Astrophysics is an incredibly interesting, exciting, and wonderful science to study. We look at the structures of stars and galaxies, figure out how planets form, and ask some of the biggest questions we know, like ‘how did the Universe form in the first place?’ It is a very rewarding field with a very rapid pace of progress.
It’s also a field that people are very excited by. When I tell someone that I’m astrophysicist I know I’ll usually be spending the next while attempting to answer a lot of very difficult and important questions. Things like, “What’s the deal with black holes?”, “Are there aliens”, “When will we travel to other stars”, etc. But at some point, after some curiosity has been satisfied, I’ll get asked another question that is usually even more important. “What is astronomy good for?”
This is a good question for a variety of reasons. The fact is, astronomy is an expensive science. It’s not something that you can just do, or run a company doing. You need to have resources and support from the government(s). And ultimately, all the new and amazing telescopes that have been built/are being built, are funded by the taxpayers.
And if someone asks me what my research is good for specifically, it’s a bit difficult to answer directly. I study galaxies, and, while they are exciting objects, my research isn’t going to benefit most people (at least right now). There are some techniques that I’ve used and partially developed that might have some use in data science, but, by large, my work is not going to affect many people. It’s not going to feed the hungry, or heal the sick. It’s not going to make cars run more efficiently or provide electricity and sewage and other important pieces of infrastructure.

I’m especially aware of this because I’m currently based in South Africa, which has one of the greatest levels of inequality in the world. It is struggling with the legacy of apartheid and has a massive level of unemployment. Given that my salary ultimately is coming from the South African government I need to be able to explain what my job is actually good for.
There are a lot of possible answers to this question. They range the practical offshoots that come from curiosity research, to how astrophysics inspires people, to how it brings countries together. A great article to read about some of these (and outreach in general) is found at Dr. Delhaize’s blog.
The aspect I’d like to focus on here is how astrophysics changes the philosophical outlook of people. It changes how people think about the world and how they think about themselves. It is somewhat subtle, but it’s also a very powerful effect.
One of the chief ways I’ve seen this happen is when people start to learn about the scale of the Universe. It is bigger than we can imagine, and I don’t think anyone (including astrophysicists) really can full picture how big it is. But, with a good explanation, it’s possible to start getting some of that across. Personally, I find that taking the time to explain to someone what a parsec is really helps, because it’s easier to picture a triangle than a lightyear. That being said, no matter the method of explanation, what I’ve consistently seen from people is a realization that the Milky Way itself is bigger than anything they had imagined. Then extending that to extragalactic distances just blows their mind.

Once someone starts to get a handle on the scale of the Universe, I’ve seen two key things happen. Firstly, their perspective changes on their size. They realize how small we are in the scale of things. Secondly, they often become even more appreciative of how amazing Earth is. They see that there is not much chance of making it to Earth 2.0 anytime in “near” future (for various definitions of near). As such, they see how important the here and now are in a new way.
This is just one example, but there are many more. As someone grapples with questions like what a black hole actually is, to how the Universe formed, to the frequency of exoplanets, they are changed internally. When people learn about astronomy I find that it changes them at a deep level. They see themselves and other people in a new light. Their outlook on life changes.
So, what is astrophysics good for? It’s good at fundamentally changing people at a deep, internal level. And those sorts of changes ultimately can change how people act. That’s at least one thing that astrophysics is good for.