There is one thing humans have relied on, well beyond the standard cliché of death and taxes. It is the universal standard of a second as an enduring constant across cultures and time. Some extremist with a jittery trigger finger can do us all in, but the clock will still tick and the earth will still age. As it was in the beginning, now is and ever shall be.
At least that was my complacent world until you and your astrophysicist colleagues informed me that a second slows down in space. You called it time dilation, first detected in sub atomic particles moving at lightning speed. Naturally you wanted to share this triumph of physics with a lay audience, but how to dumb it down? Your solution was to blithely announce that astronauts do not age in space. An astronaut returning from Mars would youthfully spring from his capsule to greet his identical twin, now decrepit and feeble.
I have never been able to believe something so fantastical. This example also propelled you into an other-worldly level of intelligence that normal humans dare not enter. Frankly, I felt patronized by this “twins separated by space” example, so bizarre that it forced me to place blind faith in the inaccessible intelligence of astrophysicists.
Dr. Hawking, I needed a believable explanation, something that I could drop into a cocktail conversation and then vicariously bask in the exalted intelligence of an astrophysicist. A suitable opening would be hard to find since casual chatter rarely veers into astrophysics. But if someone uses the cliché “you know it’s not exactly rocket science,” I could be ready to pounce with “You know, rocket science is really not as complicated as you might think. Here’s a simple explanation.”
I hustled off to the library to consult your best seller “A Brief History of Time,” and even better the companion volume “A Briefer History of Time,” with the appealing subtitle, “The Science Classic Made More Accessible.” However, I am sorry to say that your two books – and I even looked in the children’s library to see if there was a third even more basic book – only got me part way there. I could see that you were trying very hard with your thought exercises that involved playing ping pong on a moving train, but you lost me when you added graphs, arrows and flashing lights.
I know your problem. You know too much and you are getting in your own way. You and I are similar in this way. I have fallen into the same situation with my vast knowledge of knitting. Sure I could delve into the history of knitting and talk about the relative merits of synthetic or natural fibers or I could talk about all sorts of fancy stitches – yarn-overs, intarsia or brioche. I would love to share my enthusiasm with an appreciative audience. But I have seen that glazed look – I am sure that you have seen it too. For a general audience of non-knitters, I keep it simple and explain just one stitch – the knit stitch. Well maybe I would add in the purl stitch also. You can create a stunning garment with these two stitches. But no more than that.
I think I can help you simplify your time dilation discussion. My AHA! moment came when I discovered nothing can travel faster than the speed of light. Let’s build on that to create one of those thought exercises that physicists love.
Imagine that a stationery person is watching me on a moving walkway at the airport, and then imagine that the walkway is moving at the speed of light. Stay with me here –also imagine that I am running late, so I start to stride along, adding my walking speed to that of the moving walkway. Now I would be moving faster than the speed of light, and that’s just not possible.
Here’s the big finish. I think that we can all agree that rate x time = distance. But something must give when the distance is fixed and the rate appears to be faster than the speed of light. And it is time. Time on the walkway slows down compared to the stationary person. Done!
Dr. Hawking, I know that I have over simplified, but frankly that was my goal. You see, I’ve gotten people interested in knitting just based on one stitch, and astrophysics should be no different. My explanation has been well received at cocktail parties with lots of appreciative nods. In fact, feel free to use my example in the next edition of your book.
However, my major take away is that time dilation has no practical implications for human aging. The twin astronauts were a bad example and unnecessarily upended my world. A second is really a second. One chimpanzee, two chimpanzees, relentlessly for millions of years.
Therefore, please add the following caveat to the next issue of your book.
“You have probably heard the saying that astronauts don’t age in space. While traveling near the speed of light does have funky effects on time, any anti-aging effects on humans are negligible and a clear overstatement of facts for dramatic purposes only. On behalf of all astrophysicists, I would like to apologize for this exaggeration and any associated misconception that physics is only for the cerebrally endowed.”
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