where do the stars go in the daytime?

Galloway Forest Park in Scotland has picked up an international award as one of the best places for stargazing in the world. The 300sq mile Forestry Commission site has been commended for its dark skies and named one of the best places in the world for stargazing.

stars

http://news.bbc.co.uk/1/hi/magazine/8362265.stm

So where do the stars go in the daytime? The answer is that they are still there of course. It is a nice reminder that our colour vision is more about contrast than about absolute intensities. With old TV sets when they were switched off the screens were grey; but when they were turned on it would be possible to see some really dark blacks. But the screen cannot emit less light than when it is turned off! So the black looks black because of contrast, not simply because of the amount of light emitted or not emitted.

Against the dark skies of night the stars contrast and appear bright – during the day, the skies are much brighter because of the sun and though the light from the stars is just as intense as it is at night the contrast conditions are very different.

One thought on “where do the stars go in the daytime?

  1. Another way to think about this – turn all the lights off at night in your house and turn on a torch (what americans call a flash light) and it seems quite bright. But go outside the next day in bright sunlight and turn the torch on – and it hardly seems to be on at all. This is the same with the stars.

    By the way, this torch/flashlight thing is one of the more humorous differences between UK and US English. When my Turkish friend (who had lived most of his life in the UK) when to live in USA he thought he could smell gas. So he went down to his cellar to have a look. And he was on the phone to the gas company. When he said he could strongly smell gas in his cellar and he was down there with a torch, the company started to panic, thinking he was down there with a flaming torch.

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