I think this is not a good idea and would result in endless disruption and confusion in engineering applications. However, I think there is an important point to be made about the definition of the metre as being dependent on the speed of light which is assumed to be constant. The speed of light is approximately constant but that is only because the tension in the fabric of spacetime is approximately constant. See:

Conference Paper THE UNIFICATION OF PHYSICS

Data Prerecording of Conference Presentation on the Unification of Physics

This leaves us in an unfortunate situation. We would like to know of there are very small variations in the speed of light from one year to the next but the speed of light in metres is always the same by definition of the metre.

We could resolve this problem by defining the metre based on a speed of light measurement made on a specific date (e.g. 31st December 2021) and then use a controlled measurement system (maybe similar to LIGO) to track the change in the speed of light with reference to the 31st December 2021 measurement. This way the metre would be defined and could be measured in any lab around the world with the correction factor for the current year being specified by the measurement laboratory.

Richard

I guess the title is not the correct header for the question.

If someone wants to reduce something to 1/3 of itself, how would you assign the new unit.

• Should we reduce the standard meter to 0.31951540592 m ?

>> Here, the new unit is still using standard unit 'm'.

Abhijeet Singh , well spotted, but I think you understand what it means, it basically means that we set the speed of light to be 938 million units of length per unit of time. Of course we could also change the second.

Richard Lewis , there has often been a bit of confusion surrounding the absolute speed of light vs the local speed of light and this is not surprising, because at this early stage of our Universe the two don't differ that much, according to my calculations only around 0.85% difference.

However as we spiral towards our inevitable fate at the nearest Schwartzchild limit, wherever that might be, the the local speed of light should go towards zero.

Steven Sesselmann , I don't understand your distinction between the absolute speed of light and the local speed of light. For example when LIGO detected a neutron star merger at a distance of 130 million light years it found that the gravitational wave and the light and gamma radiation all arrived at the same time.

Would you consider this to be the result of the local speed of light or the absolute speed of light?

Richard

[ Richard Lewis said: I don't understand your distinction between the absolute speed of light and the local speed of light.]

The sped of light is constant for the observer, but this is somewhat of an illusion because the observer on our case lives in a local potential depression, and this affects the absolute speed of light by a factor as follows.

c(local) = c * 1/ √(1 - (2gm/rc^2))

Since the Earth is not very large nor very dense, the difference is not very large, but it increases with time, because Earths ground potential is falling, i.e the earth is slowly cooling, shrinking and becoming a little denser.

In ground potential theory I show how electric potential is absolute, with the proton being the highest positive potential and the electron being the lowest negative potential, and everything else being somewhere in-between.

I was lucky to discover a formula for the exact value of ground potential, it can be calculated by knowing the mass of the electron and the proton respectively.

It's really simple and it works, but it will take time to gain acceptance.

Steven

As an engineer, please, keep the 1 m = 1 m, because going back to something that looks like 1 foot would be a nightmare (and I don't want to hear the Brits grumble "we were right" :) )