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If you look up at the sky during the night (and it’s not too cloudy) then you can see thousands of stars and galaxies. The reason that you can see them is because they emit optical light and that’s what your eyes are able to detect. But they’re not the only things out there – space is filled with all kinds of weird and wonderful objects, but most of them don’t emit optical light, so you can’t see them with your eyes.

The highest energy objects in the Universe emit radio light – just a different wavelength to optical light – and to see them we need to build radio telescopes. Why? Because the radio sky is beautiful. And full of information about things we can’t see with our eyes.

Radio telescopes work in a different way to optical telescopes. Optical telescopes are basically a souped-up version of your digital camera. If you have one radio antenna (probably a big dish like the one at Jodrell Bank) then it will tell you the amount of radio power coming from a particular direction on the sky and you need to move it back and forth across the sky to weave together a picture of the thing producing that power. If you have lots of radio antennas (an array of dishes) then you’re really in business. Then you have a “radio interferometer”, also known as a “synthesis telescope”. A radio interferometer collects signals from each pair of dishes in the array and can combine them to make a picture directly. To do that you still need to do a load of computer processing though and the bigger your telescope, the bigger your data…

The radio interferometer that I’m helping to build will be bigger than anything we have at the moment. The bit made from dishes will produce ten times more data than the whole of the world internet right now… The bit made from aperture arrays will produce one hundred times more data! (Don’t know what an aperture array is? Ask me!) If you tried to play back a day’s worth of data from this telescope on your iPod it would take you two million years. That’s a long song.

And that’s Big Data.