How is it possible to see stars in the daytime from the depths of a well?
How is it possible to see stars in the daytime from the depths of a well? asks Balaji, via email.
In Charles Dickens’ popular novel “The Pickwick Papers,” first published as a serial in 1836 and 1837, we hear about law clerks working in a very unpleasant office:
“In the ground-floor front of a dingy house, at the very farthest end of Freeman’s Court, Cornhill, sat the four clerks of Messrs. Dodson & Fogg….catching as favourable glimpses of heaven’s light and heaven’s sun, in the course of their daily labours, as a man might hope to do, were he placed at the bottom of a reasonably deep well; and without the opportunity of perceiving the stars in the day-time, which the latter secluded situation affords.”
In other words, if these poor clerks must work in a “dark, mouldy” room behind a high partition during the sunlit hours, they should at least be able to see stars during the daytime – as someone at the bottom of a real well might. Dickens’ sentiment should resonate with any office worker trapped in a dingy cubicle (or student in a dim classroom) on a sunny afternoon.
More than 2,000 years before, the Greek philosopher Aristotle had also mentioned the idea of seeing daytime stars from a well. However, according to modern astronomers, looking at the sunlit sky from the bottom of a deep hole- like a mineshaft-won’t help us see stars. (Unless, of course, we fall headfirst into the hole.)
Take a noon trip up in the space shuttle, and you’ll see the dark of space, studded with stars. But the Earth’s atmosphere, lit up by our own nearby star, the Sun, drowns out the faint light from distant stars.
According to astronomers, standing at the bottom of a shaft measuring 50 feet deep and 6 feet wide is like looking at the sky through a paper towel tube. Neither helps us see stars in the daytime; the sky is just too bright. However, while looking at the sky through a tube doesn’t increase the contrast between the stars and the sky, there is a reason why the well idea may have taken hold. The darkest, bluest part of the sky is directly overhead. Forced to look overhead, someone in a deep shaft might be a bit more likely to see a star than if he were looking at another part of the sky.
So a well won’t help, but sharp eyes scanning the sky will. Sirius can often be seen just after the Sun rises. The very bright star Canopus can sometimes be seen in daytime, too. We can also see planets in the daytime. From December 2008 to March 2009, look to the upper left of the late afternoon Sun, keeping the disc covered by your hand. You should see Venus. Even the Red Planet, Mars, will be visible in the daytime when it makes its next closest approach to Earth in 2018.
See photos of Venus in daytime at www.galaxypix.com/solarsys/Venus/venus.htm. Read “The Pickwick Papers” online at www.bibliomania.com/0/0/19/40/frameset.html.
