u/Mammoth_Steak_69

For context: I am in math/theoretical cs, EU-based.
My supervisor left for the whole month of July, during this month me and a postdoc did substantial progress on an important paper we are working on, we are happy about it. The postdoc left for their vacations, and I've met with my supervisor twice now this month.

First meeting, they were all happy and agreeing with our ideas and how the paper is looking. Next meeting, they backtrack their words (without acknowledging it), says "I have big doubts on all your methods and proofs", tries to change the approach we collectively agreed on (with them) before they left, and demands a clean draft quickly to review.

I am just sick of this guy always doubting my abilities, backtracking without at least saying sorry, and trying to change things last minute.

My other supervisor is nice when the other is not around, otherwise he is a yes-man to this guy.

Hi all,

Who’s your "rubber duck" during a PhD?

I explain: In software engineering, people often use a "rubber duck" (or some stand-in) to talk through ideas out loud. I feel like in a PhD you kind of need a person for that, someone to bounce messy ideas off, ask naive questions, etc.

I’m in theoretical CS, and I initially thought my supervisors would fill that role, but our weekly meetings are mostly about reviewing polished work (papers, proofs, etc.), not brainstorming. When I try to discuss half-baked ideas, it doesn’t really land well.

I also don’t feel super comfortable asking "basic" questions there as I sometimes get the sense I’m being judged for things I "should" already know.

My group isn’t really in my area, and the one close person has a reputation for scooping, so I’ve been avoiding that. At this point, my "rubber duck" is basically LLMs… which feels a bit sad.

Do you have a go-to person, or do you just figure things out solo?