PDA

View Full Version : Thoughts on Simple Motion

dark
27th-September-2010, 04:54 PM
Ok, I have been reading "Realitivity and Its Roots," by Banesh Hoffmann, and I came to some realization that I can't seem to understand or visualize correctly, here is what I wrote as my immediate thoughts to my thoughts...

Man A and Man B are stationary on a planet, Man A is on a mountian, Man B is at the lowest ground level on the surface of the planet. This makes Man A farther from the center of this planet than Man B, if they are both on the equator area, spinning around with the planet, Man A will be traveling a longer distance than Man B in the same period of time. So with my understanding of movement thus far, Man A is moving faster, yes? If we assume E=mc^2 then then Man A would be undergoing less time than Man B, or as what I've heard from Stephen Hawkins show on the Discovery Channel, would be aging less since its reaching more velocity...
Taking this all in I know each object has a certain gravitational pull, so, would this mountain Man A is on pull enough gravity on him to negate the entire process of the velocity he is obtaining in comparison to Man B? I will draw a simple picture on MS paint to show a diagram. Ok nevermind the picture until I learn how to put one on here haha.

Thaklaar
27th-September-2010, 07:37 PM
As far as I can tell, the difference in velocity between sea level and the top of Mt. Everest (roughly .6 m/s) would net you about 8 picoseconds over the course of a 65 year lifespan. The general relativity field equations are beyond me, mathematically, but I wouldn't figure the dilation due to the two newton or so gravitational difference would be greater than that.

DesertSmeagle
27th-September-2010, 09:18 PM
The time dfference would only be a very very small amount of time. The guy who has spent themost time in space is only a few 10 thousanths of a second behind us. In order to see a difference of time, someone would have to be moving at like 100 miles per second, or near light speed.

So if you can get to light speed, deos time stop completely? I know it at least slows down. So does that mean that time is moving as fast or faster than light? So if you were to move faster than light, you could go backwards in time? I wish einstein never died, he would still be finding out crazy shit. We would probably know how to percieve a 4th dimension if he was still alive.

typus
27th-September-2010, 09:23 PM
The time dfference would only be a very very small amount of time. The guy who has spent themost time in space is only a few 10 thousanths of a second behind us. In order to see a difference of time, someone would have to be moving at like 100 miles per second, or near light speed.

The time difference is bigger than what you seem to think, the clock of a person who engages in a lot of air travel will eventually become a few seconds off, even if it runs perfectly.

I constantly bob my head. Just side to side, all the time. This delays the arrival of Alzheimer's.

People call me insane.

dark
28th-September-2010, 03:13 AM
Yes but isn't it fascinating that this can exist, that 2 people on the same planet at different altitudes can experience different at rest motions. But I am not all to convinced at Einsteins theory about the speed of light being the ultimatum. Think of it this way, just because our bodies have yet to evolve past a form or percieving the outside world greater than light, doesn't mean light is the ultimate existance, it could, but it is not certain. Remember without our senses to perceive the world outside our owm mind and body, we wouldn't know they existed, without eyes we couldn't phathom light, without ears we wouldn't know sound exists, etc.

fullerene
28th-September-2010, 01:44 PM
2 things:

1. Like you said, the guys are both under the effect of gravity. Their reference frames are not inertial, as there is some centripetal force keeping them stuck on the surface of the planet, and so the typical rules of special relativity don't apply. When a person is undergoing acceleration, a lot of crazy stuff happens with respect to "how much time passes" that has nothing to do with relative velocities

2. More importantly: man A is not "moving faster". One of the assumptions of special relativity is that you cannot tell how fast you are moving without another reference frame to compare it to. Man A is moving faster in the reference frame of the planet... but that doesn't matter at all. The planet is moving around the sun, and the sun rotating in a galaxy, and those galaxies moving with respect to one another.

This means that when you ask the question "how fast is this person moving?" it has in mind "with respect to the reference frame of the observer." If you're person B, suppose you look out and see person A moving. Fine. But in the same situation, if you were person A, you would look out and see person B moving.

No matter which person you are, time seems to be moving at the same rate for you. You can't get a longer life by moving fast, because to yourself you are always at rest. Ignoring the acceleration of the people while on a planet, which breaks these rules anyway, person A would still not live "longer" because of his speed. Person A says person B is moving, and person B says person A is moving; both people say that the other one moves through time slower than they themselves do.

dark
30th-September-2010, 09:57 PM
That all makes sense, but think of what I'm saying, all I propose is this, isn't it interesting that these 2 men can experience rest in two different ways, it's the same with all moments of rest.

Also speed or velocity is defined by the relation of the distance traveled and the time, so with the distance of each mans arch of travel, and the time it takes for each, which is identical, Man A will be going faster, yet they can look upon one another and see that the other is moving right along with them, if you don't believe this go to a running track and look at the starting postions compared to the finish line. Yes I ran track, so I know this, and I did long jump, used my rudimentary knowledge of physics to help me out on both.