Pulsar timing array

Have you heard about pulsars? They are like cosmic clocks in space that keep ticking and sending out regular pulses of light and radio waves. Scientists use them to study the universe and learn more about things like gravity and black holes.

Now, imagine you have a lot of pulsars in different parts of the sky. These pulsars all send out their pulses at different times, just like clocks ticking at different speeds. But if you listen carefully and record the pulses over a long time, you might notice that they all have something in common - sometimes they arrive just a tiny bit earlier or later than expected.

This is where the pulsar timing array (PTA) comes in. It's like a big network of telescopes and computers that listen to these pulsars and measure those tiny differences in their timing. By doing this, scientists can detect very faint ripples in the fabric of space and time, called gravitational waves.

Gravitational waves are like the waves you see when you throw a stone into a pond, but instead of water they are ripples in space itself! They were predicted by Albert Einstein's theory of general relativity, but it wasn't until recently that scientists were finally able to detect them.

Now, with the help of pulsar timing arrays, scientists are hoping to detect even more gravitational waves and study them in more detail. This could help us understand some of the biggest mysteries of the universe, like why there is dark matter, how galaxies form, and what happens inside black holes.