Cosmology 101

www.AllAboutScience.org writes: Big Bang Theory - The Premise
The Big Bang theory is an effort to explain what happened at the very beginning of our universe. Discoveries in astronomy and physics have shown beyond a reasonable doubt that our universe did in fact have a beginning. Prior to that moment there was nothing; during and after that moment there was something: our universe. The big bang theory is an effort to explain what happened during and after that moment.According to the standard theory, our universe sprang into existence as "singularity" around 13.7 billion years ago. What is a "singularity" and where does it come from? Well, to be honest, we don't know for sure. Singularities are zones which defy our current understanding of physics. They are thought to exist at the core of "black holes." Black holes are areas of intense gravitational pressure. The pressure is thought to be so intense that finite matter is actually squished into infinite density (a mathematical concept which truly boggles the mind). These zones of infinite density are called "singularities." Our universe is thought to have begun as an infinitesimally small, infinitely hot, infinitely dense, something - a singularity. Where did it come from? We don't know. Why did it appear? We don't know.After its initial appearance, it apparently inflated (the "Big Bang"), expanded and cooled, going from very, very small and very, very hot, to the size and temperature of our current universe. It continues to expand and cool to this day and we are inside of it: incredible creatures living on a unique planet, circling a beautiful star clustered together with several hundred billion other stars in a galaxy soaring through the cosmos, all of which is inside of an expanding universe that began as an infinitesimal singularity which appeared out of nowhere for reasons unknown. This is the Big Bang theory.

Taz writes:Almost universal red shifts. Basically, everywhere they looked, everything was red shifted. The further away the objects, the more red shifted they were.

Taz writes:If everything is expanding at an accelerated speed right now in every direction, it doesn't take a genius to work it backward to a lot smaller and compact universe.

Taz writes:The BBT predicted a very hot, very dense universe near the beginning. If so, an afterglow of this early condition should be found everywhere we look. I can't remember off the top of my head the guys that first discovered it. What happened was they kept picking up a background noise in their instruments. At first, they thought the instruments were faulty, but they couldn't find what was wrong. Then they decided to point the radio telescope to a different direction and they got the same background noise. In fact, everywhere they looked they saw the same thing. BINGO! They found the "afterglow" predicted by the BBT.

Taz writes:No, not all stars. Remember that we are talking in cosmic scales here. Stars are insignificant. We are talking about galaxies, globular clusters, etc.

Taz writes:Because everywhere we look things are accelerating away from us.

Taz writes:HahahahahahaIt's an electromagnetic "noise". It's not sound wave if that's what you mean. It's within the electromagnetic spectrum, specifically microwave.I referred to it as "noise" because in a sense it is noise. Imagine yourself in a party with a lot of people. Every direction you could hear background noises, and clearly these background noises aren't coming from any single source you could identify. That's what the cosmic background radiation is. It's clearly not coming from any single source that we could see. Yet, everywhere we look it's there at 3K.

Taz writes:Just to get something clear, no part of the electromagnetic spectrum can be "heard" by the ear.

agobot writes: The strentgh of the fundamental forces in the universe(force of gravity, speed of light, strong nuclear force, weak nuclear force, proton mass, etc.) is so finely tuned(to support life?), that the only good explanation for the existence of these finely tuned conditions besides god, would be a multiverse and multiple big bangs giving rise to multiple universes.

Taz writes:Because everywhere we look things are accelerating away from us.

Alasdair to Agobot writes:"How peculiar", thought the puddle. "This hole I am in is perfectly shaped to hold me. Obviously it was specially designed for me and only me to fit inside of it"

Agobot to Alasdair writes:That's not even funny. What would you think if you saw a perfectly shaped pentagon puddle?

Agobot writes:If it's so easy to win the lottery, why is none of you a lottery winner yet?

Agobot writes:How many puddles will it take till you get the perfect pentagon shape?

agobot writes:How many puddles will it take till you get the perfect pentagon shape?