Category Science

Who made the first telescope?

Hans Lippershey, a Dutch man who made spectacles, probably made the first telescope in 1608. He noticed that if he put two lenses at different ends of a tube and looked through them, objects seemed to be nearer and clearer.

Is it true? Newton saw a rainbow in his telescope.

Yes. Isaac Newton noticed that the edges of objects seemed coloured when you looked through a telescope. That’s how he began to work out that clear white light is made up of many different colours.

How does a telescope work?

The lens (curved piece of glass) at the front end of a telescope gathers light to make an image of an object that is far away. The lens at the back magnifies the image so it can be seen more clearly.

Who put mirrors in a telescope?

Isaac Newton was the first person to make a mirror or reflecting telescope. He replaced the front lens with a dish-shaped mirror at the back. The mirror reflected the image on to a smaller mirror, and then into the eye.

Amazing! You can see Saturn’s rings through a telescope. Telescopes magnify images (make them bigger) so much that you can even make out Saturn’s faint rings – which are about 1.3 billion km away!

Picture Credit : Google

Who first wrote about the stars?

The Babylonians were the first to write down their findings from studying the stars – around 5,000 years ago! They noticed that stars seem to form patterns, which we call constellations. The Babylonian empire was roughly where Iraq is today.

Is it true? The Babylonians were maths wizards.

Yes. At first their findings about the night sky were based on looking and guessing. By around 500 BC, the Babylonians used sums to predict exactly when events such as eclipses would happen.

How do we know about the first astronomers?

The Babylonians didn’t write on paper like we do. They wrote on clay tablets, so fragments have survived. Scientists called archaeologists dig in the ground for clues about ancient peoples such as the Babylonians.

Amazing! The Babylonians didn’t see the same night sky as us. There were no twinkling satellites, and the stars were in different places because our Solar System has moved since then.

What was a Babylonian year like?

The Babylonians worked out a 12-month year. Each month began with the first sight of the crescent Moon. The months were called Nisannu, Ayaru, Simanu, Du’uzu, Abu, Ululu, Tashritu, Arahsamnu, Kislimu, Tebetu, Shabatu and Addaru.

Picture Credit : Google

How did sailors know where they were going?

Out at sea, there are no landmarks. In the Middle Ages, sailors had special instruments that used the position of the Sun and stars to tell them where they were. These included compasses, astrolabes and cross-staffs.

Amazing! The first astrolabes were made 1,500 years ago! Indian and Arab astronomers used pocket-sized instruments called astrolabes in the AD 500s.

Is it true? Astrolabes only worked at night.

No. You could use the position of the Sun instead of the stars, when you were sailing during the day. You looked at its position compared to the horizon.

What is the pole star?

The only star which doesn’t appear to move is above the North Pole. Sailors could tell where they were by looking at the pole star – it’s lowest in the sky at the Equator.

How did an astrolabe work?

An astrolabe had two discs, one with a star map, and the other with measuring lines and a pointer. You compared them with the Sun or a star and the horizon to work out your position.

Picture Credit : Google

Who gazes at the stars?

We all enjoy looking up at the starry night sky, especially on a clear moonless night, away from bright city lights. Some people even star-gaze as a job. They are scientists called astronomers. Astronomy is the science of studying space and all the objects in it.

Amazing! You can see about 2,500 stars in the night sky! When the sky is clear, you can see that many different stars even without a telescope!

Is it true? You can see the Moon’s craters through binoculars.

Yes. Binoculars allow you to see the Moon’s surface so clearly that you can make out individual craters – from 400,000 km away!

Can you only see the Moon and stars at night?

The Moon and stars are easiest to spot, but even without a telescope you will see meteors (shooting stars) and the brighter planets, such as Venus, Jupiter or Mars. Venus shines white and is nicknamed the ‘evening star’. Jupiter looks greeny-blue and Mars glows red.

Can anyone be an astronomer?

Anyone can learn about stars as a hobby, but it takes years of study to do it as a job. You’ll need books of star charts and maps, so you can recognize what you see. Binoculars or a telescope will let you see further.

Picture Credit : Google

Is there anybody out there?

We don’t know. Life might be such a fluke that it only exists on Earth. But if scientists can find just one other place where there is life, we’ll know life’s no accident – and that there could be millions of aliens!

How will we find out?

People around the world have joined the Search for Extra-Terrestrial Intelligence (SETI). They spend their spare time on computers, studying waves from space, hoping to find alien messages.

Do aliens know about us?

It’s unlikely. Humans have only been making radio waves for about a century, so aliens would have to live very nearby to tune in.

Is it true? Aliens have visited the Earth.

Probably not. There’s no proof that aliens have visited us. Even if they could travel at the speed of light, they would take at least four years to reach us from the nearest stars.

Amazing! Some people think that the Universe is a living thing – and that the planets, stars and galaxies are just parts of its ‘body’!

Picture Credit : Google

What is gravity?

Gravity is one of the basic forces in the Universe, like electromagnetism. It makes things with mass pull towards each other. More massive objects, such as the Earth, pull smaller objects, such as you, towards them until they stick together.

Is it true? An apple taught us about gravity.

Maybe. According to legend, super-scientist Isaac Newton first realized how gravity works over 330 years ago, after gravity pulled an apple from a tree he was sitting under, and it landed on his head!

Is the Universe expanding evenly?

No – the force of gravity stops everything from flying outwards. Lumpy bits of space become even lumpier, moving at different speeds. Gravity locks together little pockets of space and matter, such as galaxies.

Amazing! There are walls in space! Galaxies aren’t evenly spaced through the Universe. They are arranged more like walls around emptier regions of space. One wall has already been measured – it’s about a billion light years across!

What is the Great Attractor?

It’s a strange little knot in space that has the pulling power of 50 million billion Suns, but is not a black hole.

Picture Credit : Google