On Sunday, May 29, 2022 at 12:20:58 PM UTC-5, Stan Fultoni wrote:
> On Sunday, May 29, 2022 at 9:10:06 AM UTC-7, wrote:
> > > > The speed of light has a value c in every such system BECAUSE the speed of
> > > > light is measured PER SECOND, and the LENGTH OF A SECOND VARIES depending
> > > > upon the speed at which you are moving.
> > > You are being blatantly self-contradictory. You have conceded many times that relativistic time dilation is not only far too small to account (by itself) for the invariance of the speed of light, it is also in the wrong direction, since the same time dilation applies both to approaching toward and receding from the light (c+v and c-v).
> >
> > c+v and c-v have NOTHING to do with time dilation.
> Look up above in your previous quote, where you claimed the speed of light has the value c in every inertial system because the length of a second varies. When you say “the length of a second varies depending on speed”, you are referring to time dilation, right? And when you say time dilation results in the speed of light being c in every inertial frame, you are trying to explain why the speed of light is c rather than c+v or c-v for a system moving toward or away from the light at speed v, right?
No. When I discuss c+v and c-v it is nearly always a discussion of radar
guns. Radar guns emit photons at c and when those photons hit a
moving target, they hit at c+v or c-v, depending on which direction the
target is moving. It has nothing to do with time dilation. It has to do
with the frequency of the photons that are returned to the radar gun
from the target.
>
> So, now that I’ve explained to you what you said, and assuming you meant what you said, look again at my reply, which points out that you yourself have already conceded that time dilation cannot account for why the speed of light has the value c in terms of every inertial reference system. There, I say again: You are being blatantly self-contradictory.
I was talking about the speed of PASSING light. It relates to Einstein's
example, from one of his books, which described how light is measured
on a body moving away from the sun at a constant speed of 1,000 kps.
> > The speed of light is NOT the same in "every system of inertial coordinates."
> Again, you contradict yourself. Look up above at your previous message, where you conceded, regarding inertial reference systems, that “The speed of light has a value c in every such system…”.
> > The speed of light IS A REFERENCE system.
> No, it isn't. Speeds are defined in terms of reference systems, so obviously a speed is not a reference system, and a reference system is not a speed. Also, per above, the speed of light in vacuum is c in terms of every inertial reference frame, thereby conclusively debunking all your beliefs. Agreed?
Okay. I guess you cannot say that light is a "reference system" if there
is no known way to compare your speed to that "reference system."
I was just trying to debunk the idea that all motion is relative, and if
A is moving at 100 kps relative to B, then B is also moving at 100 kps
relative to A. That is nonsense. We know who is moving faster because
one of them had to ACCELERATE to get to the higher speed.
> > Since nothing can go faster than the speed of light, all other speeds
> > are a PERCENTAGE of the speed of light.
> That makes no sense at all. Remember, the reason nothing goes faster than light in terms of any inertial reference system is that light has the same value in terms of every inertial reference system, which you have agreed… and then denied… and then agreed…. and then denied… and so on. Also, each time you agree, you explain it by invoking time dilation, and then you deny time dilation has anything to do with it, and then you re-assert it, and then you deny it, and then you re-assert it… and so on.
Okay, there is no way to measure your speed relative to the speed of light,
so while you speed may be some percentage of the speed of light, there
is no way to calculate that percentage.
> > The speed of my refrigerator depends upon what you are comparing
> > that speed against. If it is relative to the wall, its speed is zero. If it
> > is relative to a refrigerator on the North Pole, my refrigerator is moving
> > at about 700 mph as the earth spins on its axis.
> But you contradict yourself yet again, because your whole claim is that the speeds of things do not depend on the frame of reference. Remember, you said it was the dumbest idea to think that object A is moving relative to object B, and then object B is moving relative to object A. But now you are agreeing that “the speed depends on what you are comparing that speed against”. And when I point this out, you will deny it, and then later you will re-assert it, and then deny it, and then re-assert it… and so on.
The speed of things does not depend upon the frame of reference because
the frame of reference does not represent REALITY. It is something picked
as a reference purely for doing mathematics.
> > If it is relative to a refrigerator on the North Pole, my refrigerator is moving
> > at about 700 mph as the earth spins on its axis.
> Be careful. You keep wanting to define velocities relative to objects, but your example shows the problem with that: How fast is your refrigerator approaching, or receding from, the refrigerator at the north pole? The answer is that the distance between those two refrigerators is not changing, so you need to ask yourself what you actually mean when you say that your refrigerator is moving at 700 mph relative to the one at the North Pole. What you actually mean is: Your refrigertator is moving at 700 mph in terms of an inertial reference system (system of coordinates) in which the refrigerator at the north pole is stationary. The crucial point is that there is more to a reference system than just a single object. That’s why scientists say that velocities are defined in terms of reference systems.
Okay.
>
> You’re agreed that you can define a reference system in which the North Pole is at rest, and you can also define a reference system in which your kitchen is at rest, and another in which the Sun is at rest, and another in which object A is at rest, and another in which object B is at rest, and so on. So all your earlier remarks, in which you vociferously denied all this, were blatantly wrong. Agreed?
I don't define "reference systems." Mathematicians do that. I was
trying to describe how the motion of all those systems affects time.
> > The speed of my refrigerator relative to the speed of light is zero, IF
> > the light you are talking about is from the light bulb inside my
> > refrigerator.
> Again, you contradict yourself, because you’ve agreed that the speed of light is independent of the speed of the source. Of course, you’ve also denied this… then agreed with it… then denied it… and so on.
> > At the same time, however, my refrigerator is moving at about 700 mph
> > as the earth spins on its axis, and at 67,000 mph as the earth orbits the
> > sun, and at 486,000 mph as the sun orbits the center of the Milky Way
> > galaxy. So, my refrigerator is moving at over 500,000 mph relative to some
> > stationary point in space. That is about 0.10006922855945% of the
> > speed of light at that stationary point in space.
> You’re confused. The motion around the center of the galaxy is less than a third of our speed in terms of the isotropic frame of the cosmic background radiation, which is over 0.1% of the speed of light. This finally brings you back to what I explained you were meaning originally, i.e., you are asserting that the local frames in terms of which the CMBR radiation is isotropic are “absolute rest”. But then you denied this, and now you are agreeing to it, and I have no doubt that in your next message you will deny it… and so on.
>
> Again, the existence of the CMBR isotropic frame doesn't in any way negate the fact that we can (and do) define systems of reference in a variety of way, and the fact that local inertial reference frames are reciprocally related by Lorentz transformations, which entail length contraction, time dilation, and the relativity of simultaneity. Agreed?
I wasn't relating anything to the CMBR. The CMBR cannot be stationary.
When I try to find a "stationary" point in our universe, I usually refer to
the point of the Big Bang. And then mathematicians argue that there
is no "point of the Big Bang," since they believe space exists only between
objects. There can be no space into which the universe is expanding.
>
> > If Object-A is moving faster than Object-B…
>
> In terms of what system of reference? The local isotropic CMBR frame? Or your kitchen’s frame? Or the inertial frame in which the North Pole is at rest? Or in which the Sun is at rest? Or in which A is at rest? Or in which B is at rest? (What is "object A" is the sun?).
> > you cannot simply decide that that also means that Object-B is moving
> > faster than Object-A…
>
> In terms of what system of reference? Obviously in terms of your kitchen’s reference system your refrigerator has velocity 0 and the refrigerator at the north pole is moving rapidly, but in terms of the system of reference in which the north pole is stationary that refrigerator has velocity 0 and your refrigerator is moving rapidly. You already agreed to this… but of course you also denied it… and then agreed with it… and then denied it… You seem very conflicted about all this.
No, we are just not talking the same language. I'm going to have to
find a better way to describe things. Plus, this thread has posed a problem
for me that I hadn't thought about before. I'm going to have to drop out
of this discussion to do some rethinking.
Ed