Recent comments in /f/askscience

Environmental_Ad5451 t1_jdx7qh9 wrote

Reply to Is there a limit to the number of sounds you can hear simultaneously? by xXxjayceexXx

I'd say the answer is yes, because our ears cannot respond to anything faster than a frequency, or tone, of about 20kHz-ish. That is kind of like sampling rate, in some regard. And then there is only so much information, so many different sounds) you can pack into a roughly 20kHz bandwidth (there's an awful lot here to unpack, and I've not done it well), which is similar in some sense to bit depth, if you give some latitude for pushing a digital domain onto an analogue system. If fact, because of that bit depth, or packing information into how fast we can hear, most of what we listen to sits in the 50Hz to about 8kHz range. It's mostly music that routinely takes us to our limit. Lots of noise will do it to.

Fundamentally, we can't hear sounds that have tones that are too high pitched, and we can't resolve separate sounds that are too close together, even if they're in our hearing range individually. So it's kind of like eyes, but our ears are much faster than our eyes, largely because they're much simpler.

Last thing, I've ignored amplitude, or loudness. Others have explained it well. If sounds are loud they can reduce your effective bandwidth at any given moment. So information (sound) in a loud place can get lost even if you could otherwise hear them.

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tdgros t1_jdx0f2y wrote

Reply to comment by [deleted] in Is there a limit to the number of sounds you can hear simultaneously? by xXxjayceexXx

>Human vision is about 576 megapixels

it's really not, we don't even have that many vision cells per retina. You can find this figure if you extrapolate the density in the fovea to the entire field of view. But in reality, the density of color cells drops off sharply outside of the fovea, which only has a few degrees of FOV.

Do the test: focus your eyes on one word of text, without moving your eyes, how far can you read the words around? our vision is really really blurry outside the center, we just don't realize it.

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the_geth t1_jdwx7pi wrote

Reply to comment by DDWingert in Around 550 million years ago the earth's magnetic field almost collapsed, but then strengthened a few million years later. Scientists say this may have been due to the formation of the inner core. But why exactly would that cause the magnetic field to get stronger? by somethingX

>They cannot directly measure the magnetic field due to the location and extreme temperatures of materials in the core

... WHAT
We can absolutely measure Earth Magnetic field (and many more, distant or not). I do not understand this sentence, what am I missing?

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