We're at week 4 of Cosmos: The Rebootening, and since last week was all about how Isaac Newton revolutionized physics, then for this week's episode, it's time (and space and gravity) for Einstein. As an English major, Yr. Dok Zoom has what you'd call a "lay understanding" of relativity and some of the crazier stuff in modern physics, which is to say that I understand it up to a point, and then I have to go lay down.
Whoa there, easy on the laying down with relatives talk! Somebody from one of them southern type states might read it... assuming of course they can read and if Wonkette allowed comments.
Old Al didn't grok tensors, until he realized he had to in order to articulate the General Theory. So, at about age 35, he learned tensor math, just because he had to. And changed the world again.
This is the anecdote that assures me Einstein was smarter than I.
Just a summary observation for Dok, and any interested folks. I should mention that I haven't yet watched Episode 4 of Cosmos.
Special Relativity is counter-intuitive, because the situations in which it differs from plain old Newtonian physics are situations that we can never observe directly -- physical things moving really close to the speed of light. Our entire mental wiring, and all our experience, are tuned to Newtonian physics. The math associated with Special Relativity (the "Special" means that it only applies to things moving at constant speed with respect to each other) is actually pretty simple. Sure, we can't completely grasp the fact that if someone going past us in a spaceship at half the speed of light shines a flashlight forward, the beam from the flashlight appears to propagate at the speed off light to us, and also to the guy on the spaceship. But the math to describe this is simple, so it's easy to fool ourselves into thinking we understand something about it.
What is a lot harder to understand is that it turns out that space and time are not different things. There is only space-time. The most simple view of this looks a lot like Calvinist predestination: everything has a world-line in four dimensions (3 space, 1 time), and it's just there. Somehow, consciousness advances down the time axis and perceives the space dimensions as it goes. Like I said, it's harder to understand, but it is kind of a consequence of Special Relativity.
A thing to remember is that there have been tens of thousands of experiments that test the predictions of Special Relativity, and so far they have all confirmed the theory.
Now, General Relativity leads us towards the deeply weird. It&#039;s &quot;General&quot; because it isn&#039;t limited to things moving at constant speed with respect to each other. The key observation that underlies the theory is that constant acceleration (change of speed) is indistinguishable from gravity. (This thought, and its working out, are what makes me sure Einstein was a genius. Special Relativity would have been worked out by somebody, because of Maxwell&#039;s Equations, but this is <i>way</i> out there).
As an aside, another reason Einstein was a genius is that his actual Nobel Prize was for explaining the photoelectric effect, which had nothing to do with relativity and also involved quantum mechanics, which he hated.
Unlike Special Relativity, the math for General Relativity is complicated. As I mentioned elsewhere, Al had to learn tensor calculus in order to work out the theory. No one should feel bad that they don&#039;t understand it. I don&#039;t understand it. I seriously doubt that any of the few relativists who have claimed to understand it actually did so. It is so contradictory to our happy nicetime Newtonian intuitive view of physics that I think you would have to be sort of deranged to &quot;understand&quot; it. (But, maybe they were just way smarter than I).
The thing is, whether you &quot;understand&quot; it or not, the math allows making predictions, and we can sort of understand the predictions. One of them is that time runs slower in a higher gravitational field. This was first verified by measuring the precession of the orbit of Mercury a few years after Einstein published the General Theory, but nowadays we recognize it because relativistic adjustments are inserted into every GPS algorithm (time runs a little faster up at the satellites than down here).
Also, with a bit of work, we get black holes, and a vague approximation of the start of the universe. (I should point out that I am a spectator in this arena. I do not have anything like a full grip on the math).
One thing that the anti-science <strike>fuckwads</strike> fundamentalists either don&#039;t understand, or intentionally ignore, is that one of the biggest drivers in science is the desire to prove some accepted theory wrong (or, more usually, incomplete). It&#039;s fine to do good experimental work, and provide more support for an existing theory, but what gets Nobels is either the very first verification of a proposed theory, or the contradiction of an existing one. Lots of very competent physicists have spent many years trying to find holes in both the Special and General Theories. In some cases, fairly large experiments have been created (e.g., the Auger cosmic-ray detector) at least partly to search for a violation.
So far, no luck on the direct measurement side. Of course, as Cosmos will probably get around to, both Special and General Relativity HAVE to be wrong (incomplete), because of quantum entanglement (turns out the EPR paradox isn&#039;t a paradox, it&#039;s an experimental fact).
But, maybe quantum mechanics deserves a different comment.
<a href="http:\/\/www.biblegateway.com\/passage\/\?search=Matthew 25:14-30&amp\;version=ESV" target="_blank">Matthew 25:14-30</a>, bitchez! Dog gave us <i>reason</i>. The fundies who refuse to use theirs are like the man who buried his talents rather than investing them. And let me tell you, Jebus is not happy unless your money is working, working, working!
The first word in <a href="https:\/\/www.youtube.com\/watch\?v=yL--io1CBDY" target="_blank">this song</a> is discorporate. It means to leave your body.</a>
Whoa there, easy on the laying down with relatives talk! Somebody from one of them southern type states might read it... assuming of course they can read and if Wonkette allowed comments.
Pix or GTFO?
they did, but they were lost to the fifth dimension
Tensors are just for folks that can&#039;t handle spinors.
If it&#039;s okay with the Hawk....
That&#039;s been my theory for fifty years now.
Old Al didn&#039;t grok tensors, until he realized he had to in order to articulate the General Theory. So, at about age 35, he learned tensor math, just because he had to. And changed the world again.
This is the anecdote that assures me Einstein was smarter than I.
Well, it&#039;s possible there is no space either, so big whoop.
I&#039;m glad to see someone with a grip on the important thing.
Unusual for Spurning to miss that.
I&#039;m not.
There once was a physicist named Frisk, Whose stroke was exceedingly brisk. So fast was his action, The Lorentz contraction Reduced his rod to a disk.
Just a summary observation for Dok, and any interested folks. I should mention that I haven&#039;t yet watched Episode 4 of Cosmos.
Special Relativity is counter-intuitive, because the situations in which it differs from plain old Newtonian physics are situations that we can never observe directly -- physical things moving really close to the speed of light. Our entire mental wiring, and all our experience, are tuned to Newtonian physics. The math associated with Special Relativity (the &quot;Special&quot; means that it only applies to things moving at constant speed with respect to each other) is actually pretty simple. Sure, we can&#039;t completely grasp the fact that if someone going past us in a spaceship at half the speed of light shines a flashlight forward, the beam from the flashlight appears to propagate at the speed off light to us, and also to the guy on the spaceship. But the math to describe this is simple, so it&#039;s easy to fool ourselves into thinking we understand something about it.
What is a lot harder to understand is that it turns out that space and time are not different things. There is only space-time. The most simple view of this looks a lot like Calvinist predestination: everything has a world-line in four dimensions (3 space, 1 time), and it&#039;s just there. Somehow, consciousness advances down the time axis and perceives the space dimensions as it goes. Like I said, it&#039;s harder to understand, but it is kind of a consequence of Special Relativity.
A thing to remember is that there have been tens of thousands of experiments that test the predictions of Special Relativity, and so far they have all confirmed the theory.
Now, General Relativity leads us towards the deeply weird. It&#039;s &quot;General&quot; because it isn&#039;t limited to things moving at constant speed with respect to each other. The key observation that underlies the theory is that constant acceleration (change of speed) is indistinguishable from gravity. (This thought, and its working out, are what makes me sure Einstein was a genius. Special Relativity would have been worked out by somebody, because of Maxwell&#039;s Equations, but this is <i>way</i> out there).
As an aside, another reason Einstein was a genius is that his actual Nobel Prize was for explaining the photoelectric effect, which had nothing to do with relativity and also involved quantum mechanics, which he hated.
Unlike Special Relativity, the math for General Relativity is complicated. As I mentioned elsewhere, Al had to learn tensor calculus in order to work out the theory. No one should feel bad that they don&#039;t understand it. I don&#039;t understand it. I seriously doubt that any of the few relativists who have claimed to understand it actually did so. It is so contradictory to our happy nicetime Newtonian intuitive view of physics that I think you would have to be sort of deranged to &quot;understand&quot; it. (But, maybe they were just way smarter than I).
The thing is, whether you &quot;understand&quot; it or not, the math allows making predictions, and we can sort of understand the predictions. One of them is that time runs slower in a higher gravitational field. This was first verified by measuring the precession of the orbit of Mercury a few years after Einstein published the General Theory, but nowadays we recognize it because relativistic adjustments are inserted into every GPS algorithm (time runs a little faster up at the satellites than down here).
Also, with a bit of work, we get black holes, and a vague approximation of the start of the universe. (I should point out that I am a spectator in this arena. I do not have anything like a full grip on the math).
One thing that the anti-science <strike>fuckwads</strike> fundamentalists either don&#039;t understand, or intentionally ignore, is that one of the biggest drivers in science is the desire to prove some accepted theory wrong (or, more usually, incomplete). It&#039;s fine to do good experimental work, and provide more support for an existing theory, but what gets Nobels is either the very first verification of a proposed theory, or the contradiction of an existing one. Lots of very competent physicists have spent many years trying to find holes in both the Special and General Theories. In some cases, fairly large experiments have been created (e.g., the Auger cosmic-ray detector) at least partly to search for a violation.
So far, no luck on the direct measurement side. Of course, as Cosmos will probably get around to, both Special and General Relativity HAVE to be wrong (incomplete), because of quantum entanglement (turns out the EPR paradox isn&#039;t a paradox, it&#039;s an experimental fact).
But, maybe quantum mechanics deserves a different comment.
The spinner you get, the tenser you be.
<a href="http:\/\/www.biblegateway.com\/passage\/\?search=Matthew 25:14-30&amp\;version=ESV" target="_blank">Matthew 25:14-30</a>, bitchez! Dog gave us <i>reason</i>. The fundies who refuse to use theirs are like the man who buried his talents rather than investing them. And let me tell you, Jebus is not happy unless your money is working, working, working!
The first word in <a href="https:\/\/www.youtube.com\/watch\?v=yL--io1CBDY" target="_blank">this song</a> is discorporate. It means to leave your body.</a>