How did the scientists come to evolve the definitive facts on the existence of the universe?

Answer 1

It is as doug states, except that nothing is ever "definitive".

The best we can do is establish bounds (upper and lower) and work at making these as close together as possible.

"...on the existence of the universe."

We infer that the universe exists because we are in it and we can see, "hear" and feel it. Also, we can confirm that different people do see, hear and feel pretty well the same things (within very close bounds).

For example, we can see the sun. We can feel its heat. We can "feel" its impact on things (e.g., the way chlorophyl captures some of the energy and turn it into chemical energy, which eventually becomes our food).

We can measure the quantity and quality of the sun's light and determine that its surface has a certain average temperature around 5780 K (9945 F). It does not really matter if I do the observation, or if you do it or if Fred, over there, does it.

Is it exactly 5780 or is it some other value between 5740 and 5820? Depending on how many decimal fractions you need for calculations, I guess we will never have a "definite" answer. But we will get closer and closer to the real value (I remember when I was younger, we were happy with "it is somewhere around 6000 degrees")

Once we know that, we can determine the quantity of energy that must come off each square metre of the Sun's surface in order to explain this temperature. Once we know the total surface area of the sun, we can figure out the total output (3.85 x 10^26 Watts).

Once we have that, we can try to figure out what can produce this much power for such a long period of time. The only thing we can think of is fusion at the Sun's core (4 hydrogen atoms turning into one Helium atom, with lots of energy being released).

The other processes that were proposed as explanations all had problems. For example, it is possible to generate that much power from simple gravitational sinking (heavier atoms sinking to the centre of the Sun would release gravitational energy). However, if that were the energy source, we would have been able to observe a measurable change in the Sun's diametre over a human lifetime.

So, we produce theories, then eliminate those that don't fit the observations.

We do this for planets, stars, galaxies, clusters of galaxies and, eventually, the universe.

We may never know the "definitive" facts, but we can get very close and we can eliminate the theories that do not fit what we actually observe.

That is how we come to draw the picture of what we think the universe is like.

Answer 2

Phenomena can be observed =that is a fact.
What facts means is subject ot interpretation ;Just like a Jury in a court of law. They look at the facts and what they conclude can be a complete jumping to conclusion Before the Facts.
Evolution of things are not spontaneous but rather forced functions, following a probability distribution.
Nothing is Certain in science .All our formulas and equations are only approximations.
As far as the Existance of the Universe we know very little about its Creation.As the Cosmologist were not there to withness it.
We cannot really understand much about creation Beyound what was revealed to Us By our Creator of the Universe in the Biblical record of Creation.

Answer 3

I agree with Raymond ... nothing in science is ever "definitive". We are always refining, revising, adjusting, finding new things to explain, and occasionally discovering better (simpler) explanations for things.

If by "existence of the universe" you mean the *origin* of the universe, you should read a bit about the history of the big bang theory. Very roughly it went like this:

1. From about 1912 on we've been discovering extremely distant objects that are moving away from us ... and from each other. In fact, the further away an object is, the faster it is receding away from us.

2. In 1924 Edwin Hubble confirmed that these distant objects were in fact other galaxies just like our own Milky Way.

3. In 1927-1931, Georges Lemaitre, a Catholic priest and astronomer, working with equations derived from Einstein's equations, predicted that the recession of the galaxies was due to the fact that the universe was expanding. He also proposed that the universe must have begun as a sort of explosion of a "primeval atom" ... one of the first formulations of the big bang theory.

3. In 1929, Hubble further confirmed the expansion of the universe through observations, establishing Hubble's Law, which observes that the more distant the galaxy, the faster it is receding from us, and from each other.

4. This led to a conflict between two alternative explanations for the expansion. One one side was Lemaitre's "primeval atom" concept, as further developed by George Gamow, and on the other side was Fred Hoyle's "steady state" model where new matter was being created continuously.

Hoyle in fact coined the term "big bang" (in 1949) as a way of ridiculing the exploding primeval atom idea.

5. In 1948, two associates of Gamow, Ralph Alpher and Robert Herman predicted that the energy from the big bang should still be detectable in the form of a cosmic microwave background radiation (CMB) with certain characteristics (it would be radiating from all directions, and at a certain radiation temperature).

6. In 1964 the cosmic background radiation (CMB) was detected and measured to be pretty much as predicted by the big bang theory. This pretty much confirmed the big bang theory, and eliminated the steady state theory.

7. Since then, additional evidence has further confirmed the big bang theory. For example, the distribution of the lighter elements (hydrogen, helium, lithium) and certain isotopes is within the range predicted by the equations of the big bang theory, and the fact that certain primordial types of astronomical bodies (like quasars) are all found at very far distances (there are no nearby quasars).

Answer 4

One fact of the universe is that we are here.
The fact that it is a quantum universe mandates that it must have a maximum and a minimum size.
Scientists attempt to go back to time zero to find an explanation for what we see.
Some good theories are out there but likely the origin of the universe will always remain speculation.

Answer 5

By observation and application of the Scientific Method.

Doug

Answer 6

By the "BIG BANG" theory.