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LogosPlease t1_ja5mep0 wrote

In Both instances materials are absorbing the energy of waves. So, sound CAN be blocked entirely, you just need enough material to absorb it. The major differences in how sound and light differ is because of the type of energy they carry. Sound waves use the mass that it is traveling through and moving to create a force... and lightwaves carry electromagnetic radiation (with no mass) that can transmute energy fields and energy onto certain molecules and not others. This lets light travel through certain molecules without effecting them much since they may not be effected by the electric or magnetic field. Sound uses the mass it is propagating through to transmit energy and so it inherently vibrates all mass around it regardless of the material.


Light waves and sound waves are different. Lightwaves are teeny tiny little packets of energy that almost have no mass and can go through certain materials and interact with other materials based off how those materials absorb energy. For example light in the visible spectrum can go through glass carbonate but not wood carbonate.

Sound waves are made from any kind of matter that does have mass. That mass bounces off other masses and your ears record the frequencies of those waves bouncing and creates a perception of sound.


IcyPause7334 OP t1_ja5n4l0 wrote

The wifi and cellular signal spreads like electromagnetic waves so they do not have mass which means that they can be blocked entirely like light?


LogosPlease t1_ja5nhll wrote

Yes, you are exactly right...and, the wifi and radio waves ARE electromagnetic waves! they are exactly like visible light just wifi and radio waves, microwaves, etc., moves in a different frequency. Your eyes can only pick up certain frequencies of Electromagnetic radiation so we can only see small amounts of the frequency spectrum but like you said, with the right materials almost all of any radiation can be blocked, it just depends what materials you are using and what frequency the radiation is. All different radiation frequencies are absorbed differently by all materials so it is likely that all frequencies have at least one material where where 99.9% of energy is absorbed and more often than not there are multiple different


RythmicBleating t1_ja5qql6 wrote

X-rays are a fun example too: your bones block them but not soft tissue, so if you use the right film you can see right through yourself!


dirschau t1_ja5mxm3 wrote

The difference in what they're waves OF.

Light can get completely reflected of or absorbed by sufficiently thick stuff (how thick is "sufficient" depends) because it can be blocked by atoms from travelling.

Sound, on the other hand, is a mechanical wave. It's atoms moving around. So you need atoms to have sound, and anything made of atoms can transmit sound.

A wall is made of atoms. Atoms in a wall can block light. But atoms in a wall can transmit sound. Hell, solids are better at transmitting some sounds better than air, it's why the old-timey technique of putting your ear to the ground works, because the low rumbling of solid wheels or hoofbeats would travel through ground better than air.


cakeandale t1_ja5n9tz wrote

Your intuition is pretty spot on - light and sound are both waves (light does have quantum behavior as photons sound doesn’t, but when they’re acting as waves they’re similar), and both can be absorbed by materials they pass through - depending on the material some wavelengths are absorbed more, and some wavelengths are absorbed less. Think like how you can hear a neighbor’s TV’s bass easier than speech, for instance.

What you’re experiencing in particular is that the wavelengths you can see and the wavelengths you can hear are impacted by typical construction materials differently. If you could see X-ray wavelengths you’d be able to see through walls just as easily as you can hear through them, for example. Conversely, if your walls were made with noise absorbing foam like are used in recording booths then they would be opaque to visible light and also “opaque” to audible sound waves.


Saporificpug t1_ja5nok5 wrote

They are both waves, but they are entirely different types of waves. Light is an electromagnetic wave, while sound is a mechanical wave.

One of the benefits of sound is that it requires a medium, such as the air to move around. When sound travels through the air and hits a wall, window or curtain, it causes the object it hits to also vibrate and disperse on the otherside.

Light however is mostly reflected off of solid objects. It's worth mentioning that while light doesn't go through walls some electromagnetic waves can. Think something like your internet wifi (typically radio waves), which is just a different frequency and wavelengths compared to visible light. Both are electromagnetic, however.


garlopf t1_ja5tqgd wrote

You can block sound completely by isolating the source of the sound from the ear with vacuum. As sound is waves traveling through matter, it can only travel where there is matter.

Light on the other hand is electro magnetic waves, which will travel wherever there is an electro magnetic field, including in vacuum. Light will interact with matter and you can block light completely by enclosing it in reflective and/or bsorbent material.


explainlikeimfive-ModTeam t1_ja62fuh wrote

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jowie7979 t1_ja5ltku wrote

Light is like a laser beam that travels in straight lines and can be stopped by things like walls and curtains. But sound is like a wave that travels through the air and can go through things like walls and doors. So, when you close your curtains to block the light, it works, but the sound can still come through because it can travel through the walls and doors. That's why you can still hear noise even when you try to block it.


schoolme_straying t1_ja5n43s wrote

At this point I'd add OP needs a little neurological insight, if he wants to sleep through the noise.

I used to travel a lot for business. I'd often sleep in noisy hotels. The recommendation then was to play a radio detuned a bit from the station. The dull meaningless noise would mask the external noises and sleep would come easy.

These days I just play Stephen Fry reading Arthur Conan Doyle's "Sherlock Holmes".

My audio book app goes to sleep after 20 minutes. If I'm still awake, I hear it play a ping 1 minute before it fades out and pauses. If I then shake my phone - the app detects the shake and resets the timer clock to 20 minutes. I've never heard the second ping


Fred2718 t1_ja5o256 wrote

Congratulations! You found a use for vocal Fry!


Odd_Perception_283 t1_ja5lwzc wrote

I think sound has a much higher frequency of waves and that allows the sound waves to survive bouncing off of objects where light just dies on impact.

At least that’s what my gut says.


jowie7979 t1_ja5mkfi wrote

Correct. Don’t know what i’m being downvoted for lol.

Sound waves have a lower frequency than light waves, and this means that they can travel through solid objects and around corners. This is why you can hear sounds that are coming from behind walls or other objects. On the other hand, light waves have a much higher frequency and are not able to penetrate solid objects as easily, which is why light can be blocked by walls, curtains, and other objects. So the lower frequency of sound waves allows them to persist even after they've been reflected by solid objects.


Odd_Perception_283 t1_ja5nxcq wrote

This makes perfect sense and I had it totally backwards. I think my completely backwards answer is rubbing off on you.

At the very least I now know the truth. Thanks!


Fred2718 t1_ja5ox8b wrote

Audible sound runs from about 10 Hz to about 25,000 hz.

Visible light runs from 4 x 10 E 14 hz to 8 x 10 E 14 hz. ( 10 E 14 hz is 100 Terahertz )