Recent comments in /f/explainlikeimfive

RevaniteAnime t1_j2d48tg wrote

They're discs that store and read data using pits and lasers. The main difference is that BluRay uses a blue laser instead of a red laser, or bluray uses a higher frequency/shorter wavelength of light than DVD for its laser. This allows a BluRay to hold a lot more data than a DVD. Why a DVD only has a SD resolution movie on it but a BluRay can have an HD to 4K movie on it.

Edit: Added Higher frequency and Shorter wavelength.

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FartyPants69 t1_j2d3ff0 wrote

Good point! Kind of analogous to a computer. A computer isn't "in" the CPU; it's an integrated system of CPU, memory, I/O devices (keyboard, mouse, monitor, speakers), ports, sensors, etc.

The mind is a function of the entire nervous system, not just the brain.

I listen to a lot of Andrew Huberman, and one interesting thing he covers is how neurons don't just exist in the brain, and they aren't exclusively for processing thoughts. Your gut actually has hundreds of millions of neurons, and they signal all sorts of things subconsciously to your mind!

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FartyPants69 t1_j2d2qb0 wrote

That's a very interesting point, and raises a tangential question: What exactly causes that sensation?

Why do we feel like our head is the center of our body, rather than something like our center of mass (our torso)?

Is it possible to shift that sensation using mind-altering techniques like meditation, sensory deprivation, drugs, etc.? What's behind that, physiologically?

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nrsys t1_j2d2i22 wrote

Sounds can be drawn as a wave, so for one of the simplest examples let's look at a sine wave - just a simple, regular wave shape.

As a simple maths experiment, if we mirror this wave around the horizontal axis so that where one wave goes up, the other wave goes down, and then add them together, they will cancel each other out.

This works with sound in headphones too. If we stick a little microphone on the outside of your headphones so that it detects the outside sound you will hear, then takes that sound and inverts it so it is upside down and plays that through your headphones, the two will cancel out and the outside sound will vanish. If you play the inverted sound alongside the music or other audio you actually want to hear, you get both at the same time - no outside sound, just the extra audio you are adding.

Incidentally, this works really well with headphones, because the microphone can easily detect exactly what your ear will. If you tried this with a whole room, the way sound reflects off of surfaces will mean that the 'noise' sound will be different depending on exactly where you stand, so it is impossible to cancel it out - you could set it up to cancel nicely in one place, but if you moved about in the room in other places it won't work at all, or may make the noise worse.

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