jajrussel

Mordred, thank you for the link to the lecture notes. Sounds reasonable, again I thank you.

So, it was my understanding of the term freefall that was causing my confusion. Thank you for telling me. Is it common for scientist to say that no force is acting on an object when there is only one force acting on it?

My current view of time is that time is as it is applied. I can view an object in space and say that as a whole that time is the same for any point in, or on the object. All parts are in sync. If I think dimensionally then time becomes part of a coordinate system that needs to be defined. I can still view the object and think all parts are in sync, but I can now coordinate any point in or on the object with a reasonable degree of accuracy as defined by the coordinate system. In order for another observer to agree with my findings a transformation may be necessary in order to satisfactorily explain the difference in observations. I need to make a correction here. I cannot actually use a 4D coordinate system. I am still in the early learning process. I tend to think and write in the first person and forget what that implies sometimes, because I am too focused on my point. I did not mean to mislead.

This link led to a discussion of time dilation and gravity. My understanding is that time dilation is an effect of gravity that is only observable to an outside observer. Is my understanding wrong? Would my having a better understanding of time dilation convince me that gravity is not a force that would more aptly (apply) to gravitons?

I finally see your point. When I apply this to an object in freefall I see an imbalance of force that in effect describes its direction of movement. The net force its not equal to zero. Yet, it is commonly said that an object in freefall has no force acting upon it. What applies to the cup on the table should apply to an object in freefall. Which seems to imply that gravity is a force, and that the geodesic is an effect of that force. Am I wrong?

Doesn't zero mean null? I think I understand what they are saying when they say gravity is the curvature of space, but wouldn't the curvature of space lend itself more to defining direction rather than force? Isn't direction an effect of force?

I am just reading this thread today, so my question is a little late in the day. My understanding is that the cup resting on the table is in equilibrium. Wouldn't this mean that no force is acting on the cup? Isn't it an imbalance of force that causes a cup to fall?

I have problems whenever people use the word pure in relation to any physical thing; except it was said that energy is a concept. So, can it be said that a concept can be pure? Does there need to be a distinction? Also, what if he had asked about a geodesic rather than a quantum fluctuation? Energy is needed to change an objects direction, but is an object actually changing direction when it follows a geodesic? I have wondered if an object changes position can that change of position be viewed as a change of direction? If there is an imbalance of energy something moves. Is this act a concept? Actually now that my brain is waking up I am confusing energy with force. My apologies...

I have been thinking about it , and I might be coming across as flippant and rude. If I am I am sorry, because I do not mean to. I have been told that my communication skills are lacking, and I know for a fact that I would not make a very good cheer leader. One look at my face and the interviewer would say, " yeah right, next.."

Some of the images of particle collisions show what I believe to be paths that are curved in appearance. Is this because they are interacting with the medium created within the chamber as a result of the collision? Are they interacting with the forces of the accelerator because they have slowed down? Or is it the way the image projector interprets the data and presents it? Meaning do the curves distinguish something other than the particles path in the image?

Can I assume that when you say "we" you are not speaking of yourself in plural? Newton was a Mathematician. I can not read his work. It is in a language I can not understand. I can rely on translations and hope that they are correct and that the translator has no agenda in the translation. Then I can try to make sense of what is being said. If one has an agenda one might accept and present a view that is not true because the presentation is not in agreement with the original statement. It starts at a point somewhere in the middle of the original meaning then transcends. I would guess that Newton was using language that he knew would be understood by the ones most interested in his work at the time. If he did not use the word straight I can only assume that he had no reason to do so. Perhaps he used a word that made a better, or similar presentation of his meaning knowing that those reading his work would know his meaning. With N1 I see a straight line. With N2 I see three straight lines. I realize that it is more complex than what I have stated and the number of straight lines I see for both N1, and N2 can increase if I want to consider different perspectives, and points of view, and now that I am thinking about it I am convinced that a straight line is more complex than a right line, so it seems to me that what you are saying is that the meaning of a right line is what has been glossed over and that you think the term straight line is a poor substitution, but I do realize that this is not what you wrote. I admit that I am easily confused and I apologize for having read something into what you have written other than your intent. I see lots of points of interest, would you care to expand on the ones you have mentioned, and perhaps doing so eliminate some of my confusion.

If this is the only problem you had with my reply I am a little puzzled? You answered my question which was, " How do we know that a photon is moving straight? How do we know that it is not constantly changing direction, but much too fast for us to see it as anything but a straight line? " Thank you... I do not consider the question to be speculative, but the thought that provoked the question I do. I could only allow myself to disagree with answers using none speculative points. I tried to remain within that boundary. Your answer was like a stop sign that I should have seen but did not because I was looking to far down the road. I was still tempted to charge full speed ahead, but the nagging thought of if you cant get past this answer that swansot has given, then the road ahead is not only going to be speculative it is going to zig zag, and bounce all over the place. So, once again thank you for pointing out the stop sign. I found the idea to be intriguing and interesting. I still do. The only thing important to me about the thought is fixing the problems that arise because of the thought. By straight line; I meant as opposed to a geodesic. Though I may have been willing to play loose with the definition of geodesic by flirting with different possible causes.

I am interested in answering your questions, but for now I have to go to work.

The marble and tube reference was poor. Why random directional changes? Wouldn't that imply an uneven distribution of space that might be obvious if the photons were a large distance apart at the start but less obvious when closer to point A and in phase at the start? Oh well, I have to take a nap and then go to work then I should have time to have a better understanding of what you mean by pulse dispersion. Thank you.

I wasn't exactly thinking in terms of zigging and zagging. That is somewhat to two dimensional. I might little better reference it to a marble moving through a long straight tube. Our best observation says that it’s path is straight, but the marbles own qualities and other variances would show that the path where the marble makes contact with the surface of the tube is not straight and we might have to assume that there are points along its path where there might be no direct contact between the two surfaces. But, even this references is poor for obvious reasons and the fact that the scale is much to large. With a photon we would have to divide time into very small increments in order to magnify and observe a minute direction change, so a direct observation would seem to fall into uncertainty. Mathematically it might be somewhat more easily predicted, but prediction does not make it so. Theories are important. The time that it takes for something to get from point A to point B is important, but does this rule out vector changes? It simply says that in a straight line something has to move at a specific velocity to get from point A to point B. Since we can not make the observation we can only say that so far as we can tell it is moving in a straight line. So, if we can not rely on direct observation to give us an exact answer then we have to look for effects that might be more easily explained if a zero mass particle was constantly changing direction. If a zero mass particle were constantly changing direction our best direct observation would only indicate that it got from point A to point B at c, but then c is based on a vacuum which is a calculated existence which is to say it can not be observed. Please note that I am not arguing with you here. Everything I am stating here are simply questions that have risen in my mind based on your answers. My questions seem reasonable to me, but that does not mean that my reasoning is right, and it certainly does not mean that your reasoning is in anyway wrong. It just means that for now I am having difficulty with it.

Thank you both for your replies. I haven't had time to consider the full implications of your answers, and considering that when it come to just about anything I am in a constant learning mode I have to look up just about everything. It would help If I had a better memory. One of the first things I looked up was the Lorenz Factor. In its description there is this explanation that I have included in brackets in order to help single it out, and it come from Wikipedia (β is the ratio of v to the speed of light c) this seems to indicate that the Lorenz Factor is factoring in a reference other than c. I realize that I still have a lot to learn, and that I may be taking part of the equation out of context since I have not entirely figured out why the Lorenz factor is necessary. So, my first question does the Lorenz factor need apply to a particle of zero mass? Second, does the Lorenz Factor have anything to do with mass, as in have I taken the bracketed potion out of context, or is it a dimensional tool?

This is basically a question, but it deals with speculation, so I am not sure that this is the proper place to ask the question, but here goes. I was watching a math video that said that when considering the orbital path of an electron we should consider the orbital motion more like a wave than a nice clean elliptical. Other comments in SFN dealing with time and motion kind of made this question come to mind, which I will eventually get around to asking. I am assuming that the speed of light is a straight line measurement, with the assumption continuing that the photon is moving in a straight line path. We know that the path itself can curve and the photon can follow it. I believe the term is geodesic and we can see the effect through what I have read is called gravitational lensing. This happens on a scale that is easily observed. There were the comments in another thread about light moving through a medium that has the appearance of slowing it down, but the actual reason being that the photon is interacting with the medium and that interaction takes time, the whole while light never ceasing to move at C, so the appearance is that it has slowed when it has not. Then there is the photons particle and wave like qualities. I am not sure if this clears up why the question entered my mind, and the truth is I had the explanation worked out better in my mind than I have presented it, but now to the question. How do we know that a photon is moving straight? How do we know that it is not constantly changing direction, but much too fast for us to see it as anything but a straight line? If it were constantly changing direction its actual path would be longer than than the straight line distance which I am assuming that c is based on, and this seems intriguing, but I could be wrong about the whole thought including how they have determined what c is.

If it is gone it is gone there isn't much I can do about it. The fact that it was unfinished, well it is probably just as well that it is completely gone, because I do not want half unfinished thoughts of mine just showing up somewhere. Now what I am referring to is twice maybe three times what I was working on disappeared because of what I did while the work was in progress. Once while writing a response to a post I wanted to review a statement made on a preceding page. It is apparently wrong to assume that just because there is a response box at the bottom of each page that what you are typing will follow you if you change pages. It is also wrong to assume that if you go back to the page that contained the box you were writing in, that what you were writing will still be there. Next it was just a small misspelled word, so badly misspelled that there were no suggestions listed. Seeing that there were no suggestions I clicked on the page to clear the suggestion box then decided to just retype the word. The word was supposed to be that and that is not that difficult to spell, but my fingers do not always go where I want them to go, and yes I was being lazy using the suggestion box to begin with. The problem apparently is that somehow I managed to highlight the word in grey then thinking I could just make the word go away because it was highlighted by hitting the backspace key. Wrong, wrong, wrong, everything gone, and I am on a different page. I looked up my own profile just to see if I had accidentally posted a half thought and simply could not remember which post I was responding to. Some of them do get to look alike sometimes, and I am a little tired. Nothing there thankfully. Though having now read some of my own past post it would be easily understood if someone reading what I have intentionally posted considered them to be half thought out thoughts. Okay, now that I an done howling at the moon, can someone tell me how to use the quote feature selectively? Do you have to take the whole quote, then delete everything but what you want to remain of the quote? How do I single out a single statement? I see where people have done it, while others seem satisfied with quoting the entire post. Is there a copy and paste trick?

You ask what someone means. You ask them to tell you what someone else means even though you have stated explicitly what they probably mean. Then you refute the probable meaning that you yourself have given. I am curious. What is your motivation? What do you believe?

I have been reading physics books, and my own thoughts tend to interrupt the learning process. There was another question about something being at rest that I had while reading (Light and Matter) which can be found from the website of the same name. I am trying to find the exact spot in the text that brought the question forward in my mind, but for the moment I haven't found it, so I am relying on my memory, which is probably not so good. Anyway - I was wondering if it is actually possible to distinguish if something is in motion, or at rest without simply stating that it is, or it is not? The statement that there is no such thing as something being at rest; I have read before, so the ball sitting on the table from one perspective is at rest, from another; it is not. If the ball were rolling across the table at any point it could be said to be at rest. The thing that seemed interesting to me is that there does not seem to be anything physically different about the ball whether it is perceived to be at rest, or if it is perceived to be moving because the ball is always in balance with the forces acting on it. If this thinking is correct then it would seem that the balls potential energy would be the same whether it is perceived to be moving, or is perceived to be at rest, and that any measurable difference between the two perceptions would simply be one of the coins that Swansont was talking about that makes up part of the balls total potential energy. There is the mass gain as the ball moves to consider. Does E=MC2 account for this gain in mass? Maybe I need to think about this question a little bit more? If the ball can not be accelerated to C because it has mass. It would seem that once the ball has been accelerated to is maximum, that the formula says that at this point there should be a measurable difference between the balls maximum acceleration energy and its total potential energy. Maximum acceleration energy would seem to mean maximum mass potential for the ball, and the measurable difference would have to be mass-less energy. This is actually a question and not a statement. Sometimes I feel like I am totally clueless, and for that reason I am not sure the questions have merit.

I forgot while reading that this is a philosophical discussion, and not a speculative one. From a philosophical point it would seem to me that all logic is flawed if it can have more than one outcome, but logic would allow that I choose. I do not believe that we can get something from nothing, but I do believe that we can get something from what appears to be nothing. Something can be divided incrementally, so definitive adjectives that describe something are logical, and it should be expected that they can be flawed, because of our limited understanding, but is the attempt to define something, illogical simply because our understanding is limited? The term (absolute nothing), seems to imply that nothing can exist in of itself in a state that is incremental. How can you divide nothing? There is nothing to divide, so no adjective is needed. Adjectives define something, so when you use an adjective like absolute with the word (nothing) you are giving nothing a quantitative measure, which may be confusing, even invitingly misleading to ones who are reading your philosophical presentation. After rereading your first post I am wondering if your intent was theosophical rather than philosophical. From my point of view it is okay if it was.

It would seem to me that the current apparent accepted explanation of gravity would suggest how one might get something from nothing in that space curves. I was watching a few minute clip on the behavior of black holes dealing with an inner horizon where centrifugal force slows things back down to the speed of light. If I remember correctly it was suggested that one should view a black hole as space actually falling inward faster than light until it reaches a point where centrifugal force creates this inner horizon. So, now I am wondering if space is exhibiting a curve in one direction and centrifugal force is opposing that direction would space begin to present mass/energy characteristics, or something from nothing?

Yes! You are right... I am pretty much getting that idea. I am one of those people who likes to see exactly why he is wrong. Sometimes, it takes a long time for me to figure out that I am wrong. Usually, someone telling me that I am wrong sends me into automatic quarry mode, but I have been trying to figure this out long enough now, to see that what I am trying to do doesn’t actually make sense. When I was a kid I was shown a formula that for me seemed to be magical. I spent a week trying to make it do different things. That is pretty much a long time to keep doing the same equation over and over again from as many different angles as I could think of; sometimes getting an answer that is close to being right, but only getting a consistently correct answer when the formula was used for what it was designed. Sometimes I long to remember what that formula was so I can try it again. Thank you for your help.

My thoughts were in agreement with uncool before I asked the question, but then I was afraid that maybe the way I was writing the equation somehow canceled itself out in both cases. You may have noticed that the result for both equations is c^2. I was hoping for an answer however minuscule of slightly less than c^2. At the moment I am not feeling very happy thinking about the amount of money I paid for this calculator, considering that I got the same results using a calculator that cost much less. Still I can see by your equations that my thinking was flawed in that I initially thought the second equation would actually widen the gap giving me a better chance of getting an answer that was not c^2. I guess I am going to have to get my book out and learn how to think this through in long hand. Thank you both...

I have entered this into my calculator several times and I keep getting the same answer could someone tell me why? c^2-(1/c)^2 = 8.987551787e16 Then I enter c^2-(1/c^2)^2 = 8.987551787e16 c is the speed of light 299792458 I am hitting the enter key at the = sign I was expecting the second calculation to have a different result.