# Relativistic Law Of Reflection

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### #18 OceanBreeze

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Posted 04 October 2019 - 11:50 AM

Oh now I am just laughing to myself about how all of you claim to know what is happening yet none of you have considered the gravitational effects. Did I say something that was above your head? did you not understand that curvature via gravity would effect the travel path of the light.

What if there is no star in the problem and the light beam comes from a distant laser pointer. You still think gravitational effects have anything to do with this problem?

Do a search of length contraction and angle rotation and aberration of light, see what you find before you laugh too hard.

### #19 ralfcis

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Posted 04 October 2019 - 12:04 PM

If you look at the photon clock video there is no mention of GR because it's a question that is about SR. A GR answer to an SR question is both overkill and irrelevant.

Edited by ralfcis, 04 October 2019 - 12:04 PM.

### #20 VictorMedvil

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Posted 04 October 2019 - 12:04 PM

What if there is no star in the problem and the light beam comes from a distant laser pointer. You still think gravitational effects have anything to do with this problem?

Do a search of length contraction and angle rotation and aberration of light, see what you find before you laugh too hard.

Without the Star and the Earth there is no gravitational effects, but he said on the Earth and coming from a star, thus it misses the eyepiece.

Edited by VictorMedvil, 04 October 2019 - 12:05 PM.

### #21 ralfcis

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Posted 04 October 2019 - 12:15 PM

Do the experiment on a ship then. The ship starts out stationary to the star and the light hits the eyepiece. The main rule of relativity is you can't tell you're moving. So from the ship's perspective, whether it's moving or not, the light hits the eyepiece. If not, the primary rule of relativity is broken. From the star's perspective, the reality is unchanged. It can't not hit the eyepiece any more than it can peer into the ship's future. The timing of when it hits the eyepiece is what's changed from the star's perspective.

PS. the gravitational effects of the earth on the light are also the same whether the earth is moving or not.

PPS. Whether you use starlight or replace it with laser pointer on the ship, both will hit the eyepiece regardless of the ship's movement.

PPPS. Model the photon clock in the video as the bottom mirror being the mirror in this example and the top being the receiving eyepiece. The photon always hits the eyepiece from any perspective no matter what the theta angle of the light is coming off the bottom mirror.

Edited by ralfcis, 04 October 2019 - 12:30 PM.

### #22 ralfcis

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Posted 04 October 2019 - 01:22 PM

I'm now even more interested in this question because it may unstick me where I'm stuck in my next investigation. The conclusion I came to before in the train/platform example was while the speed of light is unchanged, it takes light longer and it has to travel further in a moving frame from a stationary perspective. This is what's happening in this mirror/eyepiece example. The light from mirror to eyepiece takes longer from the star's perspective than from inside the ship's perspective and yet there is no movement between the eyepiece and mirror. The red herring here is the idea the angle of the mirror changes due to length contraction when there is actually some sort of non-physical length expansion between the mirror and eyepiece. I need to think on this more.

### #23 GAHD

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Posted 04 October 2019 - 03:35 PM

The mirror doesn't care what's happening to the star or the reverse. The only effect either moving thing has relative to the light (because C is invarient) is what wavelength the light is "perceived" as when interacting. If there's enough relative motion for there to be perceived contraction the light would just blast though the reflector as a hard gamma burst rather than actually reflect/refract. It's not going to miss anything.

### #24 ralfcis

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Posted 04 October 2019 - 04:06 PM

It's like with a big enough engine even light will fly right through a mirror.

Anywho, the answer I was looking for was right there in front of me. The important interaction between light and velocity is not that the relativistic velocity combo law dictates any relative velocity to c is always c thereby keeping c the same from all perspectives. No, velocity itself is what determines the light's time duration and distance travelled in the MMX, the train example and any other relativistic problem. The video I posted shows this clearly. It's velocity that determines how far and how long the reflected light travels from mirror to eyepiece. This is how velocity isn't just eaten up by c like a bug in a supernova but how it actually controls and affects both distance and time components of c. Ok it's a start, now I have to build up the theory of Ralfativity around this.

Edited by ralfcis, 04 October 2019 - 04:09 PM.

### #25 OceanBreeze

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Posted 05 October 2019 - 04:35 AM

OK, here is a much better explanation than what I provided.

It does include all of the things I talked about, the change in the mirror’s tilt, thus changing the angle of reflection as well as the aberration of light changing the angle of incidence, and it includes all of the math.

In particular, the math is shown that a mirror that is 45 degrees from the vertical in the rest frame, will present itself at only 30 degrees from the vertical in a frame moving at a relative velocity of 0.8165c (with respect to the rest frame). I did know that the angle from the vertical would decrease, but this is a surprising result; I thought the change would be much smaller.

They also worked out the change in both the angle of incidence due to aberration and the angle of reflection and show that the reflected beam will always hit the target in both the moving and rest frames, as we should expect.

Although it looks to be complicated, is just algebra so Ralfcis should enjoy it!

(I have a ship to catch so I will leave you all in peace for a while, try to behave yourselves )

### #26 ralfcis

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Posted 05 October 2019 - 10:29 AM

Umm so you're no longer standing by the assertion, that was incorrectly attributed to me, that the changing of the mirror's angle is compensated by the changing of the light's reflected angle due to time dilation. I said it's one or the other in relativity, length contraction does not work in tandem with time dilation. If you try to do the math with both of them contributing to an effect, they don't cancel out, they add up to double the effect with Y2.

There's no such thing as physical length contraction or time dilation. It's all handled by relativity of simultaneity and it's all illusion. Time does not slow nor does length contract. What's happening is the information of time or distance is delayed by the speed of light. Velocity adds a rate of delay of that information. If you had a camera on the face of your alarm clock and your alarm clock was speeding away from you, the rate of information being transmitted to you would be received slowed while all the while your alarm clock is ticking away normally. It is not ticking slower due to being in some sort of slow time warp as Dildostein said.

People just don't seem to understand the difference between clocks and time. Einstein tied the two together when he said time is what clocks measure. Colbert illustrated this in his monologue when he as Trump was calling Australia to find out if he was going to make any mistakes tomorrow because they are 14 hours in the future. Sounds ridiculous unless Einstein says the same thing. The future or the past are not what's on a clock face. Time dilation is not slowed time just because you can see the face of a clock look like it's measuring slowed time. All you're witnessing is the information from that clock face being affected by a rate of light delay. Why can no one in the world understand this?

Perspective brings in relativity of simultaneity. Because a ray of light is involved between the mirror and eyepiece, the information that it represents is affected by the velocity of the ship. The information is the relative position between the mirror and eyepiece and the time it takes light to traverse that distance. It's like refraction in water. The water bends the light so distances look off. Velocity is adding a rate of delay to the light but the actual distance between the mirror and eyepiece remains unaffected.

Now I know Popeye will ignore all this because he has a ship to catch and is too busy to try to understand it. The thing is, I give him a lot more credit than the philosophers on this "science" forum. His motivation is not that he has better things to do, his motivation is fear that I'll confuse him and his stature in the flock of parrots will be compromised. Unlike Dumbamp, I see no problem in ad hom, ad hominem, admonition, addition/subtraction, and double poisoned wells because you can't really understand where a person is coming from unless you understand his motivation. For example, Damp and XC's motivation is preserving their intelligence (manhood) from attack through dishonesty.

Edited by ralfcis, 05 October 2019 - 10:55 AM.

### #27 ralfcis

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Posted 05 October 2019 - 10:49 AM

PS I know I said both distance and time information is being distorted by velocity's effect on information rate transfer but I only believe the time information alone is being distorted. I just can't prove that yet.

### #28 sluggo

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Posted 05 October 2019 - 11:32 AM

OceanBreeze;

The x and y components are a mixture of space and matter.

The space does not contract, only the matter. If the mirror was captive in a frame, and the frame contracted, then the bottom end would move relative to the top end, and the mirror angle would change.

### #29 OceanBreeze

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Posted 05 October 2019 - 12:12 PM

OceanBreeze;

The x and y components are a mixture of space and matter.

The space does not contract, only the matter. If the mirror was captive in a frame, and the frame contracted, then the bottom end would move relative to the top end, and the mirror angle would change.

Yes, the angle does change according to the observer in the reference frame that is in relative motion to the mirror. Earlier, you said the angle remains constant, I’m glad to see you are now in agreement on that point. But there is no need for the mirror to have a frame* in order for this to happen (where frame* is not referring to a frame of reference but something like a picture frame)

But it is more complicated than just the angle changing as Snell’s Law does not hold in this case, the angle of incidence does not equal the angle of reflection.

The math in the link is well done and very clear, worth going through it.

For Ralfcis: I am still standing by my statement that the changing of the mirror's angle is exactly compensated by the changing of the light's reflected angle, and the link supports this. The compensation means the light will still hit the target despite the changing angle.

I didn’t attribute that to you, I said what you wrote is vaguely similar.

This question turned out to be more interesting than I had at first thought and I learned something from it too as I thought the change in angle would be at most only a few degrees.

(My ship is already at sea, having just departed port in Davisville, Rhode Island, on the way down to Miami to begin the next expedition of mapping along the southeast US coast. I will probably post again in November when the dives are happening)

### #30 ralfcis

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Posted 05 October 2019 - 01:31 PM

Ok it's a lot tougher than I thought. It's exactly the same as a light clock moving through space but instead of horizontally or vertically aligned, it would be tilted at a 45 degree angle. The angle of the mirrors would change according to relativity and the angle of the light reflected off the mirrors due to time dilation would have to compensate for the mirror angle changing in order for the light clock to work the same in any relative frame.  I'd have to do the math to see how this is really working because I just don't believe that length contraction and time dilation can work together to cancel each other out. I forget all my trig so I'd just use basic algebra instead. Don't know when I'll have the time.

Edited by ralfcis, 05 October 2019 - 01:39 PM.

### #31 LightStorm

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Posted 07 October 2019 - 12:58 AM

Relativistic law of reflection in a light clock. I wrote to a journal about this, they got back to me and said, relativistic law of reflection applies only to mirrors that not horizontal. They're just making stuff up.

### #32 ralfcis

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Posted 07 October 2019 - 09:12 AM

I think so because a horizontal light beam gets reflected vertically off a 45 degree mirror which is the same direction  as a vertical light clock. This means that the relativistic effects on the angle of reflection must be the same as in the video I posted. I have to stand by my original analysis, you can only apply either length contraction or time dilation to solving a problem, not both concurrently. The physics forum solution only solves the problem from the perspective of length contraction. They do not invoke time dilation like the video I posted. If they invoked both they would not cooperate and counteract each other, they would double the effect on the angle and the light would miss the eyepiece. Using only one or the other analysis and the light hits the eyepiece.

Edited by ralfcis, 07 October 2019 - 09:44 AM.

### #33 LightStorm

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Posted 07 October 2019 - 10:32 AM

If they invoked both they would not cooperate and counteract each other, they would double the effect on the angle and the light would miss the eyepiece. Using only one or the other analysis and the light hits the eyepiece.

I am not sure I follow.

### #34 ralfcis

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Posted 07 October 2019 - 11:20 AM

If you look at the video, it shows that a vertical beam from a light clock hits the eyepiece (top mirror) at an angle from an outside stationary perspective when the light clock is moving. The bottom mirror is horizontal so length contraction does not come into play. If instead of a light clock, you have the vertical beam coming off a 45 degree mirror, the vertical light beam can't tell the difference whether it started from a horizontal light clock mirror or a 45 degree mirror deflecting a horizontal light beam upwards. Hence, length contraction of the base of the 45 degree mirror also can't come into play because it's irrelevant to the path the beam takes from an outside perspective. This path is due to time dilation. Now if you want to solve the problem using length contraction of the mirror, you have to ignore time dilation other wise the beam will miss the eyepiece by gamma. The angle will be gamma squared.

It's like the muon example. You can't say the muon sees the length of the atmosphere it must cross as length contracted AND the time it does so is also time dilated. It's one or the other. This is the main reason why Einstein's assertion that both time dilation and length contraction work together to ensure c is constant from all perspectives is false.

Edited by ralfcis, 07 October 2019 - 11:26 AM.