Time travel becomes easy when you are an astronomer. You travel backwards in time simply by looking further into space. If we look far enough out, we can see the universe during its infancy. As it turns out, the universe was a very violent baby. We can see massive black holes out there at the centres of early galaxies. These black holes send out huge super energetic rays, enough to fry an entire planet in just the blink of an eye if it would dare to wander close by. Still, being safe back on Earth, we can observe these vicious objects, and use them to measure distances – and hence the age! – of the universe.
Guest post by: A. Acharyya and N. E. Sommer