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The 1st Generation of Stars
Andy_Howell writes "Astronomers may have found members of the first generation of stars in the universe. Using the Hubble Space Telescope and the Keck I telescope, they observed a faint red blob that had been magnified into a double image by a gravitational lens. The blob was found to be a cluster of stars 13.6 billion light years away, seen when the age of the universe was less than a billion years old. The clump appears to contain only about a million stars, and is less than a few million years old. It is thought that swarms of these clumps came together over the age of the universe to create the galaxies we see today."
U GOTS TO B KIDDING ME..........BRITNEY SPEARS IS LIKE THE FIRST AND BESTEST EVER ... THERE AINT NO STARS B4 HER IN MY BOOK!!!!!!!!!!!! I LUV BILLY!!!!!!!
If you celebrate Xmas, befriend me (538
The blob was found to be a cluster of stars 13.6 billion light years away, seen when the age of the universe was less than a billion years old.
Perhaps I've been out of touch with my astronomy studies for too long, I know there are a lot of discoveries being made. However I was under the impression that there was still a great deal of uncertainty about the age of the universe. It was generally agreed that it was somewhere between about 13 billion and 20 billion years old but exactly how old wasn't/isn't clear.
Is there something I don't know about or is this age prediction just an assumption? Have there been some consensus on this recently that I didn't hear about? Anyone know for sure? I'm always suspicious when I see "discoveries" like this whose results depend on something that hasn't been definitely proven.
Sensational is more like it. I tried to get into it in the bookstore one time, but every time the author got up to the really juicy part where he was going to explain everything, he dropped his thread and referred me to a later chapter. Also, he was attacking mostly the exterior consequences of Big Bang theory, and as I recall he failed to really get to the main premises. I opted to put the book down. It looked like a crank to me.
The author is intellectually dishonest: at one point he is discussing some electromagnetics simulations that have a spiral galaxy-like appearance, and saying how those support his cosmological electromagnetism theory. What he doesn't tell you is that the images are *cross sections* of tubular structures, and that the field strengths needed to create those structures are *enormous*.
If that BOOK were posted to USENET it would be UTTERLY INDISTINGUISHABLE from the other PHYSICS CRANKS.
-- ;-)
Kuro5hin.org: where the good times never end.
It is by observing the doplar shift, or "red shift", in the wavelength of a stars light that the length to almost every distant object is measured.
Think of yourself as being on the surface of an expanding baloon: relative to other objects that are close to you on the surface, you are moving very slowly. Relative to objects at the center of the baloon or halfway around the surface, you are moving a little faster (remember this is as the crow flies). Relative to objects clear on the other side of the baloon, you are moving the fastest of all.
On the scale of the universe, objects on the other side of the galaxy are moving extremely fast (relative to you). I'm not sure exactly how fast, but I remember reading somewhere that it is getting close to the speed of light (after all, they have had to cover a huge amount of space to get so far away). This is easily fast enough to have an affect on the wavelength of the light - even a small relative speed will have a small (but probably unmeasurable affect).
IANAAstroPhysicist, so whether this explains the visibly red shift (since scientific spectrographs are much more sensitive than our eyes ), I cannot say. Another explaination might be that the stars are young and therefore cool, but I couldn't say that for sure either.
It presumes the Big Bang, or something like it. Obviously you can't have young hydrogen-only stars unless the universe was different than it is today.
Either the universe exists into the arbitrarily distant past or it has some kind of a start. I've never heard a good hypothesis for a beggining to the universe that doesn't involve some sort of a big bang. Which premise is that book trying to sell? That we always existed?, or that we started from something other than a big bang?
"It is a profound and necessary truth that the deep things in science are not found because they are useful; they are found because it was possible to find them." -Robert Oppenheimer
Robert Moody from the Department Mathematical Sciences, University of Alberta illustrates the importance of curiosity based research in his paper using lasers as an example of why curiosity based research is necessary.
Carl Sagan in his book, The Demon Haunted World, also stresses the importance of curiosity based research using James Clark Maxell's discoveries as an example of how it effects our lives today by providing the necessary building blocks for radio, television, computers, lasers, etc.
Basic science is nice, but erstwhile star captains probably wouldn't find the universe's origins very relevant.
It may not seem very relivant at first, but there are those who would argue in order to even begin to piece together data for a theory of everything (which may be vital to even approach the idea of star captains), we need to gather as much data as possible to reduce our error bars of knowledge.
All in all, Good question... I'm sure some of you have better answers...
"Communism is like having one [local] phone company " - Lenny Bruce
The horizon expands.
When the universe was two billion years old, no one object could receive information about anything farther than two billion light years away. But a billion years later, there is time for information to have come from objects that were originally outside of its light cone, but the light cone (in this case called a horizon, because it can't be seen beyond) has expanded beyond them.
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Ok, now for the more complex bit, actually saying what these are.
A photon multiplier is a device which takes in a stream of very low energy photons and generates a stream of much higher energy photons, as a result. It's a basic amplifier, for photons.
A very large telescope gives you a huge collection area. The larger your collection area, the more light you gather. By squishing that light into a much smaller area, you essentially generate a much brighter image.
The same is true of a long baseline. The idea, here, is to increase the time over which you collect the light. Double the time, double the light.
The consequence of using all three techniques is that you can easily collect a few photons from a vast distance, and turn them into an actual, visible image. But don't expect it to be easy. I imagine that the Hubble Telescope had to be pointed at that same spot for 24-48 hours, to generate such a view.
(When you recall that the Earth is rotating on its axis, that it's also rotating round the sun, and that the sun is moving round the galaxy, and that the galaxy has its own motion relative to other galaxies, and that ALL of these are complex, N-body problems, the challange of being able to keep the telescope pointing at a tiny cluster, billions of light-years away for more than a few seconds is an achievement. To manage it for maybe 1-2 DAYS is staggering.)
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Most astronomers had previously ignored these stars, which had been modded down heavily for posting annoying "First star!" messages.
When all you have is a hammer, everything looks like a skull.
The problem with "The Big Bang Never Happened" (which I have read) and other alternative cosmologies is that they don't even attempt to go deep enough to prove their points. There's a reason for this. All of modern cosmology is based on General Relativity. If you are going to say that the Big Bang Never Happened, then your alternative cosmology has to not only come up with an alternative explanation for the Universe, but also explain everything that GR does without having a Big Bang. This is a very tall order.
It isn't enough to point out the contradictions in the standard model. It is also necessary to build a new model that explains all observations. To date, no one has been able to do this without having a Big Bang at the start.
A well-crafted lie appears unquestionable - Dama Mahaleo
No, I think you'll find those stars are actualy quite hot. Well, were. I guess they're cool -now-.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Looking at the images, they look like they've got pretty good S/N. I haven't seen the spectra, so I can't comment on that, but if they have spectra for the two different images that both give the same redshift, that's not likely noise.
Then it's haze that happens to shift all of the photons redward by a factor of 6.58. In both images independently. And doesn't make them fainter.
That's an interesting topic. All dust that we see in the universe is inside of galaxies, and preferentially blocks red light. So the places that you'd expect dust to make a difference is in the galaxy itself, in the Milky Way, or maybe in the cluster that's lensing the images (if you can come up with a way of expelling the dust out of a galaxy into the intracluster medium without destroying the dust, which isn't easy to do - dust is pretty fragile)
The only possible evidence for gray dust in the voids between large scale structure is as a way out of having the Type Ia Supernova measurements argue for the existence of a positive cosmological constant - some have argued that the reason that the supernovae are fainter isn't that they're farther away, it's that there's some fairly uniform gray dust (it can't be normal dust because then it would preferentially block red light, and we don't see that happening) that is absorbing some of the light. But there is plenty of other evidence pointing towards a positive cosmological constant, so the dust explanation is unlikely.
Hope that helps.
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No, we have a small number of poorly designed studies that seem to show that prayer unknown to the patient has an impact, and a number of better-designed studies that show no such thing. Every major "double-blind" study which has shown an effect from prayer on healing has later turned out to be unblinded indeed, with the personnel conducting the study having discarded evidence which didn't fit their hypotheses. Irwin Tessman, among others, has shown this quite thoroughly.
As far as the subject of this article goes: astronomers (and biologists, and geologists) are under no more obligation to consider the beliefs of creationists than historians are to consider the beliefs of Holocaust-deniers, or geographers are to consider the beliefs of the Flat Earth Society.
The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
They are moving away from each other because the universe is expanding. The amount of space between the two points is increasing as the light travels between. Relativity imposes no limit on how fast space can expand. During the inflationary era, the Universe expanded faster than the speed of light.
I have discovered a truly marvelous sig, unfortunately the sig limit is too small to contain i
Anyhow, assuming you're serious:
- Try radio astronomy data. For example, pulsar searches (related to what I do, forgive my bias) use simple time series data I(t) which would seem to be ideal for your work. Try this:
http://www.atnf.csiro.au/research/pulsar/pmsurv/
- HST data is always available for download,
once the proprietary period has expired, from the HST archive.
You don't care what the data is from, right? Note, though, that this is a 2-dimensional image, so it might have some "fake" compressibility due to redundant information. Radio data does not have this weakness, so I recommend that instead.
- For most astronomy data, you'll need to learn to read FITS format: try this.
Hope this helps - if you're serious and need help, feel free to drop me a note. (shami at astro dot cornell dot edu)"I will take the Ring," he said, "though I do not know the way."
Let's look at this classically. The classical picture is not correct, but it can give some rough idea of how this is possible.
We have two objects moving apart in the early universe. Classically, the distance D between them will be the relatvive velocity, v, times the age of the universe at the time the light in question was emitted.
So lets say D = v*1 Gyr (10^9 years)
Now light from one get's emitted and starts travelling towards the other at the speed of light, c.
In order to see the light from the other source, it has to catch up to us. In other words c*t = v*t + D, where t is the time since the light was emitted.
Substituting for D and solving for v, we get v = c*t/(t+1 Gyr). Hence in a strictly classical approximation, the two objects must be travelling apart at a relative velocity of 0.93c, in reality relativity and cosmology would probably tell you they don't have to moving apart nearly that fast, but the idea is there.
If two objects are moving apart fast enough it will take the light from one a long time to catch up with the other.
In the first stage you have some phenomena that you want to try to 'explain' (in scientific parlance 'explain' actually means 'predict through use of appropriate mathematical formulae). The scientists will come up with hypotheses that yield testable formulae for predicting the phenomena in question.
In the second stage you gather lots of empirical data and see if the predictions of your hypotheses agree with the data you have gathered. You may gather data specifically chosen to prove your hypotheses false (since it should be easy to predict what measurements are most likely to disagree with your hypotheses) or you may just use whatever data comes easily to hand (there may be a large mass of existing data, as with Tyco Brahe's astronomical measurements used by Kepler to derive the shapes of the planets' orbits).
Once you have gathered enough data you can see where your hypotheses disagree with the measured data and adjust the hypotheses accordingly. Eventually your hypotheses agree to the measured data to within the current error bounds, at which time you have an official theory.
Importantly, you never actually have access to truth. Nothing is ever proven (though many things may be disproven) and everything is open to some level of doubt. It's just a matter of how much doubt you find acceptable for any give application. For common, everyday tasks, the precision required of most measurements is very low:
- speed of light = faster than anything else
- speed of sound = not as fast as light but faster than most other things
- age of the universe = age of the earth = older than we care to think about
- mass of a subatomic particle = as close to zero as makes no odds.
For specific applications you will require greater precision, but still not perfect precision:The real problem with your use of the terms 'truth' and 'proof' is that they don't mean the same thing to a scientist as they mean in common english. In common english Truth is absolute and Proof is irrefutable. To a scientist, however, truth simply means that the formulae yield answers close enough to measured values that we can't tell the difference (modulo the accuracy of our measuring devices), and proof simply means that no data has been found that clearly contradicts a specific set of formulae (aka, an hypothesis).
Just because science isn't accessing some cosmic Truth doesn't mean that sceintific theories are really just opinions. An opinion is a though in someone's head that has no concrete basis in fact. A scientific theory, on the other hand, is a set of formulae that serve to predict objective, measurable values for physical phenomena to within some specified error range. It may not be too similar to what most people think of as Truth, but it is pretty far from the common definition of option as well. It is certainly a damn sight more reliable that the assorted forms of propaganda, superstition, and outright ignorance that have passed themselves off as Truth for most of history.
It's probably the case that these are very hot stars with peak emission at blue or uv wavelengths. The reason for the red color is probably almost entirely due to the red shift of the objects, and possibly a small amount of interstellar dust (depending on how much intervening dust there is).
More often you see H-alpha emission from the gas clouds surrounding newly formed stars in star forming regions and such, it's somewhat rare (although not unheard of) to see strong hydrogen emission in a stellar atmosphere.
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