Wednesday, October 6, 2010

Einstein's Dream Come True

I remember when I was younger, the bestselling book, Einstein's Dreams by Alan Lightman, spent a few months on our family room coffee table. It inspired many conversations with friends and family and I, a teenager at the time, was especially intrigued because its ideas were represented in such a way that I could grasp them, even if only slightly more significantly, than the ones in my high school science textbooks. Each chapter of Einstein's Dreams being a fanciful rendition of a proposed daydream which Einstein, as a young scientist himself in 1905, likely could have delved into considering his intimate contemplations with time and relativity at that time.

A memory that has stuck with me involves one of its 30 chapters, a chapter about people experiencing time differently depending on the altitude at which they live on Earth. My first interpretation was that people at higher altitudes who make a larger orbit as the earth spins on its axis, would obviously experience time more slowly. With this rationale, people living in valleys making a smaller orbit and would experience time faster than those living up high. For my own proof, I imagined a race track where 2 people, one on the inner track and one on the outer track,  set out to walk one complete lap with the finish line representing death. Who would get there first? The person on the inside, of course. To me, that meant that the people in the valleys (the inner track) would experience time more quickly and therefore live shorter lives. So you can understand my perplexed reaction when I was told that my ideas were in complete opposition to Einstein's theory of general relativity.

As my mother desperately tried to explain that the reverse of my postulation was in fact more in-line with the theory of general relativity, she used one of Einstein's Dreams to illustrate her point. In this dream (based on gravitational time dilation, which is the effect of time passing at different rates in regions where the gravitational potential if different; the lower the gravitational potential (i.e. closer to the center of a massive object), the more slowly time passes) people flock to the valleys in order to live longer lives and eventually, the valleys become crowded civilizations devoid of beauty. Meanwhile a few people, willing to trade the romance of an extended life for the serenity and peacefulness of the mountains, live happier and more contently, albeit for a shorter lifespan at the peaks. At least, that's how I remember my mother recounting the chapter; how close that is to Lightman's description is up for obvious debate. In the end, it all still made little sense to me and seemed intuitively contradictory.

Today I was tickled to stumble upon this recent article, Einstein's theory is proved - and it's bad news if you own a penthouse. Turns out that some scientists at the US National Institute of Standards & Technology have proved Einstein's predictions by placing atomic clocks at different heights and recording their lapsed differences. Their results? Well it looks like a person will age 90 billionths of a second faster (per average lifespan) for every foot above the ground in which they live. Not to be surprised by these findings, because it was never a matter of actually proving Einstein right. There's absolutely no need to do that. What's amazing is that with modern technology we can systematically prove that Einstein was right, just over a hundred years since he was daydreaming about time and space... completely unaware of what lay ahead for the world of science and technology. If he could be here now, what would he be dreaming about?

For further reading, buy the book. Alternatively, here are a couple excerpts from Random House.

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