• Register
PhysicsOverflow is a next-generation academic platform for physicists and astronomers, including a community peer review system and a postgraduate-level discussion forum analogous to MathOverflow.

Welcome to PhysicsOverflow! PhysicsOverflow is an open platform for community peer review and graduate-level Physics discussion.

Please help promote PhysicsOverflow ads elsewhere if you like it.


PO is now at the Physics Department of Bielefeld University!

New printer friendly PO pages!

Migration to Bielefeld University was successful!

Please vote for this year's PhysicsOverflow ads!

Please do help out in categorising submissions. Submit a paper to PhysicsOverflow!

... see more

Tools for paper authors

Submit paper
Claim Paper Authorship

Tools for SE users

Search User
Reclaim SE Account
Request Account Merger
Nativise imported posts
Claim post (deleted users)
Import SE post

Users whose questions have been imported from Physics Stack Exchange, Theoretical Physics Stack Exchange, or any other Stack Exchange site are kindly requested to reclaim their account and not to register as a new user.

Public \(\beta\) tools

Report a bug with a feature
Request a new functionality
404 page design
Send feedback


(propose a free ad)

Site Statistics

205 submissions , 163 unreviewed
5,064 questions , 2,215 unanswered
5,347 answers , 22,741 comments
1,470 users with positive rep
818 active unimported users
More ...

  Why do we need a theory of quantum gravity?

+ 2 like - 2 dislike

Why do we need a theory of quantum gravity?

Why can't gravity be classical, while matter and the other fundamental forces be quantum in nature?

asked May 12, 2015 in Closed Questions by Rawsha [ revision history ]
closed May 13, 2015 as per community consensus
Most voted comments show all comments

@Prathyush it's no way a great question,  the correct answers are given on the linked duplicate, but more importantly - it's a duplicate.

@Prathush please look at the revision history. The original version was  a plainly obvious layman question, which is really not suitable for PO.

Also, to cast a "Leave Open" vote you have to downvote the closevote both me and @Dimension10 linked to. Just posting a comment here does not achieve this.

@Upvoters and otherw who think the question should not be closed can vote to reopen here.

I disagree with the down votes, as a lay man, but I respect the integrity of this forum.

However, I would argue that this question is way beyond "popular". Answers and comments would presumably be valuable to this forum. I also believe that the answer is arguably more diffficult than appropriate for a popular science  forum. Indeed, how many really really do understand these two theories? Although I am not a physicist (I'm a physician and statistician) I would try to grasp a non-popular answer.

@Rawsha It is expected that you have some familiarity with both Quantum field theory and General Relativity before you can ask this question, even to remotely try and understand it. Without that kind of effort it is simply futile to talk about this. And listening to video lectures for 30hrs simply does not count. 

I will answer the question(modified) to the best of my knowledge. The simplest reason to search for a theory of QG is because there are domains of experiences that in principle can be created in out universe that we cannot explain.

For instance when one studies quantum field theory on the background geometry of a black hole it becomes apparent that black holes evaporate thermally.(Along with having an entropy proportional to their area.) 

We among many things want to understand how to describe such a process. Certainly this situation can be created in the universe(atleast in principle)

Most recent comments show all comments

Duplicate of http://physicsoverflow.org/8828, and voting to close as such.

@Dimension10 I am not sure how wise it was to edit the question into a better form, if we want to close it (as quick as possible) anyway. In the original version it was plainly visible that it is a popular question apart from possibly a duplicate...

But it is probably not too important in this case, I am not sure.

user contributions licensed under cc by-sa 3.0 with attribution required

Your rights