I don't know too much about relativity but here are 2 questions I have:?

Question

1.If C is an observer and if A goes to the left with a speed close to the speed of light and B goes to the right with the same speed, doesn't that mean that A (for instance) would say that B goes faster than light? Is that possible?
2. Wouldn't C see them as going the same? ClockA and ClockB would be the same for C, but for A and B the same clocks would be different? How is that possible?

Answer 1

Nothing can go faster than light. That's the rule.

There is no point in trying to think about what's "possible" - meaning, what's reasonable in the sense that we understand things in our normal experience. When you are talking about relativity and quantum physics you have to put aside what you know about normal life and follow a different set of rule. The rules of everyday life don't apply.

It's as if you were playing cricket and someone started to complain that the players werent following the rules of American baseball. What happens in our normal, everyday, human sized world and what happens at the speed of light follow different rules. The rule for speed is that it cant be faster than light. If you want to understand relativity you have to start with that.

When physicists first understood what Einstein was talking about when he explained relativity, they didnt get it either. Many of them were really angry with him - like, shouting angry, throwing things angry! -- but it didnt matter. He was right and his bizarre ideas have been so far proved correct, whether they are comfortable for us to understand or not.

Answer 2

Great question. The subject requires alot of thought, but you are correct, that, relative to A, B would be moving away at two times the speed of light and that C would see them as traveling at the same speed.

When studying relativity, the question of possible is not relevant. Only the application of the ideas which are brought to fruition through the study of data is truly relevant. If you want to travel at the speed of light or faster, there is much work to do to make the possiblity a reality. But you will not commit yourself fully to the endeavor until you know it will benefit you. This is the relevant truth. When people who would like to (or want to or need to) travel at superlight speeds want to badly enough, they will find a way. So, although your question is not relevant, if you believe it is possible and are committed to making it happen, then the answer for you is yes, it is possible to travel at a speed faster than the speed of light, although not presently. There, are, however, many dangers to overcome. For example, it would take an extremely long time to accelerate from 0 mph to 186,300 miles per second safely. Acceleration causes increased G pressures on the human body. How can a human being be safely accelerated to the speed of light in an acceptable time? How can humans learn to safely travel in space at speeds above the speed of light? Very challenging questions.

One thing that I found difficult about relativity study was that the study of relativity does not count a time standard. I was really out in the cold trying to understand reletivity apart from the time standard of earth. In other words, although I can measure time relative to two objects moving in different directions, I am not able to apply the knowledge or data, really, to any real application until I have a time standard to work with. People will always live with a time standard; the theory of relativity, however, does not allow for any time standard. Actually, there is one standard of time which is used in relativity calculations, that is that time is measured in standard seconds, minutes, hours, days, etc., but scientists would probably rarely agree that this is a standard, rather a convenient system of measure based on the rotations of the earth and of the earth around the sun. They are correct, but the fact still remains that to make the study of reletivity meaningful, there must be some positive benefit to people, and, apart from a universal standard of time, people could not develop the technologies that make the study relevant. Consider how necessary the earthly time standard is in the lives of people and then extrapollate to imagine what life would be like without a universal standard of time. I suppose it's the age old "study is for man" rather than "man is for study" argument or debate.

After I had some time to really reflect on relativity, I began to understand that the practical application of relativity data is as important as any other type of data application. I learned to mesh the knowledges of the theory of relativity into a real, universal model in my mind.

The Universe began with a big bang, and ever since, there has been time. Things move, sometimes very fast (also, according to me and according to everyone on earth, really). While the perception of differing times may occur, in reality time is passing at the same constant rate, according to the universal standard of time. Either man invented the standard, or the standard has always existed, but the debate is irrelevant, really. What matters is that people have the things they want and/or need.

In summation, yes there is reletivity, but it matters only isomuch as people are affected positively by the forces of reletvity and of the study of reletivity!

This is probably not anything you would want to challenge your teacher or professor over, although you may. Most of the teachers and professors that I have learned from, with regards to the theory of relativity, really hadn't deeply considered the issue, or they considered it a private matter, that time is only partially relative. Yes, time is fully relative in the abstract, but people do not live and work in the abstract.

Moreso, see if you can get a grip on how the data gathered through use of the theory of relativity might have a meaning or value to your life, then see if you can construct a universal model of time that you can live with.

Do I believe that Einstein is a hero? Absolutely. A genius and a hero. However, I believe that he just touched on the knowledges that can been learned in relativity studies. He probably didn't have time to be constructing universal models, but I wouldn't be surprised if he had one through the entire time of his studies.

Most scientists are egomaniacs. They cannot stand the remotest possiblity that a standard may exist which they did not discover or invent. Professors and teachers are, really, too. I am thankful that I had the opportunity to learn reletivity, but I do not believe anyone helped me understand the issue, really. And, honestly, although I do believe the subject can be taught, I believe also that people will always be left to learn for themselves the importance and relevance of relativity studies and, really, that they will always be left to themselves to learn the relationships of time.

Very deep subject. The most important thing about reletivity studies is to do the work as it is assigned, if you are taking, for example, Modern Physics. You may feel like you're working blindly with a study you can't understand, but in time you will understand. You'll also probably understand just how crazy scientists and professors are too, he he he. Take your professor's word at the changes that happen in time and so forth, and, over time you will develop your own viewpoint of reletivity. Try to get a grip on what they are asking you to do and just do it as the math is concerned. You may, also want to do some outside reading or study. Good luck!

P.S.: If you haven't seen it, you might like to watch the movie "Real Genius" with Val Kilmer. Very funny stuff about studying things like reletivity in college...

One thought...consider the possiblity of gravity reletivity. In other words, is gravity reletive to any constant? I. E. is gravity relative to inertia...tough one, especially if you haven't yet studied inertia (the potential energy of a moving object)! In this case, I would be measuring the energy of the moving object reletive to the potential energy of one stationary object, or there would be no way to make the measurement. Sort of like measuring speed against the universal time standard. Could it be that everything is reletive or measured reletive to an earthly standard?