I was going to do this as a comment to a post in Peldredge’s blog, but it seems a bit long for that so I will try to explain how to measure the universe here.
The universe encompasses everything, and there is nothing outside the universe. Energy is part of the universe and exists; it can not be created or destroyed, only altered.
Energy can travel at the speed of light for a long time and still be in the universe because where ever it exists, so does the universe. Entropy slows things down to the point to where this energy stops moving. Because energy can only be altered, the light becomes something else. Maybe matter, I don’t know.
Gravity kicks in and everything begins to collapses together, accelerating to the speed of light as it approaches the universal center of gravity. An overload occurs when everything in the universe attempts to occupy the same space at the same time, resulting in something like a big bang. This big bang produces energy, which begins to travel, or disperse, again and we start the process all over.
If you accept the forgoing, it should be simple to figure out how big the universe is. Just figure out how long it takes energy (in the form of light) created in an event so cataclysmic as to produce an abrupt change from matter into energy, to slow down (entropy) and become matter again. Call this period of time something like “T” for short. Multiply “T” by the speed (“S” for short) of light and you should have the at least the long dimension of the universe. As a bonus, let’s figure out the interval (let’s call this “I”) between big bangs. Simply multiply T by two, because this is a round trip ticket. If the speed of light and rate of entropy are constant factors, and the current age of the universe is known, we can now predict the next big bang.
Or we can forget all this and just say it’s a big, old universe and leave it at that.
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