Comments about the article in Nature: Did Physisist create a Wormhole in a Quantum computer
Following is a discussion about this article in Nature Vol 612 8 December 2022, by Davide Castelvecchi.
To study the full text select this link:
https://www.nature.com/articles/d41586-022-04201-6
- The text in italics is copied from the article
- Immediate followed by some comments
In the last paragraph I explain my own opinion.
Reflection
Introduction
-
Physicists have used a quantum computer to perform a new kind of quantum teleportation, the ability to transport quantum states between distant places, as though information could travel instantly.
-
In principle you can have 2 qubits which are correlated, in the sense that when the state one quBit is measured 1 the state of the other quBit is measured 0.
The main issue is the coherence time, that means the time that this correlation exists.
A different issue is teleportation, the process to copy the state from one qubit to a third qubit.
The main issue is accuracy.
In both: no instantaneous action is involved. Information (?) does not travel instantaneous.
-
Quantum computers could help to develop a quantum theory of gravity in these 'toy' universes.
-
What are 'toy' universes?
A QC is in principle a calculator, to solve a specific mathematical problem. This mathematical problem can be a model of a physical process.
The question is: what is the benefit to use a QC to solve Quantum mechanical problems.
To study (quantum) gravity, to find out what it physical means, you must use the real physical universe.
-
(Developing a quantum theory of gravity for our own Universe is one of the biggest open problems in physics.)
-
Start small.
-
-
-
-
Tunnels in space-time
Physicists Albert Einstein and Nathan Rosen proposed the idea of wormholes — passages through space-time that could connect the centres of black holes — in 1935.
The question is if there exists any connection between black holes. My understanding is that there is no connections between black holes.
Exceptions are binary stars, specific when you have a combination of a large one and a small one. See also here: https://en.wikipedia.org/wiki/Cataclysmic_variable_star
Of course BH's can be in that same situation, but its explanation and behavior does not require a worm hole.
* They calculated that, in principle, wormholes were allowed by Einstein’s general theory of relativity, which explains gravity as an effect of the curvature of space-time.
This sentence is tricky. It consists of two parts:
- They calculated that, in principle, wormholes were allowed by Einstein’s general theory of relativity.
- Einstein’s general theory of relativity explains gravity as an effect of the curvature of space-time.
But what is space-time? It is a mathematical representation of our universe in 3 coordinates where the time coordinate is handled separate. In reality such an universe does not exist.
What you can do, is to draw with your finger a curved line on the flat screen in front of you, in 2D. You can also place colour points at this line, each a second apart, to show the positions, where you are and when.
You can also do that with a 3D drawing indication the positions of stars and galaxies.
See: https://www.eso.org/public/australia/images/eso0303c/
In a 3D image you can also draw a curved line, but neither that line, nor in 2D, does not show any curvature of space-time.
See also Reflection 1 - Proper Science
(Physicists soon realized that even if wormholes exist, they are unlikely to allow anything like the interstellar travel that features in science fiction.)
That is what you can call: mustard behind the meal. The concept of: Time travel, https://en.wikipedia.org/wiki/Time_travel does not belong to proper science.
From an universal point of view, the time everywhere in the universe, is the same. That moving clocks tick slower is a physical problem.
** Because the latest teleportation experiment used an exotic toy universe, it didn’t simulate anything resembling the kind of wormhole that could conceivably exist in our Universe, as envisioned by Einstein and Rosen.
This sentence does not belong to proper science. See also Reflection 1 - Proper Science.
Exotic physics
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Reflection 1 - Proper Science
Proper Science involves the way we perform science in a scientifical accepted method.
Proper science includes that we define all concepts used in a clear and unambigous manner.
The sentence * does not belong to Proper Science. In that sentence a concept that is not clear,(The ralation between wormholes and gravity.) is explained by a different concept that is also not clear. (The curvature of Space-time.)
The sentence ** does not belong to Proper Science.
- In that sentence a concept that is not clear,(the ralation between teleportation and an exotic toy universe) is explained by a concept that is also not clear. (The ralation between a wormhole and our Universe, as envisioned by Einstein and Rosen.)
).
- But here scientific reasoning raises an other doubt: maybe both concepts are not true.
Reflection 2
If you want to give a comment you can use the following form Comment form
Created: 30 March 2021
Back to my home page Index
Back to Nature comments Nature Index