John Wayne in a Blizzard. So said my dad.
No Stupid Questions
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!
I remember putting my finger near the CRT display of these televisions during the animated static and noticing the weird electrical tingle in my finger. I even did this with my hair. It was so fun... and also potentially dangerous.
Now that's something I can't replicate anymore with my modern telly.
Its just static electricity. Not dangerous at all and not exclusive to the scramble screen.
Copied from an old reddit post:
Old cathode ray tube (CRT) televisions have an electron gun which fires electrons at the back of the screen. And the screen is coated with phosphorus phosphors which emit light whenever struck by an electron. The side-effect of this process is that each electron increases the static charge of the screen, and over time as the image on the TV changes it increases the charge. Meanwhile, rubbing your hand, which has a slight negative charge, across the screen will remove some of this built-up static.
Good to know
i approve of British people and their television channels
I'm glad I had access to those despite living in Morocco
The TV will try and amplify and display any signal. Without a station, it will end up amplifying random radio noise and tiny fluctuations in the amplifier circuits themselves.
The momentary signal strength is interpreted as brightness of a spot which is rapidly scanned over the display. In this case the signal is random so every spot on the screen will be a random brightness, changing every frame.
Modern digital TVs won't do this, because with compressed video recognizable data is needed to even attempt displaying a picture.
As for the sources of the radio noise, most of it is from electrons being jostled by heat, some from space. (Including the cosmic microwave background others have mentioned)
The electron jostling (thermal noise) is the reason the receivers on radio telescope as cooled to insanely low temperatures often with liquid helium.
This is the closest to the correct explanation. The reason televisions based on AM radio reception showed static is because of a circuit called the AGC (Automatic Gain Control) which worked like a robotic volume control. Its job is to keep the recovered video signal within a certain amplification range. As long as there was a carrier (the TV station was "on the air"), you'd see whatever the station broadcast. But when they turned off their transmitter, the signal strength would fall and the AGC would increase the amplification until what you see is white noise, mostly due to the random motion of electrons in the electronic components. We can minimize that by cooling, but it can't be totally eliminated. Audio amplifiers often come with a "hiss" specification that tells you how much of this kind of noise you can expect at normal operating temperature.
BTW, modern digital TVs -will- show a noise picture if they lack a video muting function when no carrier is detected. I have an LG bought in 2019 that does this, and it's hella annoying when I accidentally hit the input selection button on the remote, switching from HDMI to TV reception.
IIRC, literally the background radiation of the universe.
Only a fraction, but yes. It’s cool to think those photons have been around since the universe turned transparent.
It's not static. It's the ant attack.
I'm glad I'm not the only one. I remember people calling it "the ant race" when I was little (very early 90s), but no one seems to recall this.
and what happens if you broadcast static, like point it at a car thats blasting some shitty radio station, and you are transmitting that same frequency? the distortion will destroy their speakers.
I wish! The boy racers have no shame (and I might be an old curmudgeon)
Cosmic microwave background. You are seeing the big bang.
https://en.m.wikipedia.org/wiki/Noise_(video)
There are many sources of electromagnetic noise which cause the characteristic display patterns of static. Atmospheric sources of noise are the most ubiquitous, and include electromagnetic signals prompted by cosmic microwave background radiation,[1] or more localized radio wave noise from nearby electronic devices.[2]
The display device itself is also a source of noise, due in part to thermal noise produced by the inner electronics. Most of this noise comes from the first transistor the antenna is attached to.[2]
If you put a TV in a Faraday cage that blocked the relevant radio spectrum, would there be no static on it? I expected the answer to be a quick Google, but it wasn't.
That is a good question, but I suspect if you tried this in real life it would still show static.
- The waves are amplified with a circuit that attempts to find a signal even if it's very weak (so you can get a picture even if you're close or very far from the tv station)
- At a certain point, the electromagnetic field from the running TV itself would start to get picked up
I suspect a better thought experiment would be if you just disconnected the input and amplification circuit entirely from the CRT tube, in which case you would probably just get white as the electron beam scans back and forth without any modulation.
It would just make a dot center screen.
Let me turn that around:
Would a TV still show static if you disconnected the input and amplification circuit outside a Faraday cage?
Input yes, amplification no
Likely a uniform white picture since the impedance of the input wire is too high for ambient noise on the line to result in any differentiated interlacing.
You'd still see static from the TV itself and any radiation that passed in to the cage. It's not a perfect EM blocking device like TV shows and movies would have you believe.
Even if the Faraday cage blocked all RF perfectly, the Johnson noise would still produce plenty of static.
Great experiment idea.
Cosmic microwave background radiation - the remnants of the big bang.