Proving quantum nonlocality, the easy way

We all know that quantum mechanics is “weird”, but it’s a lot harder to understand how we can be sure that there isn’t a “non-weird” explanation out there somewhere. Back in 1964, John Bell proved a theorem (Bell’s Theorem) that shows that if the predictions of quantum mechanics are correct, then it’s impossible for any local properties to produce the outcomes of some experiments.

Shortly after I was born, my intellectual grandfather (that is, the dissertation director of my dissertation director) together with a couple other physicists came up with an alternative version of Bell’s theorem that allowed it to be tested experimentally. (One of those other physicists, John Clauser, just got the Nobel prize for this work.) But their version is still not very intuitive.

So here’s another version that is even simpler. There’s no quantum calculations, no probilities, hardly any math — just multiplying a few positive numbers and a few negative numbers. To make it even easier, the only number we’ll use is 1. If you can multiple -1 by +1, you should be all set.

No, there’s lots of gravity in the ISS.

While taking some books out to the Little Free Library we put up, I noticed a children’s book that bugged the heck out of me when I first read it to my kid years ago.

The book is called Floating in Space, and it aims to teach kids about gravity: how it is produced by the material the Earth is made of, how gravity is weaker on the moon (because it has less material), and how you are weightless when you are floating in space — or in orbit.

And that’s where the book’s explanations go off the rails.

On Ethnic Pride and Nationalism

The other day the president of the United States told a violent group of “Western chauvinists”– the Proud Boys – to “stand by.” This has ignited several conversations in my circles about whether the Proud Boys are white supremacists, what it means to champion “Western culture,” and whether such a view implies an animosity towards other ethnicities.

I happen to be a third-generation Croatian, ethnically, but when I was growing up in California we considered ourselves Yugoslavian – because that’s what the old country was back then. We would occasionally attend events at a local Yugoslav group – a picnic, or what have you – and I was even a member of the Yugoslav choir for a bit, singing traditional Croatian songs.

In 1990, I visited Jugoslavia for the first time. This was right before the war between Croatia and Serbia broke out, and during my visit we were constantly paying attention to the news, aware that if the shooting started we might have to high-tail it to the airport to get out of the country.

Soon after I arrived, I was drinking with some locals in a pub, and I mentioned to them that I was Yugoslavian, and my family was from the area. They quickly corrected me. I was not a Yugoslav. I was a Croatian. And they welcomed me warmly because I was a Croatian.

We were brothers, children of the same nation. I was not a Yugoslav, because I was not a Serbian. Yugoslavia didn’t actually exist – you’re either a Croatian or a Serbian. You’re either with us or against us. You’re either family, or the enemy.

I think of this when I engage in these conversations about whether “white nationalists” and “Western chauvinists” are evil, or whether they’re simply proud of their ethnicity – like the “Kiss me I’m Irish,” on St. Patty’s day and the French on le quatorze Juillet.

It’s fine to be proud of America (though we shouldn’t ignore its shortcomings) and treasure one’s European heritage. I view this like my childhood experience as someone with Yugoslavian roots born and raised in the United States. I was Croatian, I was Yugoslav, I was American. There was no conflict. And, of course, there were many people of different ethnic backgrounds who were just as American as I was.

But that sort of pride is very different from white nationalism. That is more like my experience before the Croatian war of independence. There the categories are exclusive. You’re not a Yugoslav. You’re either a Croatian or a Serbian. This is nationalism. Only certain people are welcome in our nation. It’s not just pride in what I am. It’s a rejection of those who are different.

That’s what I see with the Proud Boys and their ilk. They’re not simply proud of having German or Danish roots. They think people of other ethnicities are not “real Americans.” They’re chauvinists. Male chauvinists and ethnic chauvinists.

That sort of nationalism is extremely heady and exciting; as a Croatian I belonged, and I could feel the pride and the revolutionary fever (and the slivovitz) flowing through my veins. It’s easy to see how it leads to war, and death, and fascism.

And that’s what we’re facing now in the United States.

Trump’s “Witch Hunt” Conspiracy Theory

The Inspector General of the Justice Department has released his report on the origins of “Crossfire Hurricane,” the FBI investigation into possible coordination between the Trump campaign and Russia’s election interference in 2016.

This episode has been at the heart of a number of right-wing conspiracy stories, which are frequently trotted out by Trump and his supporters to push back against everything from the Mueller investigation to the impeachment hearings into Trump’s using the presidency to get Ukraine to help his campaign.

The IG report does offer some criticism of how the FBI conducted its investigation. However, it also destroys the key pillars that Trump’s conspiracy story is built on.

Here are some of the key points that debunk the story Trump supporters are trying to spin:

1. There was a solid basis for the FBI opening the investigation.

2. The decision to open the investigation, and the decisions about how to gather information in the investigation, were not motivated by political concerns (in particular, there is no reason to believe that anything the FBI did was based on a desire to prevent or undermine Trump’s presidency).

3. While the use of “Steele Dossier” was problematic, and indicates a need to fix FBI protocols and the FISA courts, it does not show that there were no good reasons for surveilling Page (there were) or even that a FISA warrant wouldn’t (properly) have been issued even if the Steele dossier never existed.

4. The FBI did not “wiretap Trump’s phone” or “plant spies in the Trump campaign.” In short, there was no spying on the Trump campaign.

To spell all this out in more detail, let’s begin by looking at the conspiracy story that has been debunked.

Fact checking the fact-checkers

For the most part I’m glad that high-profile fact-checking has become a thing, and most of the time I think places like Snopes and the Washington Post fact checker do a good job.

But there are times when I think they go a bit off the rails.

Not surprisingly, many of the fact-checks that bother me are ones that criticize politicians I’m sympathetic with, so I need to consider the possibility that my biases are coming into play. But at the end of the day, I usually have reasons for my complaints. So let’s look at some.

Today Glenn Kessler, the Washington Post fact checker, gave Adam Schiff “Four Pinocchios” for saying, “We have not spoken directly with the whistleblower”

Articles of Impeachment

Given the current debate about whether the House should go for one quick big reason for booting Trump (Ukraine) or generate a long list of articles of impeachment, I thought it might be useful to put together a working list of impeachable offences that I recall Trump committing.

I’m sure I’ll add to it and have more to say on them (and other wrongdoings) at a later date.  

Road Trip!

Having just come back from a 1300 mile road trip, I think I can speak authoritatively here: this is the best road trip song ever.

On Bee’s Free Will

Sabine Hossenfelder, over at her Backreaction blog, is arguing for hard determinism — that is, for the claim that we don’t have free will.

She’s making the mistake that many (but not all) scientists make when they confront this question: she’s assuming that the libertarian analysis of freedom is correct, she’s not recognizing the compatibilist’s account of free will, and she’s slipping into conflating determinism and fatalism.

To quickly recap, libertarians believe that we can be free only if our decisions are not fixed by pre-existing physical laws and facts (or any pre-existing laws and facts, for that matter). If we make a free choice, they say, then it is impossible that anyone — even a Laplacean Demon — would be able to predict the action I choose. Determinism is not compatible with freedom.

Compatibilists (also known as soft determinists) argue that it doesn’t matter if our actions are the result of physical laws and pre-existing facts. The only think that matters is whether we acted because we wanted to act in that way. As long as we weren’t coerced, as long as nothing forced us to do something against our will then we acted freely. Free will is compatible with determinism.

I’ve made the case for compatibilism before, so I won’t rehash it all here. But I do want to step through and highlight the specific point where Bee (I hope Dr. Hossenfelder won’t be offended if I use her nickname in the informal context of blogging, even though we aren’t acquaintances) goes astray.

Barr Lied

The Mueller report has finally been released, and while there’s a lot in there to discuss,  there isn’t too much that we didn’t mostly know already (as I predicted earlier).

At the moment I want to focus on another issue though.  Last month Attorney General Barr refused to release the report summary that Mueller had written up, and instead issued his own summary of “principle conclusions” of the report.

It’s now clear that this was an attempt to spin the report in a way that helps Trump.  And it also turns out that this isn’t the first time Barr has pulled this trick.

As an exercise in spin, most of his claims are technically true, if one takes care to read them in a narrow lawyerly way.  It’s fair to say his presentation was dishonest, but can I really go as far as to say he lied?

Yes.  Yes, I can.  Because I stuck a marker in the ground. Let me explain:

Supermassive Black Holes Aren’t Dense

So, the big news of the day is that we have a picture of a black hole event horizon for the first time.  If you haven’t already heard, you should realize that the M87 black hole is really really big.  XKCD provides a nice comparison.  (Though you should also know that the shadow you see is about two and half times bigger than the event horizon itself, so between the orbit of Pluto and Voyager 1.)

You might think that such a massive black hole would be extremely dense.  But you’d be wrong.

Of course, the notion of the “size” of a black hole can be a bit tricky.