Having seen what I think may be an example of quantum computing in post #516, I am wondering three things: First, who would create the software for quantum computations?, second, How would any who wanted to use it, define the data to be entered?, and third, how would the results be understood??
And now the brutal question: Just what actual value could this actually provide????

Bingo, these problems are mostly esoteric, low qubit requirement, demos designed to showcase some very narrow case where the QC might be better than a classical computer today. What it really shows IMO is how useless current systems are at solving 'real' problems because primitive technology and engineering limitations are keeping useful qubits far below the number of qubits needed to solve 'real' problems. Nobody really know for sure if the useful qubit problem can be solved in a practical manner.

 

For the case of computer driven cars, for the foreseeable future, the requirements exceed the capabilities by a large amount. THAT is the current situation. In addition, the costs presently exceed the benefits by a large amount, considering that the benefits to most people would be minimal at best.
IN ADDITION, presently the ability o produce bug-free software at a price that would be accepted simply does not exist. The testimony to that reality is the current proposed concept of automated updates for the software running the computerized cars.!!

The very acceptance of the concept of repeated automated updates admits that the software is not anticipated to be adequately reliable. So compare the inconvenience of a computer crash with the "inconvenience" of an automotive crash.

Then consider the probability of producing a few million lines of totally bug-free code.

Hi,

Well lets just hope that if the car crashes the hard drive in the computer doesn't crash

 

https://www.nature.com/articles/d41586-025-00829-2
Microsoft quantum computing claim still lacks evidence: physicists are dubious
Some attendees of a packed presentation were curious about the prospect of the first ‘topological’ qubits, but left with questions unanswered.

 

https://www.theverge.com/tech/633248/beyond-the-hype-of-quantum-computers

Drama over quantum computing’s future heats up
Physicists continue to argue over Microsoft’s qubit claims. The entire field hangs in a delicate balance.


Quantum computers won’t be able to tackle anything useful for at least another decade, says physicist Andrea Morello of the University of New South Wales in Australia. And that’s if investors don’t lose patience and jump ship. The technology remains a full-stack problem, from engineering the materials to make the qubits, to connecting the qubits together, to manufacturing the chips at scale — and not to mention software.
...
The anxiety over losing their funders’ trust has led to physicists’ current furor over Microsoft’s claims. Frolov, along with several other researchers, has spent years calling out what he said were discrepancies between Microsoft’s announcements and their experimental data. The community seems to be more receptive to critiques lately, he says.

 

https://www.eetimes.com/why-is-quantum-stuck-on-the-error-problem/
Why is Quantum Stuck on the Error Problem?

Today’s best quantum computers suffer from high error rates—of the order of one error in every few hundred operations.
...
For context, classical computers boast error rates far below one in a trillion. This disparity is not merely a minor inconvenience; it renders many ambitious quantum algorithms completely infeasible. Simply improving the quality of individual qubits, while crucial, is insufficient to bridge this gap without scientific breakthroughs.

The error rate needs to decrease to one in a million to unlock even basic applications, and a reduction to one in a trillion is required to access the transformative potential of quantum computing.

 

Quantum Teleportation Achieved Over Internet For The First Time


​

"Our work shows a path towards next-generation quantum and classical networks sharing a unified fiber optic infrastructure. Basically, it opens the door to pushing quantum communications to the next level."

 

Quantum Teleportation Achieved Over Internet For The First Time
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[QUOTE ]"Our work shows a path towards next-generation quantum and classical networks sharing a unified fiber optic infrastructure. Basically, it opens the door to pushing quantum communications to the next level."

That's pretty cool. The ability to exchange the needed photons via normal filber circuits instead of using dedicated fiber is great but quantum Teleportation has a different physics meaning from what most people think Teleportation means.

Quantum teleportation is a procedure for remotely copying the exact quantum state of one particle to another, while destroying the original state. There is no transfer of a physical object, although a pair of entangled states needs to be distributed ahead of time.

The procedure works roughly as follows:

Create a pair of quantum entangled particles in a known state, such as one of the "Bell states."
Move one of entangled particles to near the particle whose state we would like to copy (the "original"), and the other entangled particle to near the particle on which we would like to copy the state (the "copy").
Perform a set of combined measurements on original and the nearby entangled particles. This destroys the original state, but information about the quantum state of the original has been copied onto the other entangled state.
Send the outcome of these measurements to the party with the copy. These results are usual classical information ("bits") and the necessity to send them is why the procedure is limited by the speed of light.
Depending on these outcomes, perform a set operations on the combined state of the copy and its nearby entangled particle. The copy is now in the same state as the original!
Wikipedia has an excellent article with more details: http://en.wikipedia.org/wiki/Quantum_teleportation

Why do we need such a convoluted procedure to copy quantum states? The intrinsic features of quantum mechanics make the usual procedures for copying classical information unworkable for copying quantum information:

When we measure a quantum state, we only obtain a single outcome out of a probability distribution of possible outcomes. This is because quantum mechanics is probabilistic. The probability of every possible outcome would be necessary to reproduce the original state, but clearly this impossible in a single measurement.
It is also impossible to copy exact quantum states. This result is known as the "No Cloning Theorem," and it follows from the linearity of quantum mechanics. So we cannot evade the first constraint by creating many copies of an unknown state to examine in turn.

Why do we care about teleporting quantum states? Suppose we have a network of quantum computers, and we would like to save the intermediate results of a calculation on one computer to resume them on another. We could transfer physical particles encoding the particular quantum state, but transferring quantum particles without disturbing their state is very hard. A better solution is to distribute entangled particles in a generic state ahead of time, as a "resource" to enable transmitting quantum information at a later time. That's exactly what quantum teleportation lets us do.

Stephan Hoyer - Physics Ph.D, UC Berkeley


The actual Teleportation is likely someone driving a car to the remote location with the other entangled particle.

 

Quantum Teleportation Achieved Over Internet For The First Time
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https://forum.allaboutcircuits.com/...r-than-the-speed-of-light.186645/post-1955642

Thought I'd seen that before.

 

Quantum Computer Generates Truly Random Number in Scientific First


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Researchers from the US and UK repurposed existing quantum supremacy experiments on Quantinuum's 56-qubit computer to roll God's dice. The result was a number so random, no amount of physics could have predicted it.

 

WIth his protocol proof maybe but we've known that QM produced random numbers that were different for a while.
https://forum.allaboutcircuits.com/threads/how-ignorant-are-we-really.151814/post-1302934

https://arxiv.org/pdf/1004.1521
Experimental Evidence of Quantum Randomness Incomputability

Quantum randomness produced by quantum systems which have no classical interpretation is provable [4] Turing incomputable. More precisely, if the experiment would run
under ideal conditions “to infinity,” the resulting infinite sequence of bits would be Turing
incomputable; i.e., no Turing machine (or algorithm) could reproduce exactly this infinite
sequence of digits. This result has many consequence; here is one example. The experiment
could produce a billion of 0s, but not all bits produced will be 0. A stronger form of incomputability holds true: every Turing machine (or algorithm) can reproduce exactly only
finitely many scattered digits of that infinite sequence. Yet this proof stops short of showing
that the sequence produced by such a quantum experiment is algorithmically random; i.e.,
it is unknown whether or not such a sequence is or is not algorithmically random. One of
the strategies toward answering this question is to empirically perform tests “against” the
algorithmic randomness hypothesis.
Our (more modest) aim is to present tests capable of distinguishing computable from
incomputable sources of “randomness” by examining (long, but) finite prefixes of infinite
sequences. Such differences are guaranteed to exist by [4], but, because computability is an
asymptotic property, there was no guarantee that finite tests can “pick” differences in the
prefixes we have analyzed.

 

Quantum Computer Generates Truly Random Number in Scientific First
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Hi,

That's very interesting. I was kind of waiting for something like this due to the inherent nature of quantum 'probabilities' or should I say 'improbabilities'.
It's hard to get that level of randomness with electronic circuits alone. Now if we could only do this at home.

 

It's not really that hard if you don't use a deterministic classical 'computer'.

They used noise diodes, various types of (random thermal noise) devices like avalanche noise generators to create randomness in cryptographic machines and systems.
Thest types of things need to be shielded and environmentally isolated to mitigate attacks that affect the randomness in deterministic ways.

https://betrusted.io/avalanche-noise.html
https://web.jfet.org/hw-rng.html

 

https://phys.org/news/2025-04-hidden-side-channels-quantum-sources.html
Hidden side channels in quantum sources could compromise secure communication

Possible loopholes like this is why most security agencies do not use QKD. The NSA has in effect banned its use for NSS applications.

https://www.nsa.gov/Cybersecurity/Quantum-Key-Distribution-QKD-and-Quantum-Cryptography-QC/

Conclusion
In summary, NSA views quantum-resistant (or post-quantum) cryptography as a more cost effective and easily maintained solution than quantum key distribution. For all of these reasons, NSA does not support the usage of QKD or QC to protect communications in National Security Systems, and does not anticipate certifying or approving any QKD or QC security products for usage by NSS customers unless these limitations are overcome.

 

https://www.quantamagazine.org/what-is-the-true-promise-of-quantum-computing-20250403/
What Is the True Promise of Quantum Computing?

Despite the hype, it’s been surprisingly challenging to find quantum algorithms that outperform classical ones. In this episode, Ewin Tang discusses her pioneering work in “dequantizing” quantum algorithms — and what it means for the future of quantum computing.

LEVIN: So, let’s talk about that presentation. You mentioned earlier that the architects of the quantum algorithm that had made kind of a big splash were also going to be there at this workshop where you were meant to present this result that you had sped up the algorithm with equal success classically. That was not what anyone anticipated.

TANG: Yeah, it was maybe summer of 2018, I think, that I went to UC Berkeley and they were there, and some other people were there who were interested in quantum-machine-learning kinds of problems.

LEVIN: So, you’re an 18-year-old senior in college. Do they even know this? At the time?

 

The tech behind a QC.

 

 

 

I do not trust anything I see on yoo-toob, although I am aware that some of it is not faked. At least some people tell me that there is actually some useful material there.

 

I do not trust anything I see on yoo-toob, although I am aware that some of it is not faked. At least some people tell me that there is actually some useful material there.

Trust is earned, here and elsewhere.

I would trust her science based opinion on just about anything. Her personal options of some other things out of hard science are IMO questionable but that's what makes her a human and not some talking head AI droid.

 

Trust is earned, here and elsewhere.

I would trust her science based opinion on just about anything. Her personal options of some other things out of hard science are IMO questionable but that's what makes her a human and not some talking head AI droid.

Trust isn't much of a concept in science. You can take any of her controversial opinions and find equally certificated scientists who disagree with her claims.