Re: The differences between LET, SRT and IRT

On Apr 15, 10:12 pm, Jerry <Cephalobus_alie...@xxxxxxxxxxx> wrote:
On Apr 15, 9:05 pm, Bryan Olson <fakeaddr...@xxxxxxxxxxx> wrote:





Jerry wrote:
kenseto wrote:
Sigh....my theory says: the leading portion of a light beam will miss
hitting the hole in the cover plate due to the absolute motion of the
detecting surface and the cover plate.

Exactly. That's the idea. As Jerry says:

Sure. And with the interruptions, you have LOTS and LOTS of
leading edges.

leading edge!          leading edge!          leading edge!
            V                      V
V
 ___________   ____________________   ____________________   ___
            |_|                    |_|                    |_|

             |<------10^-8 sec----->|        10^-10 sec-->| |<--

At a distance of 100 meters, as I recall, it takes 2.7x10^-8 sec
before the beam will shift enough to hit the hole in the cover
plate. So keeping the pulses only 10^-8 sec in duration will
mean that the discontinuous beam never hits the hole.

You didn't have any problem with this concept when I presented
10^-8 sec pulses emitted at a rate of 1000/sec on the "I need
help" thread:

 ______|__________|__________|__________|__________|___

You wrote:
| "Hey idiot runt.....if there is only 1000 pulses /sec. then the gaps
| between the pulses are much larger than 2.7e-7. This means that all
| the pulses will miss the 3 mm detecting surface. That's why I
| specfied
| a continuous laser. BTW that's the reason for the Uncertainty
| Principle....the absolute motion of the detector makes a short pulse
| of light (or a photon) to miss the detector and that's why you can't
| detect the velocity and the position of a photon simultaneously."
Would you prefer programming the AWG for 1000 pulses/sec instead?
That's fine with me.

But then the spot is much less obvious. The nice thing about a
pattern that keeps the laser on for a significant fraction of the
time is that we can do away with the fancy detector and directly
observe where the spot lands.

I kind of like half-on, half-off, with a frequency less than twice
Ken's leading-edge time. View in a fixed-width font:

           ______        ______        ______        ______
    ______|      |______|      |______|      |______|

          |<-- 50 ns -->|
             (or less)

There will certainly be less problems with heating, and given
that I haven't yet found a commercial Kerr cell with liquid
cooling, that would actually be preferable.

Is the Ker cell really necessary?

Probably not. There are undoubtedly lots of ways to set up
this experiment, and somebody expert in the technologies
involved could easily think up better ways of performing
it than the way I proposed.

Google up, laser+modulate+GHz.
Looks like available technology can turn a laser on and off that
fast, or two or three orders of magnitude faster.

Yes. Diode lasers used in the telecom industry are cheap,
and can be switched at multi-gigahertz frequencies.

Ken would not need a 100-meter hallway to run his experiment. With
modern laser modulation, ten meters, or even *one* meter is enough.
That's actually kind of important, because focusing a laser spot to
about a mm at a 100m range is somewhat challenging.

A CCD detector is probably the way to go, since you ought
to be able to detect "absolute motion" drift over distances
of a few tens of centimeters.

Assuming it exists, of course...  :-)

To Bryan:

Reading over my response, I didn't properly thank you enough for
kicking me into different modes of thinking. I was getting really
frustrated reading Kerr cell specs and had serious sticker shock
looking at the price of AWGs.

Your suggestions appear to have brought the price of the
experiment down to something actually doable. Thanks!

Jerry




.

Relevant Pages

  • Re: The differences between LET, SRT and IRT
    ... They cut off the light before the spot has a chance to move to the ... So keeping the pulses only 10^-8 sec in duration will ... | Principle....the absolute motion of the detector makes a short pulse ... pattern that keeps the laser on for a significant fraction of the ...
    (sci.physics.relativity)
  • Re: The differences between LET, SRT and IRT
    ... hitting the hole in the cover plate due to the absolute motion of the ... So keeping the pulses only 10^-8 sec in duration will ... | Principle....the absolute motion of the detector makes a short pulse ... pattern that keeps the laser on for a significant fraction of the ...
    (sci.physics.relativity)
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  • Re: Renormalization in QED
    ... > You asked to be included in the list of the runts of the SRians ... > The grating or crystal moves wrt the light (absolute motion). ... > relative motion between the source and the detector. ...
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  • Re: The differences between LET, SRT and IRT
    ... 0.1/300,000 seconds to reach the detecting hole. ... Subsequent pulses will hit the hole. ... Since the gap between the pulses is adjustable, ... If there is absolute motion the B detector will detect less pusles ...
    (sci.physics.relativity)
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