can humans survive without sunlight?

Question

my uncle and I are having a HUGE debate. I said I remember hearing somewhere, that humans cannot survive without natural sunlight. He says it's not true. I also recall there is a place in Alaska that doesn't receive sunlight for many months a year, my uncle cited that as an example of people who survive without sunlight. Still I think I'm right! Does anyone know whether humans can survive if the sun "died" out?

Answer 1

Humans do not need sunlight as is proven by prisoners who spend years incarcerated in a cell with no sunlight and the worst they get is a pale complexion! In medieval times people would remain locked in dungeons for years also.

However, every living thing on this Earth needs the Sun to survive, for besides giving off light to stimulate plant growth, without it the Earth would turn into a giant ice ball where no life could exist!

Answer 2

Some of the answers here seem to be answering whether or not we can survive without the SUN. Of course this is impossible. But the question asked was wheter we can survive without "sunlight".

The answer is both yes and no. Sunlight helps our body to process and even produce some vitamins (Vitamin D for instance). Sunlight (or the lack of) also affects us psychologically. So, in nature, over long periods of time, we - as a species - would adapt into something else as we could not survive over generations in our current form. We'd either lose our eyesight or our eyes would become super sensitive -- like owls eyes. We would also have to adapt to eating different food thats richer in vitamins our body would normally lose today.

But for extended periods within our life, yes, we can live without sunlight. It would be difficult to live your whole life without it, but it is possible with the right diet and exersize levels to counteract the loss of vitamins. Certain kinds of tanning beds or sun-lamps may help this. People at NASA have been thinking about this problem as it is something that will be faced when Astronauts will be expected to go on long voyages. People have lived on the International Space Station and the Russian Space Station MIR for as long as a year without sunlight.

I actually work in Alaska above "the Arctic Circle". This is an area at the top of the Earth that doesn't recieve sunlight for months during the winter time. But for an equally long time, we have daylight 24 hours a day. It get's depressing after a long time without sunlight. But we live without it up there, as have the Eskimos for thousands of years.

Answer 3

As long as we eat a diet that has enough vitamin d there's no need for sunlight on us.

We'd have a hard time feeding ourselves without the sun though. Most of the earths life depends on the energy we get from the sun. There are a few things that get their energy from breaking down chemicals around geothermal areas, but they probably aren't good eatin'.

Remove the sun and humanity would most likely go or come close to being extinct.

Answer 4

We do need sunlight othherwise we have a sickly complexion. Yes in Alaska there is a place where for like six months there is no sun but I think you would have to stay out of the sun longer than that to die. Also, if they go outside there is probably enough risidual sunlight that cannot be seen to be good for them.

Answer 5

Not for long, maybe..because lack of sunlight would cause humans to have mental depression. Sunlight helps our brain to manufacture the neurotransmitters needed to keep us in good mood. You know what could happen if a person suffers from severe mental depression..he's likely to commit suicide. So, if the sun "died" out..humans could become extinct.

Answer 6

In the centuries gone by, I don't think humans could have survived without sunlight. Plants would die and many of our needs would not be met. We would generally have become sick and would die out slowly.

In areas where sunlight is not present for many months, the sunlight returns and stays for many months. This phenomenon can occur at the north and south poles of our planet. Not many people survive there without some means of getting certain nutrients and it is usually a logistical nightmare to survive there for a prolonged period of time.

These days we can survive without sunlight because we can manufacture our Vitamin D, we can cultivate plants without sunlight and we have the technology to have our needs met.

Still, loss of sunlight would be a big blow to our energy intake. We would have to spend LOTS of energy to replace it in terms of warmth and light and in raising plants and animals.

We could of course obtain such energy by constructing huge towers and growing crops of human embryos to generate the BTU's and keep their minds enslaved by connecting them to a computer simulation of the real world! ;-)

Answer 7

There is geological evidence of a major blackout across our planet, approximately 70,000 years ago due to a super volcano explosion.

This resulted in freezing the planet within hours.

Almost all species died. Fossil evidence shows very few continued to evolve. Among them were some primates leading to our species !

Answer 8

we know water as a source of life right....then the sunlight could be a partner for that kind of source. why, any life being needs either water, food, lights, air and so on. if one of this thing lost, not even viruses can live :)

Answer 9

human can't survive without sunlight

Answer 10

that's true people can survive without sunlight but u will find them Vitamin d deficient.