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        riddles >> general problem-solving / chatting / whatever >> Maximizing the Daytime
        
(Message started by: Barukh on Aug 13^th, 2013, 3:39am)

Title: Maximizing the Daytime
Post by Barukh on Aug 13^th, 2013, 3:39am

I suddenly came to the following interesting (IMO) question.

Although not completely correct (http://en.wikipedia.org/wiki/Daytime_(astronomy)), define Daytime at a certain location, specific day as time interval between sunrise and sunset (if the first doesn't occur, define it to be 0; if the second doesn't occur - 24 hours).

Then, we can define Year Daytime (I admit it’s a bad name) as the sum of the Daytimes over a calendar year.

It seems that several interesting questions may be asked about Year Daytime. Here’re a few:

1. At a given location, is Year Daytime a constant?

2. Which location(s) maximize/minimize Year Daytime?

For those who find it interesting, the following link (http://www.timeanddate.com/worldclock/sunrise.html) might be relevant.

Title: Re: Maximizing the Daytime
Post by Grimbal on Aug 20^th, 2013, 9:02am

1. I think it depends how exactly you define "sunrise" and "sunset".
2. max at L1, min at L2

Title: Re: Maximizing the Daytime
Post by Barukh on Aug 23^rd, 2013, 10:11pm

on 08/20/13 at 09:02:26, Grimbal wrote:

1. I think it depends how exactly you define "sunrise" and "sunset".

This. (http://en.wikipedia.org/wiki/Sunrise#Measurement)

Quote:

2. max at L1, min at L2

Not clear.

Title: Re: Maximizing the Daytime
Post by Grimbal on Aug 26^th, 2013, 7:31am

I was referring to Lagrange points.

With the definition you mention, the visible part of the sky is a bit more than an hemisphere. Without any math, I guess you optimize the dayligh on the arctic circles. You benefit from full days in the summer, without loosing all light near the winter solstice.

Title: Re: Maximizing the Daytime
Post by Barukh on Aug 29^th, 2013, 12:27am

Grimbal, your intuition and/or knowledge of astronomy is exemplifying! I did it the hard way (experimentally).

It turns out that - taken into account another parameter of Earth’s orbit – the average daytime is maximized at just one arctic circle.

A follow-up question: where is it minimized?