Physics and Astronomy Major Guide (USA)

What a physics or astronomy degree covers

A US bachelor's degree in physics builds from a calculus-based introductory sequence into the core pillars of the field: classical mechanics, electricity and magnetism, thermodynamics and statistical mechanics, and quantum mechanics. Mathematics runs alongside throughout — calculus, linear algebra, differential equations, and often mathematical-methods courses tailored to physics.

Astronomy and astrophysics degrees share much of this physics core, then add specialised coursework such as stellar structure, galactic and extragalactic astronomy, cosmology, and observational techniques. At many universities, astronomy is offered as a concentration or track within a physics department rather than as a fully separate major. Review each university's official course catalogue, which is the most reliable description of what you will actually study.

• Core physics: mechanics, electromagnetism, thermodynamics, quantum mechanics
• Mathematics: calculus, linear algebra, differential equations, mathematical methods
• Astro track: astrophysics, cosmology, stellar and galactic astronomy, observation
• Most programmes require a laboratory and/or computational sequence

Lab work, computation, and undergraduate research

Hands-on work is central. Most programmes include instructional laboratories in optics, electronics, and modern physics, where students learn measurement, error analysis, and instrumentation. Computational physics has also become a standard component — students typically learn to program (often in Python, C++, or specialised tools) to model systems, analyse data, and run simulations.

Many physics and astronomy students take part in faculty research, sometimes for course credit or through summer programmes. Research experience is frequently emphasised by graduate admissions committees, so it is worth exploring early. Check each department's official page for research groups, observatory or facility access, and undergraduate research opportunities.

Degree structures and how programmes differ

Common degree titles include the B.S. in Physics, B.A. in Physics, and B.S. in Astronomy or Astrophysics. A B.S. is usually the more technically intensive track; a B.A. may allow more flexibility for students combining physics with another field. Some universities offer applied-physics or engineering-physics options that lean toward technology and industry.

Departments vary in size, facilities, and research emphasis — a large research university may have telescopes, accelerator access, or major collaborations, while a smaller college may offer closer faculty mentorship. None of these is universally better; the right fit depends on a student's goals and learning style. Compare official programme pages directly.

Graduate school and research pathways

A large share of physics and astronomy students who want a research career pursue a Ph.D. Doctoral admission typically rests on undergraduate coursework in the core areas, research experience, a statement of purpose, and letters of recommendation. The GRE General Test and the Physics GRE Subject Test are required by some programmes and optional or no longer used at others — these policies differ widely and have shifted over time, so confirm the current requirement on each programme's official admissions page and on the official ETS test page before relying on it.

Graduate study allows specialisation in fields such as condensed-matter physics, particle physics, astrophysics, optics, biophysics, or computational physics.

Where the degree typically leads

Physics and astronomy graduates follow a range of directions. Some continue to graduate school and research; others move into quantitative roles where the training in mathematics, modelling, and data analysis is valued — for example data analysis, software, finance, engineering-adjacent work, instrumentation, and teaching. Astronomy-specific research careers are concentrated in universities, observatories, and national facilities, and often require a doctorate.

No guide can predict employment conditions, and no major guarantees a particular outcome. For official, current labour-market context, the U.S. Bureau of Labor Statistics publishes occupational outlooks for physicists, astronomers, and related roles in its Occupational Outlook Handbook — figures there change with each edition, so check the latest version on the official site.