What is (one of) the hardest thing about astronomy?
Sometimes problems that leaves astronomers scratching their heads are more mundane than you expected! An old professor told me once: the bane of astronomy is that we can only see two dimensional projections of an inherently three dimensional universe.
What does this mean? Since we are stuck on Earth, we perform astronomy by pointing light collecting buckets (telescopes) at different directions. We can point our telescopes up or down, and left or right, but we cannot point it ‘forward’ or ‘backwards’. We point it north, towards Polaris, or south, towards Crux, but it does not make sense to point our telescope to 300 meters in front of Polaris, or a few kilometers behind it. The telescope will serve ALL the light coming to it from Polaris’ direction on its neat little eyepiece. It does not care where exactly the light is produced, as long as it is in the line of sight. A telescope is like a one-eyed cat: it lacks depth perception. Telescopes are essentially blind to the third direction.
Astronomical objects, our observation targets: stars, planets, galaxies, on the other hand, are of course three dimensional structures. This mismatch between two dimensional observations and three dimensional targets is the bane of astronomy my old professor mentioned.
Fortunately, all hope is not lost. You see, many astronomers are rather clever. This site will guide you towards understanding a clever trick that astronomers can use to image the third dimension. We will then show how the trick was used by Professor Tracey DeLaney to image an exploding star in all its three dimensional glory.
You can find Professor DeLaney’s original work here. Be warned: you will need at least a first or second year college level physics to understand it!