|MadSci Network: Physics|
Hello, Richard! A stupid question? You know better than that! :-) It's a good question, and I'll give it the serious attention it deserves. That doesn't mean I won't have some fun answering it, so beware of bad puns! There's an inverse relationship between velocity and the flow of time. The usual way of thinking is to assume no or little movement and usual time flow, because here on earth that's how things are. So we think of objects going faster and faster, and time going slower and slower. But a more mathematically correct point of view is to start at the speed of light and work backwards, because t at vc=0, or the flow of time at light speed has stopped. Using c as our starting point, the more we decrease velocity, v, the more time, t, is increased. Viewing the question like this, we could write t at vc/x=x-1, where x is any velocity between 1 and c. Of course, by making x less than 1, velocity has become greater than light speed, and time flow has become a negative number. So time would flow backwards, if this lineal equation holds true. However, there's a problem with this, and not just the obvious objection to velocity exceeding the speed of light. In 1957, H. Bondi's paper "Negative mass within general relativity" (Rev. Modern Physics, Vol. 29, No. 3, 423) proposed the existence of matter having negative inertial mass. More recently, Harold E.Puthoff has shown Bondi's concept to be impossible. In doing so, he also showed negative time flow to likewise be impossible. So even if v>c, t must not be negative. We seem to have a contradiction here. This contradiction must be confused, because every contradiction knows that quantum physics is where all the other contradictions hang out. Why do we have one in a linear equation? It's a question of definition. V, by definition, cannot exceed c. Another way to look at Dr. Puthoff's work is since t must not be negative, v cannot exceed c. It doesn't seem like a contradiction at all when worded like that. Asking questions about what happens at velocities greater than light is like asking what's the universe expanding into. Some questions are illogical (therefore, unanswerable), but are worded in such a way that an answer seems possible. So, what do you tell your acquaintances? I suppose you could really impress them by hosting an international theoretical physics seminar, and inviting them to hear cutting edge ideas on the topic. But if your bank account resembles mine, you can't afford to host a luncheon of peanut butter sandwiches for your neighborhood scout troop. A more practical idea would be to explain that the very linear equation which allows for -t contains within itself an upper limit, c, which disallows v>c, the precursor to -t. Now that I've said that, allow me to pull that contradiction out of my pocket and say that I believe the speed of light can be exceeded. But that's okay, because I'm wandering into the quantum world where this contradiction feels at home. Heisenberg said that we may know the direction and velocity of a quantum particle, or we may know it's location in space-time, but we cannot know both. Einstein disagreed, and proposed a test in which a subatomic particle at rest was split in half. Newton's laws say that half of the particle would travel along a line at velocity v, and the other half would travel along the same line at -v, or the same speed, but opposite direction. Part A could be measured for location, and part B could be measured for direction and velocity. The location of part B could be inferred without direct observation by the location of part A, so both the direction and velocity, and the location of part B could be known. Trouble is, it didn't work. As soon as part A was observed, part B altered its course. Let's assume that something was emitted from part A as soon as it was observed. And let's assume further that whatever it was that was emitted reached part B, and part B interprets this emission as the signal to alter its course. Measurements show that in order for this mysterious emission to reach part B fast enough to alter its course before the direction and velocity measurement on part B was taken, whatever was emitted from part A must have traveled faster than light. How do I account for this? I don't. Einstein couldn't, and nobody can today. Either some undetected signal from part A was sent to part B at faster than light speed, or we have a fundamental misunderstanding of how matter behaves. Go figure! Now our lineal equation tells me that if our invisible emission from part A exceeds the speed of light, by the time it reached part B it would have gotten there before it was emitted, as judged by its own internal clock. And to exists before it is created is my pocket contradiction's companion for the evening. They'll get along fine - they seem to have quite a lot in common. But their relationship may be short, because our invisible emission can't exist before it's created, so it blinks out of existence as soon as it has told part B what to do. It may be possible that this phenomenon accounts for the zero point energy field, where energy particles flicker in and out of existence constantly, even in a vacuum. I'm straying from known science into the arena of speculation. We don't know that such emissions exist. I may be asking a question like "what is the universe expanding into?" To keep it safe and simple, I'd stick with the self limiting nature of the lineal equation, and accept the fact that x cannot be negative. But nobody ever made a name for himself by keeping it safe and simple. Layne Johnson p.s. Graffiti on a subway wall - Heisenberg was here, probably
Try the links in the MadSci Library for more information on Physics.