As expected, you were unable to answer the straight-forward questions that I posed. Changing the subject doesn't suit you, by the way.
Posted on 03/16/2006 11:31:54 AM PST by The_Victor
Physicists announced Thursday that they now have the smoking gun that shows the universe went through extremely rapid expansion in the moments after the big bang, growing from the size of a marble to a volume larger than all of observable space in less than a trillion-trillionth of a second.
The discovery — which involves an analysis of variations in the brightness of microwave radiation — is the first direct evidence to support the two-decade-old theory that the universe went through what is called inflation.
It also helps explain how matter eventually clumped together into planets, stars and galaxies in a universe that began as a remarkably smooth, superhot soup.
"It's giving us our first clues about how inflation took place," said Michael Turner, assistant director for mathematics and physical sciences at the National Science Foundation. "This is absolutely amazing."
Brian Greene, a Columbia University physicist, said: "The observations are spectacular and the conclusions are stunning."
Researchers found the evidence for inflation by looking at a faint glow that permeates the universe. That glow, known as the cosmic microwave background, was produced when the universe was about 300,000 years old — long after inflation had done its work.
But just as a fossil tells a paleontologist about long-extinct life, the pattern of light in the cosmic microwave background offers clues about what came before it. Of specific interest to physicists are subtle brightness variations that give images of the microwave background a lumpy appearance.
Physicists presented new measurements of those variations during a news conference at Princeton University. The measurements were made by a spaceborne instrument called the Wilkinson Microwave Anistropy Probe, or WMAP, launched by NASA in 2001.
Earlier studies of WMAP data have determined that the universe is 13.7 billion years old, give or take a few hundred thousand years. WMAP also measured variations in the cosmic microwave background so huge that they stretch across the entire sky. Those earlier observations are strong indicators of inflation, but no smoking gun, said Turner, who was not involved in the research.
The new analysis looked at variations in the microwave background over smaller patches of sky — only billions of light-years across, instead of hundreds of billions.
Without inflation, the brightness variations over small patches of the sky would be the same as those observed over larger areas of the heavens. But the researchers found considerable differences in the brightness variations.
"The data favors inflation," said Charles Bennett, a Johns Hopkins University physicist who announced the discovery. He was joined by two Princeton colleagues, Lyman Page and David Spergel, who also contributed to the research.
Bennett added: "It amazes me that we can say anything at all about what transpired in the first trillionth of a second of the universe."
The physicists said small lumps in the microwave background began during inflation. Those lumps eventually coalesced into stars, galaxies and planets.
The measurements are scheduled to be published in a future issue of the Astrophysical Journal.
Nope. Hindu. Google "Hindu turtle creation" (no quotes), and you'll find the info.
Nope, see #78 and #83 and several others in this thread.
Umm, no. We have no basis whatsoever to conclude that there is nothing other than the universe. So far as we know, there is no way at this point in time to reach a valid conclusion one way or the other.
Sometimes I wonder why so many people have such a hard time giving the simple, honest answer: We just don't know.
And they're all swaying back and forth going, "Heyyyyy, whoahhhh".
As expected, you were unable to answer the straight-forward questions that I posed. Changing the subject doesn't suit you, by the way.
Actually the turtle thing is common to several creation myths, including the Balinese, Iroquois, and others. The creation sits on the back of a turtle.
So, the question is: What does the turtle sit on?
The answer is: It's turtles all the way down.
IT? How about the one infinitesimal into the one infinite expanse, thereby creating the unlimited number of infinitesimalities it takes to fill that expanse. The children of infinite "male" and infinite "female", which are two "sides" of the same coin, from our perspective, now making a coin's edge.
However, the three are dynamic at an infinite rate as well as static, as well as all the "velocities" in-between... our Universe.
Very simplistic analogy, dealing with the domains part only, to help me express what I feel comfortable with.
If you ever do get curious, there are good Q/A sites on inflationary cosmology. I do not hold my breath. I have spent enough time in the past trying to put information into a notched bullet and shoot it into your head.
Can we conclude from this that we can exceed the speed of light...provided we have a large enough explosion behind us?
Yeah, the best answer is that we can describe the dynamics of the expansion with equations and show how it relates to gravity. We really have no observational data to say anything about 'what it is expanding into' or even if there is anything to 'expand into' at all.
Umm, yeah, actually it does do all that. In fact, it has basically done so since the 1917 de Sitter cosmological model which seems increasingly to be on the mark, and which was extrapolated on purely mathematic grounds directly out of Einstein's General Relativity.
Why is it that you think that just because you're ignorant about something that everyone is ignorant about something?
Nope. See the actual *article* for this thread, which claims a starting point of all mass inside space the size of a marble...and then explain how that mass was accelerated at speeds vastly greater than C to position the galaxies in their current locations and our stars and planets in their current sizes.
NOTE: how many atoms are in the universe versus how many atoms can fit inside a marble.
So let me see if I understand. When the universe was the size of a marble, matter was so densely packed that certain radioactive radiation could not exist?
"And God said, 'Let there be light,' and there was light. God saw that the light was good, and He separated the light from the darkness."
Nope, my explanation was correct.
Momentum is alway m*v. Plugging in for relativistic effects give your equation above, but that doesn't prove that the photon doesn't have mass, just that it isn't needed for the photon to have momentum. Since relativity provides that mass and energy are interchangeable, the kinetic energy of a "massless"object still has mass.
From here: http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/photon_mass.html
If the rest mass of the photon was non-zero, the theory of quantum electrodynamics would be "in trouble" primarily through loss of gauge invariance, which would make it non-renormalizable; also, charge-conservation would no longer be absolutely guaranteed, as it is if photons have vanishing rest-mass. However, whatever theory says, it is still necessary to check theory against experiment.
It is almost certainly impossible to do any experiment which would establish that the photon rest mass is exactly zero. The best we can hope to do is place limits on it. A non-zero rest mass would lead to a change in the inverse square Coulomb law of electrostatic forces. There would be a small damping factor making it weaker over very large distances.
The behavior of static magnetic fields is likewise modified. A limit on the photon mass can be obtained through satellite measurements of planetary magnetic fields. The Charge Composition Explorer spacecraft was used to derive a limit of 6x10-16 eV with high certainty. This was slightly improved in 1998 by Roderic Lakes in a laborartory experiment which looked for anomalous forces on a Cavendish balance. The new limit is 7x10-17 eV. Studies of galactic magnetic fields suggest a much better limit of less than 3x10-27 eV but there is some doubt about the validity of this method.
Thank you!
Don't blame me for the length of this swiped from Google:
"How does a light-mill work?
In 1873, while investigating infrared radiation and the element thallium, the eminent Victorian experimenter Sir William Crookes developed a special kind of radiometer, an instrument for measuring radiant energy of heat and light. Crookes's Radiometer is today marketed as a conversation piece called a light-mill or solar engine. It consists of four vanes each of which is blackened on one side and silvered on the other. These are attached to the arms of a rotor which is balanced on a vertical support in such a way that it can turn with very little friction. The mechanism is encased inside a clear glass bulb which has been pumped out to a high, but not perfect, vacuum.
When sunlight falls on the light-mill the vanes turn with the black surfaces apparently being pushed away by the light. Crookes at first believed this demonstrated that light radiation pressure on the black vanes was turning it round just like water in a water mill. His paper reporting the device was refereed by James Clerk Maxwell who accepted the explanation Crookes gave. It seems that Maxwell was delighted to see a demonstration of the effect of radiation pressure as predicted by his theory of electromagnetism. But there is a problem with this explanation. Light falling on the black side should be absorbed, while light falling on the silver side of the vanes should be reflected. The net result is that there is twice as much radiation pressure on the metal side as on the black. In that case the mill is turning the wrong way.
When this was realised other explanations for the radiometer effect were sought and some of the ones that people came up with are still mistakenly quoted as the correct one. It was clear that the black side would absorb heat from infrared radiation more than the silver side. This would cause the rarefied gas to be heated on the black side. The obvious explanation in that case, is that the pressure of the gas on the darker size increases with its temperature creating a higher force on that side of the vane. This force would push the rotor round. Maxwell analysed this theory carefully presumably being wary about making a second mistake. He discovered that in fact the warmer gas would simply expand in such a way that there would be no net force from this effect, just a steady flow of heat across the vanes. So it is wrong, but even the Encyclopaedia Britannica gives this false explanation today. As a variation on this theme, it is sometimes said that the motion of the hot molecules on the black side of the vane provide the push. Again this is not correct and could only work if the mean free path between molecular collisions were as large as the container, but in fact it is typically less than a millimetre.
To understand why these common explanations are wrong think first of a simpler set-up in which a tube of gas is kept hot at one end and cool at the other. If the gas behaves according to the ideal gas laws with isotropic pressure, it will settle into a steady state with a temperature gradient along the tube. The pressure will be the same throughout otherwise net forces would disturb the gas. The density would vary inversely to temperature along the tube. There will be a flow of heat from the hot end to the other but the force on both ends will be the same because the pressure is equal. Any mechanism you might conjecture that would give a stronger force on the hot end than on the cool end with no tangential forces along the length of the tube cannot be correct since otherwise there would be a net force on the tube with no opposite reaction. The radiometer is a little more complex but the same principle should apply. No net force can be generated by normal forces on the faces of the vanes because pressure would quickly equalise to a steady state with just a flow of heat through the gas.
Another blind alley was the theory that the heat vaporised gases dissolved in the black coating which then leaked out. This outgassing would propel the vanes round. Actually, such an effect does exist but it is not the real explanation as can be demonstrated by cooling the radiometer. It is found that the rotor then turns the other way. Furthermore, if the gas is pumped out to make a much higher vacuum, the vanes stop turning. This suggests that the rarefied gas is involved in the effect. For similar reasons, the theory that the rotation is propelled by electrons dislodged by the photoelectric effect is also ruled out. One last incorrect explanation which is sometimes given is that the heating sets up convection currents with a horizontal component that turns the vanes. Sorry, wrong again. The effect cannot be explained this way.
The correct solution to the problem was provided qualitatively by Osborne Reynolds, better remembered for the "Reynolds number". Early in 1879 Reynolds submitted a paper to the Royal Society in which he considered what he called "thermal transpiration", and also discussed the theory of the radiometer. By "thermal transpiration" Reynolds meant the flow of gas through porous plates caused by a temperature difference on the two sides of the plates. If the gas is initially at the same pressure on the two sides, there is a flow of gas from the colder to the hotter side, resulting in a higher pressure on the hotter side if the plates cannot move. Equilibrium is reached when the ratio of pressures on either side is the square root of the ratio of absolute temperatures. This is a counterintuitive effect due to tangential forces between the gas molecules and the sides of the narrow pores in the plates. The effect of these thermomolecular forces is very similar to the thermomechanical effects of superfluid liquid helium. The liquid, which lacks all viscosity, will climb the sides of its container towards a warmer region. If a thin capillary is dipped into the superfluid it flows up the tube at such speed that a fountain effect is produced at the other end.
The vanes of a radiometer are not porous. To explain the radiometer, therefore, one must focus attention not on the faces of the vanes, but on their edges. The faster molecules from the warmer side strike the edges obliquely and impart a higher force than the colder molecules. Again these are the same thermomolecular forces that are responsible for thermal transpiration. The effect is also known as thermal creep since it causes gases to creep along a surface where there is a temperature gradient. The net movement of the vane due to the tangential forces around the edges is away from the warmer gas and towards the cooler gas with the gas passing round the edge in the opposite direction. The behaviour is just as if there were a greater force on the blackened side of the vane (which as Maxwell showed is not the case), but the explanation must be in terms of what happens not at the faces of the vanes but near their edges.
Maxwell refereed Reynolds's paper, and so became aware of Reynolds's suggestion. Maxwell at once made a detailed mathematical analysis of the problem, and submitted his paper, "On stresses in rarefied gases arising from inequalities of temperature", for publication in the Philosophical Transactions; it appeared in 1879, shortly before his death. The paper gave due credit to Reynolds's suggestion that the effect is at the edges of the vanes, but criticised Reynolds's mathematical treatment. Reynolds's paper had not yet appeared (it was published in 1881), and Reynolds was incensed by the fact that Maxwell's paper had not only appeared first, but had criticised his unpublished work! Reynolds wanted his protest to be published by the Royal Society, but after Maxwell's death this was thought to be inappropriate.
By the way. It is possible to measure radiation pressure using a more refined apparatus. To make it work you have to use a much better vacuum, suspend the vanes from fine fibers and coat the vanes with an inert glass to prevent out-gassing. When you succeed the vanes are deflected the other way as predicted by Maxwell. The experiment is very difficult but was first done successfully in 1901 by Pyotr Lebedev and also by Eenest Nichols and Gordon Hull."
References
Original papers by Maxwell and Reynolds:
"On stresses in rarefied gases arising from inequalities of temperature" James Clerk Maxwell, Royal Society Phil. Trans. (1879)
"On certain dimensional properties of matter in the gaseous state" Osborne Reynolds, Royal Society Phil. Trans., Part 2, (1879)
Original papers on detection of radiation pressure:
P.N. Lebedev, Ann. Phys. (Leipzig) 6:433 (1901)
E.F. Nichols and G.F. Hull, Phys. Rev. 13:307 (1901)
Historical details are taken from these sources:
"The genius of James Clerk Maxwell" by Keith J. Laidler in Phys 13 news of the University of Waterloo Department of Physics.
"The Kind of Motion that we Call Heat" S.G. Brush North-Holland 1976
Other useful articles about the radiometer:
"Crookes' Radiometer and Otheoscope" Norman Heckenberg, Bulletin of the Scientific Instrument Society, 50, 40--42 (1996)
"Concerning the Action of the Crookes Radiometer" Gorden F. Hull, American J. Phys., 16, 185--186 (1948)
"The Radiometer and How it Does Not Work" Arther E. Woodruff, The Physics Teacher 6, 358--363 (1968)
General text books:
"Light", R.W. Ditchburn, Blackie & Son (1954)
"Kinetic Theory of Gases", Kennard, McGrawHill (1938)
Acknowledgements
Light mill image and animation by Torsten Hiddessen.
Thanks to Norman Heckenberg and Bob Ehrlich for useful comments.
No, AntiGuv, the de sitter model proposes universal expansion at exponential rates *forever* (remedial tour here: http://www.site.uottawa.ca:4321/astronomy/index.html#deSittermodel). Didn't happen.
Of course you need several negative stellar masses of matter to make the distortion, so we won't be building this any time soon.
Wormholes are another way, instead of going all the way across space, you take a shortcut. Of course, to keep the wormhole open and stable, you need several negative stellar masses of matter. (Notice a theme here?)
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