daveb writes "There was some discussion back in September regarding the first pictures from the Chandra satillite obervatory. I thought you might be interested in this article about identifying the source of much "background" x-ray radiation. "
Getting transcendental!
by
Anonymous Coward
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· Score: 2
First, I would like to thank Hemos for not making any witty comment about the subject. Just kidding...
Second, I'd like everyone to extend their imagination. The article talks about 70 million röntgen radiation (x-ray for the US) sources. That's like a lot. I mean, if you start thinking how big the universe is, it's just mindboggling. There are, as we all know, to quote Carl Sagan, "billions and billions" of stars.
And to think that what we are seeing right now is something which in actuality happened many thousands if not millions of years ago. That is, that EM radiation has travelled for a long time in space before we finally managed to observe it.
So the universe is BIG. Now bear with me for a second. Of the stupendous vastness of space and the multitude of stars, we know for certain that life exists on only one planet, the Earth. Therefore we think Earth is special. Well, it is. After all, it is our home. But Earth is just one out of many billions of objects in the universe. It's utterly and completely insignificant on a cosmic scale.
And if you zoom in to this planet, you'll find a lifeform, a human being. One human is insignificant to this whole planet. Hell, one human is insignificant to the country s/he lives in.
Now comes the bottom line: how insignificant am I, a human, in a cosmic scale?... It's like one small microbe vs. the galaxy. The level of insignificantness (heh) is so enormous, that there is no significance at all.
This thought was a big "wow" to me. I'm insignificant! I'm a nano-scale microbe on a universal scale, and that feels wonderful!
Maybe I don't understand something about/. moderation, but the above poster is absolutely correct, the people talking about the result taking a chunk out of big bang theory are making a catagoreical error; certainly doesn't deserve a score of 0. Why the hell do some people just HAVE to comment on something regardless of the fact that they know they don't know what they are talking about?
The article wasn't moderated -- all anonymous articles start with the score 0, as opposed to normal users. Moderators later can moderate anonymous articles up, but this one was just posted, so it remained with its initial score.
-- Contrary to the popular belief, there indeed is no God.
Of course, everyone knows this is hogwash. Black holes are black, period. That's why they're called black holes and not multicolour rainbow holes!
This post is part of a larger conspiracy originated by Hollywood more than 20 years ago. You may remember a rather cheesy movie called "The Black Hole" that came out in 1979. Well, it seems clear this whole theory was created simply for sensationalization purposes. After all, who wants to watch a movie about a black hole in space that no one can see. Pretty boring stuff!
Of course, since then more and more movies and television shows took advantage of neat hole-in-space special effects, so it was obviously in their best interest to support this campaign of disinformation.
Fight the conspiracy!
(uh oh, I think I'm starting to sound like "The Conspiracy Guy" on Space!)
I think the issue here is that a post based on misinformation has been moderated upward twice as "Informative" while a post providing correct information languishes at zero. The facts here shouldn't be controversial: even if the Big Bang Theory is a Big Bust, or even if the cosmic background radiation is a measurement error (doubtful, but for the sake of argument let's say it is), such radiation is in the microwave region, not X-ray. So this new discovery has nothing to do with the background radiation claims of the Big Bang Theory.
I don't want to be hard on the original poster-- many is the time that I've had this kind of an "Aha!," then further information shows me to be embarrassingly mistaken. And I'm sure the two moderators made exactly the same mistake the poster did. This happens all the time on Slashdot where something seems insightful/interesting/informative at first glance and gets moderated up (moderators are busy people, after all), with a correcting post coming some time later when there is so much else competing for moderators' attention that the correction lays untouched at 0 or 1.
Even though this offends my sense of justice a bit--misinformation getting marked as "informative" isn't one of moderation's finest hours--moderation works well enough that cases like this only call for its imporvement, not its abolition.
As for whether the original article being "news:" Hell, yes! The cosmos proves more wondrously strange each time we expand the "eyes" and "ears" we use to examine it. There is a good chance that there will be far more questions than answers generated in astrophysics during our lifetimes, given the new technologies we'll be able to point "out there," but that makes it all the more interesting and inspiring.
I am not an Astronomer/Physicist, but this whole idea of dark matter seems suspect to me. If the expansion rate of the universe and the observation of galaxies indicates more mass than we can observe, maybe there is something missing from our understanding of gravity or other forces. Chalking it up to dark matter, which conveniently can't be observed, and is a form of matter that has never been detected in a laboratory, is a bit like saying that lightning is caused by invisible thunder gods. Of course you can't see them, they're invisible.
-- Mea navis aericumbens anguillis abundat
First Haiku (humor, not troll)
by
Kaufmann
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· Score: 2
We stare at the sky Shouldn't one be taking care of one's own wallet?
-- To the editors: your English is as bad as your Perl. Please go back to grade school.
The people who do these calculations are undoubtedly taking note. In their next predictions the detail should include this. If they don't offer enough detail, their peers will not accept the descriptions.
This is light above the hole
by
SEWilco
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· Score: 2
The X-Rays come from stuff falling in before it enters the black hole. What is really being seen is the scream on the way down, not something leaking out from inside the hole.
While I dislike scientology for spouting the same "shut-off-your-brain-and-think" mantra as every other semi-popular fringe religon, I am a bit offended by the fact that a religous statement that was actually on-topic was moderated down to "-1 flamebait".
I realize that the scientologists have tried very hard to burn their bridges with the rest of the world (e.g. suing anyone that publishes negative info about them), but we should rise above their level and treat this message objectively. It's not flame-bait, it's a statement of opinion. I can see it neever going up any, as there wasn't much in the way of useful info, but it's not a first-post, and it was on-topic, so just leave it alone.
Would someone with some moderator points push the post back up to a 0, please (underrated would be fine).
The most interesting thing is that these objects (theoretically "vieled galaxies") are nearly 14 billion light years away. This means (please correct me if I'm wrong) that either a) the universe is older than we thought (9-12 billon?) or b) there is matter in the universe that pre-dates the big bang.
Personally I'd be prepared to believe the latter. There seems to be a basic assumption that the entire universe must have been contained in the big bang, just becasue space is expanding outward as a result. How does this follow, exactly? Could the "force" of the big bang not be simply expanding a small section of the universe outward? In fact, the influence of surrounding matter would certainly be a good explanation for why the known universe is "lumpy".
I do agree that the matter in "our neck of the woods" would almost certainly all have come from the initial singularity, but why does that say anything about what is at the edge of the big bang propagation?
Then of course, I start wondering: does this mean that somewhere there's another big-bang like event that is speeding toward us at the speed of light? Will I feel it?;-)
I lost a reply to this as Netscape was being wonky (will someone please finish any one of the really nice browser projects for Linux).
Ok, so you made the point that:
1) My karma went up 2 points for this: no it didn't I start at a 2.
2) My weak grasp of physics made me leap to the silly conclusion that space/time could "expand into" something outside of it: nope agian. I am simply putting forth a question, but let's phrase it like this instead. If a singularity at the heart of a largish galaxy were to "explode" (actually I think I remember hearing a theory that this could happen if some massive gravitational force "smeared" the black hole out enough that part of it passed its own event horizon: was that Hawking?) what would we see? I think we would see something very much like a miniature version of our universe's big bang. We would see an area of space-time "expand" outward in the form of a catalysmic explosion and from inside that explosion there would be a beginning of time and a boundary to space that matched the orginal singularity's explosion.
Someone else said that their pet theory for why space is lumpy was the UP. I find this to be a circular answer, as the UP is an artifact of the complexity of our universe. Thus, the question remains: why is our universe complex? Why is everything not ordered in perfect symetry? Was it the hand of some capricious god or is there a force outside of our singularity-borne frame of reference. If there is a force outside of this frame of reference, does it interact with ours in the same way that our region of space would interact with the results of the above explosion? Could we, perhaps detect some trace of that outside?
As to my having the mathematical background to understand graduate-level physics/cosmology texts: no, I don't and I don't really think that should be relavent. In reading some of all and all of some of the sources that you cite for "amatures", I have come across this assumption time after time, and yet no one has ever stooped to explaining why. If the pros are to educate the masses (as I, for example, seek to educate others in the use of computers) simple assumptions must be clarified and explained.
I would, for example, never suggest that in order to question the assumptions of programming languages, a layman should read and understand Knuth's Art of Programming. It often takes a non-computer scientist (like Larry Wall, creator of Perl and a linguist by training) to question assumptions and come up with "the wrong answer". Often that wrong answer is, in fact, wrong. However if you cannot answer without re-stating the assumption (e.g. programming languages should not be context sensitive), you have a problem.
Thank you for the clarification on the current age theories. Last I heard there was a debate that set the lower limit at 9-point-something billion, but it certainly was a while ago, and I appreciate the update.
Erm, I don't know about you, but I find Heisenberg's Uncertainty Principle a much better explanation for why the known universe is lumpy. If it had been totally smooth while in the singularity, we'd have known the positions and velocities of everything! As it is, there were irregularities in the singularity which are also expressed as lumpiness now.
This is circular. The uncertainty priciple is the result of a complex universe. Why is it complex? Why not an ordered smear of energy that could never result in... well, us; stars; galaxies; etc. What force acted upon the early universe to cause such a dramatic non-uniformity?
Re:14 Billion Light Years
by
MikeBabcock
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· Score: 2
What is even more interesting is that if these are 14 billion light years away, then the x-rays emitted are 14 billion years old. That means that either this universe was that size 14 billion years ago (making the universe a _lot_ older that 14 billion years), there are conditions under which we receive this data faster than the speed of light, we are measuring the wrong data (pretty hard, but theoretical physics might tell us something related in a few years), etc.
What fascinated me even more was that they thought the heavy X-ray emissions might be coming from black holes... someone want to explain how 70 million (or even 2) black holes formed 14 billion years ago, 14 billion light years away from us?
My thought is that we might be near one of the "rims" of the universe and have been moving away from these point-sources ever since the beginning of the universe which may be expanding in certain regions faster than others. In this case, the X-rays have simply been following us and finally caught up...
Re:14 Billion Light Years
by
Mister+Attack
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· Score: 2
It is like we get to suspend the light speed limit for a few time factors of 10 just to make observations fit better.
not really. Objects are still moving away from each other at sublight speeds. It's just that the space _between_ them is expanding really, really fast during the inflation period, so the net result is that they get too far apart to be causally connected. Yes, it makes observations fit better, but we stay within the rules at all times.
I would encourage you to e-mail me if you want more information.
Jeez... I can't believe your karma got bumped up by two points for this...
You're more prepared to believe that there is matter in the universe that pre-dates the big bang than that we've got the age of the Universe slightly wrong? So we've got matter existing "before" the creation of space, time, and even the higgs scalar background necessary for "mass" to exist? Not only that but it surviving the singularity at t=0 ?
Anyway, moot point, last time I checked mosts people seemed to think the Universe was 12-15 billion years old +/- 10% ish, and the 14 billion figure in the article has probably got a pretty hefty error range on it itself. So it's perfectly possible that these were created after t=0.
Your grasp of elementary cosmology it fundametally flawed as you are attempting to apply traditional Newtonian/classical physics to the creation and expansion of the Universe. In your second paragraph you twice refer to space expanding outwards, this dosn't really make any more sense than the idea of events "before" the big bang, just as there was no time "before" the big bang for events to occur in, there is no "space" outside the universe for objects to exist in or for space to expand into. Modern physics, whether classical, quantum or relativistic, cannot be applied to to events outside the universe.
Your third paragraph almost touches on a valid physical point. We can observe that two regions of space which are not causally connected (ie a light signal cannot have travelled from one object to the other within the age of the universe) abide by the same laws of physics without there being any real reason why they should (major oversimplification, but that's a key point) and this is a topic of debate and research within the physics community.
If you've got very good (graduate level or better) physics and maths, plus good astronomy (at least one college course with "cosmology" or "extra-galactic" in the title) then try Principles of Physical Cosmology by Peebles, if not then wade through the last 10 years back catalouge of New Scientist, Scientific American, and Astronomy, and buy a copy of A Brief History of Time.
No, Hawking radiation explains why we aren't constantly being bombarded with micro-blackholes left over from the big bang. These micro-holes would have been very light - I think the event horizons would have been far smaller than the "interaction cross-section" of protons and neutrons, and rarely mass more than a few grams - and even that might be overstating the mass by many orders of magnitude.
In contrast, any black hole we observe from earth will have a stellar mass and will *not* evaporate. At least, not until long after the last star has reached thermal equalibrium with the rest of the universe.
-- For every complex problem there is an answer that is clear, simple, and wrong. -- H L Mencken
I'm not an astronomer; anyone know what the ramifications this has on the Big Bang theory? My guess is that it doesn't disprove it. But it sure takes a big chunk out of it...
I doubt it has much influence on the big bang theory, but it is worth mentioning that there are a few reputable scientists which have doubts about the big bang.
The conspiracy theorists love to point out how the Vatican commishioned a priest who knew some physics to reinvolve the church in the discussions of the origin of the universe, then this guy descided that the idea that pushing something like the big bang on the scientific community would be the best way to do that. This guy ran arround to various scientists tring to push the idea and got noware untill people noticed the universe was expanding, then people started beliving him. (Note: You should not take this story as an argument against the big bang, but as a warning about how religious people follow there biases)
It is a good test of your understanding of the scientific method to think about exactly why the expansion of the universe provides evidence for the big bang. Example: if we lived in a cluster of galixies which had an eliptical orbit arround soemthing really big then it might appear that al the galaxies were moving appart. It's fun to think about what exactly is wrong with this alternative explination.
Jeff
-- The Christian religion has been and still is the principal enemy of moral progress in the world. -- Bertrand Russell
Chandra was recently featured at NASA's "Astronomy Picture Of The Day" web site ( http://antwrp.gsfc.nasa.gov/apod/ap000114.html }.
For the amateur astronomer or just the astro-curious, this NASA site ( http://antwrp.gsfc.nasa.gov/apod/astropix.html ) presents a different photo every day with explanation and reference links. This needs to be in your list of "sites to start the day with".
Dark matter as "optical molasses"?
by
Myself
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· Score: 2
Or their measurements were based on the idea that light always moves at approximately the same speed, given that most of space is a vacuum.
I seem to remember an article on Slashdot about light slowing down as it passes through a Bose-Einstein condensate. Has anyone considered that the "dark matter" out there might also be transparent but dense, such that it slows down light in a similar manner?
We're talking about delaying light for about 2-5 billion years in order to make the math come out right. The researcher in that article thinks she can get it down to 120 feet per hour. If the light from our distant galaxies had to go through a couple lightyears of this goop before it reached us, that would account for the differences.
Yeah, it's easier just to say that there was stuff here before the big bang. But where, then, did it come from? And did it have a hand in creating the big bang?
Re:Dark matter as "optical molasses"?
by
Todd+Stewart
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· Score: 2
From yesterday's NPR news:
New Ways to See Black Holes http://www.npr.org/news/
We are living in fantastic times. I remember when I use to watch astronomy programs on PBS in LA in the late 70s(anyone else remember Krupp(sp?) from Griffith Observatory?) that all the important stuff was discoverd at the turn of the century with Einstein.
Man was I wrong.
Confirmation of extrasolar planets. We may be able to determine the atmosphere on some in the not too distant future!
Confirmation of black holes. I remember when they were just crazy scifi objects - fun to talk about, but you didn't really believe something so outside of human experience could exist. The book mentioned below is in many ways a history of people trying to come to terms with a concept so alien to our common sense notions of space and time.
Possible ocean on Europa...and life? In progress.
"Black Holes and Time Warps" by Kip Thorne is a great lay introduction to subject and its history. He is one of the authors of one of the classic texts on gravitation. I skipped the book for a long time because of its title - it sounded like other 'wacko' science books. It turned out to be a joy to read.
Posters have asked "Could the 'dark matter' be made up of these distant galaxies, just detected in X-rays by Chandra? Or could it be made up by MACHOs?" There is a very strong reason to believe that the answer to both these possibilites is "no." Here's why:
One of the strongest pieces of evidence in support of the Big Bang theory is the very good match between the abundance of light elements (hydrogen, deuterium, helium, lithium and beryllium) predicted by the BB, and actually observed by us. The BB theory places some limits on the amount of the "critical mass density" of the universe which can be made up of ordinary baryonic matter. That limit is much less than 1.0, closer to about 0.1. What that means is that _if_ the BB is correct, and _if_ the universe contains the critical mass density, _then_ most of that mass density must be non-baryonic matter.
Now, baryonic matter is good old protons, electrons, and neutrons: we and most of what we can see in the current universe (stars, planets, galaxies, etc.) are made of baryons. The galaxies just discovered by Chandra are undoubtedly made of stars (baryonic). Black holes are made of baryons, under most scenarios in the literature. MACHOs are just low-mass stars or high-mass planets, and they, too, are baryons.
So what the heck _isn't_ baryonic? Well, neutrinos aren't. There was a hope about twenty years ago that most of the mass of the universe might consist of neutrinos -- but recent experiments indicate weakly that the neutrino mass is too small to do the job. A universe of neutrinos would also lead to large-scale structure of galaxies and galaxy clusters very different than that which we observe. So, neutrinos are probably out. That leaves exotic stuff: wierd particles called "axions" or "WIMPs", or "strange matter"; all of these are theoretical, not experimentally confirmed (as far as I know)
In short, _if_ the density of the universe is even close to the critical density, it means that a) some exotic sort of matter dominates or b) the current theory of BB nucleosynthesis is wrong.
-- Michael Richmond "This is the heart that broke my finger." mwrsps@rit.edu http://stupendous.rit.edu
More Chandra Accomplishments
by
koolade
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· Score: 2
Here's a link to another story about another one of Chandra's accomplishments: finding "the coolest black hole ever detected".
X-rays are produced here by accelerating electrons to very high speed and smashing them against a target. Kinda like a miniature acelerator, I think. That's why televisions create x-rays, because the tube is essentially a low-energy particle accelerator, smashing the electrons against the phosphor of the screen and making them glow.
I'm not one hundred percent sure of how the black holes create them, but I think it has something to do with the kinetic energy of the electrons as they fall over the event horizon... someone feel free to correct me.
Scientists have also discovered a "black hole" 1600 light years from earth. This begs the question of what we really know about the universe. Ironically, I tend to think of 1,600 light years as kind of close to us. I am a layman, but I want to throw out a question to the astrophysics type people here... how fast can a black hole grow? Could the hole 1,600 light years away absorb us in say a billion years from now? Just wondering. I won't be around... but if we know it will, it would give long term planning a ridiculous new meaning.
You're right, 1600 light years is close. Astronomically speaking anyway. In terms of anything else...well the strength of an object's gravitational field varies as the inverse square law. Say you're at point A some distance r from the black hole. Now move to point B, distance 2r from the black hole. Now the gravity you feel is only 1/4th of the field at point A. So being 1600 light years away from a black hole pretty much precludes us ever feeling its effects. You could take the formula for the strength of a gravitational field and plug in numbers to see how big the black hole would be...ok hold on...oh this is great, for a black hole 1600 light year's away to have the same effect on use as the moon's gravitational field the black hole would have to have a mass of 3.5 * 10^39 kg. That's basically a 4 followed by 39 zeroes. The put that in context Our sun has a mass of 1.99*10^30 kg. So the black hole would have to weigh 10 million times as much as our sun for us to feel it as much as we feel the moon. hope that puts this in perspective:).
This is so great! It makes me very happy to know that there are people out there who can and did build this complex/amazing satellite. It is efforts like this (10+ years start to finish) that dramatically expand the limits of human knowledge about our world. Thanks US, thanks NASA, thanks, TRW and it's subcontractors! But most of all, thank you engineers!
-- I pitty the foo who reads my sig
Re:X-rays can beat black hole gravity?
by
SEWilco
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· Score: 3
Here's a drawing. As stuff gets sucked in, it swirls around. Very fast. As it speeds up and the particles bump into each other they heat up. They heat up as much as they can heat up. As they fall screaming in, some of the "heat" leaks away as photons in the X-Ray spectrum.
I think this will be a big change for many of the calculations for mass in the universe. People have spent a lot of time looking for "dark matter". Can these non visible galaxies be counted?
Also I wonder how much closer this will put us toward making the universe a closed system?
Also the age of the universe is calculated finding the oldest light we can. This makes it sound like there may be much older things out there not giving off any light.
--
Be insightful.
If you can't be insightful, be informative.
If you can't be informative, use my name
Actually, it is. All electromagnetic radiation is easily pinpointable to a certain star, or cluster, or galaxy. But there was always a universal background radiation. Before now, everyone thought that the cosmic background radiation was heat (and EM radiation) left over from the big bang, still in the process of dissipation.
I'm not an astronomer; anyone know what the ramifications this has on the Big Bang theory? My guess is that it doesn't disprove it. But it sure takes a big chunk out of it...
It is thought that quasars are early versions of galaxies where the formation gasses are being pulled into a central black hole ( billions of solar masses ) and shining tons of light. Then after awhile an equilibrium sets in and eventually spirals and other older type galaxys form. I often wondered what could have kicked this off.
This seems to be the answer. One of the things Hawkings theorized was that there could be primordal black holes created during the big bang. It is possible that trillions of these things existed and as such started the initial imbalance required to create structure as we see now in the visible part of our universe.
These objects are said in the article to be the oldest things ever observed. I would say just younger than the 2.7 degree kelvin background radiation marking the time when the universe was opaque.
These smaller primordal blackholes would collide and create the gravitational engines that galaxies would form around. Initially, they would suck in gas and burn like a quasar then eventually settle down and become boring old spirals like ours.
As things were far more compact at this time most of the primordals would be gone, but a few may have "slingshoted" from near misses and be cruising near light speed through the universe right now.
People are mostly looking for dark matter within galaxies. The biggest problem right now is that given the rate that galaxies are spinning, they should fly apart if the only mass in them is the stars we see (assuming that we're doing a good job of calculating the mass of stars).
IMVHO, the "dark matter" is mostly a bunch of sub-stars like Jupiter (these are known as the Massive Astrophysical Compact Halo Objects, or MACHO, a term which covers all big dark matter, like black holes and brown dwarfs), which would have to be about a hundred times more common than stars to explain it. I believe in small MACHOs because small stars are much more common than large stars; a lot of people like to believe that black holes are common, but if matter tended to group together that much you'd expect larger stars to be more common than smaller stars.
That's Hawkings radiation
by
coyote-san
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· Score: 4
That's Hawkings radiation, something which provides a mechanism for small black holes to "evaporate" over time. It's an exponential conversion of mass to energy, so you do *not* want to be near one at the final moments!
Hawkings radiation is interesting for a different reason. Some people had observed that black holes physics have a lot of similaries with thermodynamics. The mass of the black hole corresponds to entrophy, iirc. However there was some minor point where the behaviors differed, and Hawkings decided to explore the "impossible" case where black holes really did match thermodynamics. He eventually identified the quantum tunneling mechanism and all hell broke loose in the physics community. Hawkings radiation is now a classic example of a situation where important discovery was made by exploring something that first appears to be a mere coincidence.
As others have pointed out, the X-rays we're talking about here are due matter falling into the accretion disk.
-- For every complex problem there is an answer that is clear, simple, and wrong. -- H L Mencken
Re:Well that's very cool!
by
CaptainCarrot
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· Score: 4
I've always been an armchair theoretical physicist, and I think this is fascinating. But what does this do to the 3 degrees above zero theory that said the background radiation was a residue of the big bang? Sure doesn't sound like it now...
So what does this do to the "big bang" theory?
It's got nothing to do with that at all. The background radiation that is thought to be an echo of the Big Bang is microwave radiation equivalent to a black body at 3K. X-rays are much more energetic, and in the spectrum fall between ultraviolet light and gamma rays.
People seem to be misunderstanding the significance of this discovery. For almost 40 years, we've known about an "x-ray glow" with no apparent source that was scattered all over the sky. With Chandra, astronomers have been able to resolve discrete sources for the x-rays, so we now know exactly where they're coming from. I don't think the x-ray glow was ever as uniform as the background microwave radiation, which is identical in all directions with no apparent source.
-- And the brethren went away edified.
Re:X-rays can beat black hole gravity?
by
Constellation
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· Score: 4
Actually the X-rays don't escape the black hole. the current theory is (since we have never actually "seen" a black hole) is that as particles fall in to the balck hole, they enter a sort of, spiraling, decaying orbit (called the accretion disk). It is the friction between all of these particles in the accretion disk, that generates the x-rays. If the x-ray is released in the right direction it can escape being sucked into the black hole, since the accretion disk exists outside of the black holes event horizon.
Slashdot Mirror
First, I would like to thank Hemos for not making any witty comment about the subject. Just kidding...
... It's like one small microbe vs. the galaxy. The level of insignificantness (heh) is so enormous, that there is no significance at all.
Second, I'd like everyone to extend their imagination. The article talks about 70 million röntgen radiation (x-ray for the US) sources. That's like a lot. I mean, if you start thinking how big the universe is, it's just mindboggling. There are, as we all know, to quote Carl Sagan, "billions and billions" of stars.
And to think that what we are seeing right now is something which in actuality happened many thousands if not millions of years ago. That is, that EM radiation has travelled for a long time in space before we finally managed to observe it.
So the universe is BIG. Now bear with me for a second. Of the stupendous vastness of space and the multitude of stars, we know for certain that life exists on only one planet, the Earth. Therefore we think Earth is special. Well, it is. After all, it is our home. But Earth is just one out of many billions of objects in the universe. It's utterly and completely insignificant on a cosmic scale.
And if you zoom in to this planet, you'll find a lifeform, a human being. One human is insignificant to this whole planet. Hell, one human is insignificant to the country s/he lives in.
Now comes the bottom line: how insignificant am I, a human, in a cosmic scale?
This thought was a big "wow" to me. I'm insignificant! I'm a nano-scale microbe on a universal scale, and that feels wonderful!
Maybe I don't understand something about /. moderation, but the above poster is absolutely correct, the people talking about the result taking a chunk out of big bang theory are making a catagoreical error; certainly doesn't deserve a score of 0. Why the hell do some people just HAVE to comment on something regardless of the fact that they know they don't know what they are talking about?
The article wasn't moderated -- all anonymous articles start with the score 0, as opposed to normal users. Moderators later can moderate anonymous articles up, but this one was just posted, so it remained with its initial score.
Contrary to the popular belief, there indeed is no God.
Of course, everyone knows this is hogwash. Black holes are black, period. That's why they're called black holes and not multicolour rainbow holes!
This post is part of a larger conspiracy originated by Hollywood more than 20 years ago. You may remember a rather cheesy movie called "The Black Hole" that came out in 1979. Well, it seems clear this whole theory was created simply for sensationalization purposes. After all, who wants to watch a movie about a black hole in space that no one can see. Pretty boring stuff!
Of course, since then more and more movies and television shows took advantage of neat hole-in-space special effects, so it was obviously in their best interest to support this campaign of disinformation.
Fight the conspiracy!
(uh oh, I think I'm starting to sound like "The Conspiracy Guy" on Space!)
I think the issue here is that a post based on misinformation has been moderated upward twice as "Informative" while a post providing correct information languishes at zero. The facts here shouldn't be controversial: even if the Big Bang Theory is a Big Bust, or even if the cosmic background radiation is a measurement error (doubtful, but for the sake of argument let's say it is), such radiation is in the microwave region, not X-ray. So this new discovery has nothing to do with the background radiation claims of the Big Bang Theory.
I don't want to be hard on the original poster-- many is the time that I've had this kind of an "Aha!," then further information shows me to be embarrassingly mistaken. And I'm sure the two moderators made exactly the same mistake the poster did. This happens all the time on Slashdot where something seems insightful/interesting/informative at first glance and gets moderated up (moderators are busy people, after all), with a correcting post coming some time later when there is so much else competing for moderators' attention that the correction lays untouched at 0 or 1.
Even though this offends my sense of justice a bit--misinformation getting marked as "informative" isn't one of moderation's finest hours--moderation works well enough that cases like this only call for its imporvement, not its abolition.
As for whether the original article being "news:" Hell, yes! The cosmos proves more wondrously strange each time we expand the "eyes" and "ears" we use to examine it. There is a good chance that there will be far more questions than answers generated in astrophysics during our lifetimes, given the new technologies we'll be able to point "out there," but that makes it all the more interesting and inspiring.
I am not an Astronomer/Physicist, but this whole idea of dark matter seems suspect to me. If the expansion rate of the universe and the observation of galaxies indicates more mass than we can observe, maybe there is something missing from our understanding of gravity or other forces. Chalking it up to dark matter, which conveniently can't be observed, and is a form of matter that has never been detected in a laboratory, is a bit like saying that lightning is caused by invisible thunder gods. Of course you can't see them, they're invisible.
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To the editors: your English is as bad as your Perl. Please go back to grade school.
The people who do these calculations are undoubtedly taking note. In their next predictions the detail should include this. If they don't offer enough detail, their peers will not accept the descriptions.
The X-Rays come from stuff falling in before it enters the black hole. What is really being seen is the scream on the way down, not something leaking out from inside the hole.
Aside from which, your comment is total crap.
himi
My very own DeCSS mirror.
While I dislike scientology for spouting the same "shut-off-your-brain-and-think" mantra as every other semi-popular fringe religon, I am a bit offended by the fact that a religous statement that was actually on-topic was moderated down to "-1 flamebait".
I realize that the scientologists have tried very hard to burn their bridges with the rest of the world (e.g. suing anyone that publishes negative info about them), but we should rise above their level and treat this message objectively. It's not flame-bait, it's a statement of opinion. I can see it neever going up any, as there wasn't much in the way of useful info, but it's not a first-post, and it was on-topic, so just leave it alone.
Would someone with some moderator points push the post back up to a 0, please (underrated would be fine).
The most interesting thing is that these objects (theoretically "vieled galaxies") are nearly 14 billion light years away. This means (please correct me if I'm wrong) that either a) the universe is older than we thought (9-12 billon?) or b) there is matter in the universe that pre-dates the big bang.
;-)
Personally I'd be prepared to believe the latter. There seems to be a basic assumption that the entire universe must have been contained in the big bang, just becasue space is expanding outward as a result. How does this follow, exactly? Could the "force" of the big bang not be simply expanding a small section of the universe outward? In fact, the influence of surrounding matter would certainly be a good explanation for why the known universe is "lumpy".
I do agree that the matter in "our neck of the woods" would almost certainly all have come from the initial singularity, but why does that say anything about what is at the edge of the big bang propagation?
Then of course, I start wondering: does this mean that somewhere there's another big-bang like event that is speeding toward us at the speed of light? Will I feel it?
No, Hawking radiation explains why we aren't constantly being bombarded with micro-blackholes left over from the big bang. These micro-holes would have been very light - I think the event horizons would have been far smaller than the "interaction cross-section" of protons and neutrons, and rarely mass more than a few grams - and even that might be overstating the mass by many orders of magnitude.
In contrast, any black hole we observe from earth will have a stellar mass and will *not* evaporate. At least, not until long after the last star has reached thermal equalibrium with the rest of the universe.
For every complex problem there is an answer that is clear, simple, and wrong. -- H L Mencken
I'm not an astronomer; anyone know what the ramifications this has on the Big Bang theory? My guess is that it doesn't disprove it. But it sure takes a big chunk out of it...
I doubt it has much influence on the big bang theory, but it is worth mentioning that there are a few reputable scientists which have doubts about the big bang.
The conspiracy theorists love to point out how the Vatican commishioned a priest who knew some physics to reinvolve the church in the discussions of the origin of the universe, then this guy descided that the idea that pushing something like the big bang on the scientific community would be the best way to do that. This guy ran arround to various scientists tring to push the idea and got noware untill people noticed the universe was expanding, then people started beliving him. (Note: You should not take this story as an argument against the big bang, but as a warning about how religious people follow there biases)
It is a good test of your understanding of the scientific method to think about exactly why the expansion of the universe provides evidence for the big bang. Example: if we lived in a cluster of galixies which had an eliptical orbit arround soemthing really big then it might appear that al the galaxies were moving appart. It's fun to think about what exactly is wrong with this alternative explination.
Jeff
The Christian religion has been and still is the principal enemy of moral progress in the world. -- Bertrand Russell
Chandra was recently featured at NASA's "Astronomy Picture Of The Day" web site ( http://antwrp.gsfc.nasa.gov/apod/ap000114.html }.
For the amateur astronomer or just the astro-curious, this NASA site ( http://antwrp.gsfc.nasa.gov/apod/astropix.html ) presents a different photo every day with explanation and reference links. This needs to be in your list of "sites to start the day with".
Or their measurements were based on the idea that light always moves at approximately the same speed, given that most of space is a vacuum.
I seem to remember an article on Slashdot about light slowing down as it passes through a Bose-Einstein condensate. Has anyone considered that the "dark matter" out there might also be transparent but dense, such that it slows down light in a similar manner?
We're talking about delaying light for about 2-5 billion years in order to make the math come out right. The researcher in that article thinks she can get it down to 120 feet per hour. If the light from our distant galaxies had to go through a couple lightyears of this goop before it reached us, that would account for the differences.
Yeah, it's easier just to say that there was stuff here before the big bang. But where, then, did it come from? And did it have a hand in creating the big bang?
One of the strongest pieces of evidence in support of the Big Bang theory is the very good match between the abundance of light elements (hydrogen, deuterium, helium, lithium and beryllium) predicted by the BB, and actually observed by us. The BB theory places some limits on the amount of the "critical mass density" of the universe which can be made up of ordinary baryonic matter. That limit is much less than 1.0, closer to about 0.1. What that means is that _if_ the BB is correct, and _if_ the universe contains the critical mass density, _then_ most of that mass density must be non-baryonic matter.
Now, baryonic matter is good old protons, electrons, and neutrons: we and most of what we can see in the current universe (stars, planets, galaxies, etc.) are made of baryons. The galaxies just discovered by Chandra are undoubtedly made of stars (baryonic). Black holes are made of baryons, under most scenarios in the literature. MACHOs are just low-mass stars or high-mass planets, and they, too, are baryons.
So what the heck _isn't_ baryonic? Well, neutrinos aren't. There was a hope about twenty years ago that most of the mass of the universe might consist of neutrinos -- but recent experiments indicate weakly that the neutrino mass is too small to do the job. A universe of neutrinos would also lead to large-scale structure of galaxies and galaxy clusters very different than that which we observe. So, neutrinos are probably out. That leaves exotic stuff: wierd particles called "axions" or "WIMPs", or "strange matter"; all of these are theoretical, not experimentally confirmed (as far as I know)
In short, _if_ the density of the universe is even close to the critical density, it means that a) some exotic sort of matter dominates or b) the current theory of BB nucleosynthesis is wrong.
Michael Richmond "This is the heart that broke my finger."
mwrsps@rit.edu http://stupendous.rit.edu
Here's a link to another story about another one of Chandra's accomplishments: finding "the coolest black hole ever detected".
How does chandra work? How are X-rays focused? Pinhole camera? I doubt that because it would really cut down on light gathering.
X-rays are produced here by accelerating electrons to very high speed and smashing them against a target. Kinda like a miniature acelerator, I think. That's why televisions create x-rays, because the tube is essentially a low-energy particle accelerator, smashing the electrons against the phosphor of the screen and making them glow.
I'm not one hundred percent sure of how the black holes create them, but I think it has something to do with the kinetic energy of the electrons as they fall over the event horizon... someone feel free to correct me.
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This is so great! It makes me very happy to know that there are people out there who can and did build this complex/amazing satellite. It is efforts like this (10+ years start to finish) that dramatically expand the limits of human knowledge about our world. Thanks US, thanks NASA, thanks, TRW and it's subcontractors! But most of all, thank you engineers!
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Here's a drawing. As stuff gets sucked in, it swirls around. Very fast. As it speeds up and the particles bump into each other they heat up. They heat up as much as they can heat up. As they fall screaming in, some of the "heat" leaks away as photons in the X-Ray spectrum.
I think this will be a big change for many of the calculations for mass in the universe. People have spent a lot of time looking for "dark matter". Can these non visible galaxies be counted?
Also I wonder how much closer this will put us toward making the universe a closed system?
Also the age of the universe is calculated finding the oldest light we can. This makes it sound like there may be much older things out there not giving off any light.
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Actually, it is. All electromagnetic radiation is easily pinpointable to a certain star, or cluster, or galaxy. But there was always a universal background radiation. Before now, everyone thought that the cosmic background radiation was heat (and EM radiation) left over from the big bang, still in the process of dissipation.
I'm not an astronomer; anyone know what the ramifications this has on the Big Bang theory? My guess is that it doesn't disprove it. But it sure takes a big chunk out of it...
Ryan Kirk
rkirk@calpoly.edu
http://topflight.net
It is thought that quasars are early versions of galaxies where the formation gasses are being pulled into a central black hole ( billions of solar masses ) and shining tons of light. Then after awhile an equilibrium sets in and eventually spirals and other older type galaxys form. I often wondered what could have kicked this off.
This seems to be the answer. One of the things Hawkings theorized was that there could be primordal black holes created during the big bang. It is possible that trillions of these things existed and as such started the initial imbalance required to create structure as we see now in the visible part of our universe.
These objects are said in the article to be the oldest things ever observed. I would say just younger than the 2.7 degree kelvin background radiation marking the time when the universe was opaque.
These smaller primordal blackholes would collide and create the gravitational engines that galaxies would form around. Initially, they would suck in gas and burn like a quasar then eventually settle down and become boring old spirals like ours.
As things were far more compact at this time most of the primordals would be gone, but a few may have "slingshoted" from near misses and be cruising near light speed through the universe right now.
And you though a big astroid would be bad!
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People are mostly looking for dark matter within galaxies. The biggest problem right now is that given the rate that galaxies are spinning, they should fly apart if the only mass in them is the stars we see (assuming that we're doing a good job of calculating the mass of stars).
IMVHO, the "dark matter" is mostly a bunch of sub-stars like Jupiter (these are known as the Massive Astrophysical Compact Halo Objects, or MACHO, a term which covers all big dark matter, like black holes and brown dwarfs), which would have to be about a hundred times more common than stars to explain it. I believe in small MACHOs because small stars are much more common than large stars; a lot of people like to believe that black holes are common, but if matter tended to group together that much you'd expect larger stars to be more common than smaller stars.
That's Hawkings radiation, something which provides a mechanism for small black holes to "evaporate" over time. It's an exponential conversion of mass to energy, so you do *not* want to be near one at the final moments!
Hawkings radiation is interesting for a different reason. Some people had observed that black holes physics have a lot of similaries with thermodynamics. The mass of the black hole corresponds to entrophy, iirc. However there was some minor point where the behaviors differed, and Hawkings decided to explore the "impossible" case where black holes really did match thermodynamics. He eventually identified the quantum tunneling mechanism and all hell broke loose in the physics community. Hawkings radiation is now a classic example of a situation where important discovery was made by exploring something that first appears to be a mere coincidence.
As others have pointed out, the X-rays we're talking about here are due matter falling into the accretion disk.
For every complex problem there is an answer that is clear, simple, and wrong. -- H L Mencken
People seem to be misunderstanding the significance of this discovery. For almost 40 years, we've known about an "x-ray glow" with no apparent source that was scattered all over the sky. With Chandra, astronomers have been able to resolve discrete sources for the x-rays, so we now know exactly where they're coming from. I don't think the x-ray glow was ever as uniform as the background microwave radiation, which is identical in all directions with no apparent source.
And the brethren went away edified.
Actually the X-rays don't escape the black hole. the current theory is (since we have never actually "seen" a black hole) is that as particles fall in to the balck hole, they enter a sort of, spiraling, decaying orbit (called the accretion disk). It is the friction between all of these particles in the accretion disk, that generates the x-rays. If the x-ray is released in the right direction it can escape being sucked into the black hole, since the accretion disk exists outside of the black holes event horizon.