I still can't get over this phenomenon that I learned in Physics
Posted on 11/19/2015 10:56:52 PM PST by LibWhacker
Physics is built out of philosophically fascinating ideas. Or, at least, ideas that fascinate us as physicists. We are often moved to reverentially proclaim the beauty of various concepts and theories. Sometimes this beauty makes sense to other people (we're made of star stuff) and other times it's opaque (Frobenius manifolds in psuedo-Euclidean spaces).
I have my own personal favorite idea. It arises from the philosophically fantastic (but mathematically moderate) workings of Einstein's relativity theory. The theory of special relativity holds that time and space are not separate entities, each operating on its own; rather they are intimately and inextricably codependent. We are born, live, and die along "world-lines" through a four-dimensional spacetime.
Here's what awes me: we travel through this 4-D spacetime always at a constant speed: c, the speed of light.
No matter what we do in our momentary lives, we are always truly traveling through our universe in time and space together, always at at the same rate. Let's consider a few facts that follow from this realization.
A man who sits still uses none of his lightspeed to travel through space. Instead he is travelling in time at the speed of light. He ages--in the view of those around him--at the fastest rate possible: light speed. (How's that for a philosophical argument against sloth?)
As we travel about in our daily lives, we use up a miniscule amount of our alotted light speed to move through the spatial dimensions surrounding us. We borrow that speed from our travel forward in time and thus we age more slowly than our sedentary neighbors. You've probably never noticed that fact, and there's a clear explanation why. It's only when you travel at unimaginablly high speeds that the weirdness of time becomes large enough to notice. The mathematical reason for this is that the effect of time dilation at a particular speed "v" is only (v/c)2.
Try putting the fastest you've ever traveled into the top of that equation and then dividing it by the 671 million miles per hour that light travels. Then square that tiny number to make it vastly smaller.
Imagine a strange jet-setter who spends an entire 80-year lifespan cruising at 500 mph on a Boeing 747. When his long flight finally touches down, the watch on his wrist, set to match the airport clock at takeoff, will be only one millisecond behind. However, we can watch a subatomic particle live five times longer at 98% of light speed than sitting still.
Maybe the strangest case of this phenomenon is light itself, the sole thing capable of travel at c. From our point of view, then, a photon is using the entirety of its spacetime velocity to travel through space. It never ages (from our frame of reference, watching)! That's why we see photons will fly through space in a straight line from one side of the universe to the other for all of eternity without changing in any way unless externally influenced. This imperviousness makes them excellent historical records. And here, the deeper general theory of relativity (also courtesy of Einstein) leads us to something more bizarre.
Many of the photons generated at nearly the beginning of the universe are still travelling through space in their birthday suits. But, over the course of their billions of years in transit to us, the space they inhabit along their path through the stars has grown more than 1000 times bigger since they were born. This expansion of spacetime has stretched the wavelength of the photons along with it, like an enormous slinky being pulled apart. Now they are a thousand times longer but still timeless to us.
Spacetime physics, adhering to relativity as we know it, reveals utterly surreal truths. Many of these are posed as famous puzzles and arguments, such as the twin paradox, the ladder paradox, and the failure of simultaneity. But the mere fact that we always travel through spacetime at the speed of light never ceases to stop me in my tracks (metaphorically speaking). I believe it is the most stunning thing I've ever absorbed in a physics class.
The cost of a PHD in it?
Just kidding.
And there’s more...
Didn’t understand a word.
You’re a smart dude.
Now back to my Netflix B Horror Movie.
Bookmark.
“The cost of a PHD in it?”
Generally free monetarily.
Here’s something mind-bending about physics I’ve recently learned.
Einstein’s great dream was the “unified field theory,” under which the four fundamental forces of nature - electromagnetism, strong and weak nuclear, and gravity - would all be seen to have descended from the same force.
At very high energies, Einstein believed, these four forces could be seen to have condensed out of the same fundamental force.
In the 1970s, particle accelerators of sufficient power were able to generate conditions under which the electromagnetic force and the weak nuclear force coalesced into one force, the electroweak force.
One of the great mysteries was the question of gravity, which is enormously weaker than the other forces.
I never thought I could understand anything about that one. But just recently, in pursuing my hobby of listening to physics lectures on YouTube, I came across an insight into this question that amazed me.
In order to understand this, you have to be aware of one of the basic features of Einstein’s Theory of Relativity. That is that as an object of mass larger than zero approaches the speed of light, its mass increases. As its velocity gets very close to the speed of light, its mass increases dramatically.
Here’s the thing. In the very first nanoseconds of the big bang, the velocity of individual particles was so great, so close to the speed of light, that their individual masses were enormous. An individual quark could have a mass of millions of tons.
And this is the key. If subatomic particles have such enormous energies, their masses become enormous. So enormous that the force of gravity becomes comparable to the other forces.
The conditions for this to happen would only have existed for a tiny fraction of a nanosecond, something like a billionth of a nanosecond. But during that time, all four forces were of comparable strength, and in effect condensed out of the same fundamental force.
To me this is an awesome idea.
“That is that as an object of mass larger than zero approaches the speed of light, its mass increases. As its velocity gets very close to the speed of light, its mass increases dramatically.”
I took an online astrophysics course from Yale. The explanation for the mass increase was fascinating. A planet in orbit has kinetic energy. The faster it goes, the more kinetic energy it has. As you approach relativistic speeds, there is so much kinetic energy that, using e=mc2 we can convert that energy into mass. The number is so high that the mass equivalent is so large, that pushing that much mass to light speed requires so much more energy as to be impossible.
What the hell am I doing on this board without at least a masters. :)
Many brilliant people on the board.
But that can’t be.
A study said conservatives are far likely to be more uneducated than liberals.
Yes, hard to wrap your mind around thinking like that when one can fixate on a horror movie. I watched one last night, "I Spit on Your Grave". Some gory revenge horror movie I wasted my time on but didn't abandon. The most-mind bending thing I think about is that when you touch something, you're really not touching anything. Your atomic particles interact with the atomic particles of what you're trying to touch. But you never quite get there. Sort of like a guy moving half the distance to a girl, then half again. And so on. Theoretically you never get there. You never touch. But the interaction is pleasant. Sort of like watching a horror movie. The characters can't touch you, but you enjoy the interaction. Now on to another movie...
I still can't get over this phenomenon that I learned in Physics
Stephen Crothers Destroys the Quackademic “Black Hole” & Relativity
https://www.youtube.com/watch?v=wRsGPq77X0Q
This is more astronomy based vs physics, but I found the event interesting, and more evidence of the immeasurable and infinite nature of space.
On June 14th, 2014, Astronomers using a telescope at the McDonald Observatory, in Fort Davis,Texas spotted a Gamma-Ray burst. This was a rare explosion of a Super-Nova 12.Billion light years away.
Gamma-Ray Bursts release more energy in seconds than the sun in its’ entire 10 Billion year lifetime.
This particular event occured not long after the Big Bang.
That’s one of Zeno’s paradoxes reformulated. It’s thousands of years old.
/nerd
This guy probably also gets excited by the shape of potato chips.
That is an amazing idea, thanks. Never thought of it like that... Hmm, what happened to all that momentum? It’s supposed to be conserved, but at the moment I’m blanking on what could’ve become of it.
Don't say that! One of the reasons I majored in math was that physics was too hard.
I like the idea in general relativity that time is more or less a point of view. Time speeds up or slows down relative to your speed versus what ever you are observing.
I probably said that poorly. My training was Metaphysics not Physics
“the four fundamental forces of nature - electromagnetism, strong and weak nuclear, and gravity - would all be seen to have descended from the same force.”
See, if the best they can do is to say that it “would all be seen to have” rather than show incontrovertible evidence then it’s no more truthful than a consensus that climate change and global warming are the direct result of human activity on earth...even if the math is seen as being correct.
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