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Q & A: pie in the sky

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Most recent answer: 10/22/2007
Q:
Dear Sir I now have a question concerning the universe. I have created a theory called the "pie vector theory" of the big bang. It’s a theory that is constructed to supposedly be able to validate or invalidate the big bang theory. This is the theory. Draw a big circle on a sheet of paper. Now put a dot in the middle of the circle to represent the origin point of the big bang. If the big bang is true it would explode in all directions creating a expanding pie universe. Now draw a line from the dot to the edge of the circle. Then on the middle of that line put another dot that represents the Earth and The sun. Now any gases or stars that blew out of the big bang before us would be ahead of us on that line, and those stars would appear like they are moving away from us. Any gases or stars that blew out of the big bang after the earth would be behind the earth on that line and would appear to be moving toward us. Now draw two more lines from the origin dot of the big bang that are at 10 degree angles to the earth line you drew (one line on each side of the earth line). Now draw a circle around the dot representing the earth with the edges of the circle within the 10 degree angle lines but touching them at the same time. That small circle represents all of the visible universe to us from the earth with our most powerful telescopes. As you can see that small circle only represents anywhere from 1% to 5% of the entire universe supposedly created by the big bang. Now lets focus on the 10 degree lines running on each side of the earth line. All gases and stars on that line that were blown out of the big bang about the same time that the earth and sun were should be traveling about the same speed as our sun, but should look like they are slowly drifting away from us as the 10 degree angles move our sun further apart from those stars. The question is this using the "pie vector theory" could one measure the directions of all the stars around the earth, and if the stars are not behaving like the "pie vector theory" says they should, this should disprove the big bang theory. Does the "pie vector theory" seem like a plausible theory, and could it make a good measuring device to either validate or invalidate the big bang theory? Any insights or answers you have would be greatly appreciated. If possible could you send the answers to my email address also. Thanks Mike
- Mike (age 39)
Grayson County College, Sherman, Texas
A:

Mike- That’s a good start in trying to think about the Big Bang, but there are a few mistakes in how you analyze the pie picture, and the standard physics picture is somewhat different in fundamental ways.

Let’s start with your pie picture. Let’s take it a step toward being a picture of the standard BB by saying that everybody leaves the from the same starting point with different velocities, not at different times. Then some of your conclusions about the relative velocity of our neighbors to us are right but others are off a little. In this picture where everybody picks up a fixed velocity at the start and those velocities don’t change everybody’s current displacement from us is just the time since the bang times their velocity difference from us. What we see from our point of view is just that velocity difference. So that leads to an even simpler effect than the one you describe, but very much along the lines of what you were after: The current velocity relative to us is a universal constant times the displacement from us.

That’s called the Hubble law. It’s approximately true, and was the first major piece of evidence for the Big Bang.


There are some obvious small corrections to take into account all the small-scale motions in more ore less random directions. There are more important, deep corrections to take into account that the geometry of our universe is given by General Relativity, not Euclid. In addition, there are a collection of fascinating corrections due to understood and not understood physical effects.

However, the general first-glance picture of the Hubble effect is well captured by your pie picture, so long as you analyze it carefully.

Mike W.

Have a look at a nice article on the Big Bang, which is still fortunately available online (at least for the moment) at https://hubblesite.org/contents/articles/the-big-bang.

Tom


(published on 10/22/2007)

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