## Comments about the article in Nature: Did Physisist create a Wormhole in a Quantum computer

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.

### 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. 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 that line does not show and curvature of space-time.

### 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.
A 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 something that is also not clear. (The curvature of Space-time).

### Reflection 2

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Created: 30 March 2021