How does General Relativity contradict quantum mechanics?

In summary, there is a common belief that General Relativity and quantum mechanics contradict each other, particularly in extreme conditions. However, this is not entirely accurate as both theories are incomplete and do not fully account for all physical scenarios. One specific case where they seem to contradict is in the concept of black holes, where GR predicts the destruction of quantum information, which goes against the principle of unitarity in QM. This is known as the "black hole information paradox."
  • #1
lizzie96
22
0
How does General Relativity "contradict" quantum mechanics?

I couldn't work out exactly where to post this. I've heard several times that QM and General relativity "contradict" each other and in certain extreme conditions this becomes a problem. Is this right? I've only heard this in very vague terms and never read a technical explanation of why. Could anyone explain?
 
Physics news on Phys.org
  • #2
They do not contradict each other, we just don't know how physics looks like if both are important at the same time.
It is expected that gravity will show quantum-effects as well, but plugging gravity into the formalism of quantum field theory leads to things we cannot calculate (more technical: renormalization does not work).
 
  • #3
One particular case in which the predictions of GR appear to be inconsistent with QM is black holes. Briefly: GR predicts that a quantum system that falls into a black hole will be destroyed in the singularity at its center, along with the quantum information it contains; but this violates unitarity, a basic principle of QM, which says, basically, that quantum information can't be destroyed. This is called the "black hole information paradox"; the Wikipedia page has a decent overview:

http://en.wikipedia.org/wiki/Black_hole_information_paradox

The bottom line is that, as we know them today, both GR and QM are incomplete theories, so they don't so much "contradict" each other as fail to cover all possible physical scenarios.
 

1. How does General Relativity contradict quantum mechanics?

General Relativity and quantum mechanics are two of the most successful theories in physics, but they contradict each other in certain aspects. General Relativity describes the behavior of large objects and their interactions through the force of gravity, while quantum mechanics explains the behavior of particles on a microscopic level. The main contradiction between the two theories lies in their different explanations of gravity. In General Relativity, gravity is described as a curvature of space-time caused by massive objects, while in quantum mechanics, gravity is described as a force carried by particles called gravitons. This fundamental difference between the two theories has yet to be resolved.

2. Can both General Relativity and quantum mechanics be true at the same time?

It is currently believed that both General Relativity and quantum mechanics are true, but they are incomplete theories that do not fully explain all phenomena in the universe. Many scientists are working on theories that aim to unify these two theories and provide a more complete understanding of the universe. However, this is still a topic of ongoing research and there is no definitive answer yet.

3. How does the uncertainty principle in quantum mechanics conflict with General Relativity?

The uncertainty principle states that it is impossible to know both the exact position and momentum of a particle at the same time. This conflicts with General Relativity, which relies on precise measurements of position and momentum to calculate the curvature of space-time. This contradiction is one of the challenges in reconciling the two theories.

4. Are there any experiments that have shown contradictions between General Relativity and quantum mechanics?

Many experiments have been conducted to test the predictions of General Relativity and quantum mechanics, but so far no experiments have shown direct contradictions between the two theories. However, there are certain phenomena, such as black holes and the behavior of matter at the very beginning of the universe, that cannot be fully explained by either theory alone.

5. How do scientists approach reconciling the contradictions between General Relativity and quantum mechanics?

There are various approaches that scientists are taking to try and reconcile the contradictions between General Relativity and quantum mechanics. Some are trying to develop a new theory that can unify the two, while others are focusing on smaller scale experiments to test different aspects of the theories. Collaborative efforts and interdisciplinary research are also being pursued in order to gain a deeper understanding of the universe and potentially resolve the contradictions between these two fundamental theories.

Similar threads

I Why doesn't relativity of simultaneity lead to a contradiction?
    • Special and General Relativity
Replies
17
Views
551
What does G mean in general relativity?
    • Special and General Relativity
2
Replies
55
Views
3K
I Does Kerr's argument against singularities apply to all black holes?
    • Special and General Relativity
Replies
12
Views
328
I Why Does Special Relativity Not Contradict General Philosophy?
    • Special and General Relativity
Replies
1
Views
797
I Existential problem on Electromagnetism and the combination of Relativity and Quantum Mechanics
    • Other Physics Topics
Replies
8
Views
1K
I Noether's second theorem: two questions
    • Special and General Relativity
Replies
7
Views
1K
I General Relativity & Quantum Theory: Where's the Limit?
    • Special and General Relativity
Replies
3
Views
967
I Uniting Quantum Mechanics & General Relativity: 3 Forces & Geometry
    • Special and General Relativity
Replies
2
Views
863
I GR: How Much Mechanics is Involved?
    • Special and General Relativity
Replies
6
Views
1K
B Linking Quantum Physics and Relativity: Theory of Everything?
    • Special and General Relativity
Replies
16
Views
1K

Hot Threads

Recent Insights

Back
Top