Observational astrophysics reference for math/physics major

[krb17]

Hi all,

I'm a math major with decent training in physics (through quantum and statmech), and I'd like to learn more about astrophysics. Not so much the theoretical cosmology kind of stuff, though, as how scientists take observational data and deduce things like "the mass of the galaxy" or how old the universe is. Right now it's beyond my imaginative capacity to understand how that kind of quantity could be deduced, and I'd like to get more of an idea.

Hopefully my intent is clear enough; if not, please help me be clearer. Thanks for your help!

 

[AndyW]

It's great to hear that you are interested in learning more about astrophysics! As a scientist in the field, I can tell you that the process of deducing things like the mass of a galaxy or the age of the universe is a complex and fascinating one. It involves a combination of observational data, theoretical models, and advanced mathematical techniques.

To start, observational data is collected from various instruments such as telescopes and satellites. This data includes measurements of the positions, velocities, and spectra of objects in the universe. Scientists then use this data to create models and simulations that represent the behavior of these objects. These models are constantly refined and tested against new data to ensure their accuracy.

One of the key principles in astrophysics is the law of gravity, which governs the motion of objects in the universe. By studying the gravitational interactions between objects, scientists can determine their masses. For example, the mass of a galaxy can be calculated by observing the orbits of stars and other objects within it.

In terms of determining the age of the universe, scientists use a variety of techniques such as measuring the expansion rate of the universe and the ages of the oldest known stars. By combining these different measurements, scientists can estimate the age of the universe with a high degree of accuracy.

I hope this helps to give you a better understanding of how astrophysicists deduce quantities like the mass of a galaxy and the age of the universe. There is still much to learn and discover in this field, and I encourage you to continue exploring and asking questions. Best of luck in your studies!