[Bored chemist]

OK, let's try going back to the start.
You asked "

What's the true explanation, free from lies?

and I said

Complicated.
It would probably take a book.
Do you now understand why it's not going to be on the web?

And your assertion was

It is on the web already.

Well, if is then you should be able to show me the bit of that video where they avoid the lie about monochromatic light by discussing things like supercontinuum lasers.

So, once again,
At what point in the video you cited as evidence that there was a video that covered everything, did they cover supercontinuum lasers?

Or do you accept that the whole story- free from "lies we tell to children"- is complicated and will not be on YT?

[hamdani yusuf (OP)]

a video that covered everything

It's not a reasonable request.

"lies we tell to children"

Do you think that MIT's videos in my reply#14 also lies?

What's the true explanation, free from lies?

Complicated.
It would probably take a book.
Do you now understand why it's not going to be on the web?

It is on the web already.

Laser Fundamentals I-III | MIT Understanding Lasers and Fiberoptics

[Bored chemist]

It's not a reasonable request.

I know; That's why I told you it's

Complicated.
It would probably take a book.
Do you now understand why it's not going to be on the web?

So why did you claim to have one?

[Bored chemist]

Do you think that MIT's videos in my reply#14 also lies?

Do they say laser light is monochromatic?
Is it?

[hamdani yusuf (OP)]

Do you think that MIT's videos in my reply#14 also lies?

Do they say laser light is monochromatic?
Is it?

This is what he says at 7:30 in the first video.

property number one now some people refer to it as high monochromaticity

Googling for images of "laser spectrum" shows various shapes of curves.

[Bored chemist]

So that video repeats the "lies we tell to children" idea that all lasers are monochromatic.
So it is clearly not an example of
 "

the true explanation, free from lies?

So why did you say such an explanation was

on the web already.

And link to the video?

[hamdani yusuf (OP)]

So that video repeats the "lies we tell to children" idea that all lasers are monochromatic.
So it is clearly not an example of
 "

the true explanation, free from lies?

So why did you say such an explanation was

on the web already.

And link to the video?

Both of what you called lies and not lies are available on the internet. My problem is why tell the lies in the first place? What was expected to be improved by telling them?

[Bored chemist]

Most introductions of laser say that laser is a source of monochromatic light. This video shows polychromatic laser instead.

How many times have I explained the idea of "lies we tell to children"?

The whole body of knowledge about lasers is immense and complex.
Nearly all of them are practically monochromatic.
But not all of them.

Most of them are built in Fabry Perot resonators.
But not all of them.
And there are a stack of other complexities and exceptions.

If the "school level" explanations we gave in YT videos tried to include all the caveats and so on, the video would take days and nobody would watch it.

If you want a more detailed view, you need to plough through three hours of the MIT videos.
And even they don't cover everything.

So why did you say they did?

[hamdani yusuf (OP)]

The whole body of knowledge about lasers is immense and complex.
Nearly all of them are practically monochromatic.
But not all of them.

Most of them are built in Fabry Perot resonators.
But not all of them.
And there are a stack of other complexities and exceptions.

If the "school level" explanations we gave in YT videos tried to include all the caveats and so on, the video would take days and nobody would watch it.

If you want a more detailed view, you need to plough through three hours of the MIT videos.
And even they don't cover everything.

They can just say that most lasers are monochromatic, without saying that it's a defining characteristics of laser.

[Bored chemist]

They can just say that most lasers are monochromatic, without saying that it's a defining characteristics of laser.

For many applications, the monochromaticity is a requirement- it's the reason they use lasers.

You can always add these side notes and complications.
But it's likely to confuse newcomers.
I'm puzzled that you don't accept the general principle of teaching the broad basics first, and only teaching the details later- to those who need to know them.

[hamdani yusuf (OP)]

You can always add these side notes and complications.
But it's likely to confuse newcomers.

There's a difference between known unknown and unknown unknown. The latter will cause false confidence in one's own knowledge, and can cause unnecessary arguments.

[Bored chemist]

Fortunately, if you realise that you didn't really study the subject, but you just watched a few YT videos, you will be aware that you have many known unknowns.

Now we have that sorted out, can you answer this?

If you want a more detailed view, you need to plough through three hours of the MIT videos.
And even they don't cover everything.

So why did you say they did?

[hamdani yusuf (OP)]

Fortunately, if you realise that you didn't really study the subject, but you just watched a few YT videos, you will be aware that you have many known unknowns.

Thanks for the great advice, which also apply for yourself.

[hamdani yusuf (OP)]

Now we have that sorted out, can you answer this?

If you want a more detailed view, you need to plough through three hours of the MIT videos.
And even they don't cover everything.

So why did you say they did?

Did I say that?
It seems like you are misunderstanding my intention of posting their videos. I tried to show that even reputable sources can provide misleading information. You can't blindly trust them. Even they must be verified.

[Bored chemist]

Did I say that?

Yes, you did.
Here

It is on the web already.

Laser Fundamentals I-III | MIT Understanding Lasers and Fiberoptics

In response to me saying that the version without lies wouldn't be on the web.

It seems like you are misunderstanding my intention of posting their videos. I tried to show that even reputable sources can provide misleading information.

That's pretty much the opposite of what you said at the time.

[hamdani yusuf (OP)]

In response to me saying that the version without lies wouldn't be on the web.

What makes you think that it's not yet found on the web?
You can simply google it.

[Bored chemist]

You can simply google it.

You tried that, and it didn't go well, did it?

[hamdani yusuf (OP)]

I just googled for laser spectrum, and here are some good results.

https://www.newport.com/n/laser-types


https://integratedoptics.com/spectral-properties-of-cw-lasers

[Bored chemist]

I just googled for laser spectrum, and here are some good results.

Do you understand them?

[hamdani yusuf (OP)]

I just googled for laser spectrum, and here are some good results.

Do you understand them?

Not yet. Perhaps with more data I would. Just like this fascinating video.

INSIDE A LASER! An Open Cavity Helium-Neon Laser!

Let's take a look at an awesome open resonator cavity He-Ne Laser!
Tweak-able and hackable, you could fit your entire body inside the Laser cavity!

I talk about the Brewster angle, and the technical specs of a NOS Brewster windowed Helium Neon Laser tube!

Optical contacting is discussed, that is used to bond glass parts with no glue, but creates a permanent bond.

I designed built a really cool mirror mount that can hold 6 Laser mirrors!

I show how to do Quick and Easy Laser alignment, and demonstrate Transverse Electromagnetic Modes (TEM), as well as extend the cavity to around two feet!

Even if we can't understand it yet completely, let's just appreciate the information it contains. It will become part of training data for future AI models.