can some one please explain the big bang theory?

Question

i don't really understand what teachers say happened?

Answer 1

Scientists noticed that the universe is expanding. If it's expanding, that means it used to be smaller. If you keep extrapolating, you eventually get to the place where all the matter and energy in the universe was in a tiny space. The science part is thinking up ways this might possibly have happened, and then testing those possibilities against known physical laws.

Answer 2

Couple people have the right ideas here. Big bang theory is the currently most widely accepted model of the universe. It states that our universe began from a tremendously hot and dense point some 13.7 billion years ago.

Unlike the name, the big bang was NOT an explosion (like that of a bomb or a star going nova), it was an expansion of the spacetime fabric itself. Think of it like a cookie dough. As you cook the cookie dough (spacetime), it expands, and the chocolate chips (representing galaxies) spread apart. That is a simply way to visualize the expansion.

Very early universe (in the order of 10e-34 seconds) went through a massive inflation which increased the size of the universe from smaller than an atom to billions of light-years across. This is called the cosmic inflation, and explains why the universe today appears flat, homogeneous, and isotropic.

Despite some common misconception that big bang originated from nothingness, this is simply not true. The big bang model does not concern itself with what happened before the big bang (or before 10e-43 seconds after the bang, as far as our laws of phyics can tell) or how this energy/matter got there in the first place. All that is irrelevant as the big bang theory explains how universe evolved and formed into the universe that we know and love today.

Of course, there is work in progress to answer what was before the big bang, and newest developements in theoretical physics and cosmology are showing us many different possibilities. Theories like M-theory (superstring theory) predicts that our universe is just one layer of a much larger mulidemensional universes and that collision of giant cosmic membranes maybe responsible for the big bang itself (which makes big bang a fairly common occurance, in cosmic terms).

Fine details of the theory is still being worked out, but the basic premise of the big bang theory has stood the test of science for more than 50 years. It is the best explanation we have of our universe and how it all got here.

Answer 3

The Big Bang Theory is the dominant scientific theory about the origin of the universe. According to the big bang, the universe was created sometime between 10 billion and 20 billion years ago from a cosmic explosion that hurled matter and in all directions

About 15 billion years ago a tremendous explosion started the expansion of the universe. This explosion is known as the Big Bang. At the point of this event all of the matter and energy of space was contained at one point. What exisisted prior to this event is completely unknown and is a matter of pure speculation. This occurance was not a conventional explosion but rather an event filling all of space with all of the particles of the embryonic universe rushing away from each other. The Big Bang actually consisted of an explosion of space within itself unlike an explosion of a bomb were fragments are thrown outward. The galaxies were not all clumped together, but rather the Big Bang lay the foundations for the universe.

Answer 4

The Big Bang Model is a broadly accepted theory for the origin and evolution of our universe. It postulates that 12 to 14 billion years ago, the portion of the universe we can see today was only a few millimeters across. It has since expanded from this hot dense state into the vast and much cooler cosmos we currently inhabit.

Answer 5

Look it up on wikipedia, but basically, 13.7 billion years ago, the universe was a singularity (very dense, microscopic point in space that contained all the matter in the universe) that expanded. Important point - it was not an explosion, it was an expansion. Like blowing up a balloon instead of popping it.

That matter eventually (10,000 years or so later) cooled enough to form atoms - mostly hydrogen, a little bit of helium. These gas clouds collapsed gravitationally to form the first stars, which formed in their cores the other common elements - lithium, sodium, oxygen, carbon - and then the stars exploded, seeding the early universe with these elements. And other stars formed, forming the first galaxies. It was all chemical evolution from there.

Answer 6

Nobody knows for certain what happened. All these people who keep talking about the Big-Bang as if it really happened, are misleading us.
The theory is that in the beginning there was a lot of sub-nuclear (invisible) matter around. Then, for whatever reason, nobody knows why, an explosion happened. And from that explosion visble matter emerged and began (nobody knows why) to accrete (hug one another). Eventually this visible matter kept touching and holding hands and hugging and tongue-kissing that led to having wild sex that produced lots of ready-made accretions (babies) and all the other hard visible world of things around us.
Except for the beginning,this explanation is very logical and based on what Mathematicians and Physicists are extrapolating from in everyday laboratory findings.
The big problem, and it so big that it cancels out all the logic that follows it, is that the explanation of the initial Big-Bang event is neither logical nor scientific.
For centuries the priests told us gods appeared out of the blue to start everything. And now the scientists, having effectively debunked the existence of gods, have become the latter day priests dishing out the same fanciful imaginings. The human mind is never going to stop going round in circles until we stop allowing ourselves to think there was A BEGINNING.
There is no beginning because (1) matter has always existed, (2) matter will always exist while furiously changing its clothes all the time to look attractive in order to get sex in order to make accretions.(See "baby" above.)
This is most comforting (not the sex part, although that, too) because life is matter, and so life has always existed and will always exist. There is life after so-called death. If you postulate a beginning, then you have to accept an end. But if you can accept there was no beginning, you have to accept there is no end. Life is eternal. We will meet again, and again, and again, forever. This is a scientific fact. Gods are not needed in order for life to be eternal. If there are gods that live, it is because there was always life that eventually accreted into gods. (Gods are accretions that skipped the baby-accretion phase. That's why gods are so god-awfully arrogant.) If gods exist, gods did not make life; life made gods.
Forget the Big-Bang rubbish. You have always lived, and you will live long after the Big-Bang has been flushed away as just a lot of hogwash.

Answer 7

The popular theory is that constant observation of the motion of all the stars and galaxies in the Universe, indicates that everything is moving away from everything else. That would imply that, by reversing the motion, everything would end up at one infinitesimally small point. Like reversing an explosion to its beginning...BANG! Or is it GNAB? Anyway, it's also theorized that when all the energy released by this "Big Bang" is depleted, then gravity will take over and pull everything back to that point and that it will start all over again, and again, and again...

Answer 8

the theory is that before there were galaxies, before there was anything, there was this small, very very tiny little ball of energy. thats all there was. and for some unknown reason that little ball of energy exploded, causing energy to be thrown in all directions. some of this energy eventually cooled and once it got around a billion degree it was able to form matter, all the elements.

there are alot more complex parts of the theory involving elementary particles like quarks and leptons, but i have a feeling you dont know what those are, so ill just leave those out.

Answer 9

Once upon a time there was nothing. (I mean absolutely nothing).

Then there was a big explosion.

The big explosion gave birth to the universe.

Answer 10

God commanded and it stood fast!