Feel free to share your thoughts
@formatik I would focus mainly on fit. Both schools have more or less similarly strong physics departments. Columbia tends to get ranked slightly higher in many rankings but especially for undergrad there wouldn’t be any difference in quality. Also both schools are similarly prestigious, well-regarded on an overall level.
However, they have many many core differences in terms of culture, campus vibe, curriculum, location etc. The differences in these areas are quite substantial so you should really look into that. For example Columbia has a common core while Penn’s curriculum doesn’t and is thus more flexible. Some people love the core others love the flexibility to explore different fields and take classes they actually want.
^What Penn95 said!
@Penn95 “and take classes they actually want”
another subtle jab at “the core”. 
the core makes you take a well rounded course load in subjects like science, humanities, mathematics, social sciences, not specific classes.
If you’re serious about physics, to the point where you’re planning to pursue graduate work in the field, go to the schools’ respective physics dept websites and see what their faculties specialize in. Both depts will cover the basics equally well but each will have clusters of profs working in particular areas. Choose the school whose dept seems more closely aligned with your own interests (if you’re already aware of them). If you’re not at that stage yet, choose the school you like better in other ways – you’ll get an excellent education at either one.
Agreed.
Of course, the question is really premature. The better program is the one that admits you.
I don’t strongly disagree with any of the points made above.
However, I see a few indications that Columbia may have a somewhat stronger physics department than UPenn.
- US News ranks Columbia's physics department #14 in the world, UPenn's in a tie for #42. This is a graduate program ranking, which may or may not have a strong bearing on undergraduate program quality. Some other ranking might place them more closely or even favor Penn.
- The two schools seem to generate a nearly equal number of physics majors. Per IPEDS, 94 Columbia graduates and 95 UPenn graduates majored in physics in 2012-16 (inclusive). However, in the 2005-2015 decade, per NSF/WebCASPAR, Columbia alumni earned nearly 2X as many physics PhDs as UPenn alumni (71 v. 38 respectively). Hard to say how significant this is. It may be the case that equally well-educated UPenn grads simply decided, in greater numbers, to choose a path other than grad school in physics.
- In the history of the Nobel prize, 37 people affiliated with Columbia University have been awarded the Noble prize in physics. 4 people affiliated with UPenn have been awarded the Noble prize in physics. Historically, at least, Columbia seems to have had the more distinguished department. (https://en.wikipedia.org/wiki/List_of_Nobel_laureates_by_university_affiliation)
Should any of these numbers matter much to a prospective undergrad?
Probably not enough to override a net price advantage or a strong personal preferences in Penn’s (or Philadelphia’s) favor. If in those respects they’re about equal, and if you’re considering an academic career in physics, then Columbia might be a better choice (unless you can determine that Penn is stronger in an area of physics that especially interests you … although this usually would be more of a factor in choosing a grad school).
As a practical matter, it is more of whether either, both, or neither chooses you. Only in the “both” case do you actually get to choose between them.
I’m curious what you feel a need for an Ivy as a potential physics major. Why not UChicago, or CalTech, or Harvey Mudd? If you have the grades for Columbia, then I’d look at schools especially strong in your major for undergrads.
@CU123 As I said some people love the core for the reasons you mention, others do not like it for the reasons i mention. no subtle jab here, just laying out both aspects of it. never said that the core contains you to take a specific class but it still is more constraining than a curriculum without a core.
@tk21769 In the domestic USNews rankings Columbia is ranked #11, Penn is #16. In the NRC rankings it is #12 vs #17. in the USNews world rankings and ARWU rankings the difference is a bit bigger. I would agree with you that in general Columbia has the edge for for undergrad the different is not really substantial, and fit is more important for more or less similarly strong schools.