Why is the speed of light the way it is?

[Admin]

We all know and love the speed of light, but why does it have the value that it does? Why isn't it some other number? And why did it become such a cornerstone of physics?

Why is the speed of light the way it is? : Read more

 

[voidpotentialenergy]

This is just my opinion but i think L speed is it's speed because the particle part of it is the fastest it can interact with the quanta distance in quantum fluctuation.
Light is particle and wave so the wave happens in the void between quanta.
Gravity probably travels in that void and why gravity seems instant.

 

[rod]

The space.com article wraps up the discussion with, "So on one hand, the speed of light can be whatever it wants to be, because it has units and we need to define the units. But on the other hand, the speed of light can't be anything other than exactly what it is, because if you were to change the speed of light, you would change the fine structure constant. But our universe has chosen the fine structure constant to be approximately 0.007, and nothing else. That is simply the universe we live in, and we get no choice about it at all. And since this is fixed and universal, the speed of light has to be exactly what it is.

So why is the fine structure constant exactly the number that it is, and not something else? Good question. We don't know."

It seems that the *universe* made this decision, *But our universe has chosen the fine structure constant to be...*
I did not know that the universe was capable of making decisions concerning constants used in physics. E=mc^2 is a serious constant. Look at nuclear weapons development, explosive yields, and stellar evolution burn rates for p-p chain and CNO fusion rates.

The report indicates why alpha (fine structure constant) is what it is and c is what it is, *We don't know*.

 

[Helio]

We all know and love the speed of light, but why does it have the value that it does? Why isn't it some other number? And why did it become such a cornerstone of physics?

Why is the speed of light the way it is? : Read more

I liked the article and its inclusion of old Ole Romer. He was going for the Spanish price to determine longitude, which requires a clock. Galileo, with his discovery of his Medici Moons of Jupiter, realized that the moons would serve as such a clock. He produced the necessary tables and invented a head-mounted small telescope to allow a ship's navigator to observe the moon's positions, revealing what time it was. But it was too difficult to use and finances were weak that year for the country he chose to fund him.

So how did Ole Romer discover light's speed... "Serendipity baby!" [I can hear that phrase in my head, but I forget what actor used it.]

 

[Helio]

The space.com article wraps up the discussion with, "So on one hand, the speed of light can be whatever it wants to be, because it has units and we need to define the units. But on the other hand, the speed of light can't be anything other than exactly what it is, because if you were to change the speed of light, you would change the fine structure constant. But our universe has chosen the fine structure constant to be approximately 0.007, and nothing else. That is simply the universe we live in, and we get no choice about it at all. And since this is fixed and universal, the speed of light has to be exactly what it is.

So why is the fine structure constant exactly the number that it is, and not something else? Good question. We don't know."

It seems that the *universe* made this decision, *But our universe has chosen the fine structure constant to be...*
I did not know that the universe was capable of making decisions concerning constants used in physics. E=mc^2 is a serious constant. Look at nuclear weapons development, explosive yields, and stellar evolution burn rates for p-p chain and CNO fusion rates.

The report indicates why alpha (fine structure constant) is what it is and c is what it is, *We don't know*.

The use of "the universe has chosen..." is understandable hyperbole. "Mother Nature" seems a bit feeble for addressing the initial constants for the entire universe, especially given how precise those constants had to be for stars, planets, and life to form. Something bigger is needed to answer how those initial conditions were established, but any answer will transcend science, so only pseudoscience, philosophy, or religion can attempt that answer.

 

[rod]

FYI. When someone says *the universe has chosen*, I am reminded of these five lessons from a 1982 Fed. court trial.

The essential characteristics of science are:

It is guided by natural law;
It has to be explanatory by reference to natural law;
It is testable against the empirical world;
Its conclusions are tentative, i.e., are not necessarily the final word; and
It is falsifiable.

Five important points about science.

 

[Gary]

If the universe is expanding , how can the speed of light be constant ( miles per second , if each mile is getting longer ) ? Can light's velocity be constant while the universe expands ? So, with the expansion of the universe , doesn't the speed of light need to increase in order to stay at a constant velocity in miles per second ? Or, do the miles in the universe remain the same length as the universe 'adds' miles to its diameter ? Are the miles lengthening or are they simply being added / compounded ?

 

[Gary]

Lets say we're in outer space and we shoot a laser through a block of glass. What causes the speed of the laser light to return to the speed it held prior to entering the block of glass ? Is there some medium in the vacuum of space that governs the speed of light ? Do the atoms in the glass push it back up to its original speed. If so, why don't those same atoms constantly push the light while it travels through the block of glass ?

 

[voidpotentialenergy]

The space.com article wraps up the discussion with, "So on one hand, the speed of light can be whatever it wants to be, because it has units and we need to define the units. But on the other hand, the speed of light can't be anything other than exactly what it is, because if you were to change the speed of light, you would change the fine structure constant. But our universe has chosen the fine structure constant to be approximately 0.007, and nothing else. That is simply the universe we live in, and we get no choice about it at all. And since this is fixed and universal, the speed of light has to be exactly what it is.

So why is the fine structure constant exactly the number that it is, and not something else? Good question. We don't know."

It seems that the *universe* made this decision, *But our universe has chosen the fine structure constant to be...*
I did not know that the universe was capable of making decisions concerning constants used in physics. E=mc^2 is a serious constant. Look at nuclear weapons development, explosive yields, and stellar evolution burn rates for p-p chain and CNO fusion rates.

The report indicates why alpha (fine structure constant) is what it is and c is what it is, *We don't know*.

Then we get into that (what is the check for that) etc etc.
I like the simple idea that light is traveling at for a better word (time) or distance to the next quanta.
A self regulated system with no need for step 2.

 

[voidpotentialenergy]

Lets say we're in outer space and we shoot a laser through a block of glass. What causes the speed of the laser light to return to the speed it held prior to entering the block of glass ? Is there some medium in the vacuum of space that governs the speed of light ? Do the atoms in the glass push it back up to its original speed. If so, why don't those same atoms constantly push the light while it travels through the block of glass ?

But is the universe expanding? or is the matter/energy filling in what is already the universe.?
Relativity won't work to answer that since it is calculated on faulty math.
So lets think of the universe as not what you see but the universe of quantum fluctuation with waste mass/energy (what we see stars/ black holes/galaxies )
Is fluctuation really expanding?
If not then L speed is simply the distance at max speed to each quanta in quantum fluctuation.

 

[Helio]

If the universe is expanding , how can the speed of light be constant ( miles per second , if each mile is getting longer ) ? Can light's velocity be constant while the universe expands ? So, with the expansion of the universe , doesn't the speed of light need to increase in order to stay at a constant velocity in miles per second ? Or, do the miles in the universe remain the same length as the universe 'adds' miles to its diameter ? Are the miles lengthening or are they simply being added / compounded ?

Light travels through space and its speed is independent of space itself so, for instance, as it passes near a star or blackhole and space is warped, it doesn't slow down or speed up, though its frequency will shift. Its speed, surprisingly, is also independent of any relative motion between the emitter and observer. This is what Einstein recognized from which came Special Relativity.

As light encounters atoms and molecules, it will propagate more slowly but that is a matter issue not a spacetime issue.

 

[voidpotentialenergy]

Light travels through space and its speed is independent of space itself so, for instance, as it passes near a star or blackhole and space is warped, it doesn't slow down or speed up, though its frequency will shift. Its speed, surprisingly, is also independent of any relative motion between the emitter and observer. This is what Einstein recognized from which came Special Relativity.

As light encounters atoms and molecules, it will propagate more slowly but that is a matter issue not a spacetime issue.

I love Einstein's theory because it shows a mind that thinks outside the box, unfortunate that it was done with faulty math but the idea remains sound.

Probably rightish for the wrong reasons.
A simple task is find out why it only rightish

 

[Helio]

I love Einstein's theory because it shows a mind that thinks outside the box, unfortunate that it was done with faulty math but the idea remains sound.

And what math error is that?

Only the Pythagoras right triangle equation is needed to derive the dilation equation in SR.

 

[sine nomine]

What about the "permittivity of free space"? That implies there is some characteristic of free space that limits the speed of light. It reminds you of the old concept of ether.
And you need to explain the fine structure constant concept as well. Blaming the speed of light on permittivity and fine structure constant sounds like passing the buck.

 

[Shinsuke Hamaji]

If the time scale changes, I think other scales may change as well.

 

[RamanarayananSp]

Why is the speed of light assigned this particular unit, which is relative to Earth (both meter and second).
If it has a speed it shall be assigned to an Universal constant. This is not happening in a relative universe.

Our mind, which is the collective function of the Brain, is tied up to the concept known as Time. Otherwise Time is illusory. At any given moment the events are happening. If we refer the event later on then we are taking about a past event. But all the events are happening at the NOW. Previously it happened in NOW of past and if it has to happen it will happen in NOW of future.

So Time has only one value NOW. With this background, the Space also looses its identity.
At this point all events are happening at NOW and HERE.

This will lead to All Pervasiveness. And this gives higher dimensions of thinking, where the Mind (brain function) is free from the Time factor.

 

[Helio]

Why is the speed of light assigned this particular unit, which is relative to Earth (both meter and second).

It's interesting how Maxwell was able to do the math for electric and magnetic fields that gave him the speed result. It was, IIRC, Lord Rayleigh that recognized that EM and light were the same, thus their speed were the same.

It was Ole Roemer, working for Picard, who accidentally discovered the speed of light almost 200 years before Maxwell. He was working on a way to determine longitude by observing Io, something Galileo proposed but failed to get funding.

 

[hayate]

So why is the fine structure constant exactly the number that it is, and not something else? Good question. We don't know.

I have very basic knowledge of physics, but I am curios. How is the fine-structure constant related to the speed of light? Very simply, I just would like to know, if the constant was 0.008 instead of 0.007 would the speed of light be faster or slower?

 

[Catastrophe]

"Why isn't it some other number? " (near the beginning).

We don't need numerology. Any number can be entirely different if calculated on a different base. The actual numbers (themselves, not the meaning) depend on the fact that we have 10 hand digits (fingers including thumbs) so we started calculating to base 10.

Cat

 

[Helio]

How is the fine-structure constant related to the speed of light?

Well, the math is straight forward (from Maxwell):

c=1/(μo*ϵo)^2
μo ~ the permittivity of free space (AKA, electric constant)
ϵo ~ the permeability of free space (AKA, magnetic constant)

Very simply, I just would like to know, if the constant was 0.008 instead of 0.007 would the speed of light be faster or slower?

Any change to either term would alter the value for c, which was originally understood as the propagation speed for an electromagnetic wavefront. I think, and I invite any correction, that it was another (Halley or Rayleigh?) that quickly recognized this as the speed of light, thus making light an em wave.

Einstein noted that this value was independent of the inertial frame. IOW, the value implied no amount of motion would alter its speed, unlike a snowball thrown from a moving bus, for instance. The constant value for c in every circumstance is the backbone of SR (Special Relativity).

 

[voidpotentialenergy]

Well, the math is straight forward (from Maxwell):

c=1/(μo*ϵo)^2
μo ~ the permittivity of free space (AKA, electric constant)
ϵo ~ the permeability of free space (AKA, magnetic constant)


Any change to either term would alter the value for c, which was originally understood as the propagation speed for an electromagnetic wavefront. I think, and I invite any correction, that it was another (Halley or Rayleigh?) that quickly recognized this as the speed of light, thus making light an em wave.

Einstein noted that this value was independent of the inertial frame. IOW, the value implied no amount of motion would alter its speed, unlike a snowball thrown from a moving bus, for instance. The constant value for c in every circumstance is the backbone of SR (Special Relativity).

I love Maxwell's math on Speed of light without a clue on what light travels through to be the speed of light.

Totally missing that light travels in wave and particle through quantum fluctuation.
IMO fluctuation and it's properties sets the speed of light because you simply can't make a wave front move through it any faster. Slowing light down just means it starts to interact with quanta orbits and so does speeding it up.
Self regulated speed of light.

 

[DLSmith]

Conjecture: Like all moving objects, the speed of light must be limited by the amount of energy imparted at the source and the resistance offered by the space through which it travels (which could be zero, or not.) Space, far from being a vacuum, is filled with fast-moving particles radiated through any point of observation from as many directions as there are stars and other radiant heavenly bodies. In the aggregate, such particles could offer a coefficient of resistance to any given beam of light.

 

[dlp]

We all know and love the speed of light, but why does it have the value that it does? Why isn't it some other number? And why did it become such a cornerstone of physics?

Why is the speed of light the way it is? : Read more

I appreciate that this is an article written to popularise and advance science, however, there are several questions I would like to raise, that, if taken at face value, amount to disinformation. For instance when you say that:

“Einstein's theories didn't say what that number was, but then he applied special relativity to the old equations of Maxwell and found that this conversion rate is exactly the speed of light.”

What exactly did the author mean by that? The fact that the author refers to, and which Einstein deduced, was that if light was a wave as held by Maxwell, Lorentz, Fizeau and most other Scientists of the time, then a person running abreast of a beam of light should see, the beam of light moving at a uniform speed. This is because waves travelling through a medium move at a constant speed. But if one were running in parallel with the beam of light, this is not what one would see, because it is an oscillating electromagnetic wave. So different parts of the wave would move at different speeds. If, however, the Lorentz transforms were used, the problem would be solved and all parts (almost all parts) of the light wave would be moving at a uniform speed. Although, anyone, even without the help of maths, can easily conjecture that this cannot be a complete solution.

One possibility, a very real possibility, I might add, especialy after Max Planck’s discovery of the discreteness of energy in the form of quanta, is that Maxwell’s theory is wrong! A plausible alternate theory using the aether can be found at: https://www.academia.edu/37258409/The_Electromagnetic_Universe_docx
Remember it was the aether that everyone was looking for, the above theory gives a logical explanation.

Again, the fact that the permittivity of free space turns out to be exactly 1/137 (0.007) is just one of those mathematical co-incidences. I don’t think any scientist in his right mind would base any practical reasoning on the fact that the fine structure constant approximates anything.

 

[voidpotentialenergy]

I appreciate that this is an article written to popularise and advance science, however, there are several questions I would like to raise, that, if taken at face value, amount to disinformation. For instance when you say that:

“Einstein's theories didn't say what that number was, but then he applied special relativity to the old equations of Maxwell and found that this conversion rate is exactly the speed of light.”

What exactly did the author mean by that? The fact that the author refers to, and which Einstein deduced, was that if light was a wave as held by Maxwell, Lorentz, Fizeau and most other Scientists of the time, then a person running abreast of a beam of light should see, the beam of light moving at a uniform speed. This is because waves travelling through a medium move at a constant speed. But if one were running in parallel with the beam of light, this is not what one would see, because it is an oscillating electromagnetic wave. So different parts of the wave would move at different speeds. If, however, the Lorentz transforms were used, the problem would be solved and all parts (almost all parts) of the light wave would be moving at a uniform speed. Although, anyone, even without the help of maths, can easily conjecture that this cannot be a complete solution.

One possibility, a very real possibility, I might add, especialy after Max Planck’s discovery of the discreteness of energy in the form of quanta, is that Maxwell’s theory is wrong! A plausible alternate theory using the aether can be found at: https://www.academia.edu/37258409/The_Electromagnetic_Universe_docx
Remember it was the aether that everyone was looking for, the above theory gives a logical explanation.

Again, the fact that the permittivity of free space turns out to be exactly 1/137 (0.007) is just one of those mathematical co-incidences. I don’t think any scientist in his right mind would base any practical reasoning on the fact that the fine structure constant approximates anything.

Traveling from point A to B at the quantum level IMO is the reason for the speed of light.
A wave of light needs a medium to be a wave so a particle of light traveling at max speed is set by the wave max speed.(min chunk of space and distance to the next min chunk)
It can't go faster because of the medium it travels through.

Duality of light a particle that sets up a wave supported by space/time and appears to have duality traveling through the medium of quantum fluctuations min points.
Just is that speed.

Lots of C speed theories but none of them address the mechanism of what the medium that causes a wave.

All JMO

 

[dlp]

Lots of C speed theories but none of them address the mechanism of what the medium that causes a wave.

Hi Voidpotentialenergy,
It’s an interesting and pertinent point that you have raised and it certainly deserves to be examined in greater detail. First of all, let us consider dark matter, which makes up 85% of the Universe. Consider that all the known matter in the Universe approximates to only about 4.5%. Just take a minute to think about how weird this is. Here is something (Dark Matter) that makes up 85% of the Universe, yet it has no form, even more important, it does not interfere with the transmission of light or electromagnetic waves in any way. Think about it, the slightest disturbance in the transmission of light or electromagnetic waves would result in huge distortions: this does not happen. Further, Dark Matter has proved very elusive to detect. If you tried to weigh Dark Matter it would sink right through the weighing scale because it has extremely low interaction with matter.

Therefore, it is plausible that Dark Matter is in fact the aether that ancient philosophers talked about, it fits all of the properties that the aether was supposed to possess.

In the new theory of the aether, it is proposed that every point in the Universe is occupied by infinitesimal, almost stationary di-pole elements that possess 360 degrees of freedom of movement. This freedom of movement allows these infinitesimal elements in space to orient themselves in the direction of travel of a photon and the energy of photon travels along this line of aligned photons.

You will be pleased to learn that the link to the article given at the end of this post, addresses in a logical and connected manner your query of what the medium is and of how energy is transferred from point to point in the Universe.
If you would like to read more about this theory read: The Electromagnetic Universe: https://www.academia.edu/37258409/The_Electromagnetic_Universe_docx