Sun pillar?

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We visited Devon about ten years ago and stopped in a caravan site near the sea. We walked down to the sea at sunset on the first day as there was a glorious sunset. Then as we got near the beach and were walking through tall grasses along the path to the beach, I saw this. I was stunned. I knew it was something to do with the sun, that had set. But I had my camera, so I took this photo. I think it’s called a sun pillar. I’ve seen sun dogs since. They are bright spots some way from the sun on either side. And brocken spectre, where your shadow is cast onto cloud by sunlight being you and it creates a sort of glowing rainbow halo. There are many other effects caused by the sun and light from it.

The world is a fascinating place.

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Solstice

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As the year waxes and wanes,

as time passes,

light rises and falls.

Life comes and goes,

hearing bird song, then silence.

Summer solstice,

the world is warm,

but days will shrink and shrivel.

Winter solstice,

the promise of warmth,

locked in ice,

day lengthens, nights slowly shrink.

North and South

seasons, polar opposites.

Hot in one hemisphere,

cold in the other.

Unless, near the equator,  

seasons are less obvious, 

No frozen wastes here.

World floating in space,

around Sol, the Sun, our star,

Earth tipped at an angle,

anchored by moon,

held in mutual gravity

Eternal?

 

 

 

 

Two sunsets, two days

A few days ago there was a reddish sunset, today it was more silvery. Each one was beautiful.

I like the glow in the sky on the second one. I’m sad when the sun goes down in the winter because of how long it is until the sun returns in the morning. As the days go on I look forward to longer days.

I’m already noticing the  change of position of the sunrise and Sunset, gently moving along the horizon, gradually changing the time it rises and sets.

The weather should look very different on Sunday. A storm called Keira is on its way,  due to give gale force winds.

In the meantime if I see more beautiful skies I will post pictures. X

How to tell the earth is a sphere…

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So how can you tell the Earth is a sphere? The ancient Greeks worked it out ( I don’t remember the name of the person who did).

The experiment was to put a stick in the sand at or near the equator, so it would have a tiny shadow directly underneath the it at mid day as the Sun was directly overhead.

If you place a stick upright, at 90° to the Eaths surface either North or South of the equator, the stick casts a shadow at mid day. (Look at the hands of a clock the hands move round in the same way). Say the equator is 3pm and the Sun is overhead, you would get no shadow, then as you go further away from the stick at the equator you get increasing angles (see diagram). Eventually at the poles the shadows would be at their longest.

So how can you tell its a sphere? The angles add up. You can calculate the curvature of the planet from these simple experiments. The ancient Greeks got very close to calculating the circumference of the Earth. Their calculations were only a small percentage out on their measurement.

 

I like noticing things…

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For instance, this is the just after full moon. Its in the same place in the sky as it was over the last few days, but not at the same time! I know the Earth and Moon orbit each other, and the moon is tidally locked with us. Which means it has one side always facing towards us. But as I say its in about the same place, but each day its a bit later, so after 5 days it’s moved from being there at 2am to 6am…..

Think about it. The Earth rotates in 24 hours, if the Moon is coming up later each day it must be going round the Earth at a certain speed. I don’t have the mathematic skill to work that out but if it takes 6 days to move 4 hours then if you multiply 4×6 you get 24 (hours) for it to end up in the same place so if you multiply 5(days)x6 you get 30, which is approximately a month to get to the same place in the sky and appear again at 2am. The Moon waxes and wanes while doing this. From that you can tell approximately where the sun is in relationship to us. If the half moon, and all the other phases are facing one way before full moon, the Sun is on the lighter side of the Moon. If its curved the other way as the moon starts to go away from full, then it’s on the other side. You can guess when the sun will rise from this, the smaller the area of brightness the more to the side of the Earth the sun must be. I can’t work out whether the sun would be rising sooner or later depending on its phase. I can see in my mind that if you were looking at both Earth and Moon from space they would be lit from the same direction, but sometimes you see the Moon in daylight, so I don’t know how that works. I think I would need to start drawing very long thin triangles, based on say a quarter of a centimeter on one side and 93 centimeters on the other two to work something out (based on the ratio of distances from the Earth to the Moon and the Earth to the Sun – .5:93…this is just scaling down the siz. I’m thinking in miles because I don’t know the distances in kilometers…. Its all got a bit complicated….

I remember once watching the moon every day for a week from the top of the hill, each day it got closer to the setting sun, till finally there was almost an eclipse. Somewhere on Earth there must have been an eclipse in the following day or so, but we missed it because the sun had already set.