why the sunlight canot reach deep in the ocean?

Question

light can travel millions of kilometres in outer space, but the deep ocean with a depth of more than 2000m is often pitch black. suggest why?

Answer 1

The water reflects the sun rays, thus not allowing it to pentrate more than a few metres.

Answer 2

When light hits a substance, it can do one of three things: it can be scattered, by hitting molecules of the substance and bouncing off in different directions; it can pass through the substance; or it can be absorbed by the substance—either wholly or in only some wavelengths. Much sunlight reflects off the ocean, but much also penetrates into it and is strongly absorbed by seawater. Several hundred miles from shore, our diver sees extraordinarily clear and pure blue water because water in the open ocean has low concentrations of dissolved matter and particles, including phytoplankton. It does not scatter and absorb as much light as murkier coastal water does, and the light that remains is blue.

Nearer the coast, light penetrating seawater provides the energy to fuel vast photosynthetic hordes of microscopic marine plants—phytoplankton—which are an essential source of food and oxygen for the entire planet. Just below the surface, our diver will see green light, depending on how much phytoplankton is present. Water with high concentrations of phytoplankton is green and darker for the same reason that dense tropical forests are: Plant pigments absorb blue and red light and reflect green light, and the cells scatter the light more than pure water does. While the diver would not be able to detect microscopic phytoplankton cells, she would see their cumulative effect on the light in the ocean.

Into the darker depths
As our diver continues to descend only a few more meters, she begins to go from day to night. She can see blue light to her sides, and white light above, but below her the view is dark. As she moves downward, the UV, green, and violet wavelengths disappear, and the light becomes an intense, almost laser-like, pure blue. At 200 meters deep, the diver would cross from the surface realm (called the epipelagic zone), where there is enough sunlight for photosynthesis, to the twilight realm (called the mesopelagic zone), where enough sunlight penetrates for vision, but not for photosynthesis.

By now, our descending diver would notice nearly continuous blue flashes around her—bioluminescent light produced by animals in the midwater zone, in response to the disturbance in the water that she caused. Below 850 meters, though, the diver would no longer be able to see anything, even looking up. Human eyes aren’t sensitive enough to detect the minute amounts of sunlight that haven’t been absorbed by the water. At 1,000 meters, even the most visually sensitive deep-sea animals can longer see the sun. The region below this is known as the aphotic (no-light) zone, but this is only true for sunlight, as bioluminescence is common.

Answer 3

As light waves try to pass through the water and whatever other stuff that is in the water diffuses the light waves so that the light only goes so deep.

Light does go down a little ways because water is not a very dense material and light waves make there way through. But the deeper it has to go, the more the light rays get diffused.

Answer 4

Space is a vaccuum, nothing there, water is a vast quantity m olecules that interfere with the wavelengths of light, therefore light can only reach a certain depth in water.

Answer 5

Water refracts and absorbs light. By the time one reaches 70 m in clear water everything is almost black.

Answer 6

It can travel through space because there's literally nothing to get in its way. Water refracts and scatters light so much that it can't get past a few meters/yards.

Answer 7

Water absorbs electromagnetic radiation.
For this reason submerged verticals cannot communicate by radio and subs must use sonar to detect things in their surroundings.
Dolphins etc use sonar at great depths.

Answer 8

Because.... Light can't penetrate everything you cass dang.