Posted by Adam on November 17, 1999, at 13:37:35
In reply to Re: science superior to religion? (CarolAnn), posted by CC on November 17, 1999, at 4:04:32
> "God does not play dice with the universe" Einstein.
Einstein made mistakes, just like everybody else. Einstein refused to accept the implications of the uncertainty principle, and thus its complete validity.
However, the uncertainty principle has withstood every experimental test. Einstein initially believed in a static universe, despite the fact his own theories
demonstrated such a scenereo was impossible, and tried to add an additional term to his equations (describing an unobserved repulsive force created by matter and
energy to counteract gravity) to preserve his cosmological preconceptions. When later observational evidence showed unequivocably that this "cosmological
constant" was ill-conceived (though perhaps still useful in explaining what appears to be an accelleration in the expansion of the universe) he described this
as "the worst mistake of my life".>Do neutrinos have mass?
It would appear that they do. Neutrinos seem to exist simultaneously as a mixture of wave states. These waves can shift out of phase, and this out-of-phase mixing
results in a wave of different amplitude, which yields a neutrino of a different type. The only way the waves can shift out of phase is if they represent different
inertial states (one will propogate more slowly than the other), which means they have mass. This wouldn't account for all the dark matter, but some of it.>What caused the big bang?
It just happened. The implications of applying quantum physics to cosmology is that, if the sum of the matter and energy in the universe and the energy of its expansion
is zero, then it can arise spontaneously out of nothing. Virtual particles do this all the time in the vacuum, and if they are created near a black hole, they can become
"real". These things happen because, given certain restrictions (the uncertainty principle), there's no reason why they can't. It makes as much sense to ask "why should
there be a universe" as it does to ask "why shouldn't there be?">What about galaxies accelerating away from us? What causes that?
It is thought that initially the universe was infinitely dense, but that due to quantum fluctuations, this state was unstable. At some point the universe expanded slightly and
thus cooled. This cooling led to a "phase transition" where matter and energy became differentiated through the creation of quantum fields that define the properties of particles.
Given the huge density of matter and energy at that time, these "scalar fields" had an enormous positive potential energy that, in effect, repelled gravitational attraction. This
huge energy density caused space and time to expand, at a rate (according to General Relativity) proportional to the square root of the density of matter and energy. The universe
got very big very quickly (sometimes referred to as the inflationary phase) and then started to slow down as the denstity decreased and gravity became more important. What is
important to remember here is that space and time are expanding, and carrying everything along with it. Everything appaers to be flying away from everything else because the
intervening space is increasing in size. That's why there's no center of the universe and that partly why everything appears roughly the same no matter what direction you look.
Everything is the "center". The center just got bigger.
>How come Quasars give of the energy of 10^10 stars, but are not much larger than a star? What known process could generate that much energy?Quasars have been shown through observations with the Hubble Telescope to be early galaxies with a highly energetic center. It is beleived that extremely masssive black holes
are found at the centers of quasars and that, given the fact we are glimpsing an early phase of galactic evolution, the center of the galaxy is dense, highly dynamic, and that
a huge amount of the matter in the galaxy is falling into the black hole. As the matter spirals in, it gets very dense and moves very fast, creating a lot of energy through
plain old friction, and also releasing a lot of "cyclotron" radiation as particles get accelerated to close to the speed of light. There are still active galaxies to be found
(so-called radio galaxies) relatively close to us, and there is even a powerful radio source near the center of our own galaxy. The origin of this energy is most likely a
massive black hole. It is likely that all galaxies at one time were quasars, or nearly as energetic, and as time passes, they settle into a calmer state like that of our own
Milky Way.>It is estimated we would need a cyclotron or other device that could generate energies around 10^40 eV to get the elusive graviton to show itself, is this possible?
There may be other ways to "observe" the graviton. Observations of the orbital periods of binary pulsars (extremely dense and massive dead stars or neutron stars orbiting each
other) have shown changes predicted by Gen. Relativity to be caused by the loss of gravitational energy through "gravitational waves". So these binary systems are radiating
gravitational energy (everything does, you just need really massive orbiting objects to detect the effect). All matter/energy is quantized. The quanta of gravitational energy
must be the graviton.>Why do galaxies spin more like spokes of a wheel rather than like water going down a drain, that is faster toward the center??
They don't rotate like spokes of a wheel. Things revolve faster near the center due to the law of conservation of angular momentum.
>Are all the forces interacting with matter known?
There may be another force (besides electric, weak nuclear, strong nuclear, and gravitational) represented by Einstein's old cosmological constant. Some astronomers think, due to
unexpected differences in the brightness of supernova in distant galaxies, that light from those supernova is getting stretched out more than can be accounted for by the predicted
rate of expansion of the universe, which should be slowing down. In other words, the rate of expansion may be slowly speeding up, and this might be due to an undescribed repulsive
force. This is a very controversial conclusion, and is nowhere near being resolved, because there may be flaws in the assumptions about star evolution that inform the accelerating
expansion theory.
poster:Adam
thread:14368
URL: http://www.dr-bob.org/babble/19991108/msgs/15390.html