Motor Daddy:
James, I've learned enough about relativity to know that it makes fundamental fatal mistakes which makes the theory a pile of trash.
No. The theory is completely self-consistent. The special theory of relativity has only two assumptions (or one, if you frame the principle of relativity appropriately). If those two assumptions are true of reality, the rest follows automatically. The two assumptions have, in fact, been tested rigorously and extensively. They have been proven correct beyond any reasonable doubt. This is why relativity is the dominant scientific theory of space and time.
In contrast, we have Motor Daddy physics. To its credit, with a slight bit of tweaking, it is also fundamentally self-consistent. That is because it is essentially Newtonian physics, with its assumption of absolute time. Confusion comes because Motor Daddy himself makes fundamental errors in deriving conclusions from the postulates of his own theory. The most egregious of these errors is that Motor Daddy likes to muddy the waters by claiming that in his theory, light travels at the same speed in all reference frames, whereas in fact the speed of light varies between different inertial frames in the MD theory. In the MD theory, in fact, there is one single preferred frame - the frame of what MD calls "space" - which is absolute. In that frame, light has the required speed; in every other frame the speed of light is measurably different. MD does not accept this because MD doesn't understand what a reference frame is.
The problem is not that physicists do not understand the MD-like picture of a Newtonian universe with an absolute, preferred frame of reference. That was, in fact, the accepted picture of space and time that all physicsts held up as the paradigm theory until Einstein's work demolished it. Today, students starting in physics are taught the absolute theory, then introduced to Einstein's theory later. The end result is that ALL students of physics today have an understanding of both relativity and the absolute spacetime picture of Motor Daddy. They also understand how those two pictures differ.
Then comes the crunch. Einstein and MD are incompatible. They can't both be right. The ONLY way to tell which is right, given that both are internally consistent and coherent pictures of a possible reality, is to compare predictions made by each theory to experimental results. When this is done, Einstein wins every time. Case closed.
Physicsts, including the physicists here, all understand in detail, the expected results of the MD theory, for light spheres in a moving box and so on. Speaking for myself, I have dealt in depth and mostly agreed with the results that the MD theory predicts for such thought experiments. The crunch comes where the rubber meets the road. Whenever such experiments are actually performed, Einstein wins and MD loses. Moreover, there are literally thousands of other much more complicated physical predictions that can be made using both the MD and Einstein theories. And again, when any of these have been tested (and they have been tested a lot), Einstein wins and MD loses. Every time.
So, this is crap:
Motor Daddy said:
Complete and utter nonsense caused by a lack of understanding of how absolute velocity works.
Physicists understand the concept of absolute velocities. They also know that experiment shows that no such thing exists in reality.
Motor Daddy said:
The entire theory of relativity was concocted under the premise that light is always measured to travel the same speed in all frames.
Yes. And the entire MD theory is concocted under the premise that there is absolute space and time, and therefore the speed of light must vary from frame to frame. Einstein wins when experiments are done.
That is simply impossible as I've shown over and over again. BY DEFINITION you are wrong and I am right. What part of "a meter is defined as the length of the path that light travels in a vacuum in 1/299792458 of a second" do you not understand??????
Motor Daddy must understand that this argument CANNOT be won by definition. MD's theory defines an MD universe. Einstein's theory defines an Einsteinian universe. Which universe do we live in? Einstein's. Experiment proves it. No thought experiment can prove things either way. Thought experiments can at best show that a theory is self-inconsistent, or inconsistent with already-known facts. Einstein's theory is not inconsistent with itself or any known fact. MD's theory is not inconsistent with itself (when applied correctly), but it is inconsistent with many known facts.
If you are actually measuring the speed of light then how could it be anything different?
I have explained this in detail in our previous discussions of reference frames, linked previously in this thread.
The MD theory
requires that measurements of the speed of light give different results in different frames of reference. Einstein's requires that measurements give the same result in all inertial frames. The tests are done. Nature says Einstein wins and MD loses.
Then there's the issue of the way you measure distance in a frame using round trip light travel time and divide by 2. Don't you see that is total BS and that only makes the length correct when the source and the mirror are at a zero relative velocity along the same axis, and at the same time each at an absolute zero velocity. If the absolute velocity would be greater than zero the length will be incorrect!
Rather than MD making empty assertions that this is what is done in all experiments, I suggest that MD produce the goods. Motor Daddy: your task is to find at least one example of a published physics paper that shows an experimental setup and results that use the "round trip and divide by 2 method" that you say is wrong. Then, we can all analyse that specific paper and agree on whether or not the method is flawed, based on what was actually done and reported, and not on some third-hand imaginings of Motor Daddy.
My prediction is that Motor Daddy will never produce any such paper.
Again, the reality is that each object has an absolute velocity, and you wouldn't know that because you've never measured the speed of light, you've only measured the relative speed of light compared to you!
This is an empty assertion, disproven by experiment over and over again.
In other words, you claim the measured speed of light is always the same regardless of your motion, so what you are saying is that since your measured speed of light is always the same and you know your motion is capable of being different, then you are saying that the speed of light must change speeds in order to maintain the same 299,792,458 m/s measured light speed in your different motion frames.
No. What changes is the nature of space and time when you change frames, not the speed of light.
To understand this, you need first to understand what a reference frame is, then to get a basic grasp of what Einstein's theory says. Motor Daddy has never even got to stage 1. It has been at least 3 years, just on this forum alone and there has been no progress in MD's understanding of what he is discussing.
....is it that you always measure the relative velocity of light to be the same regardless of your motion, which means light knows how fast you are traveling, and it adjust its motion in order to maintain your measured relative velocity between you and it???
Light never adjusts its velocity. What happens is that your measuring instruments depend on your state of motion. Or, to put it another way, space and time itself change when you change reference frames - in a way that is completely, mathematically and numerically, specified by Relativity. This has been tested. Einstein wins over and over and over again. MD loses.
Impossible! By definition you are wrong!
I repeat: this is not a dispute that can be settled "by definition". What we have here is two competing physical MODELS of reality. Which one actually matches reality? Einstein Einstein Einstein. MD loses. The data are in.
An expanding light sphere does not travel in space it expands its radius in space.
A bizarre statement, but I think I know what you mean.
The center point is incapable of motion. HOWEVER, the source that emitted the light is an object in space, capable of motion during the same duration of time the light is in motion. That means:
If the source was in motion while the light sphere radius was expanding then the source will no longer be at the center of the light sphere.
True in the MD universe. True in Einstein's universe for somebody watching the source moving. Not true in Einstein's universe for somebody sitting on top of the source and moving with it.
No longer at the center means that the source is closer to one point of the light sphere than the other points. That means points of the expanding light sphere will be a different distances away from the source after a time has elapsed. So according to the source, the speed of light is measured to be different depending on which direction he measures the distance to the edge of the light sphere.
True in the MD universe. Not true in Einstein's universe.
Let's reconvene again 9 months time, Motor Daddy, and start all over again. We can pretend this discussion never happened. Agree? That's what you've done all the other times.
