In Summary
  • Another way of thinking about this is that the coin can be placed as far as 2.57m away and it would still block the sun from view.
  • Anything farther than that and the sun begins to “peep” over the edges.
  • Let me extend this line of thought further.
  • We know that the sun is a star, but, when we look at it, it doesn’t look anything like the other stars. It is a large bright disc, not a sparkling dot.

A few weeks ago, I showed how to calculate the distance one would need to be from earth in order to be able to see the entire planet.

The answer came to about 4,267km or more. Now Dickson Mwangangi has extended the problem a little bit. He asks how far should a one-shilling coin be placed for it to appear the same size as the sun.

Now, currently, there are three valid one-shilling coins in Kenya. They have different colours and sizes. I will use the latest edition that was issued from 2005. It is about 24mm in diameter.

The sun is about 1,400,000km in diameter and about 150 million kilometres away from Earth.

Therefore, the ratio of its distance to it diameter is 150/1.4, that is, about 107 times. If the shilling coin is to appear the same size as the sun, the ratio of its distance away to its diameter should also be about 107 times. Therefore, the coin should be placed about 24x107 millimetres away; that is, 2,568mm, or 2.57 metres.

Another way of thinking about this is that the coin can be placed as far as 2.57m away and it would still block the sun from view. Anything farther than that and the sun begins to “peep” over the edges.

Let me extend this line of thought further. We know that the sun is a star, but, when we look at it, it doesn’t look anything like the other stars. It is a large bright disc, not a sparkling dot.

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