I came across this article in Wikipedia.
PHYSICAL CONSTANT
A physical constant, sometimes fundamental physical constant or universal constant, is a physical quantity that is generally believed to be both universal in nature and have constant value in time. It is contrasted with a mathematical constant, which has a fixed numerical value, but does not directly involve any physical measurement.
[b]There are many physical constants in science, some of the most widely recognized[/b] being [b]the speed of light in vacuum c,[/b] the gravitational constant G, [b]Planck's constant h[/b], the electric constant ε0, and the elementary charge e. Physical constants can take many dimensional forms: the speed-of-light signifies a maximum speed for any object and is expressed dimensionally as length divided by time; while the fine-structure constant α, which characterizes the strength of the electromagnetic interaction, is dimensionless.
The term fundamental physical constant is sometimes used to refer to universal but dimensioned physical constants such as those mentioned above. Increasingly, however, physicists reserve the use of the term fundamental physical constant for dimensionless physical constants, such as the fine-structure constant α.
Physical constant in the sense under discussion in this article should not be confused with other quantities called "constants" that are assumed to be constant in a given context without the implication that they are in any way fundamental, such as the "time constant" characteristic of a given system, or material constants, such as the Madelung constant, electrical resistivity, heat capacity.
More interesting reading a:
https://en.wikipedia.org/wiki/Physical_constant#Universal_constants
2. Another Article:
A Constant Paradox
The speed of light in a vacuum is a universal constant.
The speed of light is a constant because the rate of flow of time is a variable.
To the best of our knowledge both of the above are true.
This implies that the meter is a fixed length.
During the twentieth century, the speed of light in a vacuum has reached the theoretical status of a “universal constant”, a fixed value of c0 = 299,792,458 m s −1 being chosen in 1983 as a basis for the international unit system.
Speed is distance divided by time.
Time is variable .
If time were a constant then distance would have to be a variable.
It is equally valid to consider distance could be a variable.
The universal constant, the speed of light is based upon two parameters, one of which is known to be a variable, the other of which could be a variable.
How can a constant be based on two parameters both of which are variables?
If c defines the length of a meter but a meter, is variable …?
Reference:
https://www.thenakedscientists.com/forum/index.php?topic=39042.0
Interesting really, isn't it?

I came across this article in Wikipedia.

PHYSICAL CONSTANT

A physical constant, sometimes fundamental physical constant or universal constant, is a physical quantity that is generally believed to be both universal in nature and have constant value in time. It is contrasted with a mathematical constant, which has a fixed numerical value, but does not directly involve any physical measurement.

**There are many physical constants in science, some of the most widely recognized** being

**the speed of light in vacuum c,** the gravitational constant G,

**Planck's constant h**, the electric constant ε0, and the elementary charge e. Physical constants can take many dimensional forms: the speed-of-light signifies a maximum speed for any object and is expressed dimensionally as length divided by time; while the fine-structure constant α, which characterizes the strength of the electromagnetic interaction, is dimensionless.

The term fundamental physical constant is sometimes used to refer to universal but dimensioned physical constants such as those mentioned above. Increasingly, however, physicists reserve the use of the term fundamental physical constant for dimensionless physical constants, such as the fine-structure constant α.

Physical constant in the sense under discussion in this article should not be confused with other quantities called "constants" that are assumed to be constant in a given context without the implication that they are in any way fundamental, such as the "time constant" characteristic of a given system, or material constants, such as the Madelung constant, electrical resistivity, heat capacity.

More interesting reading a:

en.wikipedia.org/wiki/Physical_constant#Universal_constants
2. Another Article:

A Constant Paradox

The speed of light in a vacuum is a universal constant.

The speed of light is a constant because the rate of flow of time is a variable.

To the best of our knowledge both of the above are true.

This implies that the meter is a fixed length.

During the twentieth century, the speed of light in a vacuum has reached the theoretical status of a “universal constant”, a fixed value of c0 = 299,792,458 m s −1 being chosen in 1983 as a basis for the international unit system.

Speed is distance divided by time.

Time is variable .

If time were a constant then distance would have to be a variable.

It is equally valid to consider distance could be a variable.

The universal constant, the speed of light is based upon two parameters, one of which is known to be a variable, the other of which could be a variable.

How can a constant be based on two parameters both of which are variables?

If c defines the length of a meter but a meter, is variable …?

Reference:

www.thenakedscientists.com/forum/index.php?topic=39042.0
Interesting really, isn't it?