How do you build a tower? One layer of bricks at a time. But before you lay down the next layer of bricks, you need to make sure the current layer of bricks has been laid down properly. Otherwise, the whole thing may be tumbling down.
The same is true in physics. Before, you base your ideas on previous ideas, you need to check that those previous ideas are correct. Otherwise, you would be misleading yourself and others, and the new theories may not be able to make successful predictions.
Physics is a science, which means that we should only trust previous ideas after they have been tested through comparison with physical observations. Unfortunately, there are some ideas that cannot be checked so easily. Obviously, one should then be very careful when you base new ideas on such unchecked ideas. Some people blame the current lack of progress in fundamental physics on this problem. They say we need to go back and check if we have not made a mistake somewhere. I think I know where this problem is.
Over the centuries of physics research, many tools have been developed to aid the formulation of theories. These tools include things like differential calculus in terms of which equations of motion can be formulated, and Hamiltonians and Lagrangians, to name a few.
Now, I see that some people claim that most of these tools won’t work for the formulation of a fundamental theory that includes gravity with quantum theory. It is stated that a minimum measurement uncertainty, imposed by the Planck scale, would render the formulation of equations of motion and Lagrangians at this scale impossible. Why is that? Well, it is claimed that the uncertainty at such small distance scales is large enough to allow tiny black holes to pop in and out of existence, creating havoc with spacetime at such small scales. This argument is the reason why people consider the Planck scale as a fundamental scale beneath which our traditional notions of physics and spacetime break down.
But why does uncertainty lead to black holes popping in and out of existence? It comes from an unchecked idea based on the Heisenberg uncertainty principle, which claims that it allows particles to pop in and out of existence, and such particles can have larger energies when the time for their existence is short enough. This hypothetical process is generally referred to as “vacuum fluctuations.” However, there does not exist any conclusive experimental confirmation of the process of vacuum fluctuations. Therefore, any idea based on vacuum fluctuations is an idea based on an unchecked idea.
Previously, I have explained that the Heisenberg uncertainty principle is not a fundamental principle of quantum physics, but instead comes from Fourier theory. As such the uncertainty principle represents a prohibition and not a license. It imposes restrictions on what can exist. Instead, people somehow decided that it allows things to exist in violation of other principles such as energy conservation. This is an erroneous notions with no experimental confirmation.
Hence, the vacuum does not fluctuate! There are no particles popping in and out of existence in the vacuum. There is nothing in our understanding of the physical world that has been experimentally confirmed which needs the concept of vacuum fluctuations.
Now, if we get rid of this notion of vacuum fluctuations, several issues in fundamental physics will simply disappear. For example, the black hole information paradox. A key ingredient of this paradox is the idea that black holes will evaporate due to Hawking radiation. The notion of Hawking radiation is another unchecked idea, which is based on …? You guessed it: vacuum fluctuations! So if we just get rid of this silly notion of vacuum fluctuations, the black hole information paradox will evaporate, instead of the black holes.