this post was submitted on 14 Jun 2026
29 points (100.0% liked)

No Stupid Questions

48658 readers
545 users here now

No such thing. Ask away!

!nostupidquestions is a community dedicated to being helpful and answering each others' questions on various topics.

The rules for posting and commenting, besides the rules defined here for lemmy.world, are as follows:

Rules (interactive)


Rule 1- All posts must be legitimate questions. All post titles must include a question.

All posts must be legitimate questions, and all post titles must include a question. Questions that are joke or trolling questions, memes, song lyrics as title, etc. are not allowed here. See Rule 6 for all exceptions.



Rule 2- Your question subject cannot be illegal or NSFW material.

Your question subject cannot be illegal or NSFW material. You will be warned first, banned second.



Rule 3- Do not seek mental, medical and professional help here.

Do not seek mental, medical and professional help here. Breaking this rule will not get you or your post removed, but it will put you at risk, and possibly in danger.



Rule 4- No self promotion or upvote-farming of any kind.

That's it.



Rule 5- No baiting or sealioning or promoting an agenda.

Questions which, instead of being of an innocuous nature, are specifically intended (based on reports and in the opinion of our crack moderation team) to bait users into ideological wars on charged political topics will be removed and the authors warned - or banned - depending on severity.



Rule 6- Regarding META posts and joke questions.

Provided it is about the community itself, you may post non-question posts using the [META] tag on your post title.

On fridays, you are allowed to post meme and troll questions, on the condition that it's in text format only, and conforms with our other rules. These posts MUST include the [NSQ Friday] tag in their title.

If you post a serious question on friday and are looking only for legitimate answers, then please include the [Serious] tag on your post. Irrelevant replies will then be removed by moderators.



Rule 7- You can't intentionally annoy, mock, or harass other members.

If you intentionally annoy, mock, harass, or discriminate against any individual member, you will be removed.

Likewise, if you are a member, sympathiser or a resemblant of a movement that is known to largely hate, mock, discriminate against, and/or want to take lives of a group of people, and you were provably vocal about your hate, then you will be banned on sight.



Rule 8- All comments should try to stay relevant to their parent content.



Rule 9- Reposts from other platforms are not allowed.

Let everyone have their own content.



Rule 10- Majority of bots aren't allowed to participate here. This includes using AI responses and summaries.



Credits

Our breathtaking icon was bestowed upon us by @Cevilia!

The greatest banner of all time: by @TheOneWithTheHair!

founded 3 years ago
MODERATORS
 

Diffraction is the deviation of waves from straight-line propagation due to an obstacle or through an aperture, without any change in their energy.

I am trying to read up on and understand diffraction. The example of a water wave under Occurrences was quite easy to understand, especially when contrasted with light waves (image below). However, aren't the water waves losing - and thus changing - their energy as they hit the narrow entrance by losing momentum? As I said, I do understand that the waves diffract from straight lines into curved lines, but the concept of not changing energy is hard to grasp.

yBGdxZDY9E4e7i5.jpg

What would diffracted light waves look like if they did change their energy at diffraction?

you are viewing a single comment's thread
view the rest of the comments
[–] vivalapivo@lemmy.today 5 points 1 week ago

You're talking about perfect categories comparing them with the real world.

Diffraction from objects without the loss of energy doesn't exist, but allows us to solve a simpler equation paving a way to the understanding geometry of the phenomenon.

Real world diffraction is affected by the properties of the material, mostly characterized by linear dielectric permittivity. When you start taking it into account, suddenly the light starts to penetrate into the material, often inducing heat -- the primary source of the losses. Equations become messy, but it kinda allows you to calculate things with high precision.