Speed of light revisited yet still again

old thought-experiment friends Alice and Bob

The speed of light has never been visited, at least not by any human.

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Certainly, reading a reputable exposition of special relativity so that he actually learns something doesn't appear to be in his make-up

And yet Bran nobody hereabout specifically controverts my assertions...

My recollection is that posters, including myself, frequently controvert your assertions

Where have I missed the boat

... I had also assumed that a clock in a spaceship circumnavigating our planet sends back clock signals at regular intervals sequentially behind, which would seem to constitute a pretty reliable indication that it's apparently running slower throughout its trip

And the discrepancy in time was how many seconds?

or is it a time amount like one trillionth of one second, which is not actually measurable with accuracy.

In 1971 two scientists, J. Hafele and R Keating, borrowed four atomic clocks from the U.S. Naval Observatory, put them on commercial airliners and flew them around the world. When compared with similar atomic clocks back in the U.S. they found that the clocks slowed down by the tiny, but very real amount predicted by Einstein and the time dilation equation

And again this thread is not about clocks in terrestrial space ships, but of those going light speed, of which there are ZERO....NADA....None....Zip

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My recollection is that posters, including myself, frequently controvert your assertions

Might you provide a link Bran to an example or two...

That easily explains for instance if Polly leaves her home planet Mars at light speed

There is no variant of relativity theory in which objects move from A to B and their internal clocks measure zero duration.

Einstein says if Marty leaves at noon her time, she arrives here a very short time later with her watch still reading 12:00...

In #5,848,802 you said:

reiterating your mistaken belief about time dilation

If for instance I state, "There might be a particle very slightly lighter than the photon," of course I'm suggesting that it might have a little mass. But for goodness sake, I said "might"; it's only conjecture, not assertion

But Para you had us ignoring relativity. That means halfway through her journey hasn't she has encountered at 2c that entire 10 seconds of photons; so during her entire 10-second trip she passes thru two such bundles, in effect 20 seconds worth of photons

And Bran I readily accede some of your confusion might derive from typos on my part. In some of my earlier postings and threads I had Marty leaving "at noon." But later I had her leave at 11;50 so that she arrives here at noon our time, of course with her watch still reading 11:50

In the special theory of relativity, a moving clock is found to be ticking slowly with respect to the observer's clock. If Sam and Abigail are on different trains in near-lightspeed relative motion, Sam measures (by all methods of measurement) clocks on Abigail's train to be running slowly and similarly, Abigail measures clocks on Sam's train to be running slowly.

But there cannot be a "particle lighter than a photon", because a photon has no mass

And what significance does a particle's weight have, anyway?

1…...I said no such thing. I said we were ignoring one type of relativity……

2.Claiming she is at 2c is contrary to the article. Time dilation means you can't ever achieve c.

3. Claiming she passed through photons is contrary to the article. The speed of light is constant no matter what reference you are in.

4. Your claim that she sees the trip as 10 seconds is contrary to the article.

She sees the clocks on the other object as slower than her clocks.