Ever noticed the rainbow of colours cast across a DVD when illuminated by light? Incredibly, this principle is being used to measure greenhouse gases in the atmosphere from space and help us understand climate change! A DVD has tiny circular grooves to store its information, more than 1000 per mm in fact! Shining light onto a DVD causes the grooves to deviate the path of light, with red light deviated more than violet light. The effect is to separate out the different colour constituents in a fantastic rainbow effect.  The rainbow effect on a DVD when illuminated by light. Credit: commun ..read more

Welcome to Part II of this climate change trilogy where we’re focusing on Land. It’s a timely post too, with a major crisis playing out in the news due to forest fires in the Amazon rain forest. We’re going to focus on forest fires and soil moisture, both of which you can measure from space with satellites – incredible!  Forest Fires Our forests provide a major role in removing the greenhouse gas carbon dioxide (CO2) from the atmosphere. Approximately 2.6 billion tonnes of CO2 is absorbed by forests every year. This is about one-third of the CO2 released from burning fossil fuels. Ac ..read more

Climate change is one of the greatest challenges we face as a human race. We know our precious planet is warming, and this has an effect on the oceans, land and atmosphere. I still find it amazing that we can measure so many things about our world from space, including those that are affected by climate change. In this first part we focus on our oceans… We know that, due to climate change, oceans have risen by about 8cm over the last 30 years, ~3mm/year. There are two major causes of this: Over 800,000 Empire State Buildings worth of ice is melting every year in polar regions and supplyi ..read more

In Part 1 we saw some truly sensational science when we explored how it’s possible to travel forward through time by travelling near the speed of light. We left it on a cliff hanger with the news that there is another way to achieve this without high speed travel. The other way was again foreseen by the genius of Einstein. Recall from Part 1 that it’s perfectly normal to travel forwards through time. You and I are doing this at one second per second i.e. for every second experienced by you, the world around you also moves forward through time by 1 second. However, if you move to a place ..read more

The short answer is yes (!!) and this is one of the most inspirational scientific concepts I learnt when I was growing up. I also get to talk about my favourite film of all time! For all those that haven’t seen the Back to the Future trilogy then you need to make this a priority. The essence of the time travel machine there is the DeLorean car. The time circuits can be set to travel to any date and time in the past or future, you need lots of energy (created through a nuclear reaction or a bolt of lightning), and the car needs to travel up to 88 mph. The DeLorean car in the film “Back to ..read more

That’s quite a statement! How can it be true? There’s several things to talk about to understand this. What are the contents of your body?How can these contents have been created in the centre of stars? How can they now be inside you? What are the contents of your body? First of all any object or living thing in the Universe is made of tiny building blocks called atoms. There are 121 different types of atoms, the lightest being hydrogen and the heavier ones being generally metals like silver or gold. The main elements of the human body as percentages of our body weight. We are mad ..read more

We see an object because it radiates or reflects light, with those rays of light travelling from the object to our eyes. For things on Earth this normally takes hardly any time at all as light travels almost unimaginably quickly, fast enough to do more than 7 full circuits of our planet every second! For two people looking at each other then the time taken for light to travel between them is virtually zero. But for objects out in space the distances are so large that this does have an effect on the time taken for light to leave their surface, and reach our eyes. Time taken for light t ..read more

It’s a question that has naturally occurred to generations of people as we stare up at the beautiful night sky. And the answer is truly astonishing, but bear with me to look at some very interesting concepts along the way. Our sun, Credit: NASA First of all our sun is a star and all stars are suns. The only reason our sun / star appears much larger in the sky than other stars is because it is much closer to us. Below is how our galaxy (called the Milky Way) could look if viewed from a distance, which shows our sun about 2/3rds of the way out from the centre. The bulge at ..read more