Recent content by Involute

As I understand it, photons are subject to the same time and space distortions under SR as anything else, which is why they don't perceive time or space, since they travel at the speed of light. To an outside observer, then, they should appear stationary, immobile at their moment of creation...

As an object approaches a black hole’s event horizon, it experiences increasing gravitational time dilation, causing it to appear to an outside observer to slow down, until, at the event horizon, it appears to stop. An object traveling in space that increases its velocity from one...

I thought the answer was no. I.e. the traveler's proper time always passes more slowly than a stationary observer's clock regardless of the traveler's direction with respect to the observer. I was watching Brian Greene's NOVA episode on time, however, and, at 23:15, he has a demonstration...

This video explains gravity in a way I haven't encountered before (regardless of how irritating the presenter may be). Nevertheless, I find it hard to believe that a squirrel falls from a tree to the ground due to gravitational time dilation between its head and its feet. The amount is so...

So, to slightly rephrase my original question, why "would we ever expect to see both types of particles arrive at Earth at the same time from the same direction, or even different directions?"

Thanks, but the first doesn't answer my question and the second is over my head, though the abstract suggests it doesn't answer it either.

Vanadium: Since the charged particles that comprise cosmic rays would travel a different path through space than neutrinos from the same source, would we ever expect to see both types of particles arrive at Earth at the same time from the same direction, or even different directions? If so...

Based on my limited understanding of special relativity, as an object's velocity increases with respect to an observer the object undergoes spatial contraction (making it appear to the observer to get thinner in the direction of travel) and time dilation (so the observer would view the object's...

I understand that the vast majority of our atomic warheads are fusion devices. I realize that fusion yields are potentially much larger than fission yields, but our most modern fusion warhead, the W88, has a maximum yield of "only" 475 kilotons, while the maximum theoretical yield of a fission...

DaleSpam: What's the "separation speed between the car and the light?"

ghwellsjr: > Can you please describe how you think someone can make this measurement? There's a reflector some distance in front of the car and precisely calibrated distance measurements to the reflector on the side of the road. Time the rountrip of the beam, adjust roundtrip distance for...

If someone stands up through the sunroof of a car traveling down the freeway at 60 mph and measures the speed of a beam of light they shine from a flashlight in the direction the car's going, they'll record it as c. This is intuitive (no need for relativity). Someone on the roadside, however...

> then he will find that yes, the astronomer has aged more. But that's a different situation. Why? How?

A spaceship takes off from Earth. An astronomer on Earth can look though a window in the ship's hull and view a clock on the inside. He notes (I assume) it's indicating that time is flowing more slowly inside the ship than on Earth. The astronaut in the ship, however, also has a telescope and...

I make computer-controlled kinetic sculpture (http://www.youtube.com/watch?v=oFNG-sxLnM8" one of my pieces). I'm working on a piece that will sort M&Ms by color. I've got the color ID and sorting parts under control, but I'm having trouble coming up with a simple and reliable mechanism for...