From household pets and tollways, through to goods in transit and railway cars, RFID tags are appearing in more places, making it easier to track and identify objects.
RFID, or radio frequency identification, tags are small electronic devices that contain information and can be scanned, a bit like a barcode. But unlike barcodes, RFID tags don’t need to be ‘seen’ by the scanner and multiple tags can scanned at once.
The technology behind RFID was first used in 1945 by Russian scientist Léon Theremin to create a listening ‘bug’ called The Thing. But it wasn’t until 1969, that US engineer Mario Cadullo designed and built the first RFID tag.
Most of the time the Sun is quiet, shining in space beaming out light and heat. But every eleven years it gets cranky – covered in dark spots and fiery eruptions. This is a time called solar maximum, or solar max for short.
The Sun, like all stars, is a big ball of plasma – mostly hydrogen and helium. Because the Sun is so big – 100 million times bigger than Earth – it has a lot of gravity. The gravity squeezes the plasma so hard that it gives off heat and light. Scientists call this nuclear fusion.
Twenty years ago, the answer this question was ‘only one that we know’. Most astronomers believed that the Sun was no different to most stars in the universe. So if we had a star with planets and moons – a solar system – than why don’t others.
In 1992, the first planet orbiting another star – sometimes called an exoplanet – was detected. Since then, astronomers have used larger telescopes and faster computers to find more than 450 exoplanets orbiting more than 300 stars.
A sail is something you’d expect to see on a boat in ocean, not in space. But that’s just what a Japanese spacecraft called Ikaros is using to fly through the solar system.
Astronomers measure the distance to other galaxies by looking at their colour. The more red a galaxy is, the faster it is moving from us and the further it is away.
Another way to measure distance is to look at the brightness of exploding stars – called supernova. These explosions are brighter the closer they are to us. By measuring the brightness it is possible to know how far away they, and the galaxy they live in, are from us.
Using these techniques astronomers have seen galaxies more than 13 billion light years away.
Space telescopes that measure cosmic background radiation, which are the remains of the Big Bang explosion. It is thought to be the outer edge of our Universe and is 13.7 billion light years away.
This is a difficult question to answer, because the number keep growing.
Almost every year astronomers find new moons, using better telescopes on Earth and spacecraft flying through the solar systen. Some moons are so small that that their width is smaller than most cities on Earth.
In 1888 German scientist Friedrich Reinitzer extract a compound known as cholesterol from carrots. He found that when he heated the liquid it changed from an orange colour to clear due to the crystal structure within the liquid.
In 1962 electronics engineer Richard Williams found that he could make the crystals move when he applied an electric current to them. A few years later the first liquid crystals displays (LCD) were built. These simple back and white (silvery-grey) displays first appeared in watches and calculators. Today LCD are also found in televisions, mobile phones and laptop computers.
Want to travel to Mars in in the next year or two? Well maybe you can’t go, but NASA is happy to take your name there instead.
The Mars Science Laboratory rover will leave Earth in 2011 and landing on Mars, driving and looking for signs of life and water.
On board will be a microchip full of names of people from planet Earth.
To add your name to the microchip, visit the ‘Send Your Name to Mars’ web page (http://bit.ly/martianname) and enter your name, country and postcode.
You can print a certificate of participation to put on your wall and look at a map showing where other names are from.
Volcanoes on Earth have rivers of red hot lava pouring down the sides or massive explosions of gas, rock and dust rising into the sky. But in space volcanoes are quite different.
Mars has four large volcanoes – the biggest is Olympus Mons. It is 27 kilometres high (three times the height of Mount Everest) and 500 kilometres wide (bigger than Tasmania). The volcanoes on Mars haven’t erupted for more than two million years.
The planet Venus always has ancient volcanoes on its surface. The biggest is Maat Mons – eight kilometres high. From above, some of the volcanoes look like pancakes and others have strange patterns that make them look like ticks. Continue reading
Stars come in different many different sizes and the bigger the star is, the faster it will burn its fuel.
Our sun is an average star and will take about 10 billion years to burn its fuel. The brightest star in our night sky, Sirius, is 21 times the size of our sun and may only last a billion years. Some stars will burn so brightly, they last less than 10 million years.
We can tell how old a star is by looking at its colour – what scientists call its spectra. A spectra is like a chemical fingerprint, showing what is inside the star. Young stars have simple chemical elements, such as hydrogen and helium. As the star gets older, heavier elements like carbon and oxygen appear.
The spectra of our sun tells astronomers that it is 5 billion years old, or about half way through its life.