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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. "
NASA could have saved a lot of time and trouble looking for intergalactic gasses if they had checked the septic system near the local A&W...
The Second Amendment Sisters
Finding God in a Dog
-Hey! That page loaded up almost instantly.. No flashy graphics or nothing.. Where is all that tax money going?
air and light and time and space
man did that stink.
----------------
Programming, is like sex.
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
This is certainly a long-standing and very interesting question to have addressed (and a kool way to celebrate a ten-year anniversary).
FYI, more information/photos/etc can be found at the space telescope website here
From the article:
"Previous observations show that billions of years ago this
missing matter formed vast complexes of hydrogen clouds -- but
since then has vanished. Even Hubble's keen eye didn't see the
hydrogen directly because it is too hot and rarified."
If much of the gas was in plasma form, it should be interesting to see if Chandra can fill in a few more details.
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...:).
Seldom-sought gas found in bathroom an hour after my dad ate a spicy meal. Scientists are now designing the first methane powered fan and are close to solving the mystery of the missing meatloaf. Standard olfactory tests do suggest the meatloaf was consumed by father, but until further tests are performed it is still speculation.
You now turn in a complete circle in one spot.
Bowie, please think about how fast you would be trying to move the end of the pole. What is the half-circumference of a circle with a radius of one light-day? The answer to your puzzle lies in the fact that you just can't do it (not the way you've described).
--
Ian Peters
Just think, all we need to do now is come up with how to make a bussard ramjet and we have all the fuel we need to accelerate all the time to go anywhere.
Probally not exactly the fastest way to get ther ("howd you get here? We left after you in a ship that was thought up of about 14 years after you left. Doh!") But it could be the first step to intergalatic conquest.
-- dieman - Scott Dier
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
You forget, some people belive that science and they systems that we peel away are actually a intriciate system setup by God to keep people like us happy. :)
Not like I subscribe to that theory, but billing off religion by saying science exists is not always a valid line of reason.
-- dieman - Scott Dier
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 ;-)
Well, it's not really a question an astonomer/physicist would likely ask, but I'll bite anyway; it's been a long day....
:}
:)
I'm not suprised you got three different answers, as it's not very definitive what you're asking. I can't tell from your post if you believe you yourself have the "answer" to the puzzle, (and you didn't say if you considered any of the answers "decent") but you could answer lots of things about it.... These gedanken experiments (esp. special relativity-related ones) tend to be very sensitive to the point you're trying to make. That is, you put bunch of physical laws on hold to illustrate another one or group of laws/theories. (Getting a person of superhuman speed aside, the pole-and-the-barn experiment requires you to assume some mechanism for closing the barn doors instantly, etc.) So, at the risk of having a long discussion of the barn doors, I'll take a couple angles on your question....
Of course, the pole doesn't matter for the physicist's take on a relativistic gedanken experiment (we just solve for the endpoints and any arbitrary point in between that you want to discuss), and the distance is on the order of 10^10 rather than 10^9 miles if you must refuse cgs.
The impossibility of the steel pole itself aside, you could make mass-energy, angular momentum arguments about the inertia of the pole and the requirements for accelerating it. And energy requirements partially aside, if you wanted to spin it at a human-normal rate, say a turn in a few seconds, relativistic effects/problems appear as you go out along the pole. So if you are referring to what a physicist means when you say what would the pole _look_ like," I could put the lorentz transformations into polar and spew, but I don't think anyone here want to listen to that. Many students/people are interested in, or think they are learning, how a relativistic object would actually _look_, whilst the example neglects relativistic doppler effects, apparent rotation, certain optics, the observers environment and attributes, etc.
As to how it would actually _look_, I'll offer that if you are turning slowly enough to keep the speed of the far end of the pole realistic, since you're looking down one end of it, to you, it _looks_ like a point (or a circle, or whatever the end/crossection of your pole is like). When you spin it around (and it would take you a long time, the time-to-travel of the light won't matter), it will still look like a point.
And the discussion of an outside observer is heavily dependent on assumptions like those above. And I've gone on long enough....
Cheers,
Kurtis
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
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).
Many creationists (myself included) do not view scientific discoveries as a threat to their faith.
If you think about it, there is little difference between the Big Big and any other creation story: a concentrated point of pure energy was the source of everything we see today.
The only difference betweeen the Big Bang and creationIST stories is that in the creationist's story, the "bang" was a form of conscienceness and expression. Proving or disproving this theory is impossible. I mean, if I argue that every sub-atomic particle is a piece of a vast conscieness, explaining to me the scientific reasons for the particle's behavior doesn't disprove my theory. Just like explaining the latest discovery in biochemistry to a thinking person doesn't disprove their theory that they are a conscience being, but it does explains how.
The X-rays from a black hole are from some other mechanism; perhaps atoms banging into each other (which is how x-rays are created on earth).
...phil
...phil
"For a list of the ways which technology has failed to improve our quality of life, press 3."
Mabye it's the fine Jamaican lager talking but that was so funny I just mailed it off to a few non-Slashdotters. Good work, and keep it up! Sadly, it would probably see more use than some of the insane Mini-HOWTOS in my Suse 6.4 disc..
.sig: Now legally binding!
Unfortunately it is impossible for a massless particle to reach the speed of light, therefore, as you turn with the pole in your hands, the end of the pole (1 light day away) cannot have a tangential velocity reaching c (the speed of light). Lets say for the sake of argument you can apply a large but finite force to the end of the pole to make it rotate, causing the speed of the end of the pole to move at just less then c. Since you are rotating the pole through a half-circle, the distance the end of the pole must travel is pi light days, thus it will take you just greater then pi days to rotate (pi days if you could move the pole at the speed of light, but you can't). Thus when you finally stop, the end of the pole will appear to you to be approximately one pi-th (around 1/3) of the distance between where the end started (because thats where it was when the light that is currently reaching your eyes left the end of the pole), and where it will appear to be (from your perspective) one day from now. Thus the pole in your hand appear to curve from pointing straigh ahead of you towards a point about 57 (180/pi) degrees from straight ahead. if you observe the pole exactly when you stop after rotating 180 degrees.
:-)
Where is my free gift
Spyky
I believe the worlds were created in 6 days probably a few thousand years ago. I believe it was in 6 days simply because that's what's recorded in the Bible and that's good enough for me. Anything beyond that is really only speculation. I've heard good creationist arguements and I've heard bad ones. The same goes for evolutionists' arguements. The point is, none of us were there to observe the beginning of the universe, and it cannot be repeated(by us) so it CANNOT be scientifically studied. Neither creationism not evolutionism is science! (As far as evolution, microevolution is fact, macroevolution is not, but evolution of the universe is what I'm discussing here) We can study the universe and guess about it's origins but nothing more. As we learn more about it, yes arguements will change. Some will be better; others will be worse. None can be proven.
How am I supposed to hallucinate with all these swirling colors distracting me?
(I'm not a physicist, but I play one on Slashdot. All of the following may be complete B.S.)
:-/ So the two studies actually agree with each other, and my entire post is moot, right?
I always thought that the amount of mass in the universe was directly related to the curvature of the universe. Too little mass means the universe is open and will expand forever; too much mass means the universe will eventually collapse; just the right amount, and the universe will expand at a constantly decreasing rate, and end up effectively stable.
Physicists have always kind of hoped for the third option, because it makes the math easy. That's why they've been looking for the "extra mass", i.e. dark matter. Now it looks like they've found the extra mass, so we can prove that the universe is flat.
But didn't they just report last week that the universe is open, not flat? Doesn't that contradict this new result?
...
Ahem. And the answer is, no, the report last week also said that the universe is flat. I misremembered.
Well, I'll post anyway, just in case anyone finds it interesting. Besides, I'd like to know if my understanding of this whole question is correct.
MSK
I'd just like to say that this backs up my argument that WIMPS (weakly interacting massive particles) do not exist and that they're a hack to explain something thats unknown. This newly detected gas, as well as newly discovered evidence of very very small and less luminous white dwarf stars removes part of the need for WIMPs to explain things.
all you have to do is accept Jesus Christ as the son of God who died for YOUR sins on the cross.
God does not lie.
Josh
For a start, this gas that they have detected is nothing to do with the requirement for dark matter of some kind at all - it merely means that we can detect all of the regular, baryonic matter that we believe to be present based on our calculations. We still need dark matter to account for the stability of galaxies and so on.
Anyway, dark matter doesn't have to be WIMPs in particular. There are other options - massive neutrinoes, MACHOs and so on. Don't get tied up into thinking there's only one alternative.
Another point I'd like to make (started by a small error in the inital /. posting) is that intergalactic neutral hydrogen has been studied for a long time by the exact same techniques used by Tripp, Jenkins, & Savage: looking at very distant, bright objects like quasars and finding neutral hydrogen spectral lines along the line of sight to the object.
What's new here is that they have detected highly-ionized oxygen without a substantial neutral couterpart. There must be a substantial amount of ionized hydrogen that is associated as a result.
Unlike star-forming regions (like the Orion nebula) where ionized hydrogen is more easily detected, the ionized hydrogen associated with this state of oxygen (it's missing 5 electrons!) is extremely difficult to detect directly. The high temperatures and low densities in these regions keep the protons and electrons from easily rejoining and producing the tell-tale cascade of light from an ionized gas that illuminates star-forming regions. Any neutral hydrogen which does manage to form is quickly rammed by high speed particles and re-ionized, escaping our detection by other techniques.
As a sidenote, these kinds of highly-ionized regions are found close by in our own galaxy. In the most obvious cases the gas has been heated to great temperatures by supernovae explosions. The sun is actually sitting in one, affectionately known as the Local Bubble.
These new regions found in intergalactic space may be fossil remants of early, vigorous star-formation in distant galaxies that has been ejected into intergalactic space. Or, they maybe something entirely new!
mh
Simple: you can not get to infinite. It's not possible. If you used all the energy in the universe, including converting all the rest of the mass of the universe (excluding yourself and the pole) to energy, you still have a finite amount of energy. Infinite is not a quantity you can reach. Sorry.
...phil
...phil
"For a list of the ways which technology has failed to improve our quality of life, press 3."
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.
If there wasn't an appreciable amount of intergalactic hydrogen out there, my thesis would have been very dull indeed, since it hinged on imaging the distribution of high-temperature (around 10^9K) electrons trapped in the gravity well found in clusters of galaxies. There the group I was working with used radio interferometry techniques to produce maps of the Sunyaev-Zel'dovich effect like this one . This matter can also be 'seen' by it's effect on gravitational lensing, where the additional matter affects the strength of the lensing. So the presence of this ionized hydrogen is well known - those electrons had to come from somewhere! Using highly ionized oxygen as a tracer for fully ionized hydrogen is the interesting step here, and I hope they have some really solid connection between the two because this entire publication rests on the assumption that oxygen is accurately tracing the hydrogen.
There is a bias in astronomy that unless you prove it in the optical wavelengths you haven't proved it at all, and this looks like one of those announcements.
Cheers,
Toby Haynes
Anything I post is strictly my own thoughts and doesn't necessarily have anything to do with the opinions of IBM.
. As usual, Spaceref.com had this posted yesterday, Slashdot is tad slow on the uptake where space science and exploration is concerned.
I don't know what time Spaceref.com posted it, but I know that I posted it here on the already started Hubble Thread yesterday morning at 7:47am.
SlashDot is a community effort, you have to credit the posts to already started threads in addition to new threads announced by Rob & Hemos, et al.
Meanwhile, we now have two new Astronomy threads started this morning, but none on the REAL Astronomical (and Astrological!) story of the day.
Work for Change & GET PAID!
The Noachian flood has too many problems to be an acceptable answer. This is the wrong venue to discuss them all (try talk.origins), but I'll name one - a flood of the scale you would need to handle the amount of water required would show a distinct amount of hydrologic sorting (heavy items like rocks moved less than light items like sand). That hydrologic sorting is evident nowhere. If you invoke another miracle to explain it's lack, then you're saying that God lied to cover up the evidence.
...phil
...phil
"For a list of the ways which technology has failed to improve our quality of life, press 3."
The article sez that the gas is invisible because it has been fully ionized, i.e., it no longer has electrons. Well, wouldn't that just be protons? Why do they call it hydrogen if it's just a bunch of protons?
Admit nothing, deny everything and make counter-accusations.
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
You should read about the "Sokal affair" - you'd find it entertaining.
"I will take the Ring," he said, "though I do not know the way."
Chris Dolan
If you're really interested in this stuff, check out the paper "Where are the baryons?" by Cen and Ostriker -- sorry I can't give you a better reference, but hunt on astro-ph or the Harvard abstract service and you'll find it.