Sunlight

Sunlight streaming through the window Shines on Christmas cards and books, ornaments my sewing kit. As the sun rises it also travels south in the sky in winter. Then in the afternoon it appears to move downwards and West. So because of the way the earth is tipped on its axis the position on the sky moves in arcs that tip further south in the winter and further north in summer. So the sun appears overhead eventually.

If the Earth was rotating on a vertical axis at 90° to the plane of the solar system, then day length would stay the same all over the world. 12 hours day and 12 hours night. There would be no seasons. There would probably be no poles as all parts of the earth would receive the same amount of heat from the sun.

Instead the tip of the axis means that the day length changes over the years. So at the solstices the earth has turned to have its poles either closest or furthest apart from the sun. It’s also complicated by the earth travelling in an elliptical orbit round the sun. In the summer in the North of the world the sun is actually slightly further away from the earth than in the winter.

Anyway enough of celestial mechanics. Don’t get me started on the moon! Happy Boxing day. X

Sunny for a while

Light at this time of year is always low. Striking across the ground rather than high above it. This is because the Earths Northern hemisphere tips away from the Sun. So much so that the North Pole dips into darkness in the winter months. Shadows are long now and when you do get into sunshine the light can be blinding from the Sun on the horizon. You can look for images of the suns track across the sky at different times of the year. It basically arcs round from East to West but tipped at an angle dipping more South as winter progresses, then from the winter solstice around the 21st of December, it starts to slowly work its way back up the sky until its almost overhead on Midsummer day at midday, then the cycle starts all over again.

Spectrum

White light

Split into colours

Created by sunlight

Rainbows glow

Chemicals create different colours, sodium used in street lights glows yellow. Chemicals are used in fireworks, like strontium (red?) or copper green, creating different colours, blues, purples, oranges.

The reason sunlight is made up of a spectrum is because the sun is made not only of hydrogen and helium but all the chemicals in the periodic table up to iron (any chemicals beyond that can only be created in Super Novae explosions). All the chemicals in the sun glow in different colours, which is why they show up when the white light from the sun passed through a prism. If you split the spectrum further you can find dark lines, these are markers of which chemicals are present. The older the star the more chemicals. As a star gets older it starts to burn up its hydrogen and helium. New chemicals are created by atoms fusing together. That’s where new chemicals are made. When you think about it, if it wasn’t for stars burning or exploding we couldn’t exist.

Sun fire

Fire, digital drawing

This popped up in my memories on Facebook and I remember doing four of these, Earth, Fire, Water, Air in ArtRage oils, but I can’t find the other three. I did them as companion pieces to four acrylic on canvas paintings of the same subjects that are in my studio down at spode which I really need to start going back to now things are a little more normal.

I’d like like to do some illustrations for a child’s book using ideas like this. Anyone interested?

Aurora

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The sun is starting to wake up after Solar Minimum. Apparently there was a coronal mass ejection from the sun yesterday. This means that a twisted magnetic line of energy had broken and exploded with plasma coming out of the Sun. The energy can fly out in any direction but sometimes the CME heads towards Earth, then the magnetic feild around the Earth shields us. Except at the poles. Its like when you put iron filings on a bar magnet. You can see the magnetic field lines and the way the iron filings follow them. The magnetic lines dip down towards the magnetic poles. This is what happens at the North and South poles of Earth. The energy from the sun is channelled towards the poles and excites the gasses in the atmosphere. I think Nitrogen glows green and Oxygen pink? I’m not sure.

Anyway there has been a CME from the Sun and the chance is there might be some Auroral displays in the next few days.

Garden today

Just when I think the plants can’t get bigger we get torrential rain and they grow! And it’s hot, they are happy.

I think our back yard is full. The hanging baskets are pulling the old fence down. But I turn round and my hubby has snuck an Ash tree in! I love it. I hope some of it survives into the autumn. I will continue to post pictures as it grows.

We even had three ripe blueberries today.

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Parallax

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The photo is an illustration and it doesn’t actually show parallax.

Do you know what parallax is?

Hold out your thumb in front of you and close one eye. Place it so that it covers something, perhaps a flower outside, or something in front of you. Maybe the moon.

Now without moving your hand open your eye and close the other one.

What do you see? The moon or the object appears to have moved! That is because your eyes are seperate. They are the base of a very long thin triangle and believe it or not you can measure distance that way.

Now stick a piece of wood in the soil on the equator, and a similar one a few miles north or south of it. At midday on the equator the sun will be directly overhead and there will be no, or hardly any shadow. But the one miles away will cast a shadow. The further away from the equator the longer the shadow. If you know the distance between the sticks, and the angle the shadow casts by the other stick. (measure the angle from the top of the stick and the end of the shadow) you can actually work out the distance to the Sun (which is casting the shadow). In this way the ancient Greeks did this and also worked out the size of the Earth approximately. You can use this idea if you look at a star at one end of the Earth’s orbit and six months later the other side of the orbit. That’s how they work out distances to stars. Amazing what you can work out by using your eyes, a couple of sticks and your thumb!

Red arrows at Rhyl

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In August last year we were at Rhyl watching the red arrows flying over the sea, with THOUSANDS of people watching the show on the seafront.

The thought of warm Welsh sea breezes really makes me sad that I can’t go there at the moment.

I remember seeing something like a helicopter, an auto giro I think it was called? And an air and sea rescue helicopter. There were all sorts of different planes doing aerobatics.

The thing is though, I could live without the planes, and the crowds. I just wish I could go and look at the sea again, with its constantly changing waves. To see white horses as the wind whips up the waves. Or a flat calm with blue ripples.

The town must have suffered because of the lockdown. How are people coping? A little town on the North Wales coast, where most of the income is raised from holidays and tourism.

But the sea, that’s what calls me. Great storms, gentle tides, boats and ships, but mainly sea.

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