Atomic Clock In Space To Test Changing Speed Of Light

[multiweb (Marc)]

https://sciencetrends.com/atomic-clo...peed-of-light/

[Wavytone]

Interesting idea - resolves the moons orbital history, "inflation" and the non-existence of dark matter.

[silv (Annette)]

Sounds like "Lichtermüdung", the tiring of light.
Which is a now oft sarcastically ridiculed idea from the olden days, right?
I don't know anything about it, haven't even dared to read a Wiki article on it. Because "everybody" says it's stupid and long since proven wrong.

[Wavytone]

Just because a particular view is popular does not mean it is entirely valid. Starting with Ptolemy vs the vast majority who believed in a flat earth (as some still do). Copernicus and Galileo vs the Catholic Church, and many others. Charles Darwin and Stephen Hawking, vs religions (all of them).

In physics a hypothesis that A is related in some way to some things B C and D means you're on the way to a useful, rational expianation of observed phenomena and it can be used to make more predictions that can be measured experimentally to test whether the hypothesis is valid. This hypothesis doesn't surprise me at all and its nice to see it has a direct experimental basis (LLRE) and that another experiment has been devised to test it (these clocks).

Einsteins postulate that the speed of light was a constant and invariant with time was always troublesome in the sense that it is more of an assumption, one that worked very well, but for no particularly good reason - yet no-one had been able to disprove the assumption was incorrect by direct experimental evidence - apart from the LLRE measurements. And a 12 sigma discrepancy regarding the moons age isn't just a teeny bit wrong, it basically means the result was totally, blatantly flat-out wrong.

What has been confirmed many times over is relativity - that the speed of light is the same as measured in all frames of reference, and all that flows from that with respect to time dilation and so-forth. Which also shows that the speed of light - and the local measurement of time - are interrelated in another way.

[Robh (Rob)]

I think the "tired light" hypothesis has more to do with a change in wavelength rather than a change in the actual speed of light.

This is an entirely new proposal - that light slows down over time. If it seems to immediately resolve some of our current issues to do with inflation and dark energy, and physicists are taking it seriously enough to test it out in space, it might have some credence!

Interesting to see what the results will show.

Regards, Rob

[billdan (Bill)]

If it is proven correct that light slows down over time, it would mean current calculations of distant stars, galaxies and quasars etc are in fact closer to us than previously thought. Plus the calculated size of the observable universe will also shrink.

[Wavytone]

-3.8 cm/s per year is minuscule - c is 300,000,000 meters/sec

For galaxies at 1 billion light years... distance may have been overestimated by 12%.

Over a distance of say 100 million light years it suggests distance may have been overestimated by 1.3 percent which is below the accuracy of distance measurements.

Anything closer it’s irrelevant.

[RyanJones]

I can't understand why the only thing that seems to stay stable is " time " in these arguments which in itself is purely relative . If we measure the velocity of anything, it is distance over time, the half life of a radioactive isotope is measured against time and so on.

What is time ? genuine question.

We can say a day is the time it takes for the world to revolve once on its axis or a year is the time it takes for the earth to revolve around the sun. However if time it's self accelerated or decelerated and we are within a universe in which this happens then observations of historic events such as inflation and the " speed " of which it happened are relative to the current observer not relative to time as it was when it occurred.

What if, the further we look back into the past, the more truncated time becomes relative to us as the current observer ?

[E23 (Andras)]

Trying to show that "c" changes with time is the same as proving Einstein's Theory of Relativity wrong. They have been trying very hard to do that for a 100 years. It can't be done.

[Wavytone]

“can’t” as assumption on your part which is neither necessary nor proven. Especially as the existence of entire modern science doesn’t span even a tick compared to the age of the universe.

[lazjen (Chris)]

Ok, assuming it's proven that c can change over time. Why does it change (is there an external effect causing it)? Is the rate of change constant?

The article noted the impact on Dark Energy, but what about Dark Matter (even if indirectly)?

Note: I didn't dive into the rabbit hole and follow links off the article, so maybe there's something elsewhere.

[multiweb (Marc)]

There's a link here outlining the primary objectives of ACES.

[RyanJones]

Originally Posted by E23

Trying to show that "c" changes with time is the same as proving Einstein's Theory of Relativity wrong. They have been trying very hard to do that for a 100 years. It can't be done.

Just like you can't prove if the cat is dead or alive until you find a way to open the box.

[Wavytone]

Originally Posted by lazjen

The article noted the impact on Dark Energy, but what about Dark Matter (even if indirectly)?

Well, if the size of the universe and the rates of expansion are revised by this apparently there is no longer a need to postulate the existence of “dark matter” which no one has found in decades of searches by various means.

OTOH perhaps it’s all too convenient.

[billdan (Bill)]

What I find is mind boggling and hard to reconcile is if you light a candle, its light is travelling towards you at 300,000Km/sec.

[OICURMT]

Originally Posted by multiweb

https://sciencetrends.com/atomic-clo...peed-of-light/

http://www.iceinspace.com.au/forum/s...0&postcount=21

[Robh (Rob)]

Originally Posted by billdan

If it is proven correct that light slows down over time, it would mean current calculations of distant stars, galaxies and quasars etc are in fact closer to us than previously thought. Plus the calculated size of the observable universe will also shrink.

In my mind, it would mean distant galaxies are in fact much further away than we think. If light was faster in the past, then it has travelled a greater distance than what we see now as it arrives at 300,000 km/sec.
Hence, the mention that really fast light after the Big Bang might get rid of the conundrums of "inflation" and "dark energy".

Regards, Rob

[silv (Annette)]

yes, all that. And indeed, very surprising, the space travelled by the slower photons would be bigger, not smaller. Cool.

Or.
Our accepted view of the time-related property of spacetime is too human-centric.

Too restricted. It doesn't feel right to me, that we aim to split up the flow of time into segments which we, and only we, have agreed on.
A civilisation on a different planet - maybe even on a moon-like planet that doesn't revolve around its own axis, such a civilisation must have developed a totally different feeling of what time means. They'd live in constant twilight. Looking at their star for any scientifically meaningful time would burn them. They wouldn't look at their own star and hence, their Ancient Greeks wouldn't develop a heliocentrical understanding of their home system. Nor would they feel the need to experiment with sun dials or to split time slices into hours and then seconds.

And still, assuming they'd become space faring, their spaceships could also be slingshot around another planet to gain more momentum on their way out of the solar system. They'd calculate differently. I don't know how.
I'm just trying to offer a more open approach to what we assume time in spacetime actually is.

One more thing about the article in #1. The author isn't writing from a neutral perspective. Without saying so explicitly, she advertises her own publications from 2012, the Springer article ("downloaded 10.000 times"? Maybe. But scholar.google says the article was quoted only 4 times...) and the book. Even uses the word "popular book", right? Without saying that's it's hers.

Offputting. But also understandable.
When I assume that she was sarcastically ridiculed by her colleagues for her approach? Of course, under such circumstances, a person would develop thorns and use them. Sadly, to her own disadvantage and to the disadvantage of her concept.

To me, the real value was in the Esa-article she also links to and (ab-)uses it to underline her own concept.

ESA:
2) Fundamental physics experiments:

• Gravitational Red-shift. To measure with an improved accuracy the Einstein's gravitational red-shift.

• Drift of Fine Structure Constant. To measure time variations of the fine structure constant α at an increased level of accuracy.

• Anisotropy of Light. To test the validity of special relativity by detecting a possible anisotropy of the light velocity with an improved accuracy.

Interesting wording. In contrast with Riofrios bold interpretation, the ESA people put it much more timid so as to not shock the scientific establishment. But they do seem to expect to some degree what Riofrio has been proposing.

[Wavytone]

Here's a thought (from CN).

If the universe is expanding faster than light that means none of your scopes going to be able to keep up. Time to chuck 'em.

If yours has Intes optics let me know.

[Sunfish (Ray)]

Wow. Everyone seems to have an opinion about relativity although after a lifetime of reading , talking to scientists and a little university physics and mathematics I am not sure I even understand it.

A better clock and access to accurate time in this project would have to be good for us. If only my mount would automatically download it to the femtosecond.

“Louise Riofrio is educated in physics and astronomy “

Hmmm. One minor peer reviewed paper with no statement of actual qualifications. I think I will wait and see. But it sounds worthwhile thinking about.

The interesting thing about the speed of light and the history of the universe to me is that there are events that we can never know about as they lie outside the cone of time created by the speed of light. Some events can never affect us here now. If time slows that changes but so unlikely.