this post was submitted on 17 Jul 2023
116 points (100.0% liked)

No Stupid Questions

35843 readers
1469 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.



Credits

Our breathtaking icon was bestowed upon us by @Cevilia!

The greatest banner of all time: by @TheOneWithTheHair!

founded 1 year ago
MODERATORS
 

Shouldn't the vacuum insulate the glass from the heat of the burning filament?

you are viewing a single comment's thread
view the rest of the comments
[–] apepi@lemmy.world 32 points 1 year ago (1 children)

Heat is infrared. Light. Vacuum doesn't have much effect.

Also many bulbs are filled with inert gases rather than being vacuums.

[–] fubo@lemmy.world 58 points 1 year ago (2 children)

Heat is infrared. Light.

All light heats up anything that absorbs it. This includes infrared, but it also includes visible light, microwaves, radio waves, etc. You can get a nasty burn from putting your hand near a live radio transmitter antenna, for example, even though it's emitting in RF, not infrared.

In addition, all physical objects glow with a light that is determined by their temperature. This includes your body. You are, right now, emitting light. As it happens, because of your body's temperature, that light is mostly in the infrared.

Why do kids' science books leave you with the impression that "heat is infrared"? Because you can see body heat with an infrared camera. Infrared is light that you can't see with your eyes — but with the right tool, you can use to see body heat. This rounds off to "heat is infrared".

Heat is not infrared. All physical objects emit light; objects around human body temperature glow mostly in the infrared; which we can't see with our eyes, but can see with scientific instruments. And when an object absorbs light (including infrared), it gets hotter.

[–] Tylerdurdon@lemmy.world 10 points 1 year ago (2 children)

Wow, I fucking learned something today. Thank you, stranger.

[–] Mr_Blott@lemmy.world 2 points 1 year ago* (last edited 1 year ago)

Go see what happens if you lick a radio transmitter aerial and report back

[–] 418teapot@lemmy.world 2 points 1 year ago (1 children)

If I super heat a metal and it turns visibly red what is happening? Was it already emitting infrared and as it gets hotter the frequency shifts up? Or is it still emitting infrared but has a wider band of frequencies it is emitting as well (i.e. is it emitting frequencies below infrared as well as visible red)?

[–] fubo@lemmy.world 2 points 1 year ago

Yes, as you heat something up to "red hot", the glow shifts from infrared to being partly in visible red frequencies. This is why a blacksmith can use the color of a piece of hot iron to tell how hot it is.

https://en.wikipedia.org/wiki/Black-body_radiation

(This isn't the only way hot things make light, though — for instance, flames can glow with odd colors like green or blue due to specific chemicals burning.)