Okay, here we go....(BTW, I'm close to finishing an undergrad physics major, so shoot off any questions you have....I'll vainly attempt to answer them
)
1. The term "Big Bang" is somewhat of a misnomer...it implies an explosion. It is really an expansion out of nothing, forming all matter, energy and forces. Before the Big Bang, there was nothing....no matter, no energy, no time, no forces (gravitation, electromagnetism, weak nuclear force, strong nuclear force). Initially, the four forces were combined into a theoretical Higgs field (some recent developments at CERN point to evidence of its existence)...after a tiny fraction of a second, gravitation and electromagnetism broke off into distinct forces, followed by the division of the strong and weak forces.
Anyway, all of these aspects would not exist beyond the "edge" of the universe...though it's hard to say if an edge exists, because some physicists believe that a Big Crunch (the possible eventual collapse of the universe) will cause another Big Bang...this process may have been repeating itself for an infinite amount of time. But all observations seem to point that the total mass of the universe is not enough to cause a Big Crunch (even accounting for 10:1 ratio of dark to normal matter). Of course, a lot of this stuff is
highly theoretical, and cannot be taken for fact.
2. Some of Einstein's developments:
- Photoelectric effect (he actually won the Nobel prize for this one, not Relativity). Included with his first paper on Special Relativity, Einstein explained the photoelectric effect, in which an energetic UV light can cause electrons to eject from the surface of a metal. Previous classical explanations, assuming that the energy of the emitted electrons would be proportional to the intensity of the light, ran into problems. Einstein showed that the energy of the electrons was proportional to the frequency of the light by the relation E = hf (h = Planck's constant of 6.626 *10^-34 Js).
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Special Relativity: Einstein's first paper on relativity re-wrote Galilean relativity. It is based on the transformations between different frames of reference. As I sit here, I am in one frame of reference; a person sitting in a plane passing overhead is in another frame.
If I were to transform the coordinates of my frame to another frame, they are related by
y = (1-v^2/c^2)^-.5, where v is my velocity (as a fraction of the speed of light) and c is the speed of light. Many of the results are based on the fact that the speed of light is constant regardless of the velocity of the source (see below about my feelings about the supposed faster-than-light signal). This is because light is composed of an oscilating electric field and an oscillating magnetic field moving perpendicular to each other. The changing electric field creates the changing magnetic field, which creates a changing electric field, and so on. The velocity of this propogation is (e*u) ^-.5, where e is the fundamental constant of electric fields and u is the constant of magnetic fields. Based on this relation, the effects of travelling near the speed of light are as follows:
t = t' * y
This is called time dilation. Since it is impossible to tell if you are moving when you are in a non-accelerating frame of reference, you will always think time is passing normally. But if I was actually in a rocket moving at .9c, time for me would pass 2.3 times slower with respect to a person in a constant frame. Thus, if I travelled for one year in the rocket, when I return to Earth I would find that I was gone for 2.3 years.
L = Lp/y (Lp is proper length, L is apparent length)
This is length contraction. If an object 2.3 meters long were travelling towards me at .9c, I would perceive it to be 1 meter long. The object doesn't actually shrink, it just looks that way.
p = y * mv (p is momentum, m is mass, v is velocity)
E = y * mc^2
(mc^2)^2 = E^2 - (pc)^2 (invariant mass)
These equations are the modifications of momentum and energy in a relativistic frame. They are important in subatomic particle collisions, where the resultant particles are moving in different frames with repect to each other and the initial particles.
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General Relativity: This redefined Newtonian gravitional with the results from Special Relativity. It states that near a gravitional source, time slows and length contracts.
About the discovery that occurred over the summer showing a light pulse moving faster than light: many people may think that this complete invalidates Einsteinian Relativity, and that physicists are scared by this prospect, but both ideas are false. The analogy can be made with the transition from classical physics to modern quantum and relativistic physics. At the end of the 19th century, physists thought they knew everything they could know about physics. But Planck, Einstein, Shroedinger, and others showed that Newtonian physics is wrong. But in no way does this make everything Newton did obsolete; in most real world senarios, it is much easier to use Newtonian physics for motion, even though it isn't
completely inaccurate. Eisteinian Relativity has been proven countless times, and is used in GPS systems, particle accelerators, nuclear power and devices, and in many other applications. Even if it is ultimately shown that something
can travel faster than light, it has been shown that Einsteinian physics works in a vast majority of cases. It will still be used a lot, even though it might not be complete...the more complete form of relativity that might be developed will have to be used in the special cases. For me, the prospect of a new form of relativity is exciting.