Einstein's fabulous century

The dance of the stars.

Last Wednesday night, Thanksgiving eve, a beautiful, full, Frost moon filled the evening sky. A luxurious carpet of stars painted a gaudy background, slowly spinning about the North Star. We were witnessing Sir Isaac Newton’s Universal Rule of Gravitation,  which determined the tracks of these myriad celestial objects based on their mutual gravitational attraction. Newton shook up the religious hierarchy in 1686 when he presented an alternative to heavenly marshalling of the skies.

Physics had supplanted the bible with a simple explanation of celestial attraction. And so we thought for well over 200 years.

But then, on November 25, 1915, Albert Einstein demolished classical physics when he presented his General Theory of Relativity, one hundred years ago. This ended our view of a static universe and opened our eyes to the spectacles of quasars, black holes, and the notion that gravity was the result of warped space-time, not a mutually attractive force. And of more practical importance, allowed us to use our GPS smartphones to navigate to the nearest Dunkin Donuts with a high degree of accuracy.

Einstein was not a gifted mathematician and relied on his friends to help him work out the difficult non-Euclidian geometry of his theory. But he was a brilliant thinker and a gifted visualizer, with an intense curiosity about how things worked. As a 16-year-old, he tried to visualize what he would see if pacing a light beam, something his high school peers couldn’t even conceive.

Einstein built his grand theory on two basic propositions:

       1. That the speed of light is constant, and;

       2. That gravity and acceleration are equivalent.

The first is based on the work of James Clerk Maxwell and others, but Einstein generalized the concept. It is very counterintuitive to us, who know that a pitcher throwing a 90 mph fastball from a 60 MPH train will deliver a 150 MPH heater to a catcher beside the tracks. But according to Einstein, a light beam launched from this train will always travel the same speed, regardless of what speed (or direction) the train is traveling.

While this is challenging to wrap our minds around, it is due to the nature of electromagnetic force (EMF) propagation. Light and heat and radio waves, all forms of EMF, traverse space by a process of alternating electric and magnetic fields, which build and alternately create further fields. The rate at which this process occurs is the speed of light, irrespective of the speed of the source. It is as if the pitcher’s fast ball would always be received by the trackside catcher at 90 MPH, regardless of the speed (or direction) of the train.

The second point was anecdotally observed by Einstein when he saw a roofer working far above the street. Imagining if the roofer were to fall, Einstein realized that he would feel no force of gravity (until impact).  It’s as if, standing on the surface of the Earth, we are experiencing a constant acceleration away from her center.

Einstein visualized this as an astronaut standing in a rocket ship at rest. As the ship fired up its engines and gently increased thrust to hover just over the Earth’s surface, the astronaut would continue to experience only her normal weight. The acceleration inside the ship is equivalent to gravity experienced outside – until it accelerates even more to rise, at which point the astronaut would feel heavier.

From all this Einstein made his great discovery – that gravity is not a force, a mutual attraction between objects as Newton posited. But rather, gravity is the result of objects (mass) warping the fabric of space-time itself. Imagine a bowling ball in the center of a suspended rubber sheet. It will cause a depression. An orange launched into that depression will tend to circle the bowling ball, much as the moon circles the earth.

Now let’s put these two ideas together. Assume a rocketship accelerating through space, its speed steadily increasing. A laser beam is pulsed from the bottom to the top of the rocket – but since light travels at a fixed rate and the detector is moving away from where it was when the beam was pulsed, it has further to go and takes a bit more time. We have already shown that acceleration is equivalent to gravity, so the same effect will occur (in reverse) when sending signals from a GPS satellite to the surface of the earth. Without accounting for this Einsteinian time dilation, our GPS positions would be off by six miles or more. Not a good recipe for finding that Dunkin.

Our world seems so familiar. We sit, and stand, with little thought that matter is 99.99% empty and that gravity is only the warping of space. It took the daydreams of a young Austrian schoolboy to reveal the true nature of the universe. Which should be inspiring to all the other daydreamers out there. Feel free to dream; revel in it. Even if you don’t discover the next theory of the universe, you will enjoy your personal journey. That’s reason enough.

On Human Adaptability

Tallgrass national Praire Preserve

A few days ago, the US Women’s National Hockey Team came from behind to beat the Canadians, 3-2, in Sundsvall, Sweden. It was a great moment for USA Hockey and speaks well of our Olympic prospects in PyeongChang, 2018.

And yet, Canada continues to wreak her revenge.

Approximately 75,000 years thence, the Laurentide ice sheet formed in Canada during a time of global cooling and spread over the Great Lakes and New England. Eventually, about 18,000 years ago, the global climate warmed once again (sans SUVs), and the glaciers retreated.

While we gained such treasures as Cape Cod and the Islands, we also harvested a bumper crop of glacial rocks. Thank you, Canada.

As anyone from around here knows, when trying to dig a hole for a fence post or to plant a shrub, there is invariably a basketball-sized boulder just a few inches beneath the surface. Imagine that multiplied a thousand-fold, as an early New England farmer tried to plow his fields with his team of oxen. He would be constantly turning up rocks, many of which required the efforts of a long pry bar to fully dislodge them.

Then, the odd, early harvest. A team of oxen or draft horses pulls a heavy sledge back and forth throughout the fields as a gang of youngsters and older teens were matched to the rocks they could handle, piling on and dragging them to the edge of the field. It is only natural that this became the raw material for New England’s beautiful stone walls.

And every spring, the frost heaved up another fresh crop of glacial rocks. And does so to this day. It is not a winning battle.

But New England farmers adapted and persevered. According to Michael Bell, writing for the American Geographical Society in 1989, “In the late nineteenth century, only 33 percent of New England farmland was classified as tilled or tillable by the agricultural census. The rest was equally divided between pasture and woodland.” So the resourceful Yankees determined that untilled land was more cost effective, and used it as pastureland or woodlots.

While these decisions were utilitarian, they gave us the lovely New England scenery of winding roads, rock walls, pastures, and forests that we see today.

Meanwhile, 1,500 miles to the west, a similar conundrum was faced by early settlers of eastern Kansas.

Much of Kansas was broad and flat, with deep rich soil and free of subterranean rock, making it an ideal granary. Wheat and corn and sorghum were grown by the ton. But in one area, a long rectangle extending south from Topeka into northern Oklahoma, another bumper crop of rocks was found. But for a totally different reason.

The Flint Hills, nearly 10,000 square miles, were formed when the shallow Western Interior Sea covered the Midwest from the Gulf of Mexico to the Arctic Circle over 80 million years ago. Over many millions of years, layers of sedimentary limestone and chert (flint) were laid down. Eventually, mountain building in the continent caused the sea to subside and, as it flowed south, limestone was worn away more than flint, leaving the Flint Hills.

When the settlers first tried farming in the Flint Hills, they found that they could only do so in relatively few creek and river bottoms. Whenever they tried to expand their farms into nearby hills, they found thin, clay soil littered with hard, sharp shards of flint. They quickly decided that ranching was a far better use of the land. Cattle found a favorable home here, and thrived.

The Flint Hills is also home to the tallgrass prairie and reconstituted herds of bison. Because of the thick growth of bluestem grass and nearly annual prairie fires, trees are only found in the creek bottoms. Gentle, rounded hills are covered in dense, tall grass as far as the eye can see. The only sound is the rushing wind, rippling patterns and rustling waves in the grass. No cars. No trains or planes. The buffalo dot a distant hillside, contentedly grazing. It is an intense solitude that heals one’s soul.

Two different geographies, two different geologies. But human ingenuity made the best of both. As we do in all places and climes, and certainly, one day, on alien planets. That is the greatest human trick – to adapt.

There is no fear for our future. We will surely adapt again and again.