quote: Some gamma rays pass near the nuclei of atoms and are transformed into electrons and positrons, or antimatter...
Wait, is that all antimatter is supposed to be?
We already get electrons and positrons bumping into each other. Why would particles with their charges flipped bumping into each other work differently?
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I'm far less bothered by this then I am by all the stories, now worldwide, about birds randomly dying, apparently from massive internal injuries as a result of running into or being hit by things.
It was weird when it happened once in a one square mile area of whichever plains state it was, then it was weirder when it happened in Louisiana. Now it's happened in Scandinavia too. It's like that scene from The Day After Tomorrow or The Core, I can't remember which.
Either way, it's friggin spooky.
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AvidReader: positrons are antimatter. When they hit an electron, there's annihilation. And yes, one of the key features of antimatter is that the particle has the opposite charge, but the same mass. Atoms and molecules composed of antimatter would act almost the same as those of normal matter in interacting with each other. As to why they do it, that's a more fundamental question, which I think is mostly answered with "that's what the theory says happens and experiment confirms"; there isn't a deep reason (except the symmetries and other deep properties of the theory).
quote:I'm far less bothered by this then I am by all the stories, now worldwide, about birds randomly dying, apparently from massive internal injuries as a result of running into or being hit by things.
The media's just making a big deal of it. Mass animal deaths happen all the time, every day. There's nothing especially noteworthy about it.
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Deliberate stupidity to sell newspaper copy. While mention is made that the dead birds were found "down the road from [such&such] High School on Louisiana state highway 1", what they failed to mention is that parallel to that road is FalseRiverRegionalAirport. The high school is located caddy-corner to the northwest on the road which sets the northern limit of the landing strip, and Highway1 forms the southern border.
In other words, HIGHLY probable that the flock got knocked down by wake turbulence. If it can knock down aircraft which follow too closely, it can certainly "tornado" down a bunch of birds.
The ClarionLedger (which I believe was the name of the first nearby major newspaper which reported the "mysterious" incident) may have been seeking to protect its advertising revenue. If you can afford to own a plane or rent a private jet, you're an advertiser or potential advertiser who could become displeased about your airport being "besmirched". And the other newsmedia were either ABSURDLY lazy by failing to Google(etc)Map the named high school, or ABSURDLY ignorant to fail to see the relevance of the airport, or just ignored the map (ie lied by omission) to rile up the public with "apocalyptic mystery" in order to inflate page views.
And no, I don't blame the public (for getting bamboozled) for expecting the news media to do their job.
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This is just a general question. If positrons are the antimatter form of electrons, and presumably negatively charged protons are the antimatter form of protons, then what is the antimatter form of neutrons--which have no charge?
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There's an antineutron that annihilates with neutrons, and also has no charge. Photons have no charge as well, but they don't have a separate antiparticle.
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When the large hadron collider failed to destroy existence I became desensitized to wierd scientific news.
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Whether photons are truly particles is debated, since they also behave like waves. I think most physicists would halt at saying photons are matter. In fact, when matter and antimatter undergo an annihilation reaction, they are converted into photons--of the highest energy type, gamma rays.
I am not denying that neutrons may have corresponding antiparticles. I am just wondering what the difference could be between a neutron and an antineutron, when charge is not involved. Could it be that they are comprised of a different combination of quarks? Or does it involve spin?
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quote:Whether photons are truly particles is debated, since they also behave like waves
Every particle also behaves like a wave, from photons to electrons to protons to whatever. This is just how matter is.
quote:I think most physicists would halt at saying photons are matter.
Just a nomenclature thing, ultimately.
quote: In fact, when matter and antimatter undergo an annihilation reaction, they are converted into photons--of the highest energy type, gamma rays.
This is a bit incomplete. Annihilating larger particle/antiparticle pairs at high energy results in funky particles some of the time.
quote:I am not denying that neutrons may have corresponding antiparticles. I am just wondering what the difference could be between a neutron and an antineutron, when charge is not involved. Could it be that they are comprised of a different combination of quarks?
An antineutron is made of antiquarks. Antiquarks are the same as the corresponding quarks, except with opposite charges (note: charges include electric charge and non-electric charges, such as color).
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Just a minor point, fugu13, about calling photons "matter." In Einstein's famous equation, E=MC˛, matter can be converted into energy.
Now, correct me if I am overly simplistic, but are not protons, electrons, and neutrons, units of matter? Are are not photons measures of energy? Are you saying that energy is matter?
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quote:Originally posted by Ron Lambert: Just a minor point, fugu13, about calling photons "matter." In Einstein's famous equation, E=MC˛, matter can be converted into energy.
Now, correct me if I am overly simplistic, but are not protons, electrons, and neutrons, units of matter? Are are not photons measures of energy? Are you saying that energy is matter?
This is a question of arbitrary definition. All the examples you give are particles. Some have mass, some don't. All have energy.
Your question amounts to: should we use the word "matter" to mean "things with mass" (in which case photons are out) or "things with energy" (in which case they're in). It has been used both ways, so there's no hard and fast rule.
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A photon is not a measure of energy- different photons have different energies. In very simplistic terms, E=MC˛ means that energy and matter exist on a single spectrum- so while one particle has low energy and looks like a particle of matter, and another particle has high energy and looks like a wave, it's all the same stuff. It's transmutable.
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Some people also break things down in a different way, using 'matter' to refer only to fermions, and lumping all bosons (force carrying particles like photons) under the moniker of 'energy without matter.'
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By the way, I'm not sure from the article why this result about storms is supposed to be at all surprising. Antimatter will probably show up whenever there are energetic photons around, and any big enough event will probably lead to some big photons. I'd imagine a few antiparticles show up when you get a paper cut.
Maybe it's supposed to be a big surprise that the storms create enough antimatter that we can actually detect the effect?
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Antimatter has always been depicted in science fiction as being "rare," to the extent that it has the connotation of being a form of unobtainium. Physicists may be aware that it's common, but laypersons and journalists certainly aren't.
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Common in the sense of occurring in many places. Common in the sense of being very much of it, not at all. Plus, the only ways to keep it in existence for any length of time are very expensive (like, billions of dollars a microgram expensive).
quote:Just a minor point, fugu13, about calling photons "matter." In Einstein's famous equation, E=MC˛, matter can be converted into energy.
Now, correct me if I am overly simplistic, but are not protons, electrons, and neutrons, units of matter? Are are not photons measures of energy? Are you saying that energy is matter?
As mentioned, it's all just terminology. They're all particles, and particles can convert into other particles in lots of different ways, at different energies (due to velocities, et cetera). For some purposes it is useful to think of some sets of particles in groups that we call "energy" and "matter", but they're all particles that behave according to the same rules in similar ways (viewed in the small; differences in behavior due to properties of the particles build up to give our highly varied world, but just like the molecules in a tree are behave very similarly to the molecules in a dog, they manifest at the macro level quite differently).
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Glenn, let's hope that antimatter remains unobtainable in practical terms. One pound of antimatter would probably be enough to blow up England. Fusion bombs only convert about 0.3% of matter into energy. Matter-antimatter annihilation converts 100% of the matter and antimatter into energy.
If you want something to really, really worry about, imagine what would happen if someone invented some simple, easy, inexpensive way to convert large amounts of matter into antimatter.
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Looking on the bright side, all of our energy problems would be over.
But the technology you describe is almost certainly impossible, since it violates well-established conservation laws. Somewhat like hydrogen power, antimatter will at best be an efficient form of energy storage. It's very unlikely to see use as an energy source in its own right.
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It might be theoretically possible to extract energy from "quantum foam." That would probably be the best source of energy. But then, it might be equally easy to extract antimatter from quantum foam. Let's just hope that God keeps this technology from us. He alone is the Creator. Fortunately!
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By the way, keep in mind that what we call "laws," even "well-established" laws, are not really laws per se, but are only the way we have observed things to behave so far. And there may be corollaries to those laws, which we might eventually discover as we get into sufficiently extreme extremes.
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quote:Originally posted by Ron Lambert: It might be theoretically possible to extract energy from "quantum foam."
In that high-energy particles are required, perhaps. Assuming this theoretical construct actually exists, of course.
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I remember an episode of Star Trek--the Original Series--where some guy and his anti-matter opposite ended up fighting for eternity in a bubble of neither-universe (neither Matter or Anti-Matter) because if either of them touched the other in either universe, they would immediately cancel out both universes. If just one atom of anti-matter met one atom of matter--it would be all over.
Of course, a few decades later they were using Anti-Matter cores and shooting anti-matter torpedoes, but that is not important to a true Trek expert.
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