## Relative To What?

Apparently the universe is 13.8 billion years old and has a diameter of 92 billion light years.

If we accept the Big Bang Theory (the principle not the TV show) the universe formed by expanding from a single incredibly dense focus out to the magnificent vista we see today. According to that master of relativity, Albert Einstein, it is not possible to exceed the speed of light (disputed of course by numerous science fiction authors and the cast of Red Dwarf). 46 billion light years, the radius of the universe, is the distance that light travels in 46 billion years. Consequently, if the universe began from a point source i.e. the Big Bang, and could not travel faster than the speed of light, it must have taken at least 46 billion years to get as large as it now appears to be. To do it in 13.8 billion years implies faster than light travel, does it not?

Don’t think for a minute that I am advocating some kind of imaginary friend creationist approach. I just don’t get the math. I have always found physics to be the science of making things up, that no one can prove or disprove (quantum mechanics, string theory, anti-matter, dark matter, etc.), in order to explain all the things we can’t make up. Now that does sound alarmingly like religion!

Dr. F. Bunny

1. #1 by Joe 'Blondie' Manco on 18/09/2013 - 12:02 pm

I started saying that what we see as 13.7b light years away was actually that far away 13.7b years ago and right “now” would be further away but then I realised I’d reached the same dilemma you’re questioning (wouldn’t that mean the universe is older than 13.7by?)

http://www.astro.ucla.edu/~wright/cosmology_faq.html#DN – This attempts to answer your question, and others similar, but I guess you have to get physics.

Can’t say it’s not mind-boggling stuff.

2. #2 by vetsbeyondreason on 19/09/2013 - 8:11 pm

Thanks for the link and attempt to uncloud my mind. Unfortunately I am going to need the version that comes with pictures, words of one syllable or less, and definitely no equations. I do, however, feel vaguely reassured that it makes sense to someone.