Ben bought me a “This Is Too Good Not To Share” gift, which arrived in the mail late last week.  It’s The Elegant Universe, a book by Brian Greene about the string theory.  It attempts to explain everything from Einstein’s disruptive conclusions that space and time aren’t what we’ve always thought up to today’s superstring theory, which (although still being developed) may prove to be the ultimate “theory of everything” that describes all matter and all forces in one neat package.  If a dozen or so dimensions can be called “neat”.

It’s a fascinating and very readable book, aimed at the non-scientist, people with little or no mathematical background, who are just curious and don’t actually intend to build bombs or time travel.  But be prepared to stretch your mind!  He hasn’t even gotten to strings yet, he’s still describing Einstein’s theory of special relativity, and already I’ve had to do some numbing mental yoga to keep up.  To his credit most of the questions I’ve had along the way have been answered a few paragraphs later. 

One question he hasn’t answered yet:  if nothing can travel faster than the speed of light, and if “speed” (as he says) is always a relative term (your speed relative to an observer) then what would happen if George sped away from me at 99.5% the speed of light in one direction, and Susan sped away from me at 99.5% the speed of light in the opposite direction?  Wouldn’t their speed relative to each other be faster than the speed of light?  Similarly, Greene describes how in a particle accelerator we can make particles go at 99.5% the speed of light.  What if the “particle” we accelerated was itself an accelerator–it should be able to accelerate its own particle to 99.5% the speed of light, but then that particle would be moving away from us at nearly double lightspeed.  I don’t understand that yet, but I trust I’ll have my trust validated later in the book.

Last night’s reading was finally something that at least felt neat:  apparently everything in the universe (including you and me) is travelling at a constant speed–the speed of light in fact–in four dimensions (time being the fourth dimension).  If you’re sitting still then all your motion is in the time dimension.  But as you go faster in one of the other three dimensions, in order to keep your total speed constant you slow down in the time dimension.  That’s why we’ve all heard that if you were to travel at 99.5% the speed of light time would slow down for you relative to time for the rest of us on earth watching you leave.

Like I said, it feels neat, even if you have to take a bit of a leap of faith to grasp it and move on to the next chapter.

Perhaps it’s best summed up in the words of George Johnson who wrote in the New York Times Book Review:

[Greene] has a rare ability to explain even the most evanescent ideas in a way that gives at least the illusion of understanding….

Definitely a good read for anyone of a curious nature.  I may share more insights here if the rest of the book is as gripping as the first two chapters have been.

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