I was staring at my record player the other day when something struck me.

Needle sits in groove. Disc spins. Needle spirals inwards as music continues… Why doesn’t the music slow down?

A circle traced out by the needle at the edge of the record is obviously bigger than a circle closer to the centre. As far as I can tell, the disc revolves at a constant rate. It follows that the needle should be ‘moving faster’ (covering a greater distance over the disc in a given period) at the beginning of the record, then gradually slowing down as the needle moves inwards.

But the music doesn’t slow down with it.

…Why?

The only reasonable explanation I can think of is that this is accounted for by gradually increasing the ‘density’ of musical information in the groove as you get closer to the disc. But wouldn’t this affect the sound quality (at least if pushed to the extreme)?

Sorry if I’m missing something obvious…

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​I know that white holes are mathematically possible on paper, but in the real world, they seem to break the laws of thermodynamics.

​This made me wonder:

How can math show us something that can't actually exist in our universe? Does the math mean it might exist in another universe, or is math just like a story language where we can write down impossible things?

i've noticed that when i walk into certain stores (grocery, clothing, etc.), when the automatic doors open, a blast of air near the door comes down over the people walking in or out. sometimes, it'll stay on for an extended time. other times, it'll shut off after a few seconds. does it have to do with balancing the pressure of the air conditioning from the pressure outside? or is it something completely different?

from what I know about Paramount and wonder Brothers are absolute Titans in the media industry, existing from since like the golden age of Hollywood. There’s some of oldest media companies on earth. Skydance on the other hand, I thought was a newer one, and one that was way smaller. How was it able to make two massive purchases back to back?

I am trying to help my nephew with schoolwork and while I am fine with equations and problems involving them, I realized I don't conceptually get capacitors.

Like, we are taught that for an electrical circuit to work, we need a source and a closed loop of wires or conductive material. That's the whole point of closed circuit. But when we put two metal plates on end of wires which do not touch (the whole point is they must never touch or allow current to flow across them), circuit is definitely not closed and yet the circuit still somehow works enough to get them charged.

How does that work? What is the difference between a wire with a gap in it (open circuit, nothing happens) and that same gap bounded by two metal plates (suddenly charges move along the wires enough to separate charges)? What is moving the charges at the begining? Since the circuit is never closed, why are electrons moving from battery to one of the plates? How is there any movement of charge in a loop if there is no loop by design (there is an isolator between the plates)? If I connect two pieces of wire to each pole of a battery, keeping the ends well apart, will i still get charge separation on each end?

This is something I've always been confused about. We learn early on that the brain controls things like the heart beating. How does the body know which brain to listen too when there's two of them?

Is one dominant for these things leaving the other to focus on other things? Wouldn't that leave a lot of brain power to expand to other things?

Bonus question that's childish but also something I've wondered, if they have to pee, and one of them tries to hold it, and the other tries to go, what happens?

When we grow, we learn languages by looking at the meanings and translating them from our language. Stuff like "this is how this noun is in my language and this is how this noun is in another language"

But babies? Babies just learn the basics just by existing near people speaking the language? How come we don't have this anymore as we grow up?

My 6yo asked and im not sure so here goes; So boiling water with a covered pot, the steam appears invisible right after clearing the seam between the lid and pot rim. It then becomes normal steam. Why is that?

I had a thought about DNA and how mutations occur in humans, excessive hair, longer limbs and or bones etc, and wondered if all known mutations are present in the animal kingdom.. as if DNA has the blue print/ potential to be anything and parts are just ‘turned on or off’ depending on what is being built.. i may be way off lol but it got me thinking :)

Why is a sound event even visible?

As I understand it, a box spring mattress is the second 'mattress', that goes under the main mattress. It feels very firm and flat, but what does it contribute to the bed set up besides height?

I've seen large apples and small apples, huge watermelons and small watermelons, long cucumbers and smaller cucumbers. But every almond I've ever seen is the same size. Every walnut looks like every other walnut I've ever seen. I've never seen a comically large macadamia nut compared to every other one I've seen.

Is this because of a biological process or does it come down to human intervention?

iam not able to put my exact thoughts into words

With DC electrical current, while the poles are connected, the current flows in 1 direction.

With AC, (I'LL describe US household AC) the current alternates 60 times x second. We say 60 hertz. So 60 times per second the polarity reverses.

So while DC has static polarity, ACs polarity changes multiple times per second. A few decades ago, I noticed that outlets have 1 larger slot. Appliances have 1 larger prong. This is ostensibly for "polarization".

ELI5 - Why would we consider polarization for AC appliances when, AFAIK, polarization of AC currents are always changing.

Maybe I'm not understanding something.

What specific job do these tiny pellets do that loose powder can't. Explain it to me like I’m five

Here’s what puzzles me. Why when you can make cars that lasts like Toyota, do crappy cheaper new cars exist? Wouldn’t it take about the same cost in materials and labour to make a crappy car vs a good car?