool, but... (Score:2)
There are anti-neutrons - the parameter that changes is spin, IIRC.
As for visiting an anti-matter galaxy, you would be mostly fine (probably just a lot more radiation from interstellar particles eroding your ship's hull. Just don't try to land on a planet.
Re:Anti-matter is cool, but... (Score:2)
No - neutrons have a half unit of spin, and the spin of a neutron can be "up" or "down", just as with other half-spin particles such as electrons and protons. The same is true of anti-neutrons, so a neutron and an anti-neutron can have the same spin (both "up" or both "down") or can have opposite spins (one "up", one "down").
It's other charge-like quantum numbers, such as baryon number [wolfram.com] and isospin [wolfram.com] (unrelated to spin), that change in the n
Re:Anti-matter is cool, but... (Score:1)
Re:Anti-matter is cool, but... (Score:2)
His name is Neutrino. His mass is real, but he is not.
Re:Anti-matter is cool, but... (Score:2)
...just as there's a difference between the mass of a hydrogen atom and the masses of the electron and nucleus - equal to the energy it requires to ionize the atom, I think. Conservation of energy and all that.... The same applies to the mass of, say, a
Re:Anti-matter is cool, but... (Score:1)
and of course there is a anti-neutron - what do you think you would get when a anti-proton and positron fuse ? Hadrons are made up of quarks and these have corresponding anti-quarks - from which you get not just anti-proton but also neutron and anti-neutron.
DUMBASS! Where do you think Dark Jedi come from? (Score:1)
Dumbass!
Sarcasm impaired people please note that this was intended to be a bad joke.
Re:DUMBASS! Where do you think Dark Jedi come from (Score:2)
I'm sorry... don't you mean "anti-midichlorians?"
Odd Cosmology... (Score:1)
Re:Odd Cosmology... (Score:1)
Diff between matter and anti-matter universes (Score:2)
Negative Matter (Score:2)
anti-blackholes? (Score:2)
Blackholes and anti-blackholes (Score:2)
Re:Blackholes and anti-blackholes (Score:2)
If a matter singularity and an antimatter singularity collided, we don't know what would happen. For all we know, mutant space hamsters fly out of their nether orifices. It all happens inside the event horizon; we can't see it, can't experience i
Re:Blackholes and anti-blackholes (Score:3, Insightful)
I was about to argue this point but I just read it again slowly and see now that it is technically correct. You can't tell the difference from the outside. However just because some form of matter passes that point which we call the event horizon doesn't mean that anything magical happens to it. I read just recently that someone, Hawking I think, proved that if you fell i
Re:Blackholes and anti-blackholes (Score:2)
Einstein's General Theory of Relativity. The Special Theory only relates mass with spacetime distortion; the General Theory has the mass-energy equivalence.
If you know the name of the governing equation that relates gravitational force to electromagnetic energy density please tell me because I would be fascinated to read about it.
E = mc**2. Or, E / c**2 = m.
Or, g = (E1/c**2)*(E2/c**2) / d**2.
Googling for "energy distorts spacetime" returns a couple of refere
Re:one observation (Score:1)
Re:one observation (Score:3, Informative)
Re:one observation (Score:4, Interesting)
I'm pretty sure that a photon from a matter-antimatter reaction is the same as a regular photon, and that gamma radiation from said reaction is just regular gamma radiation also, not "anti-gamma". Therefore, I don't think anti-hydrogen fusion is going to be that different from regular hydrogen fusion. I don't think you would be able to tell the difference between a matter and an antimatter star just by looking at it, you'd have to get close enough (or observe something made of matter that got close enough) to get caught in its solar wind (anti-hydrogen is definitely different from regular hydrogen, see).
Re:one observation (Score:4, Informative)