Google Announces Quantum Supremacy Again

Google announces what appears to be quantum supremacy:

Today I’m delighted to announce Willow, our latest quantum chip. Willow has state-of-the-art performance across a number of metrics, enabling two major achievements.

The first is that Willow can reduce errors exponentially as we scale up using more qubits. This cracks a key challenge in quantum error correction that the field has pursued for almost 30 years.

Second, Willow performed a standard benchmark computation in under five minutes that would take one of today’s fastest supercomputers 10 septillion (that is, 1025) years — a number that vastly exceeds the age of the Universe.

We have been down this road before. These results are published in the Nature journal, showing that they are accepted as correct.

This mind-boggling number exceeds known timescales in physics and vastly exceeds the age of the universe. It lends credence to the notion that quantum computation occurs in many parallel universes, in line with the idea that we live in a multiverse, a prediction first made by David Deutsch. ...

Of course, as happened after we announced the first beyond-classical computation in 2019, we expect classical computers to keep improving on this benchmark, but the rapidly growing gap shows that quantum processors are peeling away at a double exponential rate and will continue to vastly outperform classical computers as we scale up.

I reported on these claims of double exponential growth back in 2019.

Have I been proved wrong? Possibly. They are still not computing anything useful, but just using the quantum computer to generate random numbers in a way that is hard to simulate in other ways. I will be interested to see what other skeptics say.

I do not think that this is any evidence for the multiverse. I will also be interested to see if the other many-worlds advocates claim this work.

Update: Gil Kalai reiterates his criticism of Google's big 2019 claim of quantum supremacy, and concludes:

I usually don’t mind “hype” as a reflection of scientists’ enthusiasm for their work and the public’s excitement about scientific endeavors. However, in the case of Google, some caution is warranted, as the premature claims in 2019 may have had significant consequences. For example, following the 2019 “supremacy” announcement, the value of Bitcoin dropped (around October 24, 2019, after a period of stability) from roughly $9,500 to roughly $8,500 in just a few days, representing a loss for investors of more than ten billion dollars. (The value today is around $100,000.) Additionally, Google’s assertions may have imposed unrealistic challenges on other quantum computing efforts and encouraged a culture of undesirable scientific methodologies.

The paper is paywalled and still being editing. All you can download is the abstract and list of about 100 Google authors.

Update: Google promotional video.

Update: Scott Aaronson comments. In short, he thinks Google made a big advance, but there is still a long way to go to get anything useful, or even a true logical qubit.

If someone thinks we’re about to get personal QCs that will speed up everything we do, they need to be told that “the age of QC” is not upon us (and indeed, might never be).

If, on the other hand, someone thinks QC is all a scam or a misconception, and quantum error-correction can never work in the real world, they need to be told that “the age of QC” is now upon us. ...

Gil Kalai #23: So we’re perfectly clear, from my perspective your position has become like that of Saddam Hussein’s information minister, who repeatedly went on TV to explain how Iraq was winning the war even as American tanks rolled into Baghdad. I.e., you are writing to us from an increasingly remote parallel universe.

Okay, tough talk, but Aaronson concedes that all Google did was to generate unverifiable random numbers. They are unverifiable because it would take a classical supercomputer longer than the lifetime of the universe to regenerate them, and there is no other way to verify them. It is not like factoring a large number, where the factorization is easy to verify.

As an analogy that someone gave, you can drop a glass vase onto the floor, shattering it into pieces, and it is nearly impossible for a simulator to reproduce what you have done. But you have not done anything useful, either.

Update: New Scientist video: Does Google’s new quantum computer prove the multiverse exists?

I think 7:57 you know the the consensus from outside 7:59 of Google is that what Harman Nan is 8:02 saying here [about the multiverse] is basically complete 8:04 nonsense okay um so I should say if 8:07 you've not heard of David Deutsch he's 8:09 he's famous for laying the theoretical 8:12 mathematical foundations for uh the 8:14 quantum theory of computation and since 8:17 the that press release mentioned him by 8:19 name I I reached out to him to ask him 8:21 what he made of that and uh you know 8:22 I've had some interaction with him in 8:24 the past and he's always been good value 8:26 once he told me that the evidence that 8:28 we live in a Multiverse is at least as 8:31 strong as the evidence that there were 8:33 dinosaurs once on Earth no I will not 8:36 allow that know that is that is also not 8:39 true yeah but I know but what a what a 8:41 fantastic quote um so you know I thought 8:44 I'd get a good response um from him but 8:46 when I asked him what he made of his 8:48 name coming up in the willow press 8:50 release he said he was the wrong person 8:52 to 8:53 ask.

Glad to see some science journalists express skepticism about the multiverse.

I have argued before that my skepticism for quantum computing is based, in part on the proponents relying on quantum interpretations that are not widely accepted. The Google announcement is an example.

Update: Dr. Bee discusses the QC multiverse claim.