The Einstein paradox

 kw: book reviews, nonfiction, biographies, social media, celebrities, albert einstein

I am presently 76 years old, just three months shy of age 77. That is eight months beyond the age at which Albert Einstein died. He passed away 69 years ago, and it seems that he is more famous now than he was during his life. He was not an entertainer, nor a politician, nor anything else we associate with being a celebrity. Celebrities come and go, and most of those who were utterly idolized just a few years ago have been forgotten.

He was famous in Germany for years before he became hated by the Nazis and had to flee to America. He spent his years in America trying to extend his General Theory of Relativity into a Unified Field Theory, or Theory of Everything. He was working on that the day he died. The brightest minds in Physics have been trying the same thing ever since, so far without success. The only one of them who still holds, somewhat, a place in the popular mind is Stephen Hawking. Sadly, he also passed away without reaching that theoretical Holy Grail.

On an airplane ride a few years ago I sat near a youngish cosmologist. I told him I had a question I'd been just itching to ask a cosmologist; he agreed to hear it. He had already said—in agreement with things I have read—that a Unified Field Theory depends on discovering a quantum of gravity, a "graviton". By analogy with the photon, a graviton is thought to be a boson (a force-carrying particle). So I asked, "If not even photons can escape the gravity of a black hole, and all of a black hole's mass is found inside its event horizon, how do gravitons get out to reach other bodies and attract them toward the black hole? What is the 'emitting surface' of a black hole?" He was silent for half an hour, thinking. Then he said, "I have the beginning of an answer. The emitting surface of an accelerated electron is much larger than the electron, which emits photons with wavelengths thousands of times greater than the size of the atoms about which electrons orbit. By analogy, gravitons must be emitted over an area larger than the event horizon of a black hole." I agreed that it is a good beginning. I hope he has continued to think about it. Such a principle may not be the key to producing a Theory of Everything, but perhaps it is a start.

Einstein's General Relativity theory, that gravity describes the shape of spacetime, rather than being a field (or boson), is quite incompatible with the notion of a graviton! Time will tell. Einstein surpassed Newton. Some future physicist may surpass Einstein.

In the meantime, we have the real Einstein, and the legendary Einstein, to content with. Little did I realize that there is a social media presence in his name. The social media accounts for Albert Einstein are mediated by an interesting fellow named Benyamin Cohen, who has written The Einstein Effect: How the World's Favorite Genius Got into Our Cars, Our Bathrooms, and Our Minds.

Mr. Cohen states that he is not a scientist, and that he doesn't try to impersonate Einstein (unlike some fool I've heard of who impersonates Jesus online and on radio). He posts new and interesting factoids about Einstein, both from others' efforts or from bits of research unearthed at the Hebrew University of Jerusalem, where the Einstein archives are.

Cohen did a bit of traveling to connect with various facets of the Einstein legend and history. Along the way, he got to see some of the remnants of Albert Einstein's brain, which was originally stolen by the pathologist who did the autopsy; he interviewed friends and fellow scientists; he visited a warehouse where Einstein memorabilia are made and sold; he tracked down a few relatives.

In many ways, Einstein was a kind of miracle. As one descendant put it, he got all the good bits and all other Einsteins get genetic leftovers. His fame began, and largely rested, on the astonishing series of articles he published in 1905, his annus mirabilis, on four subjects:

1. Photoelectric Effect
2. Brownian Motion
3. Special Theory of Relativity
4. Mass-Energy Equivalence

It is necessary to dig into each of these very briefly, more briefly than the book does:

1. Photoelectric Effect – When light shines on any material, only the light "bluer" than a characteristic wavelength will eject electrons from it. This proved that light is carried by particles that we now call photons. The color of light we see depends on the energy of the photons. We see only a very narrow range of photon energies, with red being lower energy and blue being higher (about twice as much) energy per photon. Einstein explained how it worked, for which he received a Nobel Prize. 
2. Brownian Motion – Tiny particles such as pollen grains in water jitter continually, as described by a scientist named Robert Brown in 1827. Anyone can see this with a microscope. Later scientists developed the statistical understanding of the particles' motions. Einstein showed that the motions were caused by thermal motions of molecules of water, thus proving that such molecules existed.
3. Special Theory of Relativity – Earlier scientists had worked out some elementary math of the consequences that result if light's speed is constant, relative to anyone observing the light. Einstein formalized the theory, which showed how relative velocity between one frame of reference and another, causes the perceived length of a moving object to change, the rate of time passing to change, and the mass to change. For example, mu mesons (muons) produced in a particle accelerator go farther than one might expect: At rest the half-life of a muon is 1.52 microseconds. But if a muon beam is zipping along at 99% of the speed of light, the half life is seven times as long, about 10.8 microseconds. Without "time dilation" the muon beam would be reduced to ½ strength after 200 meters, and to ¼ strength after another 200 meters. But instead, the ½-strength distance, at 0.99c, is 1,400 meters. Much closer approaches to light speed allow muons to persist much longer.
4. Mass-Energy Equivalence – The famous equation E=mc² encapsulates the idea. Where it becomes practical is with nuclear energy (or nuclear bombs). The "atomic bomb" works by the release of energy of nuclei of uranium or plutonium: when the nucleus is split, the products weigh just a bit less than the original nucleus, and this tiny difference in mass yields a huge amount of energy. This is because c² is a very large number. The "hydrogen bomb" is even more energetic because the percent of the mass of hydrogen released by fusing it to helium is about 100x as great as that from splitting uranium.

This leads us to a paradox in Einstein. He was a determined pacifist. But, once E=mc² became known to scientists, he and others realized that Hitler's scientists could produce a devastating weapon. Thus, he sent a letter to President Roosevelt urging him to begin a project to produce that weapon first. The President did two things: he started the Manhattan Project, and he ordered his generals in Europe to intensify the war against Germany, to forestall their chances of developing an atomic weapon.

Einstein was reserved, disturbed by the limelight, the incessant publicity. He was also subject to a lot of harassment because of his fame. He might be rather bemused by his current popularity. I think he would appreciate that someone like Mr. Cohen is taking care of the social media accounts (none of which existed until about 40 years after he died!).

Here is one way Einstein's work affects us daily. Wayfinding depends on both theories of Relativity. GPS navigation depends on satellites that constantly emit precisely timed signals giving their present location in orbit. Because the satellites are moving, relative to Earth's surface, at about 2.4 miles per second (3.9 km/s), their clocks run slow by a few microseconds per day. The actual velocity of the surface depends on latitude, but ranges from zero at the poles to 0.46 km/s at the equator. All this is corrected for using the math of Special Relativity. Also, the satellite orbits are a 12,500 miles (20,200 km) above the surface, and the lower gravity field causes their clocks to run fast by a few microseconds per day. Correcting for this requires the math of General Relativity. These effects don't quite cancel out. Wouldn't that be convenient! Einstein in the sky!

By the way, I have to correct an error. On page 42 I read, "Let's say your car is moving at sixty miles per hour and headed west. Your phone sends those coordinates to the satellite, which in turn, sends back information on where you need to go…" Not even close! Here's what actually happens:

• There are 32 satellites in orbit (more are planned), in groups of orbits designed to keep three or more satellites in view from any place on Earth, all the time.
• Each carries a hyper-accurate atomic clock.
• They continually broadcast their location and the accurate (to the billionth of a second) time the signal was transmitted.

That is what the satellites do. They do not receive signals from GPS receivers in our cars or phones, nor do they calculate our driving directions. They would need to be huge supercomputers to handle the traffic of billions of devices on a continuous basis.

Your receiver, whether it's a phone or stand-alone, receives signals from satellites it can hear. This is a view from a diagnostic screen in a GPS receiver, showing ten satellites in view, and five being "listened to". Then,

• The receiver calculates the distance to each satellite based on the time signals they send compared to its own clock.
• Each distance implies a sphere in space centered on the satellite's position.
• The receiver does the math to find where the spheres all intersect. That is the position of the receiver. Three satellites can pinpoint one location on Earth; four can pinpoint that location and its elevation; five can refine the position more accurately.
• The receiver updates the screen to show its (your) current position on the map.

When you begin navigating, you tell the receiver where you want to go, and perhaps where you want to start from, or allow it to find out where it is by checking the satellite signals. It then calculates one or more routes from start to finish. Once you choose the route you want, it displays the tracking screen, updating it as you go.

The satellites don't know where you are, or anything else. They just know where they are. Your GPS receiver does all the work.

OK, back to the book. On his various trips, Cohen learned more and more aspects of Einstein's life and the ongoing hype surrounding him and his legend. A lot is there! One company still sells a warehouse full of bobblehead Einstein dolls about yearly. Hats, T-shirts, posters; Einstein look-alike contests. An Einstein exhibit near "Area 51", which is still considered by many to hold a crashed flying saucer. One celebrity attendee told Cohen, "I'm celebrated because people understand me. Einstein is celebrated because nobody could understand him."

That's the bottom line. Nobody understands what Einstein really did, except for a very few physicists who are trying to extend his theories into a Theory of Everything. Perhaps someday somebody will do it, or more likely it will be a collection of scientists. Modern science is too big for solitary geniuses to grasp it all. In the meantime, we have Albert Einstein to look up to, as someone who transcended the bounds that restrain the rest of us, at least a little. Recently, now that most light bulbs have been replaced with LED bulbs, the last patent of Thomas Edison became obsolete; of the thousand patents he was awarded, none are currently in use. Of the four articles Einstein published in 1905, and the General Relativity article he published a dozen years later, all are still in use. Whether we know it or not, we touch the results of his work daily.