Deep sea physics questions

[Alleya]

Is this spam? idk. Anyway. Here's some kind of interesting thoughts.

Say you take a submersible many miles deep into the ocean. To those points where absolutely no light can penetrate from above, blacker than the blackest black that is black. And say you have a nice big spotlight on your sub that you turn on to see all the crazy ass fishes.

I was thinking about this last night and I wondered...what would happen when you turned on the light? It's a weird question but when I thought about it I realized, there's not really anything down there to reflect the light back to you unless something crosses the path of your light beam. So would you see a few flecks of debris floating around and nothing else until something substantial comes into the view of your light? Just the same blackness as before? How would the physics of light be different at such immense depth/pressure?

I managed to creep myself out pretty good with this thought. It's like being in an utterly dark room, you turn on a light, and nothing happens. You know the light is on, but you don't see anything until it comes close. Freaky. ._.

(I'm bored.)

[Remyo]

you'd die from the pressure. and the light wouldn't go very far. national geographic has sent some subs down and taken pics of the creatures that have never seen light, i think all are blind.

[Maguspk]

Thinking about it from a purely logical point of view, I have no concrete physics evidence to base this off of, you'd think it'd simply reflect off the water itself and the particles in the water. The water isn't a vacuum devoid of other stuff that light can hit and bounce off of.

[Khamsin]

Is this spam? idk. Anyway. Here's some kind of interesting thoughts.

Say you take a submersible many miles deep into the ocean. To those points where absolutely no light can penetrate from above, blacker than the blackest black that is black. And say you have a nice big spotlight on your sub that you turn on to see all the crazy ass fishes.

I was thinking about this last night and I wondered...what would happen when you turned on the light? It's a weird question but when I thought about it I realized, there's not really anything down there to reflect the light back to you unless something crosses the path of your light beam. So would you see a few flecks of debris floating around and nothing else until something substantial comes into the view of your light? Just the same blackness as before? How would the physics of light be different at such immense depth/pressure?

I managed to creep myself out pretty good with this thought. It's like being in an utterly dark room, you turn on a light, and nothing happens. You know the light is on, but you don't see anything until it comes close. Freaky. ._.

(I'm bored.)

Go outside at night and shine a flashlight at the sky.

You'd see whatever light you can observe directly from the light source itself, and then anything that's reflected back (dust, debris, etc.) and that's it. There'd likely still be a bit of a glow around/through the lightsource itself the same as in any other situation, but that's about it.

Given that the water won't be pure and pristine, you'll still see some glow along the path of the light beam so it won't be totally black.

[zoobernut]

Water does reflect the light so it eventually diffuses out. It will not continue to travel on. Light at extreme depths behaves no differently because of the pressure it just behaves like a bright light in water. It hits little flecks of plankton and detritus in the water which reflect the light back.

Most of the videos I have seen of deep sea submersibles with bright lights on them the water is fairly murky so you will see the water.

[Woozie]

Thinking about it from a purely logical point of view, I have no concrete physics evidence to base this off of, you'd think it'd simply reflect off the water itself and the particles in the water. The water isn't a vacuum devoid of other stuff that light can hit and bounce off of.

Water does reflect the light so it eventually diffuses out. It will not continue to travel on. Light at extreme depths behaves no differently because of the pressure it just behaves like a bright light in water. It hits little flecks of plankton and detritus in the water which reflect the light back.

Most of the videos I have seen of deep sea submersibles with bright lights on them the water is fairly murky so you will see the water.

This is what I was thinking. Kind of like how if there's enough dust around, you can see a laser beam, I'd assume that the scattering from the water would allow you to see the light beam itself as well as any debris/objects/animals in it's path.

[Aerin]

I agree, I remember seeing some film of them going down to where it's pitch black. Turn the light on and it's mostly just murky water with little white specs floating around.

This reminds me of "If a tree falls in the woods and no one's around to hear it, does it make a sound?" lol

[Kaylia]

Is this spam? idk. Anyway. Here's some kind of interesting thoughts.

Say you take a submersible many miles deep into the ocean. To those points where absolutely no light can penetrate from above, blacker than the blackest black that is black. And say you have a nice big spotlight on your sub that you turn on to see all the crazy ass fishes.

I was thinking about this last night and I wondered...what would happen when you turned on the light? It's a weird question but when I thought about it I realized, there's not really anything down there to reflect the light back to you unless something crosses the path of your light beam. So would you see a few flecks of debris floating around and nothing else until something substantial comes into the view of your light? Just the same blackness as before? How would the physics of light be different at such immense depth/pressure?

I managed to creep myself out pretty good with this thought. It's like being in an utterly dark room, you turn on a light, and nothing happens. You know the light is on, but you don't see anything until it comes close. Freaky. ._.

(I'm bored.)

Water would diffuse the light, and so will the debris. You would just see a beam of light that fade out similar to the one you see when you turn a flashlightinside a dust cloud.

http://ca.youtube.com/watch?v=00YJIyoZ56U
Something similar to the one you see at 3min53

[Mizango]

Questions been answered but yes Ma'am, you would see self luminescent polyps or protozoa all around you but your light theory would be definitely needs some sort of particles crossing the path of the beam to see any significant distance. Like Khamsin analogy stated, shine a light into the sky and you are pretty much replicating the conditions you would see down there.

Off topic but on topic. Science Illustrated had a really neat article in its July issue about the blackest material on the planet and it talked in full detail. I have the Mag but they apparently dont have a link to it online But here is a link about carbon nanotubes.

http://www.technovelgy.com/ct/Scienc...p?NewsNum=1411

Man I wish I could find the Science Illustrated article online, if anyone else subscribes/reads SI, it is in the Edition with the captures and Phoenix photos of Mars and the Crater on the cover. It went into detail and was really easy to understand for anyone that has difficulty understanding Physics.

[aurik]

Alleya's a dude, don't pull a JerseyProphet.

[Mizango]

In my defense I will say "ma'am" is an intentional slight as a way of questioning said manhood. >.>

Yeah, lets stick with that one.