the big bang theory happened 15 million years ago.how might scients been able to determine this?
2007-09-10 12:10:18 · 9 answers · asked by **ic** 4 in Science & Mathematics ➔ Astronomy & Space
Not million. Billion.
Scientists look at the Universe now and backtrack. Knowing what we do about physics, there are reasonable speculations about the nature of the Universe when it was only 10e-44 seconds old.
2007-09-10 12:14:59 · answer #1 · answered by Brant 7 · 2⤊ 1⤋
dont listen to all of the people saying the big bang isnt true. its true that its a theory so u can prove it wrong sure, but its well supported by scientists and pretty much anything in the universe.
it happened about 13.7 billion or so years ago.
they can determine this by the fact that the galaxies are moving away from eachother and how fast so they can just backtrack and see how long it wouldve tekn them to reach the spots they are at.
and heres some evidence for the big bang that no one on here except a few ppl seem to take into consideration.
1. the galaxies are all receding from eachother, what else could cause this except a massive explosion? nothing.
2. the amount of hydrogen and helium in the universe is rpetty much exactly what the theory predicted it would be.
3. since space is a vaccum the tempurature should be absolute 0. but its not, its 3 degrees above that. that heat is leftover radiation from the big bang.
4. in the 90's a the cosmic microwave background was taken. its basically a map of all the microwaves (not microwave ovens...) in the universe. it turns out that the CMB was exactly like the big bang theory said it should be like.
thats only 4 of the main pieces of evidence, there is alot more.
2007-09-10 13:49:06 · answer #2 · answered by Anonymous · 1⤊ 1⤋
They look at the furtherest star and then speculate how long it takes for free protons and electrons to form hydrogen and for hydrogen to gather into one area and they add that amount of time to the furtherest known star and speculate that is the time line.
It is generally expected that it took about 500 million years for the first stars to form from the cosmic Plasma, based on what we know about physics.
There is certainly room for error. The error can be 10 or even 100 times as much as the current minimum.
So the furtherest known stars are around 14 to 14.25 billion light years so they assume the universe end was 14.5 to 14.75 billion years.
In actuality it could be as much as 20 or 30 billion light years.
See there is no way to actually measure the distance to the Cosmic or Gamma Radation the was first emitted.
One day there might be, but today, no.
So we go by stars and what we assume based upon Hydrogen Bomb explosions.
The assumption is something like this
IF small amounts of heavy matter (grains of the singuarity) were thrown out near the speed of light (say at the speed of Quasars which are 3/4 the speed of light) how long would it take that mass to attract free protons and electrons and how long would it take them to meld and become hydrogen and how long would it take to form a large bubble of hydrogen taht gets compressed and starts a smaller fusion reaction (becomes a star).
There is some math to back it up, but it's ALL hypotheical.
The figure of just under 15 Billion Light years is a minimum.
Some view the maximum as twice that or 30 billion.
Thus the Universe is anywhere from 30 to 60 billion light years in diameter and moving outward at the speed of light.
In the time it took you to read this the universe expanded 1 to 2 billion miles.
2007-09-10 15:39:00 · answer #3 · answered by Anonymous · 0⤊ 0⤋
the big bang theory has a lot of holes in it. it is becoming less and less popular, but it is still our best guess at what happenned to create the universe. scientists have backtracked, if you will, the movement of out galaxies, stars, planets, ect. beleice it or not, out univese is expanding right now this very moment and will never cease to stop! this is the major point of the big bang theory. hope this helps
2007-09-10 14:47:44 · answer #4 · answered by Kate S 2 · 0⤊ 0⤋
Yes, about 15 BILLION years ago.
(1) Scientists backtrack the motion of the galaxies. It looks like 13.8 billion years ago, they were all in the same place.
(2) They look at the ratio of hydrogen to helium (and other elements) in today's universe, and figure out this ratio could be made. It turns out the everything being crunched together 13.8 billion years ago would explain the ratio.
---- (added later) ----
If I understand souljourner answer below, it's like saying they keep changing the train schedule, so it must be that trains don't exist.
2007-09-10 12:23:30 · answer #5 · answered by morningfoxnorth 6 · 1⤊ 1⤋
Oops.....Error.
Not 15 Million...
Correct that to about 15 Billion Years Ago.
If almost all of the objects you see in space with telescopes are moving away from a central point, then it is possible to reverse their movement using math and calculate where they came from and about how long they would have been traveling to get to that original point....THAT'S HOW.
2007-09-10 12:23:55 · answer #6 · answered by zahbudar 6 · 0⤊ 1⤋
Sorry, the big bang theory is less than 100 years old. Please rephrase your question.
2007-09-10 13:29:32 · answer #7 · answered by Renaissance Man 5 · 0⤊ 0⤋
the big bang is a bust, they keep moving the date
2007-09-10 12:31:36 · answer #8 · answered by souljourner 5 · 1⤊ 2⤋
Lol they cant! its all theory.....
how can they tell this and that about the earth IF everything they use is manmade????
2007-09-10 13:24:40 · answer #9 · answered by Anonymous · 0⤊ 1⤋