Elegant Universes, the Speed of Light, and a Big Announcement
A weird universe, and some great news.
Quote of the Week
Slim, having just spent all his savings on a new Trans Am, goes with his brother Jim to the local drag strip to give the car the kind of test-drive forbidden by the dealer. After revving up the car, Slim streaks down the mile-long strip at 120 miles per hour while Jim stands on the sideline and times him. Wanting an independent confirmation, Slim also uses a stopwatch to determine how long it takes his new car to traverse the track. Prior to Einstein's work, no one would have questioned that if both Slim and Jim have properly functioning stopwatches, each will measure the identical elapsed time. But according to special relativity, while Jim will measure an elapsed time of 30 seconds, Slim's stopwatch will record an elapsed time of 29.99999999999952 seconds—a tiny bit less…. On another test run Jim uses a clever trick to measure the length of Slim's new car: he starts his stopwatch just as the front of the car reaches him and he stops it just as the back of the car passes. Since Jim knows that Slim is speeding along at 120 miles per hour, he is able to figure out the length of the car by multiplying this speed by the elapsed time on his stopwatch. Again, prior to Einstein, no one would have questioned that the length Jim measures in this indirect way would agree exactly with the length Slim carefully measured when the car sat motionless on the showroom floor. Special relativity proclaims, on the contrary, that if Slim and Jim carry out precise measurements in this manner and Slim finds the car to be, say, exactly 16 feet long, then Jim's measurement will find the car to be 15.99999999999974 feet long—a tiny bit less.
From Brian Greene’s The Elegant Universe
These entertaining thought experiments are common in Brian Greene’s book, The Elegant Universe, in which the Columbia University quantum physics specialist sets out to try to help us wrap our reptilian brains around the mind-bending concepts often at play in modern physics and string theory.
I’ve been re-reading Greene’s compelling book as I re-work my essay “Parallel Universes”—expanding and broadening it, as I am with many of my fly fishing essays.
More on that shortly in my big announcement at the end of this post.
These passages come well before Greene really delves into the mysteries of a world with potentially up to 10 or 11 dimensions, 7 or 8 more than the standard height, width, length and time we know so well, dimensions that remain “wrapped” up on themselves and which we have no capacity to see (or even to fully visualize).
Greene provides these creative examples to help us begin to grasp just how radical Einstein’s pre-quantum physics theories were (which opened the door to the quantum realm, a door he, however, refused to enter). While working at a patent office in Switzerland, the 26 year old Einstein discovered that light, time, and space were remarkably weird, interacting in fundamentally counterintuitive ways. The passages above demonstrate something that remains as breathtakingly odd now as it was in 1905, when scientists read Einstein’s papers and knew that everything they thought they understood about physics had changed.
Yes, the faster you go, the slower time moves. And, if that weren’t enough, the faster you move, the smaller you become. These are measurable, verifiable facts.
Greene employs another brilliant example to help us conceptualize this, a kind of “clock” consisting of a single bouncing photon. The figure above demonstrates how moving this photon clock, elongates the movement of the photon, no longer traveling simply up and down, but now at an angle—taking longer to arrive at the top/bottom—hence time slowing down.
A second Einstein principle Greene addresses was that unlike the strange relationship between motion and time and stationary and moving objects, the speed of light is not relative. While this is not on the surface as radical as the time-bending nature of motion, it’s equally jarring and perhaps even more strange.
If you use a radar gun to clock a car going 100 MPH, and you are stationary, it will read 100 MPH, but if you are driving away from the car at 90 MPH, it will read 10 MPH (the speed it is going relative to you). This ordinary, logical way of thinking about motion and speed doesn’t work for light, however.
Light moves at a speed of about 670 million miles per hour, and will always be measured at that speed no matter how fast you are moving toward or away from it.
If you could jump in a craft that could somehow move at, say, 660 million miles per hour and measure light’s speed, it would still be 670 million miles per hour (not the expected 10 million miles per hour). (Insert “mind-blown” noises here).
Greene uses a wonderfully amusing thought experiment of astronauts “George and Gracie” floating through outer space to help explore the far-reaching consequences of these theories (and other concepts).
In addition to these, Greene charts how Einstein also upended Newton’s theories of gravity, envisioning it as acting on a vast membrane of “space-time” upon which all matter resides—as objects of different mass might interact with each other on a taut, thin cotton sheet.
I’m impressed with how accessible Greene manages to make these concepts, even as he delves into the still more strange and counterintuitive world of quantum matter, and rereading the book has certainly helped me expand and enrich my essay. I’m also reminded of how little we really understand about the basic structures at the core of us, the stuff we are fundamentally made of—all those spinning, electromagnetically vital, infinitesimally small particles whose physical behavior can only be measured and known in terms of probabilities.
Now The Big News
I’m reading Greene and revising “Parallel Universes” and other fly fishing essays (many of which have appeared here) because I’m delighted to announce that my book of fly fishing essays, Two Thirds Water, will be published by Lyons Press! They are a long-time publisher of fly fishing literature, established by the legendary writer, fly fisherman and publisher, Nick Lyons. Nick himself, now 91, read and enjoyed the book, recommending it to his former press (and he has even agreed to say a few words on the jacket cover). The book should hit bookshelves sometime next spring. I’m thrilled, and I’ll be sure to keep you posted.
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Outstanding! Congratulations.
Arnie! Congratulations on getting published! Truly impressive.