To offer a different perspective, I think more mechanically, so physics was more intuitive than life sciences for me, so physics would be easier. I won’t comment on which course is more rigorous because that will vary by university and professor, and I also can’t comment on which is more intuitive because, as #3 astutely points out, some sciences are more math based. For me, I prefer relying on intuition and reasoning over memorization. (Sounds dismissive to life sciences. That’s not my intent.)

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