PhD MUST be on same area as masters degree?

[U.Renko]

I'm still an undergraduate but I was wondering about the future and all that.
I do like love physics as a whole, but I don't think there is a subfield which I REALLY like or REALLY dislike. I also like "versatility" as a way of life.

So I was wondering: "can I move to and from subfields as I please? "

For example: Can I take an internship in astrophysics, take a master course in Statistical Mechanics and then a PhD in Mathematical physics? Or whatever other sequence, with whatever other subfields.

As a bonus: is it possible to, after PhD, make research in yet another area?

 

[Useful nucleus]

Changing theme from MSc to PhD is fine. You can do it within the same school or even by applying to another school after the MSc.
Post PhD research in "yet another area" is a bit difficult. First, you need to work with people who are welling to accept the fact that you came from a different background and need sometime to catch up. In the past this was acceptable. Nowadays with the harsh competition and the urge to publish fast, it is hard to find somebody who is welling to wait until you learn the new field. Moreover, as you get older you need to get deeper into one area and you gradually lose the stamina to delve into new fields far from your own (Although you could be an exceptional person who can do it!)

I have noticed however, that some professors start to pick up new research fields gradually. But for professors it is much easier as they can put most of the learning curve load on a student or a postdoc whom they hire to work on the newly adopted research area.

 

[Choppy]

I agree with Useful Nucleus.

It's common for graduate students to switch fields in my experience (in Canada). In the US, it's a lot more common to jump straight into a PhD, but even then, if you do a year or so and it's not working out, it's still possible to move to a different field - although some restrictions may apply (such as you need to be able to find someone in that other field who is willing to take you on).

I see post docs who jump fields, but usually the case is that you have someone who has a particular skill in one area that is in demands in another area. So it's not like you can arbitrarily finish a PhD in one field and then randomly apply for any other field you want for post doctoral work. It's more a case of looked at what's available at the time and what you're qualified to do.

 

[U.Renko]

I see
thank you very much for your answers.
I was kind of gettting worried about it.