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Hubble Spots Long-Sought Intergalactic Gas
hubie writes: "NASA is announcing that Hubble has indirectly detected the long-expected existence of intergalactic hydrogen gas. This is important because it confirms some of the Big Bang models that predict how much hydrogen should have been created. Hubble used a quasar as a light source for spectroscopic measurements. "
The press releases is available in HTML format (and with an active link to additional information on the Hubble website) here. As usual, Spaceref.com had this posted yesterday, Slashdot is tad slow on the uptake where space science and exploration is concerned.
"The first time I got drunk, I got married. The second time I bought a chimpanzee, after that I stayed sober" Arian Seid
The problem with Bussard ramjets is that unless the hydrogen is quite dense, the drag is greater than the thrust. The cool thing to do is to maximize drag and get rid of the thrust altogether. Then you have a magnetic solar sail. Since the article seems to imply webs of flowing hydrogen, maybe we could see a sort of cross between Star Trek and The Pirate Movie.
On second thought, that's not such a good idea. I don't think I could take hearing Shatner say "Shiver me timbers!"
--Shoeboy
(former microserf)
Slashdot screwed up the links for me somehow (or I screwed up). The press release is here.
"The first time I got drunk, I got married. The second time I bought a chimpanzee, after that I stayed sober" Arian Seid
If large ammounts of not only interstellar but intergalactic hydrogen exist out there, it may eliminate the need for "dark matter" in explaining the continued expansion of the universe.
Since we've never been able to prove the existence of WIMPs (weakly interacting massive particles) this does seem to be a more plausable explanation based on our current understanding of physics. However, we need much more information about the ammount of intergalactic hydrogen, it's distribution, and it's density before we can make that judgement.
Anonymous Luddite: "What do you think of the dehumanizing effects of the Internet?"
Andy Grove: "Not Much."
Creationist arguments are always pretty amusing. They're a constant backpeddaling of partially-informed responses to old news as the science constantly pushes back the frontiers of understanding. A chronological summary of such arguments over the centuries is an interesting, and amusing study (particularly, for juxtaposition, if you know some astronomical and other scientific history).
The business of science and scientists is thorough testing and skeptecism, and nearly every discovery/hypothesis/etc brings about published counterarguments probing its weak points and challanging its assumptions.
Not necessarily to put down creationists themselves, but their arguments given are usually just a latching-on to these skeptics criticisms, with only a pseudo-understanding of them or the original issue.
"Scientific" evidence/support articles/books about creation are usually a pretty quick read (though their entertainment value wore off on me some time ago...:).
It's a trick question. It would take you much longer to turn around (assuming for the sake of argument that you can stay within the dictates of the law of conservation of angular momentum by spinning like a flywheel) than the day it'd take for the light to travel -- even if you could do it at the speed of light, you'd have to sweep out an arc of pi*1lightday.
If you're going to go ahead and disregard contraints like that and posit instantaneous transportation, then go ahead. But don't be surprised if you end up with a paradox. Nature has a wonderful tendency to resolve physical paradoxes before we get to see them.
"If one is really a superior person, the fact is likely to leak out without too much assistance" -- John Andrew Holmes
From data on nucleosynthesis (thermonuclear reaction hydrogen-> deuterium, tritium, helium, lithium and a little bit of other stuff) and from recent Boomerang data we know that most of the mass in Universe is not in hydrogen or other baryonic matter. It is a simple argument, actually. If density of gas is high, thermonuclear reactions would go much faster and isotopes that are fast to be consumed (deutherium, Helium3) would not survive to our time. But there exist deuterium and other fast burning isotopes in interstellar gas. Therefore, there were not enough gas to account for all mass in the Universe. See this link for details. There is other evidence as well for dark matter that is not hydrogen or other baryonic gas. Hey, I wrote it right this time --- baryons ;-)
I love how they call it "fully ionized hydrogen". Last time I checked, fully ionized hydrogen was a fancy term for "a proton".
www.eFax.com are spammers
Suppose you have a light which state is determined by a switch that takes zero time to turn on or off, timed in a halving geometric progression. Thus, the lamp turns on for one second, then off for the next 1/2 second, then on for the next 1/4 second, then off for the next 1/8th and so on. At the end of two seconds, is the lamp on or off?
Even if you have an instantaneous switch, that is, a switch that turns on or off instantly once you get the photon (or whatever triggers the cahnge) to the switch, you will probably reach a saturation point at which the switch is actually faster than whatever you are switching with.
An easy way to imagine this is to rephrase the question as: "What if we make the switch toggle as fast as it can?" Somewhere there is going to be a limiting factor and the switch is going to oscillate at some frequency. Then you'll probably have some kind of light (or EMF) source.
However, another interesting take off from the idea of an instantaneous switch is the concept I like to think of as "instant eternity". What if, instead of a switch which toggles at increases rates, you have some space-time phenomena (a black hole maybe) which causes the observer to experience time twice at an exponential rate? This is somewhat the opposite of time dialation where time slows. So the first second I experience is 1/2 second to you, the next second I experience is 1/4 second to you, and so on. I would in effect experience an eternity or an infinite time passage while you would only experience a finite time passage.
The interesting thing about this is that it could happen. All that has to happen is that the entire universe has to accelerate away from me as I remain at rest such. That's pretty improbable, but maybe there is some shortcut to this. The point is, there is a physically possible way to do this, only we need a technology to make it practical. Suppose there is such a way. Now what if different people used this technology, but each one used it at a different time. Would they all wind up in the same place?
I'm not a journalist, but I play one on slashdot
This week, a million fraternity brothers rushed to join NASA. The reason: scientists have discovered beer in space.
Well, not beer exactly. But they did find alcohol: ethyl alcohol, to be precise, the active ingredient in all major alcoholic drinks (antifreeze Jell-O shots, quite obviously, are exempted from this category). Three British scientists, Drs. Tom Millar, Geoffrey MacDonald and Rolf Habing, discovered this interstellar Everclear floating in a gas cloud in the contellation of Aquila (sign of the Eagle, the mascot of Anheuser-Busch! Hmmmmm).
Millar and his compatriots have estimated the size of this gas cloud at approximately 1,000 times the diameter of our own solar system; there's enough alcohol out there, they say, to make 400 trillion trillion pints of beer. These guys are British, mind you; if you were to translate this in terms of American beer (which the British, with some justification, regard as fermented club soda), the amount of potential brewski just about doubles.
In human terms: remember that double-keg party you threw at the end of your Junior year in college (the second Junior year)? Imagine throwing that same party, every eight hours, for the next 30 billion years. You'd STILL have beer left over. And boy, would YOUR bathroom be a mess! Simply put, no one could ever drink 400 trillion trillion pints of beer, except maybe Buffalo Bills fans.
The sheer volume of all this alcohol begs the question of how it managed to get out there in the first place. Despite the simplifying effect it has on the human brain, ethyl alcohol is a reasonably complex molecule: two carbon atoms, five hydrogen atoms, and a hydroxyl radical, all cavorting together in beery camaraderie. It's not a compund that is going to spontaneously arise out of the cold depths of space. It can lead to speculation: What is this cloud?
1.It's God's beer. After all, He worked for six days creating the universe, and on the seventh day, He rested. And after you've had a hard week at the office, don't YOU grab a beer? Since man is made in God's image, it could be that this cloud is the remaining evidence of the first, and best, Miller Time.
2.It's Purgatory ("400 trillion trillion bottles of beer on the wall, 400 trillion trillion bottles of beer! Take one down, pass it around, three hundred ninety-nine septillion, nine hundred ninety-nine sextillion, nine hundred ninety-nine quintillion, nine hundred ninety-nine quadrillion, nine hundred ninety-nine trillion, nine hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-nine, bottles of beer on the wall!")
3.Proof of an undeniably highly advanced but chronically dipsomaniac alien society. This particular theory is shaky, however: it's reasonable to assume that if the aliens were going to construct a nebula of alcohol, they'd also have large clouds of Beer Nuts and pretzels nearby for snacking. Advanced spectral analysis has yet to locate them.
The truth of the matter, however, is far more prosaic. In the middle of this gas cloud is a young and no doubt quite inebriated star. As the star heats up and contracts, sucking the dust and gas of the cloud into a smaller area, complex molecules form as a result of greater interaction between the elements. Ethyl alcohol forms on small motes of dust in the cloud, and then, as the motes angle in closer towards the star and heat up, the alcohol is released from the motes in gaseous form.
And there you have it: an alcohol cloud. Or, as Dave Bowman might say, "My God! It's full of booze!"
Enough with the science lesson, you say. Just tell me how to GET there! Sorry, Chuckles. You can't get there from here. The gas cloud (which, by the way, has the utterly romantic name of "G34.3") is 10,000 light years away: 58 quadrillion miles. Even if you hijacked the shuttle and headed out with thrusters on full, by the time you got there, the guy in Purgatory would be done with his tune. You'd have had time to work up a powerful thirst, but you'd also be, in a word, dead.
No, the Space Beer Cloud will have to wait for the far future, when men can leap through the universe at warp speed. One can only imagine what they will do when they get there:
Captain Kirk: My....GOD! Sulu! What....is....THAT?
Sulu: It's a free floating cloud of alcohol, sir.
Kirk: And we've just run out of Romulan Ale! Could it be a trap, Bones?
Bones: Damn it, Jim! I'm a doctor, not a distiller of fine spirits!
Kirk: We need that booze! But if we fly through that cloud, we'll be too drunk to drive!
Spock: May I remind you, Captain, that I am a Vulcan. We are a race of designated drivers.
Kirk: Well, all righty, then. Spock, drive us through! Bones and I will be out on the hull. With our mouths... open!
To boldly drink what no man has drunk before.
-- What you do today will cost you a day of your life.
Todd Tripp (the main author of this work) was my office mate until a few years ago and his collaborator Blair Savage is just down the hall from me.
The problem is that we can only directly see matter which is giving off light (i.e. stars). How do we study the cold, non-glowing matter in the universe? The solution is that you find a very bright, very far away source to act as a light bulb. In this case it is a quasar. The quasar itself it not important. If there is anything in between us and the quasar, it might block some of the light. However, this is tricky because different matter aborbs different light.
Normal hydrogen (one proton and one electron) is good at absorbing some visible light. When the light hits, it energizes the electron. After some random time, the electron calms down and re-emits the light, but usually not in the same direction from which it came. Thus, you lose a lot of light along the original line of sight.
However, in hot gas, there is thermal energy to knock the electrons entirely free. (picture hydrogen atoms smacking into each other very hard) In this case, the protons and electrons alone are terrible at blocking incoming light: they are nearly transparent. The trick that many spectroscopists use is to look for "tracers." A tracer is a substance that coexists with hydrogen but is much less transparent.
In this case, oxygen is the tracer. Oxygen is usually about 1500 times less common than hydrogen in our solar system and about 6000 times less commmon in typical interstellar gas clouds in our galaxy. One of the difficulties in this work is to figure out what is the ratio of oxygen to hydrogen. For intergalactic gas it is almost certainly lower than the above numbers (because oxygen comes primarily from stars and there are virtually no stars in intergalactic space). If you think you know this number, you can extrapolate how much hydrogen is there by measuring the amount of oxygen. We can guess this ratio by looking at the ratio of oxygen to other elements, like iron, nitrogen, etc -- whatever is available to be seen. But it's *very* difficult work.
Previous studies found tons of cold, normal hydrogen, but this one is special because it looked for the hot gas and found it.
Chris Dolan, astro grad student