13th January 2005 - 09:40 AM
Hi Jolly Rodger,
Jolly Roger Posted on Jan 13 2005, 01:47 AM
I'm going to have to disagree about your point that electromagnetic phenomena and physical reality being separate things
This is sort of a debate to say if when you travel near the speed of light is space and time actually being warped around you or is this just the optical effects of very high speed travel.
I am going to use some “dumb” ideas on relative time and space velocities but I hope you understand in what context I am going to do this.
Lets say if you travel closer and closer to the speed of light relative to a person living in earth orbit the progress of "real" earth time (I hate to use this idea) for the traveller his clock is slowing by relative comparison (relatively speaking the ticks of his clock are lengthening relative to a person on or near earth). If our traveller calculates speed as distance divided by (his) time he will see an open velocity scale with no upper bounds (ignoring physical constraints such as the size of his rocket engine etc.). To him he thinks he can increase his speed without bound and notices the external effect is that he see things moving past him faster and faster. There are other optical effects that I will not discuss just here.
Others interpretations would say that there is a "redline" on his speedo that he can't seem to cross (see the video below). This is not actually what happens because the faster he goes the less time he will experience relative to "stationary" observers (yick!). If he were able to "touch" the speed of light, all time for him would be an unending suspended moment in which, between the ticks of his clock, he could travel to the ends of the Universe. Externally relative to "stationary" (bleh!) clocks the time he would take to do this is exactly the same as if a beam of light did the same. A very long time to travel to the end of the Universe indeed.
In the external world we never see the traveller travel faster than what should be the speed of light (and he never does). Not even light can do that. This is a physical constraint of the system. But our clocks are keeping the "right" time (Ur... sort of I think you get that point) The travellers clock is losing time relative to this “right” time "hand over fist", running slow, but because it is his actual experienced time he interprets this as travelling faster (velocity equals distance divided by "his" time). He could potentially travel across the entire universe in a really short time (his time) and his apparent calculated speed (internally) could be many times the speed of light based on distances previously reckoned before the trip. This is standard theory. All the texts suggest this but they often fail to see all the conclusions of this idea through.
To the normally moving bodies (slow pokes) in space this fellow is travelling close to light speed but cannot exceed it so will take the requisite time to travel those distances according to those external observers clocks. However depending on how much acceleration the traveller has undergone he can reduce the total number of ticks (of his clock) of his journey to as small a count as he likes. All he does is wind up the acceleration and approach "externally" incrementally closer to the speed of light (internally he is putting on warps Star Trek parlance eh, or so he thinks!).
Now to your question. The length contraction will be an effect but that just makes things appear close through optical phenomena such as the stereoscopic effect of distances through parallax. If there was a straight paved footpath to the stars and we were travelling along it... The apparent distances between the equally spaced paving cracks will appear to shorten exactly along the direction of the line of travel. Perpendicular to this line of motion (out the port and starboard portholes) the pavement appears relatively undistorted (though moving fast). In between these extremes with variations in the angular distance away from the direction of travel up to 90 degrees, we see gradations of these effects.(highly warped to not warped at all). In three dimensions (which is what we actually see) this effectively "twists" the pavement along the line of the direction of travel causing it to "bunch up" in the forward direction and apparently "rotate". See this movie for the effect (but please note the dumb speedo – that is the apparent external speed measurement of some one standing on the pavement).Distorted Red Shifted Biker and seeing around corners
As I have pointed out there has been some liberties taken for clarity sake. Right click on the movie and save it to the drive.
These movies come from 1979 the 100th anniversary of Einstein's Birth a BBC Program called Einstein's Universe. Mostly deals with the effects of Gravitation. There are many more short movies here related to the program.Einstein's Universe
They show "some" visual effects due to relativistic speed. Please note that not all effects are shown simultaneously for clarity. This was mentioned in the original full length video. These links and more are explained in another post of mine you can find this in PhysOrgForum Science, Physics and Technology Discussion Forums -> Relativity, Quantum Mechanics and New Theories -> Relativity, Quantum Mechanics, New Theories -> SR vs Ether (Good Elf - latest). Some good stuff there.
The exact reverse happens in the backward direction. Combined this with his apparent increase in his speed due to the effect of slowing time relative to an external observer, and Doppler red shifting and a dark point aft and Doppler blue shifting and a white point forward, I say these effects are optical illusions. In actual fact this is due to the light approaches from different directions to normal (the speed of light is still approaches at a velocity relatively of C to all observers and always remains the same).
If it were possible – lets say a beam was chasing the traveller’s ship along the pavement so we can see part of the beam.shine on that pavement. The light does not change speed just because external observers might see the two (light and traveller) at almost the same speed (at or near the speed of light) and converging on a the traveller at a few Kms per second. The traveller measures light’s speed with his clock and he has lost most of the ticks “out of it” so the relative velocity of light will appear faster to him than apparent relative velocity does to the observer on the pavement. The traveller’s clock loses just enough ticks to make light appear to be approaching at the speed of light.
Here is the point... There is no "physical" bunching up or physical distance shortening or rotation in the “real” external world. Anyone standing on the side of the pavement would not personally experience any warping or twisting or mass increase as seen by the traveller as he goes by, and he does see these things. Still I would not like to stand so close. The light is not really curved at all. It is still travelling in straight lines but it is equivalent to optical aberration or refraction and it is an effect for the traveller like being completely immersed in an optically deforming lens. This is not an effect due to physically deformed space (although that is the debatable point). In a similar way I say that mass also appear to have EM "measurables" that indicate increasing mass but this is also an electromagnetic effect of the velocity. Remotely determined mass is subject to "optical" effects since all instrumentation is affected by the “exchange particles” or force carriers in our universe (light photons).
Many would say that it is not an optical effect and it is actually space and time that are deformed by this activity and true mass would also be affected. I do not agree.