The Unknowable One-Way Speed of Light—and Occam’s Razor
February 23, 2023
Here is a fellow who says nobody has measured the speed of light. You may think they have, but all that has been measured is the round trip speed of light—derived from the time taken for a beam of light to reach this distant point and bounce back. So what they have is an average of two speeds—the time it takes light to reach the faraway place and the time it takes light to return.
What if the one-way speed of light is not the same in all directions? There are symmetries in the universe so that you might think it is. But there are also asymmetries in the universe so that you might think it is not. Anyone doing the math problem of rowing the boat at the same speed but traveling different distances going upstream or downstream begins to favor the second possibility. The rowboat travels at different speeds upstream vs downstream, though it relative speed is the same.
“Of course, it is simpler if light should travel the same speed in all direction, but that is a convention, rather than an experimentally verified fact,” says Derek Muller in the above YouTube video. Einstein made note of that in his 1905 paper; to say light travels the same speed in all directions is “a stipulation that I can make of my own free will to arrive at a definition of simultaneity.” Glad it works out for him.
And it works out for us too. The physics works the same for us so long as the round trip speed is c [the variable that stands for the speed of light]. It is just easier to think it travels one way as easily as in another, but it is not knowable, for reasons explained in the video. If, say, it moved like molasses in one direction, but was near instantaneous in the second, so long as the round trip is the same, we wouldn’t know. Why assume it is the same both ways? It’s easier, more testable. It is Occam’s Razor employed—that the simplest solution is the one with which to run.
However, those logicians too reliant on Occam’s Razor forget that Occam regularly fumed at his wife for ‘borrowing’ and all but destroying his razor to shave her legs. Whoa! You should have heard him scream every morning!
If Occam’s Razor does not hold with regard to the speed of light, what then? If it were the extreme mentioned above, molasses vs near-instantaneous, then light from the James Webb scientists to the edge of the universe (as though out there anyone cared what they were doing) would be traveling at the speed of molasses, but the James Webb scientists would be looking at the edge of the universe in real time. Those perfectly formed stars on the edge of the universe would not be from eons ago, but from right now—whatever ‘now’ means.
perfectly formed stars link to prior post
Ah well, so what? It makes no difference, Muller says. But it may make a difference should there ever be a reconciliation of the four fundamental forces, which don’t appear to get along with each other that well. It won’t upset my world. But to scientist chowing down their morning Feynman Flakes, it just may. I wish them well. When scientists start carrying on about how reality is much more complex than Newton and so maybe his conclusions of uncovering God’s handiwork don’t hold, just counter with, “How come you can’t just chalk it down to seeing but the “fringes of his ways?” It’s nothing but human pride at work—the refusal to acknowledge that anything could be true other than what they figure out themselves—and it doesn’t look that they will anytime soon, per the video.
to be continued.
****** The bookstore
The Michaelson-Morely experiment in 1887 showed that the speed of light is the same no matter what direction the light source is pointing. Similar, and more accurate, experiments since then have had the same results.
Special relativity sprang from the Michaelson-Morely experiment. I find it odd that the fellow in the video you linked to would use the time dilation of special relativity to rule out synchronizing moving clocks when special relativity itself requires that the speed of light be the same for all observers regardless of the motion of the light source or observer. If the speed of light does vary, then special relativity is false and time dilation could not be used to rule out synchronizing moving clocks.
So, the speed of light has been measured.
[ans: Plainly, I should get out of the way and let you two have at it. Would that that could happen. I thought I took from it that since we can only be on one end of the test at any time, we cannot say for certain. If the universe is expanding, is there a difference in light speed ‘against the current’ as ‘with the current?’ It does smack a little of ether, though.]
Posted by: WitnessFTP | February 23, 2023 at 02:01 PM