Andrew
2012-03-03 17:39:11 UTC
Anyways, so the other day I was drunk and high when I had a series of thoughts:
1. it is impossible for ONE SINGLE OBJECT to exceed the speed of light...
2. but, what about objects WITHIN an object??
Okay, so here's the situation:
For simplicity I have chosen to model this after a "conveyor belt". Reason being is that I trust that it is simple to understand that when a rubber sheet is stuck in between 2 spinning rubber wheels on each side, this causes the sheet to move with a certain velocity.
Anyways there is a "conveyor belt" that moves by being stuck between two turning wheels and it is 4.7302642 × 10^16 m long (x-axis) (this is 5 Light Years (LY)), 500 m wide (y-axis), and 1 m deep (z-axis). note from above: the wheels are being turned by an "engine" underneath the belt.
For convenience, we will only examine the xyz plane from (2 ly, 0, 0) to (3 ly, 0, 0). When speaking, (2 ly,0,0) replaces (0,0,0) as the Origin and 3 ly becomes 1 ly. ALL coordinates mentioned throughout are in reference to this new Origin. KEEP THIS IN MIND!!!
Back to laying out the structure. I'm not going to go over details. This is theoretical obviously. I am only going to cover the parts that are important to the question at hand:
So, we have a conveyor belt, or any sheet of any material for that matter, called Belt A. Belt A is capable of moving at .9c. PHYSICALLY BONDED/ATTACHED to the top of this 500 m wide belt is an engine that measures the same length (in this case, the length is only 1 LY because of the interval we are examining), I guess we'll call it 25 m deep (the depth is unimportant for my question), and ONLY 400 m wide. So, it is less wide is the main idea. Also attached to the conveyor belt are objects or "poles" (for instance, metal poles, but the make-up of the object is irrelevant, so they are "poles" as far as I am concerned) that have two wheels pinned to them. The aforementioned engine powers these wheels causing them to spin. In between these wheels is another sheet/belt of whogivesafuckwhat material because honestly the material is irrelevant in reference to the theoretical question. For identification convenience, it is called Belt B. Belt B has the same x and z dimensions (i.e. 1 ly and 1 m tall), but it is only 400 m wide (y dimension). For use later in my question, take note that the TOP of Belt B sits 30 m above the BOTTOM of Belt A. Belt B is also capable of moving at .9c.
You should be able to see where this is going. Here's how I have thought about it and where my question lies:
We start with everything at rest. Now, we turn on Belt A and leave Belt B off. After a finite amount of time, Belt A is moving at a constant velocity of .9c. With respect to (w.r.t. for convenience) Space, any object attached to Belt A is moving at .9c. Belt B is therefore moving at .9c w.r.t. Space. HOWEVER, Belt B is moving at ZERO m/s w.r.t. Belt A. Example to emphasize this:
Point P0 is located at (0,250,420). P0 represents a point in Space. It could be anywhere, but since I smoke weed a lot I chose 420 in the z lol. I chose 250 in the y for convenience. Take a point called P1 on Belt A with the coordinates of (0,250,1) this would be the very top of belt A (1 meter up) and in the middle of its width (500/2=250). Now, take a point called P2 with coordinates (0,250,30), which is on the top of Belt B, in exactly the same xy coordinates as point P1. As P1 moves at .9c in the x, P2 also moves at .9c in the x. They are always at the same place on the x-axis which means that P2 is moving at (0,0,0) w.r.t. P1. Right? or have my math skills somehow failed me on an epic level.
Back to our Scenario. So, Belt B is NOT MOVING w.r.t. Belt A. NOW, we turn on Belt B, and after a finite amount of time Belt B and ANY object attached to Belt A is moving at .9c WITH RESPECT TO BELT A. But with respect to Space, any object on Belt B is moving at 1.8c. NOW, in 202.778 days we turn Belts A and B off. Assume we can turn them off instantaneously. It would take days to slow them to 0 m/s, but for simplicity assume instantaneous. At this point in time P2 would have moved an entire light year while P1 would only have moved .5 ly.
Herein lies the question: am I right? if not explain why.
In theory, my flashlight is exceeding the speed of light w.r.t. Space. Why? Earth is moving at 29,000 m/s around Sun and the photons coming out of my flash light are moving at 300,000,000 m/s, so, if we assume that the flash light shines in the same direction as the earths movement, an observer in space that was moving at 0 m/s would see it move away from them at 300,029,000 m/s, if they could see it from so far away. or am I wrong.