Presenting next week's key text: Next Monday, we'll continue our examination of what we've called the "culture of incoherence." This award-winning course of study will be unfolding months.
Next week, we plan to move to Nova's recent hour-long broadcast, Inside Einstein's Mind. You can watch the program here.
The Nova program aired last November. It was timed to coincide with the hundredth anniversary of the general theory of relativity.
Whatever that is!
Nova is reputed to be one of our brightest news orgs. Was Nova able to make Einstein easy? How about slightly intelligible?
Why not take the Nova challenge? Starting next Monday, we'll be reviewing a standard part of Einstein-made-easy material. As presented by Nova, it involves the man who's standing on the railroad platform and the lady who's passing by on the fast-moving train.
Complete with two lightning strikes!
Nova's imaginary situation is taken from Chapter 9 of Einstein's 1916 book for general readers, Relativity: The Special and the General Theory.
To read Einstein's book, you can just click here. Nova's treatment of the topic can be found roughly eleven minutes into its recent program.
Do you understand what Nova said about the man on the platform and the lady on the fast-moving train? Next week, we expect to suggest that no, you do not.
For your perusal, here's the relevant text. We're starting at 8:55 of the Nova broadcast:
PROFESSOR SCHAFFER: Einstein's world in 1905 was dominated by two kinds of physics. One was about 200 years old, founded by Isaac Newton, British natural philosopher.The highlighted statement, along with its earlier highlighted kissin' cousin, is said to have "mind-blowing significance."
For Newton, all there is in the world is matter, moving.
NARRATOR: Newton showed that the motion of falling apples and orbiting planets are governed by the same force—gravity.
His equations are so effective, we still use them today to send probes to the farthest reaches of the solar system.
The other important theory of Einstein's day covered electricity and magnetism. That branch of physics had been revolutionized in 1865 by the Scottish physicist James Clerk Maxwell.
Maxwell's theory described light as an electromagnetic wave that travels at a fixed speed.
In Newton's world, the speed of light is not fixed.
PROFESSOR SCHAFFER: Einstein could see that there's a contradiction between Newton and Maxwell. They just don't fit together. And one of the things Einstein, hated—hated!— was contradiction. If there's one kind of physics that says this, and another kind of physics that says that, and they're different, that's a sign that something's gone wrong, and it needs fixing.
NARRATOR: For months, Einstein wrestles with the problem. Eventually, to resolve this contradiction, he focuses on a key element of speed—time.
WALTER ISAACSON: He realized that any statement about time is simply a question about what is simultaneous. For example, if you say the train arrives at 7, that simply means that it gets to the platform simultaneous with the clock going to 7.
NARRATOR: In a brilliant thought experiment, he questions what "simultaneous" actually means, and sees that the flow of time is different for an observer that is moving versus one that is standing still.
He imagines a man standing on a railway platform. Two bolts of lightning strike on either side of him.
The man is standing exactly halfway between them, and the light from each strike reaches his eyes at exactly the same moment. For him, the two strikes are simultaneous.
Then, Einstein imagines a woman on a fast-moving train traveling at close to the speed of light. What would she see?
As the light travels out from the strikes, the train is moving towards one and away from the other. Light from the front strike reaches her eyes first.
For the woman on the train, time elapses between the two strikes. For the man on the platform, there is no time between the strikes.
This simple thought has mind-blowing significance. Simultaneity, and the flow of time itself, depends on how you're moving.
PROFESSOR CARROLL: If there's no such thing as simultaneity, then there's no such as absolute time everywhere throughout the universe, and Isaac Newton was wrong.
NARRATOR: This concept, that time and space as well are relative, became known as special relativity. It led to remarkable results, such as the famous equation relating energy to mass.
Do you understand why that would be true? Do you even understand what the highlighted statement means? Do you understand how the statement can be derived from the example involving the man and the lady?
Next week, we expect to say you don't. We'll even explain our work!
After that, it's on to Chapter 9 of Einstein's book. Remember:
According to Isaacson, Einstein's teen-aged niece said it was clear as a bell!
Key disclosure: In his historic book, Einstein didn't mention a man and a lady. He merely described a railway platform and a fast-moving train.
Presumably, Nova added the man and the lady to introduce a hint of romance. Presumably, the PBS program was looking for ways to keep us the lunkheads involved.