[hamdani yusuf (OP)]

More or less the one given in that video- in which the guy cites Feynman's books on the subject.
Those books are older than I am

Well that's pretty humorous, so apparently the video is accurate it's just that hamdani doesn't understand it.

What's even funnier is that you think you already understand it when you haven't even seen it.

[hamdani yusuf (OP)]

You are not physicist (probably haven't even taken a single physics course) and your posting history is full of errors and misconceptions, so if the video disagrees with mainstream physics and aligns with your ideas then it is not worth watching.

Your way of thinking is not scientific, speculative, and often committed logical fallacies, especially appeal to authority which tends to be dogmatic. Your blind faith to mainstream ideas made you fall into group thinking and herd mentality.

[Deecart]

What's your explanation?

Not sure, but i guess it has to do with the wavelength.
After some search i found this :

At very high frequencies, the value of electric permittivity is very slightly less than one.

https://www.quora.com/Why-is-the-refractive-index-of-x-rays-less-than-1

X-ray is a very high frequency wave.

[Bored chemist]

More or less the one given in that video- in which the guy cites Feynman's books on the subject.
Those books are older than I am.

Most physics textbooks explain refraction using Snell's law which is derived from Fermat's principle. Feynman's explanation is more similar to derivation using Huygen's principle. They leave the part of how the media change phase velocity of light unexplained.

https://en.m.wikipedia.org/wiki/Snell%27s_law

So, your "complaint" is that the school text books offer a less detailed 9and less complete) explanation than those written for university students.

What did you expect?

Once again, we are in "lies we tell to children" territory.

[Bored chemist]

often committed logical fallacies, especially appeal to authority

You don't know what that means do you?
We can probably assume- at least for the purpose of this post- that Einstein is an authority on physics.
If someone tells me "The speed of light is constant;  Einstein says so" it is reasonable for me to believe it- because he is an authority.
But if someone tells me "Manchester is a bigger city than Liverpool; Einstein says so"  it is not reasonable for me to believe it because he's good at physics, but I really don't know if he's any good at geography.

Only the second of those situations is a logical fallacy.

It is not a fallacy to say that physicists are good at physics.

And, while we are at it.
It is not "dogma" to believe experimental results.

[Bored chemist]

it's just that Hamdani doesn't understand it.

That's not a short list...

[hamdani yusuf (OP)]

What's your explanation?

Not sure, but i guess it has to do with the wavelength.
After some search i found this :

At very high frequencies, the value of electric permittivity is very slightly less than one.

https://www.quora.com/Why-is-the-refractive-index-of-x-rays-less-than-1

X-ray is a very high frequency wave.

The link just restates the question and cites experimental results. It doesn't show the underlying mechanisms based on first principles.

[hamdani yusuf (OP)]

often committed logical fallacies, especially appeal to authority

You don't know what that means do you?
We can probably assume- at least for the purpose of this post- that Einstein is an authority on physics.
If someone tells me "The speed of light is constant;  Einstein says so" it is reasonable for me to believe it- because he is an authority.
But if someone tells me "Manchester is a bigger city than Liverpool; Einstein says so"  it is not reasonable for me to believe it because he's good at physics, but I really don't know if he's any good at geography.

Only the second of those situations is a logical fallacy.

It is not a fallacy to say that physicists are good at physics.

There are many scientists. Sometimes they disagree with each others. You can choose one of them to follow, which implies choosing the others to ignore. If the reason for your choice is based on the number of followers, then it is unscientific choice.

It's possible that you end up with the correct model by choosing the most popular one. Or even by picking randomly. But they are unscientific reasons. We should choose a model based on its explanatory power, i. e.  capable to explain more phenomena with less assumptions.

[Deecart]

The link just restates the question and cites experimental results. It doesn't show the underlying mechanisms based on first principles.

I agree that the common explaination i actualy get looks more like a "what" answer than a "how" answer.
It is surprising that because "the what" answer seem complicated for most peoples, they accept and confuse it with the "how" answer every smart people would require.

[Deecart]

It's possible that you end up with the correct model by choosing the most popular one. Or even by picking randomly. But they are unscientific reasons. We should choose a model based on its explanatory power, i. e.  capable to explain more phenomena with less assumptions.

I think so.
Therefore, in the first place, we should not talk about "light".
Light is some very complex interaction of photons.
A laser beam is also some special association of photons.
In my opinion, we should first study and be able to explain the behavior of some single photon.

If we do so, and only rely on facts, we cant talk of photons traveling from one place to one other.
We need to agree that if we dont interact with the photon, its position, and even its reality, is unknown.
We can only do the deduction : There was a photon after it has disappeared.
Therefore i like to say that the photon is some virtual entity, until it is no more.
A strange entity...

Concerning the propagation of the single photon, we have to consider it as "a wave".
What it means (in my opinion but you could have some other) is that there is some particle, the photon, that travels into some spacetime, and the spacetime specific to this photon is expanding.
This "area" where the photon is traveling back an forth is expanding at the speed of light.
But the photon itself, within this area, is traveling much faster than the speed of light, relativ to the outside of the area.
This do not contradict any physical law, because within the area (localy) where  the photon bounce back an forth (and this is why you have some "wave"...) the photon do not travel faster then the speed of light.
"The area" (the place where the photon exists as a particle) is some place where time do not flow at the same speed as outside the area.



 

[Bored chemist]

There are many scientists. Sometimes they disagree with each others. You can choose one of them to follow,

...
or you can look at the evidence.

But they are unscientific reasons. We should choose a model based on its explanatory power, i. e.  capable to explain more phenomena with less assumptions.

OK, so what facts and observations  are not explained by the current models in physics?

[hamdani yusuf (OP)]

So, your "complaint" is that the school text books offer a less detailed 9and less complete) explanation than those written for university students.

What did you expect?

Once again, we are in "lies we tell to children" territory.

I'm not the only one who complaint. The authors of the videos in the first post also think that we have misled children. They deserve better explanation. At least, they must be told where the model we told them fails.

[hamdani yusuf (OP)]

OK, so what facts and observations  are not explained by the current models in physics?

With a lot of online sources, it's hard to decide which explanation is considered mainstream at a given point in time. You can find them in the first videos in this thread.

[Bored chemist]

With a lot of online sources, it's hard to decide

Who finds it hard to decide, and why?

[Bored chemist]

At least, they must be told where the model we told them fails.

OK, so tell us where the model fails.

[Origin]

With a lot of online sources, it's hard to decide which explanation is considered mainstream at a given point in time. You can find them in the first videos in this thread.

Go to .edu sites, since those are generally university sites you can be reasonably sure the information there will be mainstream.

[hamdani yusuf (OP)]

Who finds it hard to decide, and why?

Anyone who does not have better information than the authors of those online sources.
You need a more trusted sources of information to reject or accept other sources of information.

[hamdani yusuf (OP)]

At least, they must be told where the model we told them fails.

OK, so tell us where the model fails.

You can find them in the first videos in this thread.

[hamdani yusuf (OP)]

Go to .edu sites, since those are generally university sites you can be reasonably sure the information there will be mainstream.

Here's the first link I got from online search.

http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/refr.html
Refraction is the bending of a wave when it enters a medium where its speed is different. The refraction of light when it passes from a fast medium to a slow medium bends the light ray toward the normal to the boundary between the two media. The amount of bending depends on the indices of refraction of the two media and is described quantitatively by Snell's Law.

It doesn't tell the mechanism for how the medium can change the light speed there. The last video I posted shows why it's false, using the refraction of X-ray from air to glass.
The first videos in this thread shows more examples. Have you watched them?

[hamdani yusuf (OP)]

Here's another link.

https://micro.magnet.fsu.edu/primer/java/refraction/refractionangles/index.html
As light passes from one substance into another, it will travel straight through with no change of direction when crossing the boundary between the two substances head-on (perpendicular, or a 90-degree angle of incidence). However, if the light impacts the boundary at any other angle it will be bent or refracted, with the degree of refraction increasing as the beam is progressively inclined at a greater angle with respect to the boundary. As an example, a beam of light striking water vertically will not be refracted, but if the beam enters the water at a slight angle it will be refracted to a very small degree. If the angle of the beam is increased even further, the light will refract with increasing proportion to the entry angle. Early scientists realized that the ratio between the angle at which the light crosses the media interface and the angle produced after refraction is a very precise characteristic of the material producing the refraction effect.

The refractive index of a transparent substance or material is defined as the relative speed at which light moves through the material with respect to its speed in a vacuum. By convention, the refractive index of a vacuum is defined as having a value of 1.0, which serves as a universally accepted reference point. The index of refraction of other transparent materials, commonly identified by the variable n, is defined through the equation:

n (Refractive Index) = c/v
where c is the speed of light in a vacuum and v is the velocity of light in the material. Because the refractive index of a vacuum is defined as 1.0, and light attains its maximum speed in a vacuum (which is devoid of any material), the refractive index of all other transparent materials exceeds the value of 1.0, and can be measured by a number of techniques. For most practical purposes, the refractive index of air (1.0003) is so close to that of a vacuum that it can be employed to calculate refractive indices of unknown materials. Materials with higher refractive indices slow the speed of light to a greater degree than those with lower refractive indices. In effect, these materials are said to be more refractive, and they exhibit a larger angle of refraction for incoming light rays passing through an air interface.

The explanation here is similar to previous one.