Parallax

Posted on August 10, 2020 Posted in UncategorizedTagged Ancient Greeks, Angles, Distance, Equator, Finding out, Learning, Measurements, Parallax, Stars, Sun, TriangleLeave a comment

IMG_20200810_160700

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

Posted on July 23, 2020 Posted in UncategorizedTagged Auto giro, Blogging, Helicopter, Planes, Red arrows, Rhyl, Sea, Seaside, Sun, Tides, Wales, WeatherLeave a comment

IMG_20180825_140514

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.

Comet Neowise

Posted on July 22, 2020July 22, 2020 Posted in UncategorizedTagged Astronomy, Comet, Comet Neowise, Dust tail, Ion tail, Life, Meteor shower, Out gassing, Persid meteor shower, Random, Spaceweather.com, SunLeave a comment

sketch-1595445833950

I have not seen it. It keeps being to cloudy. But I just read this at Spaceweather.com so I tried to draw it.

COMET NEOWISE APPROACHES EARTH: Tomorrow night might be your best chance to see Comet NEOWISE for the next 6,800 years. On July 23rd, the comet makes its closest approach to Earth. The fading comet is still visible to the naked eye from dark-sky sites and an easy target for photographers everywhere. Get the full story at Spaceweather.com .

There is then the Persid meteor shower in August. Around the 15th? That might be a good show. Meteor showers are caused by the dust thrown off from comets as they get close to the sun. It’s called out gassing when cometary ice is heated by sunshine and boils off into space taking dust with it. A comets tail is made up of two different parts, the dust tail and an ion tail which is made up of ionised gas. The comets tail always points away from the sun because it is blown by the solar wind.

Before the storm

Posted on June 13, 2020June 13, 2020 Posted in UncategorizedTagged Description, Lightening, Poem, Poetry, Rain, Say what you see, Storm, Sun, ThunderLeave a comment

The sky turned orange

Then maroon.

The sun crept under the curtain of cloud,

Sneaking out and staring through the rain.

Rainbows end in the murk

Towards the other horizon.

Light spills, then disappears.

The thunder thrills through the air,

Bouncing from chimneys and roofs,

Clattering slates,

Boom-rumble-thudding,

Flash, crash, splitting the new dark.

The storm is here.

Friends garden colours

Posted on June 10, 2020June 10, 2020 Posted in UncategorizedTagged Beauty, Flowers, Garden, Gardening, Green, Orange, Plants, Red, Six years ago, Sun, Sunshine, TimeLeave a comment

Six years ago.

I took these in a friends garden because they were so colourful and interesting. I think some of the plants are Swiss chard, nasturtium, marigold, sweet peas and poppies. Most of the day the sun shone in it except later on when the sun webt behind the hill. Some lovely colour combinations.

Sun pillar?

Posted on May 31, 2020May 31, 2020 Posted in UncategorizedTagged Beach, Devon, Life, Light, Past, Pathway, Photo, Setting sun, Sun, Sun dogs, Sun pillar, Sunlight, Sunset2 Comments

FB_IMG_1590953857691

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.

Solstice

Posted on May 19, 2020 Posted in UncategorizedTagged Hemispheres, Life, Light, Moon, Poem, Poetry, Solstice, Space, Summer, Sun, Thinking, Time, WinterLeave a comment

FB_IMG_1584841102527

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?

Sunlight finds a way

Posted on February 17, 2020February 17, 2020 Posted in UncategorizedTagged Blogging, Letting light in, Light, Photo, Poem, Poetry, Short poem, Sun, Sunlight, WordsLeave a comment

The sunlight sneaks in

Through the cracks in the door

Through the chinks in the fence

Under the trees

Through the blinds

Past the steel reinforced concrete

Over the brick wall

Tumbling down the chimney

Through the grid over the window

When it’s sunny

Sunlight finds a way.

Two sunsets, two days

Posted on February 5, 2020 Posted in UncategorizedTagged Dawn, Dusk, Horizon, Photos, Pictures, Sun, Sunset, TreesLeave a comment

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…

Posted on January 28, 2020 Posted in UncategorizedTagged Ancient Greeks, Angles, Earth, Flat earth, Geography, Life, Measurements, Myth, Not flat, Science, Space, Sphere, SunLeave a comment

sketch-1579765873048

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.

Mallaband-Brown

Tag: Sun