Star In A Jar 245
hyehye writes: "Discover magazine's current issue has a fascinating look at the first astrophysics experiments. By 'experiment,' they mean that actual experiments are being conducted in a lab, rather than just taking observations. What's basically occuring is a ton of lasers are being fired at very tiny objects, producing heat, pressure, and shock waves very similar to the ones produced when stars explode, i.e. go supernova. This is exciting stuff -- producing miniature supernovae in a lab! Take a look!"
Re:Mod me down if you want... (Score:1)
Oh great... (Score:1)
Now we're learning how to make a supernova. I have a feeling nukes will look like firecrackers compared to these things.
Has anybody really thought about the weapon possibility of this? It would take alot of nukes to destroy our planet. I'm guessing one of these could take out our planet, and really screw up the moon at the same time.
Even if nobody uses one as a weapon, what if somebody screws up? Oops there goes earth. Remember early on in the nuclear experiments they were afraid the chain reaction would spread through the earth and destroy it the first time they set off a bomb. That's why they had them explode a bit off the ground. We got lucky then and it turned out it didn't work like we were afraid it would. What if we're not so lucky this time?
I really wish discover wasn't getting slashdoted so I could read more.
The Krone Experiment (Score:2)
I'd say more, but I don't want to give away the ending. But trust me, it's on topic.
Not a bad read. Not Great Literature, but a good beach book - if you can find a copy.
I'm tired of the argument (Score:1)
This [mit.edu] will explain that Eisteing jew connection a bit better, I think.
~^~~^~^^~~^
Re:Anti-progress vs. anti-culture (Score:1)
More to the point, The Arabians were very good at astronomy, but so was Egypt thousands of years before as well as China and others contemporary to Aristotle if not before. (e.g. I heard that China could predict the occurance of Haley's commet in the B.C. era. Yet, and this is what ties in the stuff on top its named after Haley.)
So he is right, we owe much to the Arabians. One could also argue that although the greeks were polytheistic they believed that the world was created with intelligence and purpose.
Eh, enough spouting. I'm just bored anyway.
~^~~^~^^~~^
Re:I'm tired of the argument (Score:1)
Arguing Einstein as an athiest is like arguing if Golf is a sport or not. Every one has a different definition of what a sport is. At least you accept this when you say "...by the teachings of the religions he was claimed to hold, makes him an atheist" It holds that he is an atheist only relative to others definitions. However if you define an atheist as someone who believes there is no grand shaper/intelligence then as you even quote Einstein calls himself an agnostic and would prefer that designation. The problem is that he clearly and self admitedly spent his life in his own persuit to find out for himself who God is and what God is. That would warrant Atheists to say that he is not Atheist. But hey, bend the rules a little bit, it looks too good having him in the Atheistic corner. The poster you are responding to correclty points out that you need to have faith that there is intelligence there before you look for it. Its funny how we look now for randomness since the early 20th century. Don't get hung up on the Orthodoxy part, the article explains that well enough. It seemed more relevant than the worn out atheistic churning I see anytime someone mentions Einstein's religious beliefs.
~^~~^~^^~~^
Re:I'm tired of the argument (Score:1)
1) -the refutation: Whose viewpoint is he an atheist?
- the counter point: From your own post...
"You may call me an agnostic, but I do not share the crusading spirit of the professional atheist whose fervor is mostly due to a painful act of liberation from the fetters of religious indoctrination received in youth. I prefer an attitude of humility corresponding to the weakness of our intellectual understanding of nature and of our own being."
That leaves it pretty clear. How in your cool intelectual atheism did you ever miss that?
2) You seem pretty wound up about it still.
~^~~^~^^~~^
Re:I'm tired of the argument (Score:1)
Funny, I never said Einstien was Orthodox. You should have gotten that I didn't think he was from my posts if not just the article that I referenced.
I'm sorry if I mistook you for an atheist. I've just found that atheists are the only ones that try to claim ol' Albert didn't belive in God (which is as far from the truth as saying he was an Orthodox Jew).
~^~~^~^^~~^
Re:I'm tired of the argument (Score:2)
~^~~^~^^~~^
How to make your own star... er, plasmoid (Score:1)
Not quite related, but here's how to create a one-atmosphere plasmoid [jnaudin.free.fr].
Re:Curiosity killed the cat (Score:2)
Hmm...what if there was a way to sustain them? Even the tiny ammount of gravitational force produced by one of these "Baby black holes" could potentially be very useful...
IANAS (I'm not a scientist) - so thake this with a grain of salt - I'm just theorizing here...
If a "Baby black hole" is functionally identical to a "real" black hole, only scaled down, what would happen if you put 3 of them in the same (tiny) area, and set them to rotate around one another? Would it be possible to get their combined gravitational forces to negate at the center of the rotation? What kind of EM variance would such a combination create? How could it be harnessed? Would physics (as we know it) change at the center of the rotation?
Fun stuff =)
Re:how a supernova explodes (Score:2)
One more thing -- this is a type II supernova. A type I (more common, I think) occurs when a white dwarf in a close binary system acretes enough mass to do the catastrophic collapse into neutronium bit.
Re:Black hole lite (Score:1)
Dastardly
Earth travels around the sun - frame of reference (Score:1)
Had Galileo used this line of reasoning, he would have saved himself a whole lot of trouble you know.
Re:Curiosity killed the cat (Score:3)
Give your heads a shake, people. Recognize a joke when you see one. "Curiousity Killed the Cat" is a blatant chain-yank, and a half-dozen of you were dumb enough to fall for it.
How To Recognize The Troll
* there are lots of adjectives: "once lush planet," "reckless desire," and the like.
* there's a personal disclaimer: "don't get me wrong."
* there's often a reference to religion: "[better to] study scripture."
But the biggest indicator is that it's every damn sentence is over-the-top hyperbole.
Don't get me wrong: I appreciate a good luddite-like troll. But, please, don't feed the trolls!
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Re:Great research (Score:4)
359 years to be exact (Score:1)
Re:Real risks with this expirement (Score:1)
No no no, you're thinking of ice-9 [amazon.com].
Re:Real risks with this expirement (Score:1)
No no no, you're thinking of ice-9 [amazon.com].
Re:Real risks with this expirement (Score:2)
Oh, please. Stop watching Star Trek.
If another civilization, one advanced enough to have advanced radio telescopes, were to start THEIR SETI program, they'd have around 50 years of our transmissions. Which means, they'd have to live in a 50 light-year area around us. The cosmos is, to quote Douglas Adams, "really big". A few thousand intelligent civilizations near the galactic core - what, 30k light years away? - would be sufficient to explain SETT's "failures". We can't hear them because their signals haven't reached us yet. The light we see today is often (said in a Sagan-esque voice) billions of years old, some of it left its star before the earth existed. A million intelligent civilizations can't overcome the speed of light and the time at which they become capable of radio astronomy.
While I'm at it, could you provide any pointers to data that says we're all going to die in this manner? Outrageous claims require outrageous evidence, after all...
Re:Anti-progress vs. anti-culture (Score:3)
Bullshit. Einstein was in religious terms an atheist, and insofar as he said things like "I don't belive God plays dice with the universe" etc. he was not talking about a "personal God" in any religious sense. I suspect the same is true of Galileo. As for Sir Isaac, he was well known as a mystic and dabbler in secret societies, so his views were certainly not "orthodox", protestant though they may have been.
Here are some quotes to make my point about Einstein:
It was, of course, a lie what you read about my religious convictions, a lie which is being systematically repeated. I do not believe in a personal God and I have never denied this but have expressed it clearly. If something is in me which can be called religious then it is the unbounded admiration for the structure of the world so far as our science can reveal it.
[Albert Einstein, 1954, from Albert Einstein: The Human Side, edited by Helen Dukas and Banesh Hoffman, Princeton University Press]
What I see in Nature is a magnificent structure that we can comprehend only very imperfectly, and that must fill a thinking person with a feeling of humility. This is a genuinely religious feeling that has nothing to do with mysticism.
[Albert Einstein]
You will hardly find one among the profounder sort of scientific minds without a religious feeling of his own. But it is different from the religiosity of the naive man. For the latter, God is a being from whose care one hopes to benefit and whose punishment one fears; a sublimation of a feeling similar to that of a child for its father, a being to whom one stands, so to speak, in a personal relation, however deeply it may be tinged with awe. But the scientist is possessed by the sense of universal causation... There is nothing divine about morality; it is a purely human affair. His religious feeling takes the form of a rapturous amazement at the harmony of natural law, which reveals an intelligence of such superiority that, compared with it, all the systematic thinking and acting of human beings is an utterly insignificant reflection... It is beyond question closely akin to that which has possessed the religious geniuses of all ages.
[Albert Einstein, Mein Weltbild, Amsterdam: Querido Verlag, 1934]
I received your letter of June 10th. I have never talked to a Jesuit priest in my life and I am astonished by the audacity to tell such lies about me. From the viewpoint of a Jesuit priest I am, of course, and have always been an atheist.
[Albert Einstein to Guy H. Raner Jr, July 2, 1945, responding to a rumor that a Jesuit priest had caused Einstein to convert from atheism. Article by Michael R. Gilmore in Skeptic magazine, Vol. 5, No. 2, 1997]
I have repeatedly said that in my opinion the idea of a personal God is a childlike one. You may call me an agnostic, but I do not share the crusading spirit of the professional atheist whose fervor is mostly due to a painful act of liberation from the fetters of religious indoctrination received in youth. I prefer an attitude of humility corresponding to the weakness of our intellectual understanding of nature and of our own being.
[Albert Einstein to Guy H. Raner Jr., Sept. 28, 1949, from article by Michael R. Gilmore in Skeptic magazine, Vol. 5, No. 2, 1997]
The idea of a personal God is an anthropological concept which I am unable to take seriously.
[Albert Einstein, letter to Hoffman and Dukas, 1946]
I do not believe in the God of theology who rewards good and punishes evil.
[Albert Einstein, as quoted in a memoir by Life editory William Miller in Life, May 2, 1955]
I do not believe in immortality of the individual, and I consider ethics to be an exclusively human concern with no superhuman authority behind it.
[Albert Einstein: The Human Side, edited by Helen Dukas and Banesh Hoffman, and published by Princeton University Press.]
I cannot conceive of a God who rewards and punishes his creatures, or has a will of the kind that we experience in ourselves. Neither can I nor would I want to conceive of an individual that survives his physical death; let feeble souls, from fear or absurd egoism, cherish such thoughts. I am satisfied with the mystery of the eternity of life and with the awareness and a glimpse of the marvelous structure of the existing world, together with the devoted striving to comprehend a portion, be it ever so tiny, of the Reason that manifests itself in nature.
[Albert Einstein, The World as I See It]
http://atheism.about.com/religion/atheism/library/ quotes/bl_q_AEinstein.htm
Whoopsie (Score:2)
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Re:Oh great... (Score:3)
15000 volts of electricity? (Score:2)
Say 10 billion watts of power.. or compare it to how long it could light up a city.. but don't just say '15,000 volts of electricity'. People have that in their TV set.
Re:The only good post on this topic!!! (Score:2)
I wanted to drop you an e-mail to thank you for the kind comment on the post. Your e-mail isn't publicly posted, so I am posting here hoping you will get a chance to read this post.
One crucial aspect of any moderation system is to obtain a reasonably well-informed and intelligent group of moderators. This is the basis of all peer-reviewed systems; while still far from perfect, one would prefer to have, say, a knowledgeable group of medical doctors review the results of clinical tests of new drugs, rather than the population as a whole.
In the early days of
As
Bob
But we can't do experiments with self-gravity. (Score:5)
HOWEVER, note that these experiments are largely concerned with a limited set of physics -- basically radiation hydrodynamics (under the conditions tested, the plasmas are so hot that the radiation pressure is comparable to the gas pressure). Supernovae are essentially hydrodynamical phenomena because the time it takes for a highly supersonic shock to pass through the supernova progenitor is much less than the time it would take for gravity to collapse the progenitor. In astrophysics, many processes (such as star and galaxy formation) are crucially linked not only to radiation hydrodynamics but also to other physics including, critically, self-gravity. It is MUCH more difficult to include self-gravity, because the real self-gravity of the system is totally negligable, and the plasma is charge neutral on a whole (charge densities obey Poisson's equation, just like self-graviting mass densities do).
So this is a very cool start, but it will remain to see if we can ever construct experiments for other kinds of astrophysical systems in the lab.
Bob
Re:What bookstore are you from? (Score:2)
But that just means that like all enduring works of fiction, it has a grain of truth at the center.
Overall though, yes, it's untrue.
The proof for it is that it's supposed to be the guided word of god, and yet even the old testament is internally inconsistent.
Other than that, just for the point of view of a bookmaker, what's the odds? That's just one god out of hundreds, why is it likely that it's the christian god which exists?
If it was one of the others, one of the non-exclusive gods, then the odds would be better because it could be any number of them. But the christian mythos can only be true if their god exists and no other do.
No matter which way you look at it, it's a losing proposition.
Re:Great research (Score:2)
Hmmmm... it's too bad someone hasn't thought up a process to quickly (probably at femtosecond speeds) *alternate* between fission and fusion.
Tritium seems to be the key, since, being radioactive, it can either spontaneously emit a neutron and become deuterium *or* be compressed by the laser pressure into the fusion process with deuterium.
Use the spontanous tritium radioactivity -- fission -- to keep sending energy back into the fusion process, thus generating a nearly constant heat flow from the fusion process and thus making fusion feasible. (I guess you'd need about twice as much tritium as deuterium.) Except for the minor engineering problem of keeping the high energy particles trapped inside the system long enough to be re-routed back into the fusion process, it seems doable. (IANANP, obviously.) Any nuclear physicists out there want to explain why this *can't* work?
Perhaps this is part of the key to how "dirty" palladium jump-starts the so-called 'cold-fusion' process. Again, IANANP.
Re:Jeeeze, the moderation nowadays.... (Score:2)
trollin trollin trollin (Score:3)
Oh yeah - I forgot. You're a troll. nice try. Too bad the mods are smoking crack today.
Re:Curiosity killed the cat (Score:3)
>>spacetime by studying Scripture.
Yup - but lots of nice people burnt at the stake.
Good thing the catholics finally worked out that whole 'sun round the earth thing'. Only took em 300 years.
So how are things in Kansas?
Re:60,000,000,000,000 watts turns me on... (Score:2)
I'd hate to see their electric bill. :)
ender
They're slashdotted already (Score:4)
Re:stars in jars make your life miserable (Score:2)
One of the funniest things I'd seen on the web in a loooong time. Check out the comments, they're very helpful.
Etc... :)
Re:Real risks with this expirement (Score:5)
Washing machines turn socks into dark matter in a similar way, using high energy washic water.
In fact, I studied high energy washic interactions and resonant sockal transduction at the Maytag Repair Guy Institute in Hoboken, New Jersey. Unfortunately, long-term exposure to sudsions has left me impotent.
Good for children (Score:2)
Maybe someone can make a Heathkit out of it.
Re:Curiosity killed the cat (Score:2)
Has anybody given any thought to the safety of these experiments, and the hazardous effects that they might have on our environment?
Yes.
Baby black holes (a theory based on the potential revision of the plank length) would not suck up anything except tiny things near by, and would very quickly decay.
Isn't there any accountability anymore? Why has the pursuit of science been pervaded with a reckless desire to perform useless experiments that could obliterate our civilization?
Yes there is still accountability. There is no reckless desire in the persuit of science. Nobody is doing any experiments that could result in the obliteration of our civilization.
Nobody ever unravelled the basic fabric of spacetime by studying Scripture
Nobody ever unravelled the basic fabric of spacetime by doing anything. They should aim those lasers at your head and do society a favor.
Re:pressures and densities of the sun (Score:2)
I couldn't get the propper figures through the lameness filters so I had to FUD them.
pressures and densities of the sun (Score:3)
Dead-trees Slashdot stories (Score:2)
Real desktop fusion (Score:2)
He died before he could get something sustainable and past the break-even point (if it were possible). The theoretical physics of the device is pretty cool - apparently, his "tube" creates concentric electric field "shells" of increasing strength, which concentrate & pinch the fuel to fusion-density. After the setup, the field apparently gets its strength from the reaction itself.
From what I read, the main reason it that the reaction isn't sustainable is because once the field becomes strong enough to initiate fusion, it also completely prevents any NEW fuel from entering the fusion area.
Pretty darn interesting stuff, and done a long time ago. I'm assuming that the electric & magnetic field "pinching" technologies are probably based on much more sophisticated approaches than this.
Ooh! I got One! (Score:5)
Ironic choice of imagery (Score:4)
That sounds like a pretty accurate description of what posting that article on Slashdot is doing in discover.com's server room...
Re:Oh great... (Score:2)
Re:supernova isn't the right term (Score:2)
Re:pressures and densities of the sun (Score:4)
more text, less graphics (Score:4)
http://www.discover.com/june_01/featstar.html [discover.com]
-ted
Re:Curiosity killed the cat (Score:2)
Ahh yes. I just love anti-science fundie types. Fear, hubris, and a call for 'scripture'. Yes, instead of finding out how the *real* world works, let's just sit around and read bad middle-eastern fiction.
Evil Overlord X
Coming to a third world country near you
Re:Anti-progress vs. anti-culture (Score:2)
Apparently you failed your history of science, because these ideas actually came from the Greeks, who did not believe in a single law-giving deity.
As for your examples, none of them were closed-minded fundamentalists. And your inclusion of Albert Einstein is disingenuous at best. He did not believe in a personal god, and stated that several times.
I would say that this latest attempt to blend science and religion is nothing more than uninformed philosophical sophistry.
Evil Overlord X
Coming to a third world country near you
Re:1.21 gigawatts! (Score:2)
The power concentrated on that pinhead-sized spot, about 60,000,000,000,000 watts
That's 60 terawatts, or 60,000 gigawatts, no? Easily more than enough...
Re:Great research (Score:3)
Ordinary nuclear reactors are fission reactors -- they split heavy nuclei into two lighter nuclei and a bit of energy. The most common fissionable material is Uranium-235, which as you might expect is extremely radioactive, and the "nuclear ash" (the lighter elements which result from fission) are also typically radioactive.
Nuclear fusion is the opposite process -- combining lighter nuclei into heavier ones. The sun produces its energy by fusing four hydrogen nuclei (otherwise known as protons) into a single helium nucleus (otherwise known as alpha particles: two protons and two neutrons). The four constituent protons are just a tad heavier than an alpha particle, and the extra mass is turned into energy.
Nuclear fusion in the lab (which *has* been done before, many times) doesn't follow the exact same process. It typically uses deuterium and tritium, which are hydrogen-2 (a proton and a neutron) and hydrogen-3 (a proton and two neutrons), respectively. Tritium is radioactive.
So while nuclear fusion doesn't have to involve radioactive substances (as evidenced by solar fusion), so far I don't think anybody has gotten away from them. Admittedly, though, fusion will still be infinitely cleaner than fission once somebody manages to generate a useful amount of power from it.
Re:Curiosity killed the cat (Score:2)
> Nobody ever unravelled the basic fabric of
> spacetime by studying Scripture.
And nobody ever made Earth spontaneously explode by performing human sacrifices.
What's your point? I certainly expected to read more logical arguments on Slashdot.
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Re:Earth travels around the sun - frame of referen (Score:2)
Re:Anti-progress vs. anti-culture (Score:2)
I agree that science and theology would be at odds if you attempt to put them together.
The belief in Law of Nature is no more a supersistious belief than the belief in the hardness of rock. A law of nature is not a law like the DMCA, which had to be drafted by human beings. It is a description of how things behave, generalised, abstractized, and summarized. Thus making the inference from law to lawgiver is just misleading yourself with a false analogy.
Re:It's JigaWatt!! (Score:2)
You say giga, and I say jiga, you say Linux and I say Leenux. Giga, jiga, Linux, Leenux oh let's call the whole thing off!
The only "intuitive" interface is the nipple. After that, it's all learned.
Re:Real risks with this expirement (Score:3)
If this was true, why aren't all stars "dark matter"? Our own atoms (above Iron in weight) were forged in a supernova. By your "facts", we should all be dark matter now.
If you are really a physics major, Mr. "Physics Major", I would have expected you to know this.
Fusion in GE pavillion at 1964 World's Fair (Score:2)
Re:Great research (Score:3)
However, a supernovae is not just any fusion reaction. All stars go through fusion their entire lives. It's what keeps them heated. But a supernovae happens when a star starts running out of fuel. I don't know the exact process (I'm sure someone around here does).
So while this supernovae-in-a-can is very cool, it's separate from energy generation as a whole.
Save a life. Eat more cheese
Energy CAN go faster than the speed of light. (Score:2)
Other lab-based supernova experiments (Score:2)
The idea is that you take these radioactive atoms and fling them at other radioactive atoms, to simulate collisions with the sort of energy you'd see in a supernova. This lets them study reaction chains and rates and stuff. Very cool.
-Erf C.
Jeeeze, the moderation nowadays.... (Score:5)
Here is the corrected version :
(a) Most of the Universe (if you believe in General Relativity) is composed of Dark Energy (70%), not Dark Matter (about 30%). Normal stuff like us is less than 1%.
(b) Neils Bohr is Scandinavian, not German.
(c) Dark Matter accretes, and in current popular models, it does not interact with matter at all (else it won't be "dark")
(d) There is no chance of shooting lasers turning us into exotic matter. Though physicists might wish it does.
(e) What the heck is "phasic" laser beams?
(f) The SETI inference is what convinced me that you are writing a parody. Good job.
SEX!s.e.x.Sex.53X!sex.Si-Ee-Eks
Mr. Wizard would have liked this (Score:3)
He mixes a two compontent apoxy in a clear plastic cup using way too much hardener (i.e. 5 times what the directions say). Be sure to do this on a large piece of metal you don't care about and do it outside cause it makes quite a mess and smells.
Basically what happens is that the apoxy undergoes an exothermic reaction, but due to the excessive amount of catalyst present, more heat is created than can be dissapated through the viscous flow of the apoxy (don't forget the apoxy is hardening the whole while). Eventually the apoxy heats enough to melt the cup, crack the hardened apoxy, smoke, etc. This gets the entire class's attention because he mixes the apoxy at the beginning of the class and proceeds to lecture for a while before anything begins to happen. It takes a little while.
Re:Curiosity killed the cat (Score:2)
Oh, and the black hole thing? Read your physics. Black holes radiate matter and antimatter off their event horizons, losing mass. Small black holes don't survive, as they aren't physically strong enough to pull mass up to the event horizon before they burn out. Hawking figured it all out. Still, this stuff is much less for certain. Still, the fusion sht is fact.
Re:I'm tired of the argument (Score:2)
/Brian
Re:I'm tired of the argument (Score:2)
I do sincerely believe (and I've said it before on Slashdot) that atheists are just as misguided as religious fundamentalists of any stripe -- you can't use logic to say there is no God any more certainly than you can do the same to assert that there is. Religion or not, dogma is dogma, and I've always found it rather interesting that being an agnostic and a believing Christian at the same time are not mutually exclusive (think about that for a moment).
/Brian
Re:Black hole lite (Score:2)
The vacuum bit is quite important.
You're so full of... (Score:2)
Nice attempt at a troll, but you should at least try to get your stuff consistent. There is no Neils Bohr Institute in Germany. It is the Niels Bohr institute (site is here [www.nbi.dk]) and it is in Copenhagen, Denmark.
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Re:Oh great... (Score:2)
Forgive me for asking, but if we "take out our planet", who's going to be around to fret about the moon?
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Trademark infringement? (Score:5)
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It's physics (Score:2)
Re:Earth travels around the sun - frame of referen (Score:2)
Actually, I don't think you can appeal to frames of reference here;
If I recall correctly, rotation is absolute. It has something to do with constant acceleration (change in velocity)...
If a person in outer space is in a closed box that is moving with linear motion, they will have no way of knowing whether they are moving or not. If they could see the universe outside, they could say, "The universe is going past me." But if the person in outer space is in a box that is spinning, they will know that the box is spinning, and they will not be able to [correctly] say, "The universe is spinning around me."
Someone who is good at Physics, please append a note to this.
Star? Jar? Bink? (Score:2)
Brain: Association search: "star" & "jar"
Results: Star War's Jar Jar Binks
Ugh! Thanks a lot, George Lucas.
No kidding: Try searching "star jar" in google: http://www.google.com/search?q=star+jar [google.com]
Or even "Star In A Jar"
ALL matches are on Jar Jar Binks. Ugh.
Is this really something that should be tested? (Score:3)
Re:The Word Police Say... (Score:2)
Main Entry: giga-
Pronunciation: 'ji-g&, 'gi-
Function: combining form
Etymology: International Scientific Vocabulary, from Greek gigas giant
: billion
So apparantly both are acceptable...
I Need Keaneau Reeves Motorcycle! (Score:2)
"Chain Reaction".... I mean, with these sorts of experiements going on, you never know when you're going to have to outrace some kind of explosion that can level 5 city blocks.
Also, I would like a few dates with that English woman he was running around with in the film.
(Ah, let's face it. I'd settle for a few dates OR the motorcycle).
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how a supernova explodes (Score:5)
A supernova has sufficient mass to heat its core to roughly a trillion degrees as elements fuse through multiple stages. When the core fuses to iron, fusion ceases to be an energy-producing process, and the chain of fusion to higher elements stops. Within the course of a very short time, the iron core cools. The outward radiation pressure stops since the core is no longer radiating, and the outer layers of the star that had been held up by radiation pressure collapse onto the core of the star.
The energy of the impact smashes into the core of the star, compressing its degenerate iron into neutronium as protons and electrons join into neutrons. This phase shift is accompanied by an incredible wave of neutrinos. A neutrino is a kind of ghost particle that interacts weakly with ordinary matter. It would fly through light-years of solid lead without pausing, but there are so many neutrinos released in the phase shift that they form a powerful explosion and blow the collapsing outer shell back off the neutronium core. The turbulence in the exploding gas cloud is so intense that it can cause fusion to atomic weights even higher than iron's. The explosion, while it lasts, briefly outshines the entire rest of the visible universe.
Eventually the expanding gas cloud becomes a nebula and takes place in later generation star and planet formation processes.
Tim
Re:how a supernova explodes (Score:2)
When fusion stops, the star cools and radiation pressure stops holding up the outer layers, like you say. The star gradually shrinks into a smaller and smaller volume, until it shrinks to the size of the earth and reaches white dwarf density, where it is only held up by electron degeneracy pressure.
At this point there are so many electrons crammed into such a small space that all the quantum states with low energies are taken- there aren't enough available states at low energies for them all to fit. So most of the electrons are in very high energy states, and the energies get higher as the star shrinks. This is actually a manifestation of the Heisenberg Uncertainty Principle. As the physical position of all the electrons becomes more definite (since the star is shrinking), the uncertainties in energy become greater.
This is how most stars end. But if the star is massive enough, electron densities and energies will get so high that some of the electrons will be able to overcome the energy barrier for URCA processes (proton + electron -> neutron + neutrino). This is when the explosion starts. The electrons with the highest energy combine with protons to form neutrons, which immediately sink to the center, and neutrinos, which are radiated away. This causes further contraction, elevating the energy states of all the remaining electrons, some of which now have enough energy to react too, and it's all over in a couple minutes. The star has to shrink to the size of a city before neutron degeneracy pressure begins to support it. (Neutrons are heavier than electrons so they pack better under these conditions.)
99% of the energy is lost to all the neutrinos. Only 1% of the radiated photons are in the visible range. But even in the visible spectrum, a supernova will briefly outshine the rest of the galaxy it's in. Not the entire universe! Supernovas occur in the observable universe with a frequency of about 1 Hz and are routinely observed in other galaxies. The last Milky Way supernova was centuries ago, unless you count SN 1987A, which was in one of the Magellanic Cloud satellite galaxies.
Nobody knows for sure how elements heavier than iron (lead, gold, iodine, uranium, etc.) are ever formed. The standard theories involve supernovas (you need a high neutron flux). Some research group recently said that supernovas cannot account for heavy element abundances seen on earth, and that a better explanation was a collision between two neutron stars or something.
Info, info, info (Score:2)
Rather than tell you everything you may or may not already know, I'll just give you a link to the main LLNL [llnl.gov] NIF [llnl.gov](National Ignition Facility) website. Believe me, working at a DOE lab is pretty cool, especially since you get to see most of the neat gadgets first hand (Like the 10m diameter target chamber, and the tiny target cylinder).
So, for the latest in inertial confinement fusion: www.llnl.gov/nif/ [llnl.gov]
If what you want to learn about isn't there, you're not allowed to know
Boycott
ahh dammit, I blew it
Re:Great research (Score:2)
The former is how stars do it, putting small nuclei together to form larger ones. The latter is how nuclear power reactors do it, by breaking large nuclei into smaller ones.
OK,
- B
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Mod me down if you want... (Score:4)
Maybe I should go into astrophysics. Sure, sysadmining gives you godlike control over users, but astrophysics allow you to play with the power of suns.
Re:Earth travels around the sun - frame of referen (Score:2)
Here's more (better) info (Score:2)
Interesting little teaser, but hardly worth a /. posting, let alone hundreds of comments. Echelon.com [echelon.com] has a MUCH more informative and SPAM-free blurb [echelon.com] about it.
Discover Mag is certainly a class act nowadays -- a credit card popup, a mini-webcam popup, and a phony message box saying "Click here to claim your prize!" Really inspires me to fling my dollars there way, by gosh.
Re:Curiosity killed the cat (Score:2)
Re:Curiosity killed the cat (Score:2)
We're not talking about the "baby black holes" created when a medium sized star, such as our sun, collapses -- baby holes that may have E.H's the size of earth or smaller. We're talking abount something nearly infinitly smaller.
Re:Curiosity killed the cat (Score:3)
Creating a black hole the size of an atom has little to no effect on the planet because its mass is meager compared to everything else around it -- meaning practically no gravitational forces. Find a way to contain it and its subatomic event horizon and you've got the coolest vacation home for your sea monkeys ever. Remember: gravity doesn't change just because you're a singularity; a kilogram with no volume is still a kilogram, still a negligible factor in the universe, and if you dropped it it wouldn't have much affect on the earth or the people around it.
As for creating micro supernovas...they're super small, dude, and only as powerful as the lasers involved. You'll see more possibility for an environmental disaster in your average Hollywood movie than in this experiment. I know, I know...your high school science teacher said that supernovas are bad. But this is a really freaking small one, controlled by people who know what they're doing and in an expensive experiment that had to be reviewed and rereviewed a dozen times over before it could be approved for the extensive grants and equipment could be divvied up. If a slashdotter can point out flaws that these eggheads can't find, well then I just lost my faith in the scientific method.
Re:Real risks with this expirement (Score:3)
Re:They're slashdotted already (Score:2)
"What are we going to do tonight, Bill?"
Re:Black hole lite (Score:2)
Your physics is rusty, or you'd remember that nothing can travel faster than light.
any black hole will continue to collect matter and grow in size regardless of how small it is
The theory of quantum black holes states that small (very small) black holes evaporate, giving off hawking radiation. Go read "A Brief History of Time", by Stephen Hawking for a light intro to the subject.
"What are we going to do tonight, Bill?"
Re:Oh great... (Score:3)
I hope they do not take it too far away (Score:2)
OOOOPS! "Doctor, I fear the rolling blackout hit us, the magnetic field wavered for a microsecond, and... well, to tell the truth, we are missing a black hole. There is a little hole in the ground, the size of a pinhead, and that's all"
"Well, son, don't panic and book me one ticket to the Space Station. I need a change of air, I've got the sinking feeling. You can say there is something gnawing at me, and at the Earth too."
--
Not quite. (Score:4)
stars in jars make your life miserable (Score:5)
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BULLSHIT physics! (Score:4)
Um, are you really majoring in physics? Are you just spouting off the top of your head? I'm not sure you know what you're talking about when it comes to dark matter.
First off, the story [discover.com] which
The benefits of this research, namely determing the mass density of the Universe (from the Berkley dark matter paper: "A parameter known as the "mass density" - that is, how much matter per unit volume is contained in the Universe") is far more important than any possible laser containment field leak. Not that any such leak is likely.
Quit with your babbling and stick to the facts. If you want, you can learn more about laser containment fields here [slayerfanfic.com].
If I were you I wouldn't bother.
60,000,000,000,000 watts turns me on... (Score:4)
A back-up sun so when ours starts to get old and engulfs us, we can just blow it up and make our own.
Add a whole new sun, besides obvious gravity problems we'd deal with can you imagine how great things would grow?
Two-story target chamber lazer gun pointed right at, um, France! Come on, you can't say you didn't think it too...
Re:Oh great... (Score:2)
From what little I could gather from the web page, there really isn't any weapons potential or real danger in this project. They're essentially taking a ton of energy and focusing it in a small area to see what happens. Really no new technology involved, it's just building the facility that's expensive.
The only threat I can think of would be the creation of a black hole. If such a thing were done, we would indeed be collectively hosed. It's been a long time since studying quantum physics for me, I can't even hazard a guess at how much energy would be required to force the creation of a black hole. Regardless, any belief that such a thing could happen stems from a feeling of overimportance. The first thing astrophysics teaches you is how insignificant the human race is in any physical measurement. I doubt there's enough energy accessible on this planet to do something like that.
We interrupt this flame war with some news. (Score:4)
First a bit of background. Commercial nuclear powerplants and naval propulsion plants operate on the principle of nuclear fission, the splitting of very heavy atoms to yield thermal energy, which heats steam, which turns an electric turbine or propeller shaft. What the_crowbar is talking about is nuclear fusion, the slamming together of very light atoms, i.e. heavy hydrogen or helium, in a chamber of superheated (in a star's case, superdense) plasma, thus heating steam and turning a turbine.
There was a major international experiment called the International Thermonuclear Experimental Reactor, or ITER. A russian-invented device called a tokamak, or magnetic bottle, can be used to contain plasma in a doughnut-shaped chamber. These are in use at several research labs and universities, including Harvard University and Lawrence Livermore Labs. The ITER was concieved as a prototype reactor to spearhead the way for commercially run nuclear fusion electricity plants, as proof-of-concept. The reactor was expected to cost over $4 TRILLION dollars. Therefore, the U.S. Congress, not wanting to any more money than necessary to get re-elected, withdrew U.S. support in 1998, and the project is expected to fail without U.S. funding. Go to Scientific American Magazine [sciam.com] for more information on this project.
Re:Entire article available (Score:2)
[Thu Jun 14 16:11:02 2001] [error] [client 12.111.37.145] File does not exist:
1.21 gigawatts! (Score:5)
This be it? (Score:2)
Links to Better Sources of Supernova Info (Score:3)
There are a lot of explanations going around this thread about how core collapse supernovae occur. Some good, some terrible, none quite right. Rather than correct what's been said, I'll instead point y'all to a few of the sources of real info out there.
A good place to start is the NASA Observatorium page on Stellar Evolution and Death [nasa.gov]
A friend in the business maintains a page full of links to SN pages [navy.mil]. Many of these are links to research groups, but there are also links to general education and image catalogs.
BTW, in case you don't believe that I know of what I speak, follow this link [arxiv.org]