Question

Along the equator, it was no-shadow-noon on September 22 ( Autumnal Equinox). When do you expect this right-above-head-Sun noon, at Bangalore, India? The latitude of Bangalore is `12.98^o N`.

Answer 1

May 1 and August 2, 2017.

Explanation:

We have no-shadow noon when, when the Sun is right overhead.

It happens at equator, on an equinox day.

At the equator, the spacing in between successive no-shadow-noon

days is nearly six months.

Elsewhere, it is not equispaced.

North or South, there is no no-shadow noon for latitudes greater

than `23.44^o`

At summer solstice, this latitude limit is reached at 23.44^o N and,

at winter solstice, this limit is 23.44^o S.

In brief, there could be no-shadow noon,

for `latitudes in (23.44^o S, 23.44^o N)`.

In 2017, vernal equinox will be on March 20 and summer solstice

on June 21. This period is 93 days.During this period, the latitude

for our event increases, from 0 to `23.44^o N` The latitude of

Bangalore is `12.98^o N` So, my expectation is on

just after`((23.44-12.98)/23.44) X 93=41.5` days, from March, 20.

This day is about May 1, 2017..

The next one would be equidistant, after summer solstice, on about

August 2, 2017..

. .