Posted on 01/10/2002 7:18:34 AM PST by JediGirl
WASHINGTON (AP) — An outburst of star formation ended a half billion years of utter darkness following the Big Bang, the theoretical start of the universe, according to a study that challenges old ideas about the birth of the first stars.
An analysis of very faint galaxies in the deepest view of the universe ever captured by a telescope suggests there was an eruption of stars that burst to life and pierced the blackness very early in the 15 billion-year history of the universe.
The study, by Kenneth M. Lanzetta of the State University of New York at Stony Brook, challenges the long held belief that star formation started slowly after the Big Bang and didn't peak until some 5 billion years later.
``Star formation took place early and very rapidly,'' Lanzetta said Tuesday at a National Aeronautics and Space Administration news conference. ``Star formation was 10 times higher in the distant early universe than it is today.''
Lanzetta's conclusions are based on an analysis of what is called a deep field study by the Hubble Space Telescope. To capture the faintest and most distant images possible, the Hubble focused on an ordinary bit of sky for more than 14 days, taking a picture of every object within a small, deep slice of the heavens. The resulting images are faint, fuzzy bits of light from galaxies near and far, including some more than 14 billion light-years away, said Lanzetta.
The surprise was that the farther back the telescope looked, the greater the star-forming activity was.
``Star formation continued to increase to the very earliest point that we could see,'' said Lanzetta. ``We are seeing close to the first burst of star formation.''
Bruce Margon of the Space Telescope Science Institute in Baltimore said Lanzetta's conclusions are a ``surprising result'' that will need to be confirmed by other studies.
``This suggests that the great burst of star formation was at the beginning of the universe,'' said Margon, noting that, in effect: ``The finale came first.''
``If this can be verified, it will dramatically change our understanding of the universe,'' said Anne Kinney, director of the astronomy and physics division at NASA.
In his study, Lanzetta examined light captured in the Hubble deep field images, using up to 12 different light filters to separate the colors. The intensity of red was used to establish the distance to each point of light. The distances were then used to create a three-dimensional perspective of the 5,000 galaxies in the Hubble picture.
Lanzetta also used images of nearby star fields as a yardstick for stellar density and intensity to conclude that about 90 percent of the light in the very early universe was not detected by the Hubble. When this missing light was factored into the three-dimensional perspective, it showed that the peak of star formation came just 500 million years after the Big Bang and has been declining since.
Current star formation, he said, ``is just a trickle'' of that early burst of stellar birth.
Lisa Storrie-Lombardi, a California Institute of Technology astronomer, said that the colors of the galaxies in the Hubble deep field images ``are a very good indication of their distance.''
Current theory suggests that about 15 billion years ago, an infinitely dense single point exploded — the Big Bang — creating space, time, matter and extreme heat. As the universe cooled, light elements, such as hydrogen and helium, formed. Later, some areas became more dense with elements than others, forming gravitational centers that attracted more and more matter. Eventually, celestial bodies became dense enough to start nuclear fires, setting the heavens aglow. These were newborn stars.
Storrie-Lombardi said that current instruments and space telescopes now being planned could eventually, perhaps, see into the Dark Era, the time before there were stars.
``We are getting close to the epoch where we can not see at all,'' she said.
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On the Net:
Hubble images: http://oposite.stsci.edu/pubinfo/pr/2002/02
Also: http://hubble.stsci.edu/go/news
In the experiment, the trajectories observed are dependent on, whether or not, the targets have no fluctuations around them, or some other magnitude of fluctuations. The data is compared to what the theoretical calcs say for the proposed conditions.
Ummm, english please?
Typical mumbo-jumbo physics response! ;)
Why are we here? We're not really here at all... We just THINK we're here...
Well, certainly in order to do any science, at some level you have to make the assumption that the fundamental laws of nature are the same all over the universe, and that we aren't in some sort of privileged bubble where general principles cannot be derived.
That being said, your question is a valid one. One of the observable effects of virtual particles is a subtle shifting of atomic spectral lines called the Lamb Shift. We can observe the Lamb Shift in emission lines from the Sun, from distant galaxies, even from absorption lines caused by the interstellar medium, which is typically a harder vacuum than any we can economically create in the laboratory. (It may seem odd that we can see any opacity in a medium so rarefied, but after a hundred thousand light years it adds up.)
I thought that the dielectric constant was determined using a vacuum as a reference (constant of 1, I believe). When you measure the effect of virtual particles, what do you use as a reference? Surely you can't use a vacuum as a reference to measure another vacuum.
Ah, but the number 1 is scale invariant, you'll agree, while the effect of vacuum polarization is not (as I illustrated above in the case of Bhabha scattering).
Again, please translate into english for someone that has only undergraduate physics knowledge and is capable of understanding concepts should they involve familiar terms and/or some further explanation. Fluctuations of what?
Not classically, once you've chosen an inertial frame. And once you claim that you know the energy of a particle, you've chosen an inertial frame.
So there was NO space, NO time, NO matter, and NO temperature. Somebody please explain to me what medium this infinitely dense single point existed in. What was the fabric of the medium this point was floating in? Where was it? When was it? It seems they are saying that NOthing suddenly became everything. What law of physics made this possible? How can there be any laws when nothing, no where, nowhen exists?
The poping of particle pairs out of the vacuum is called the vacuum fluctuation. To understand the experiment consider an electron sitting out in space. Now there's a machine shooter with an electron gun taking shots at it. We use a machine shooter, 'cause he doesn't shake. If there are no fluctuations near the electron you smake the target every time in the same place. You have a pic of the target now. Now if their are particles jumping in and out around the target, the targets going to jump around, because they're all charged. Some will push, some pull. It's going to effect the hits, and a different picture obtains. In this case the shots look scattered on a screen behind the target. You din't need the first experiment, because all the shots hit and there's only one hole in the screen. That's your calc. reference.
In real experiments there are more causes for jitter in both cases, so they both appear scattered, but the results are the same.
Point poop.
" Where was it?"
Everywhere.
When was it?
Before the point flipped it's lid over the stench.
" It seems they are saying that NOthing suddenly became everything."
You don't smell anything do you?
" What law of physics made this possible?
Murphy's law.
I'm not speaking of an idealized subset of objects. I am stating an outcome of physical world in relation to all material objects. If object "A" is "moving" it is "moving" in relation to some other object "B". If it so happens to be stationary in relation to object "C" then "C" is also in "motion" relative to "B". "B" moves in relation to both "A" and "C". All things are "moving". The universe is not inertial.
Hmm.. Maybe stating it philosophically will illustrate my point. If something "moves" the universe is changed. Everything "knows" that the universe is changed. (quantum spookiness)
You're right it is and was. Your post reminded me of an exchange where a turtle held the world on it's back. My apologies, I didn't know you were that serious. Here's some answers.
"So there was NO space, NO time, NO matter, and NO temperature."That's correct. There was only the other place, the vacuum. Folks can't go there, so they only as much of it as they can see from this world.
"Somebody please explain to me what medium this infinitely dense single point existed in. What was the fabric of the medium this point was floating in?"
The single point idea is only used as a mathematical tool at present by the folks in this world to understand things we see in this world. My understanding is that there was not a single point initially, but an occurrence in the other place, the vacuum, out of which this world arose. I don't know the physics of it. Something akin to the developement of a disaster wall in Physicists post #65.
"Where was it?"
As far as I've seen the universe appears to have roughly a crunched spherical shape. You could go back from the edge of the visible universe and locate a spot for where the initial creation happened, but you must realize there was nothing here originaly to say where it was. If you were in the other place, you would have a reference to say it was here.
"When was it?~15 billion years ago.
" It seems they are saying that NOthing suddenly became everything.
Out of the vacuum arose all that we see.
" What law of physics made this possible?
Don't know.
" How can there be any laws when nothing, no where, nowhen exists?
The laws we have in this world arose and are consistent with those in the vacuum. No one can go there to observe, or determine exactly what's there.
Indeed, the concepts are difficult when first encountered.
So perhaps, "In the beginning God.... " is just as apt a way of explaining "it" to a layman as any.
I would suggest that it's the very worst way of explaining it. There are several reasons why:
1. It's not an explanation at all; it's the declaration that it's in inexplicable miracle.
2. When a physical event is declared to be a miracle, it is culturally closed off from all rational inquiry.
3. That sets up an unnecessary conflict between religion and science, which isn't good for either.
4. By linking one's religion so closely to fairy tales about natural events, it is inevitable that one's religion will look silly as science makes progress. Society needs the ethical benefits religion, but these benefits are few when religion is subject to ridicule.
That seems to be what science is doing, since about every other week some cosmologist comes up with a new theory to explain the inexplicable. These theories of course are never proven, just postulated as a possible explanation. When they finally get it down to the final, absolutely final explanation of how it all came about, (And since the existence of God cannot be disproven) "In the beginning God......" will suffice. However, I wish the good luck.
Ever her of the inflationary theory?
Sure. Just read a good article on it in the Economist. It is a descriptive theory of what happened (space increased in size) without explaining how or why it expands. It just says that it does. There is no empirical reason for it to expand--it just fits with observation with no rationale for the motive power behind it that offsets gravity.
Now there are also theories of negative gravity and a fifth force that counteracts it--but no experimental evidence for them.
Space is a vacuum, right? Essentially a large void of nothing between the planets and galaxies. In empty space there is no gas, solid, or liquid. So, how can it be expanding? Gases expand with increased temperature or lower pressure. How can nothing expand?
This just seems to fly in the face of what we know about the physics of gases and vacuums.
The laws applying to gases don't apply to the expansion of space. The expansion of space is required by the general theory of relativity, which states that matter and energy deform and shape space. With the expansion of matter, space also expands. The inflation theory says that space expansion actually drives the spreading of the universe.
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