Tuesday, August 14, 2018

Republican tells brazen lie while "apologizing" for telling brazen lies

Lying has apparently become endemic in the Republican party.  Florida congressional candidate Melissa Howard dropped out of the race today after being caught lying about her academic credentials:
A day after saying she planned to continue running for a state House seat despite revelations that she lied about having a degree from Miami University and went to great lengths to deceive people, Melissa Howard reversed course Tuesday and dropped out of a contest that has received national attention.
That's not so remarkable.  Politicians get caught telling lies all the time, and having to drop out of a race as a result is not so unusual.  What struck me about this episode is that Howard kept right on telling brazen lies even while apologizing for telling her brazen lies!
“It was not my intent to deceive or mislead anyone,” Howard said Monday.
Is that so?  Then why did you go to such lengths to double down on your initial lie, even going so far as to produce a falsified diploma?
Howard's troubles began when a conservative news website published a report questioning whether she had graduated from Miami University, as she claimed. 
Howard pushed back hard. She flew to Ohio to obtain her college transcripts and what she said is her diploma, displaying pictures of both online
But the story unraveled when Miami University general counsel Robin Parker sent an email to the Herald-Tribune and other media outlets saying Howard never graduated and the diploma “does not appear to be an accurate Miami University diploma.” 
Howard first responded to reports about Parker's email with a statement from her campaign manager Saturday calling it “fake news.”
If it was not her intent to deceive or mislead, what was her intent?  Of course her intent was to deceive and mislead!  Unless Howard is mentally ill, there is no other possible explanation.

Worse, despite being exposed as a liar and then piling more lies on top of her original lies, the Republican party leaders still support her:
“Honorable and smart move by Melissa Howard,” tweeted prominent GOP consultant Brett Doster...
Smart, maybe.  But honorable?  There is nothing about Howard's behavior that comes within hailing distance of honorable.

But piling lies on top of lies and calling them "honorable" is just another normal day in a party led by a pathological liar.  Lies have become the Republican party's stock in trade.  Republicans lie, and when they are caught lying they lie about the lying, and when that's not enough and they are forced to finally slink away with their lying tails between their lying legs they lie about that.

But at least they are all honourable men.

Tuesday, August 07, 2018

Trump fiddles while the West burns

Fire officials in California first started keeping records in 1932, when the Matilija fire burned 220,000 acres.  It would be 71 years before that record was broken by the Cedar fire (273,000 acres) in 2003.  That record was very nearly broken 9 years later, by the Rush fire (272,000 acres) in 2012, then it was broken 5 years later by the Thomas fire in 2017 (282,000 acres).  Now, less than one year after that, the record has been definitively shattered by the Mendocino complex fire, currently at 290,000 acres and still burning.  Of the top ten largest fires in California, eight of them have been in the last 15 years.

Meanwhile, looking at the TFR (temporary flight restriction) map, the Western U.S. looks like it has broken out in a case of the measles:

Almost every one of those red areas is a wild fire burning sufficiently out of control to require air support (there are a few exceptions where the TFR has been issued for other reasons).

Donald Trump, of course, blames all this on environmentalism run amok.  Because climate change is a hoax.  Fake news.  Nothing to see here.  It's all being obscured by the smoke.

More from the Republican hypocrisy files

Republicans are oddly selective about which parts of the Constitution they pay attention to.  A new poll shows that 43% of Republicans approve of giving the president the power to shut down the media, a clear violation of the First Amendment.

So... Republicans go absolutely apoplectic when the government threatens to take their guns, but have absolutely no problem with the government taking away their printing presses.  Apparently they think ideas are more dangerous than bullets.

Maybe they're right.

Sunday, August 05, 2018

Trump digs in deeper

Today's tweet from the Trumpster fire is essentially a confession to violating federal law:
This was a meeting to get information on an opponent, totally legal and done all the time in politics — and it went nowhere
It's true that meetings to get information on opponents are common and routine, but not when the counterparty is a foreign agent.  Then it's a crime.
It is illegal for a federal campaign to accept something of value from a foreign agent — and, according to Lawrence Noble, former general counsel for the Federal Election Commission, so is soliciting such a contribution.
It doesn't matter if "it went nowhere":
Noble said of that meeting: If members of the Trump campaign “were soliciting something of value, it may well have been illegal. If they were told, ‘You go to this meeting, and Russia will give you $2,700 for the campaign,’ and you went to that? It would be illegal — even if you didn’t get it.”
It begs credulity that Donald Trump does not know this.  If he sincerely believes that there was nothing wrong with meeting with Russians to get dirt on Hillary, why did he try to cover it up?

Pause for a moment to reflect on what we now know for certain simply because Donald Trump has publicly admitted it:

1.  There was in fact collusion between the campaign and the Russians (this is what he admitted today).

2.  Donald Trump actively tried to cover it up.

3.  Donald Trump has been continually and systematically lying about (1) and (2) for over a year.

Then on top of that there is the rather damning circumstantial evidence that Trump not only knew about the meeting, but approved it, and was gleefully anticipating the results he thought it would produce.  If it can be definitively established that Trump did in fact approve the meeting (and, come on folks, can there really be any serious doubt of that?) then that would be the smoking gun.  That is called conspiracy, and it is a crime.  This is why Michael Cohen's testimony matters.

At this point anyone who tries to defend Donald Trump is deep in tin-foil-hat territory.  All sane people know that the earth is round, humans really have walked on the moon, and O.J. did it.

And so did Trump.

Saturday, August 04, 2018

Fitch's paradox

A while back I had a private exchange with @Luke about Fitch's paradox of knowability, which I think of more as a puzzle than a paradox.  The "paradox" is that if you accept the following four innocuous-seeming assumptions:

1.  If a proposition P is known, then P is true

2.  If the conjunction P&Q is known, then P is known and Q is known

3.  If P is true then it is possible to know P

4.  If ~P is a logical tautology, then P is false not possible (and, it follows logically, also false)

Then you can prove:

5.  If P is true, then P is known

In other words, if 1-4 are true, then all truths are known.

You can digest this result in at least two different ways:

1.  It's formal proof of the existence of an omniscient being, i.e. God

2.  The conclusion is clearly false, and so at least one of the premises must be false.

If, like me, you choose to cast your lot with option 2 then it makes a fun little puzzle to try to figure out which of the premises is (or are) false.  You can read up on all of the different ways that philosophers have tried to resolve Fitch here (with some extra food for thought here).  Personally, I think the answer is obvious and simple, and a good example of why modern philosophy needs to take computability and complexity theory more seriously than it does.

If you want to try to work it out for yourself, stop reading now.  Spoiler alert.


It seems pretty clear to me that the problematic assumption is #3.  There are a lot of ways to argue this, but the one that I find most convincing is simply to observe that the universe is finite while there are an infinite number of potentially knowable truths.  Hence, there must exist truths which cannot even be represented (let alone known) in this universe because their representation requires more bits of information than this universe contains.  QED.

But the problem actually runs much deeper than that.  Notice how I had to sort of twist myself into linguistic knots to cast the premises in the passive voice.  I started out writing premise #1 as, "If you know P, then P is true."  But that raises the question: who is "you"?  The modal logic in which Fitch's proof is conducted is supposed to be a model of knowledge, but it makes no reference to any knowing entities.  KP is supposed to mean "P is known" but it says nothing about the knower.  So in the formalism it is not even possible formulate the statement, "I know P but you don't."  The formalism is also timeless.  If KP is true, then it is true for all time.  So it is not possible to say, "I learned P yesterday."  If you start with an agent-free and time-free model of knowledge then it's hardly surprising that you end up with some weird results because what you're reasoning about is some mathematical construct that bears no resemblance at all to the real world.

Real knowledge is a state of an agent at a particular time, which is to say, it is a statement about physics.  If I say, "I know that 1+1=2", that is a statement about the state of my brain, a physical thing, and more to the point, a computational device.  Hence the theory of computation applies, as does complexity theory, and my knowledge is constrained by both.  So premise 3 is not only false, but it is provably false, at least in this physical universe.

That would be the end of it except for two things: First, it is actually possible to carry out the proof with a weaker version of the third premise.  Instead of "all truths are knowable" you can instead use:
3a: There is an unknown, but knowable truth, and it is knowable that there is an unknown, but knowable truth
and still get the same result that all truths are known.  That formulation seems much more difficult to dismiss on physical grounds.  I'll leave that one as an exercise, but here's a hint: think about what 3a implies in terms of whether the state of knowledge in the universe is static or not.  (If you really want to go down this rabbit hole you can also read up on possible-world semantics of modal logics.)

Second, there is this objection raised by Luke in our original exchange:
But one can just restrict the domain to those truths we think are knowable and re-state the entire paradox. When restricted to knowable truths, the axioms lead to the conclusion that all knowable truths are already known. Surely you don't wish to accept this conclusion?
I'm going to re-state that with a little more precision:
One can just restrict the domain of the model of your modal logic to those truths that are tractably computable.  Because the proof itself is formal, it is still logically valid under a change of model domain.  When restricted to tractably computable truths, the axioms lead to the conclusion that all tractably computable truths are already known.
Again, I'll leave figuring out why this is wrong as an exercise.  Hint: look at the axioms of the modal logic of knowledge and think about whether or not the domain of tractably computable truths really is a valid model for them.

Monday, July 30, 2018

I didn't do it... but if I'd done it...

Team Trump's rhetoric is starting to sound like the Cell Block Tango.
They had it coming, they had it coming!
They had it coming all along!
I didn't do it, but if I done it
How could you tell me that I was wrong?
Seriously, go through the ten iterations (at least) of Trump's story and tell me that it doesn't remind you of those lyrics, particularly Rudi Giuliani saying, "The President wasn't in the meeting, and oh by the way, collusion is not a crime."  (So even if he had been in the meeting, what would be the big deal?)

The "they" who "had it coming", of course, are the Democrats, who are the greatest threat this country has ever faced.  Seriously, that's what Hugh Hewitt says.
Electing Democrats to a majority in the House or the Senate ... would be a disaster: Impeachment, demands for massive income tax hikes and the effort to abolish ICE would follow, while also throwing the military rebuild into reverse and the economy into paralysis because of the inability of business to predict the future with anything like certainty.
In other words: simply ignore the fact that the president of the United States conspired with a foreign power to interfere in our democratic process, that this interference very likely tipped the scales in his favor... just ignore all that.  Because the Democrats will raise taxes.

Oh, the horror.  Surely it is worth risking the legitimacy of our entire democratic process, our world-wide reputation for being the good guys, for being a nation where the rule of law applies, to keep taxes low.

Of course, the ultimate irony is that Hewitt would surely have made the exact same argument if Democrats had been the ones who lowered taxes, except that then the boogeyman would be the deficit.  Remember the deficit?  Of course you don't remember the deficit.  What deficit?  There was never a deficit.  Witch hunt.  Fake news.  Oh, look, a kitten!

Sunday, July 29, 2018

For at least one Trump voter, heaven is about new appliances

The Washington Post has a really great in-depth profile of evangelical Christian Trump voters in one small Alabama town, and Daily Kos did a terrific analysis.    There's not much I can add, except to say that I think both pieces are worth reading in their entirety, especially the original Post piece.

The part of that piece that really struck me was this:
She rubbed her sore knee, which was caked with an analgesic. 
“In heaven, I won’t have any pain,” Sheila said. 
“No tears,” said Linda. 
“I think it’ll be beautiful — I love plants, and I think it’ll be like walking in a beautiful garden,” said Sheila.  ... “I’m going to be in my kitchen,” Sheila said, imagining heaven would have one. “I think it’s going to be beautiful to see all the appliances.”
I find it soul-crushingly sad to see a human being whose world is so small that the greatest thing she can think of to aspire to even in the afterlife is new kitchen appliances.  I don't really want to judge a person's desires, but I have a hard time believing that Sheila's yearning for a new Frigidaire comes entirely of her own free will.

[UPDATE] Maybe there is a God after all, and he has a dark sense of humor.  We have a range hood which we hardly ever use.  The control panel consists of half a dozen membrane type-buttons all in one monolithic unit mounted inside a slot cut into the hood's a stainless steel housing.  This evening I was making dinner and the lights in the range hood started to flutter on, like a scene out of a B-horror movie.  I went to push the button on the panel to try to turn the lights off (they were already off, at least as far as I knew) and the whole panel popped off and vanished inside the unit (it was apparently attached with epoxy) with the lights now on full bright.  I had to pop the circuit breaker to turn the lights off.  So maybe heaven is a kitchen full of new appliances with life-time warranties.  In an eternal afterlife, that would be a helluva deal.

Fire TFR update: from bad to worse

A week ago I reported on an unprecedented number of fire-related temporary flight restrictions in southern Oregon.  This is what the situation looked like this morning:

As you can see, what used to be half a dozen separate TFRs (temporary flight restrictions) have merged into one monster TFR (though they are still officially listed separately).  And it's still only July.  It will likely be at least 2-3 months before it rains.  Welcome to the new normal.

Saturday, July 28, 2018

The Republican's three-step plan

Republicans have a three-step plan to try to protect Donald Trump from facing the consequences of collaborating with the Russians.

Step 1: Deny that it happened (c.f. "Witch hunt")

Step 2: When there is evidence that it happened deny the evidence (c.f. "Fake news")

Step 3: When the evidence becomes undeniable, deny that it was ever a big deal.

To those currently implementing step 3, I pose the following question: if it was never a big deal, why bother with steps 1 and 2?  Why not just come right out and admit it from the beginning rather than attempt to cover it up?  Enquiring minds want to know.

The wheels on the bus go round and round

I don't know if the wheels are actually coming off the Trump bus yet, but at least a few of the lug nuts might be starting to loosen up a bit.  It has been pretty clear from the outset that Donnie pater not only knew about the Trump Tower meeting before it happened, but was eagerly anticipating its results.  The Trumps have been digging themselves into a pretty deep hole by insisting otherwise, and that hole has now gotten a lot deeper now that Michael Cohen has flipped because the evidence of Trump's malfeasance is no longer purely circumstantial.  At the very least, at some point Trump is going to have to answer the question: what exactly were the circumstances that led you to say this on June 7, 2016:
“I am going to give a major speech on — probably Monday of next week [June 13] — and we’re going to be discussing all of the things that have taken place with the Clintons,” Trump said. “I think you’re going to find it very informative, and very, very interesting.”
And also, what were the circumstances that led you not to follow through on that promise?  Was it purely coincidence that that the June 9 meeting, which produced no results, just happened to take place between when you promised a "major speech" about the Clintons and when you failed to follow through on that promise?  If it wasn't the Tower meeting that led to all that, what was it?

I can't help but marvel at the irony that Trump, the supposed master negotiator, may be brought down by the incredibly stupid mistake of promising something before he was sure he could deliver it.  If he hadn't done that, he might have been able to maintain plausible deniability.  Sometimes you have to take risks, but the Second Rule of Business is that you should only take risks when you have to. Trump didn't have to.  He could have waited two days until he knew if the meeting was going to be fruitful or not.  But Trump has the patience of a six-year-old, and so he took this risk gratuitously and recklessly simply because he felt like it, and thus gave up plausible deniability.  What a maroon.

In other news, some Republicans are starting to call for Trump's impeachment.

Friday, July 20, 2018

I've never seen anything like this before

Speaking of ominous developments, have you noticed how much  more often you hear the phrase, "I've never seen anything like this before" in reference to the weather nowadays?  Well, now it's my turn.  For those of you who don't know, I'm a private pilot.  I got my license in 1996 so I've been flying for over 22 years.  This is a map of south-western Oregon as it showed up on my flight planning software this morning:

(This is not what I would actually look at to plan a flight.  I've turned off all the aviation-y things that would normally show up, like airports.)

See those red circles?  Those are Temporary Flight Restrictions, commonly known as TFRs.  They are places you can't fly for various reasons, like if the President is in town.  But those are not presidential TFRs, they are fire-fighting TFRs.  Those are not uncommon this time of year, but usually there are only one or two of them in any given area.  Today in this part of Oregon alone there are ten.

I've never seen anything even remotely like this before.

Three ominous developments

Ominous development #1: Bank of America (and, apparently, only BofA) has started asking its customers whether or not they hold a dual citizenship.

Ominous development #2: The Trump administration is moving aggressively to strip U.S. citizenship from anyone who lied on their application, even if the lie was immaterial or inadvertent.  The last time anything like that happened was during the McCarthy era.

Ominous development #3: The Washington Post published an op-ed by a former Trump administration official arguing that birthright citizenship is a "historical and Constitutional absurdity" and should be abolished.  To defend this position he has to argue, of course, that the Fourteenth Amendment doesn't actually mean what it plainly says, what the people who wrote it said it says, and what everyone has agreed for 150 years that it says.  But we've known for a long time that those who travel in Trump's circle have no qualms about rewriting history.

I think there's a quietly hatched plot somewhere deep inside the vast right wing conspiracy to eviscerate the fourteenth amendment and expand the government's power to strip people of their citizenship beyond all historical precedent.  It is, of course, all based on lies, but that is just a standard part of the right's play book.  They have used this strategy very effectively to move the needle on gun rights and abortion, so there's no reason to believe it won't succeed on citizenship.

Anyone who has any kind of paper trail linking them to another country should be very afraid.  You may have a dual citizenship and not even know it.  You may not even be able to renounce it once you find out.

My grandfather had no idea he was a Jew until the Gestapo knocked on the door one day and told him.  This is how these things begin.

Wednesday, July 18, 2018

Republican voters are completely insane

If you were hoping that Helsinki might be Donald Trump's Joseph-Welch moment, think again.  Donald Trump will not suffer any negative consequences from his disastrous and treasonous remarks.  This is why:
A new tracking poll from Reuters/ Ipsos on Tuesday showed that rank-and-file Republicans not only continue to support President Trump but refuse to believe he’s doing anything wrong. The most galling number from the survey is: 71 percent of Republicans approve of Trump’s handling of Russia... 
Overall, more than half of those polled (55 percent) disapproved of Trump’s handling of Russia and agree (59 percent) with U.S. intelligence findings about Russian attempts to tamper with the 2016 election. But, also worrying, is the fact that only 32 percent of Republicans believe that Russia attempted to intervene in the election.
This is really getting scary.  I used to think that Trump's claim that he could shoot someone in Times Square and get away with it was hyperbole.  I'm not so sure any more.

Tuesday, July 17, 2018

I don't even know what to say here

Oh my.  Sharp-eyed CNBC reporter Christina Wilkie noticed that in a photo of the written prepared remarks of Trump's lame rollback of his catastrophic Helsinki news conference, there was a line that was crossed out.  But it wasn't crossed out all the way, you could still see what it said in the image.

Here's a close-up (flipped 180 degrees so the text is right-side-up):

It says, "Anyone involved in that meddling to justice."  (Obviously, the words "should be brought to" can be interpolated there.)  So now we know that Trump specifically does not want to see the people who attacked the U.S. brought to justice.  Gee, I wonder why.

On a not-wholly-unrelated note, former CIA director John Brennan pointed out that having a private meeting with Putin on his home turf with no one else in the room might not have been the brightest thing Donald Trump has ever done because Putin may have recorded the private conversation (gee, ya think?) and Trump may have said something stupid (gee, ya think?) that Putin can now use as leverage against him.

(This just occurred to me: Trump's lawyers are fighting tooth and nail to keep him from having to talk to Robert Mueller because they just know that if he does Trump will say something stupid.  But they were on board with having him give two hours to Vladimir Putin behind closed doors?  What were they thinking?)

A worst-case scenario is starting to look frighteningly plausible.

But what about the witch hunt?

Donald Trump is frantically backpedalling on his treasonous remarks at yesterday's Helsinki news conference.
“The sentence should have been, ‘I don’t see any reason why it wouldn’t be Russia.’ Sort of a double negative,” Trump told reporters. “So you can put that in, and I think that probably clarifies things pretty good by itself.”
In other words, Donald Trump wants you to believe that what he meant to say was the exact opposite of what he actually said.

OK, let's give the man the benefit of the doubt.  It's a high-pressure situation.  He's old and has no stamina.  The difference between "would" and "wouldn't" isn't all that big (except for, like, being antonyms, but why split hairs?)

So now he accepts that Russia might have interfered with the 2016 election.

So, um, what about the witch hunt?

Remember the witch hunt?  Donald Trump has been tirelessly flogging two mantras since the day Robert Mueller was appointed in the wake of Trump's firing of James Comey: 1) there was no collusion between the campaign and the Russians, in no small measure because 2) the whole investigation was a witch hunt.  There is nothing for Mueller to find, no wrong doing of any sort by any party.  The whole investigation should be shut down with all deliberate speed.

But now:
I accept our intelligence community’s conclusion that Russia’s meddling in the 2016 election took place.
That is a major concession.  That is an acknowledgement that the investigation was not a "witch hunt", that we really were attacked by a foreign power.   So does that mean that Trump is contrite for having made such an egregious mistake?  Does that mean that he is now going to take the Russians to task for attacking us?  Hell no.
"Could be other people also. A lot of people out there,” Trump said, reading mostly off a sheet of paper, before a meeting with Republican members of Congress at the White House.
And of course, there is still Mantra #1:
“There was no collusion at all,” he added, dismissing the notion that his campaign coordinated with Moscow in 2016.
 So let's take stock.  The President of the United States has now acknowledged that:

1.  We were in fact attacked by Russia, and that therefore...

2.  He was wrong when he repeatedly called the Mueller investigation a witch hunt.  However...

3.  He has not yet explicitly acknowledged #2.  In fact, to the contrary, he is still trying to deflect attention away from Russia by suggesting on no evidence whatsoever that it "could be other people."

And yet, he still expects us to take him at his word that there was "no collusion" between the campaign and Russia.  You know what?  It's a moot point.  There is open collaboration between the Trump administration and Russia!

Imagine if Hillary or Obama had done what Trump is doing.

Remember this day

If you remember nothing else about this extraordinary time in American history, remember this day, and remember this quote: “Dan Coats came to me and said they think it's Russia.  I have, uh, president Putin, uh, who just said it's not Russia.  I will say this, I don't see any reason why it would be."

Let that sink in.  "I don't see any reason why it would be."

So... president Trump does not accept Russian interference in the 2016 election even as a hypothetical possibility, let alone as a by now excruciatingly well-documented fact.  He can't think of any reason why Russia might want to interfere with our election, never mind that Putin admitted in that very same news conference that he wanted Trump to be president.  And then there is the fact that his own intelligence agencies say that Russia interfered, members of his own party say Russia interfered.  Russia's innocence is less tenable than O.J. Simpson's.

The Constitution defines treason as "adhering to [the] enemies [of the United States and] giving them aid and comfort."  If this isn't treason, I don't know what is.

There are clearly only two possible outcomes now: either Donald Trump will go down in screaming flames, or the United States of America will.  There are no other options left at this point.  Trump's supporters need to think long and hard about which option they prefer as they decide what to do next.  This is about to get seriously ugly.

Wednesday, July 11, 2018

Roe is a distraction. The real problem is much, much worse.

The United States of America has always had a somewhat tenuous relationship with its own ideals.  The disconnect between "We hold these truths to be self-evident, that all men are created equal" on the one hand, and chattel slavery on the other, cannot result in anything other than some pretty severe cognitive dissonance.  But despite being deeply rooted in contradictions, the history of this country has nonetheless been one of steady (albeit all too often agonizingly slow) progress towards greater personal freedom and empowerment for all of its people, indeed for all of the people of the world.

All of this social progress has been built on a foundation of material prosperity driven by industriousness and technological advancement, which, in turn, was built on a bedrock of respect for objective truth.  We were able to invent the airplane and the transistor and put men on the moon not because "We're America, bitch", but because we had people who understood physics (and political science!), an understanding which once commanded respect.

No more.

Liberals should not delude themselves: Brett Kavanaugh will be confirmed to the Supreme Court, whereupon 242 years of social progress will begin to be methodically and deliberately unmade.  It has already begun, with the recent evisceration of the power of labor unions.  Roe v. Wade will probably be next to go; even if the court doesn't reverse it outright, they will twist the meaning of "undue burden" beyond the recognition of native English speakers.  And conservatives will celebrate, blissfully unaware that they have been the victims of an elaborate con.

You see, the fact of the matter is that opposition to Roe has nothing to do with a principled stance of defending a "right to life."  It is perfectly evident to anyone who looks at conservative policies today that they don't really care about life, they only care about birth.  If they really cared about life, they would care about health care and early childhood development and public education, and not ripping children from their parents.  But they don't.  After a woman has given birth, both she and her baby can go to hell for all that modern conservatives seem to care.

What is less evident is that even the semi-plausible concern for the "rights of the unborn" is a recent invention.  Modern conservatives would have you believe that Roe was a fringe decision that was immediately controversial.  It wasn't.  It was a 7-2 decision, and it was years before anyone thought to try to get it overturned.  And even then it was not a principled stance fighting for the "rights of the unborn" (what's next, fighting for the rights of the unconceived?), it was a cynical ploy to try to unite Protestants and Catholics to get them to vote for political candidates who would support segregation and be friendly to business.

All this is academic, though, because the abortion debate has been successfully and irredeemably (and, let is be ever-mindful, falsely) framed by conservatives to advance a wholly different agenda.  But the loss of personal reproductive freedom is just the tip of the iceberg.  In order to achieve this victory, conservatives have made a deal with the devil.  In exchange for lower taxes and less regulation and less government constraints on racial gerrymandering, they abandoned the truth.  They have allowed all manner of crackpottery -- birtherism, misogyny, and a dizzying variety of denialisms, from climate change to the Holocaust -- to don the mantle of respectability.  And that will ultimately cost us much, much more than our freedom.

To cite but one example which is not, as far as I can tell, on anyone's radar screen, having been totally eclipsed by all the hysteria over abortion (which is exactly what conservative strategists intended, by the way): Brett Kavanaugh has expressed the view that internet service providers have a first-amendment right to exercise editorial control over the content they deliver, and so it is not only wrong as a matter of policy for the government to impose net-neutrality rules, it is unconstitutional.

The utter absurdity (to say nothing of the extreme danger) of this position should be immediately obvious, and it would be immediately obvious if we still lived in a society that valued truth and education, but we don't.  Kavanaugh's argument is that the Internet is like cable TV: because a cable operator can decide what channels to offer, and ISP should be equally free to decide what web sites its users should be allowed to access.

That might be a valid argument if the internet had been privately developed, but it wasn't.  The internet was developed by the government with taxpayer dollars, which is to say, by the People.  There are other fundamental structural differences between cable TV and the Internet too: cable TV providers typically have to pay for content.  ISPs don't.  Furthermore, cable TV providers are subject to government regulations on what content they carry, and have been since their inception.

Brett Kavanaugh would throw all that precedent out the window and put both cable TV and the internet forever out of the reach of public regulation by declaring both to be morally equivalent to printing presses.  Except that they aren't.  The internet in particular is not a printing press.  Web servers are (the modern equivalent of) printing presses.  The internet is not the means of producing content, it's the means of delivering it.  It is the modern equivalent of the postal service, access to which is enshrined in the Constitution as a public right.  (Originalists insist that the Constitution keeps pace with technology when it comes to weapons, but not when it comes to communications.  Originalists are hypocrites.  What else is new?)

I am able to write this blog and you are able to read it only because of net neutrality.  Yes, this blog is hosted by Google, but if Google tried to shut it down I could move it somewhere else.  That is the beauty of the internet.  It enables free speech like nothing else before it in human history, not even the printing press.  But if your ISP decides to block access to blog.rongarret.info then there is nothing you or I could do about it.  That would be the very antithesis of free speech.  Editorial control is something that should be practiced by content producers, not distributors.  Editorial control practiced by content producers is free speech.  Editorial control practiced by distributors is censorship.

Brett Kavanaugh either does not understand this, or he does and is willing to intentionally disregard this truth to promote the business interests of large telecommunications companies.  Either way, it should disqualify him from a seat on the U.S. Supreme Court.  But I haven't heard any politician or advocacy group advance this argument.  Everyone is acting like deer in the headlights of Roe v. Wade.

The abortion debate was never anything more than a cynical ploy by conservatives to get people who care about freedom, social progress, and truth to take their eye off the ball.  And you know what?  It worked.

Thursday, July 05, 2018

Trump is a personality cult

If you want proof that Donald Trump has become a cult of personality look no further than this story in the LA Times:

Workers in this town may become victims of Trump's trade war, but they're behind him 'no matter what'

Jimmie Coffer, a machine programmer at the nation’s largest nail-making plant, voted for Donald Trump partly because he was confident he would bring manufacturing jobs back to America. 
So the 39-year-old factory worker was shocked last month when 60 of his co-workers were laid off after the Trump administration imposed a 25% tariff on the steel his company imports from Mexico. Now, as his bosses cut back hours and warn they may have to let 200 more workers go in the coming weeks, he worries he may lose his job as a result of the president’s policies. 
But Coffer is still gung-ho about Trump. 
“I support him 100%,” he said last week. “In fact, I’d like to shake his hand. He’s doing a great job.”
So... Donald Trump is enacting policies that have the exact opposite effect of what they were supposed to have; instead of promoting manufacturing in the U.S., Trump's tariffs are actually pounding the last nail into its coffin.  And yet, the victims of this economic destruction still support Trump "no matter what".  Simply because he's Trump and not Obama.  That is the very definition of a personality cult.

I try to be respectful of other people's point of view, but I am having a really hard time marshaling any sympathy for people like Coffer.  Anyone who follows a person "no matter what", even to their own manifest financial ruin, deserves what they get.

I wonder... when Coffer and all of his friends and neighbors are out of work and have depleted their life savings and are living on the street (because, you know, the social safety net is an evil liberal conspiracy), will they still be following Trump "no matter what"?  Is there really no price too high to pay to have a white guy in the oval office?

[UPDATE]: Just now stumbled across this:
Conservative radio show host Joe Walsh said Thursday that he’s “pretty damn sad” some of his callers dismiss President Trump’s “lying” because he’s “their guy.” 
“On my radio show earlier this [week], I asked Trump supporters if they were ok with Trump lying so much,” Walsh said in a tweet. “I told them that I wasn't.”  
“The consensus? The vast majority of callers said they're ok with all Trump's lying because he's ‘their guy,’ ” Walsh continued. “Their response left me pretty damn sad.”
To which I say:  I'm pretty damn sad about it too, Joe.  Now, how about taking some personal responsibility for the world you and your fellow conservative talk show hosts have helped to create?

Monday, June 18, 2018

Damn straight there's a moral equivalence here

Germany, 1945:

The United States of America, 2018:

It's true, the kid in the second picture is not being sent to the gas chambers (yet).  But here's the thing: she doesn't know that!  This kid is two years old.  All she knows is that her mother is being taken away, and she may or may not ever see her again.

The government of the United States of America has run completely off the rails, and it has done so at the behest of its president, Donald J. Trump.  There is no law requiring children to be separated from their parents.  Donald Trump says there is, and he says that this non-existent law has something to do with Democrats, but as with nearly everything that comes out of his mouth, these are lies.  Children are being treated inhumanely because Donald Trump wants it that way.  He's using them as a kind of sick bargaining chip.

Donald Trump is able to do this because Republican members of Congress fear losing their jobs if they stand up to him, and not without cause.  Ultimately, Trump's power is rooted in tens of millions of American citizens who support him, whether tacitly or overtly.  If you are one of them, remember: this kid is two years old.  She may be here illegally (or maybe not -- a lot of these immigrants are legally seeking asylum) but she doesn't know that.  What is being done to her is monstrous, and it is ultimately possible only because of you.  If you vote Republican this November, the damage to these innocent kids' psyches, and the blood that is shed when they are shipped back to the gang-infested countries they fled from, will be on your hands.

Saturday, June 16, 2018

Suffer the little children

Nothing illustrates the complete moral and intellectual bankruptcy of Donald Trump's supporters, apologists, and enablers better than Jeff Sessions's Biblical justification for separating children from their families:
“I would cite you to the Apostle Paul and his clear and wise command in Romans 13, to obey the laws of the government because God has ordained the government for his purposes,” Sessions said during a speech to law enforcement officers in Fort Wayne, Ind. “Orderly and lawful processes are good in themselves. Consistent and fair application of the law is in itself a good and moral thing, and that protects the weak and protects the lawful.”
Perhaps Sessions has forgotten that the Holocaust was conducted entirely in accordance with German law?  Or that American slavery was likewise according to law (and Biblically justified by the very same passage that Sessions invoked)?  Or that Otto Warmbier was tortured to death in strict accordance with North Korean law?  Or is he seriously suggesting that it is the Will of God that we meekly accept these atrocities?

I'm frankly surprised that Sessions decided to invoke Romans rather than Mark.  After all, Jesus himself says that the little children should suffer.  If you're going to pervert the message of the Bible why not go all-in?

Wednesday, June 13, 2018

Trump makes it look easy

One has to wonder, after Donald Trump's tidy wrapping-up of the North Korea situation (he did everything short of come right out and say "peace for our time!"), what all the fuss was ever about.  It took only a few months (or forty minutes, depending on how you count) to go from the the brink of nuclear war to BFFs.  Today the U.S. seems to be getting along better with North Korea than with Canada (or, frankly, any western nation).  If dealing with North Korea was that easy, why hadn't anyone done it before?  Maybe Donald Trump really is the master negotiator he portrays himself to be?

Um, no.  The outcome of the Singapore summit is just another Trump flim-flam, and not just because the only tangible result it produced was a major unforced error by the U.S.  Imagine if Barack Obama had done what Trump just did.  The exact same words spoken, the exact same outcomes.  What would be the Republican's response?

Happily, we don't have to imagine it.  We know exactly what their response would be, because we know what their response was when Obama produced an actual verifiable deal for Iran to give up its nuclear weapons.  They were absolutely apoplectic about that.  It was a terrible deal!  So bad that it had to be unilaterally torn up and re-started from scratch.

But the North Korea non-deal?  The unilateral cessation of war games with no corresponding concessions from the North Koreans?  The Orwellian re-writing of North Korea's atrocious human rights record?  That is masterful statecraft.  Because that was done by Trump and not Obama!

There was a time when politicians put country before party.  In the 1970s, Congress overrode Richard Nixon's veto to pass the Clean Water Act.  (Imagine that happening today!)  Then a few years later, the Senate voted 77-0 to establish a select committee to investigate the Watergate scandal.  (Ditto!)  Donald Sanders, the man who discovered the existence of the Watergate tapes and arranged for that knowledge to become public, without whom we would never have known that Richard Nixon was, in fact, a crook, was a Republican.

Those days are long-gone.  Today's Republicans stand for party loyalty over country, over the truthueber alles.  Everything Obama did is bad.  Everything Trump does is good.  Never mind the actual merits, what matters is that Trump "succeeded" where all of his predecessors failed.  Especially Obama.  Oh yes, especially that illegitimate un-American Muslim-loving Barack Husssssssein Obama!  Thank God that nightmare is finally over!

Sunday, June 10, 2018

If the shoe fits

Fox-and-Friends host Abby Huntsman, in a rare moment of lucidity, today referred to the upcoming summit between Donald Trump and Kim Jong Un as "a meeting between two dictators".

The best part is that nobody on the show seemed to notice, perhaps because there is such a thick pile of lies and self-deceptions that Trump apologists have to keep track of that sometimes the truth can slip through the cracks.

Wednesday, June 06, 2018

PSA: Blogger comment notifications appear to be kerfliggered

I normally get an email notification whenever anyone posts comment here, but I just noticed that this feature doesn't seem to be working any more.  I hope this is temporary, but I wouldn't bet my life savings on it.  I don't think the Blogger platform is a top priority for Google.  So until I can figure out what to do about it just be aware that I might not be as responsive to comments as I usually am.  It's not because I don't love you any more.

Tuesday, June 05, 2018

SCOTUS got the Masterpiece Cake Shop decision badly wrong

The Supreme Court issued its much-anticipated decision in the gay wedding cake case yesterday.  It hasn't made as much of a splash as expected because the justices tried to split the baby and sidestep making what might otherwise have been a contentious decision.  But I think they failed and got it wrong anyway.

The gist of the ruling was that Jack Phillips, the cake shop owner, wins the case because the Colorado Civil Rights Commission exhibited "hostility" towards Jack Phillips religion when its members failed to contest the following statement made by one of its members:
I would also like to reiterate what we said in the hearing or the last meeting. Freedom of religion and religion has been used to justify all kinds of discrimination throughout history, whether it be slavery, whether it be the holocaust, whether it be—I mean, we—we can list hundreds of situations where freedom of religion has been used to justify discrimination. And to me it is one of the most despicable pieces of rhetoric that people can use to—to use their religion to hurt others.
About which the Court's opinion says:
To describe a man’s faith as “one of the most despicable pieces of rhetoric that people can use” is to disparage his religion...
But the statement does not describe Jack Phillips faith as  "one of the most despicable pieces of rhetoric that people can use."  What is despicable is not Phillips's faith, it is the use of that faith to hurt others which is being said to be despicable.  (And it is.)

The opinion goes on:
The commissioner even went so far as to compare Phillips’ [sic] invocation of his sincerely held religious beliefs to defenses of slavery and the Holocaust. This sentiment is inappropriate for a Commission charged with the solemn responsibility of fair and neutral enforcement of Colorado’s anti- discrimination law—a law that protects discrimination on the basis of religion as well as sexual orientation.
Again, it is very important to distinguish between two very different things.  It would indeed be inappropriate to compare Phillips's specific claim to slavery or the holocaust.  There is absolutely no moral equivalence there.  But again, that is emphatically not what the CCRC commissioner's statement says.  That statement is making the general observation that, historically, atrocities have been justified on religious grounds.  And that is simply a fact.

Ultimately this opinion is a reflection of Christian Persecution Complex, the unfounded belief held by many Christians in the U.S. that the mere existence of public critiques of Christianity is an attack and potentially an existential threat.  To say that Christianity was overtly used as a justification for slavery in the U.S. is disparagement and conclusively indicative of covert and nefarious bias, never mind that this is in fact demonstrably true.  The First Amendment apparently protects people from hearing anything unpleasant said about their religion by a government agent, even if those things are factually correct.

I do respect the Court's attempt to thread the needle here and come up with an inclusive ruling that would leave neither gays nor Christians out in the cold.  Unfortunately, it's simply not possible in this case.  The sad fact of the matter is that Jack Phillips and his ilk are simply on the wrong side of both history and morality, just as the defenders of slavery and segregation were in their day.  There is nothing wrong with being gay, just as there is nothing wrong with being black.  Discriminating against gay people is every bit as wrong as discriminating against dark-skinned people, notwithstanding anything you may believe, however sincerely, about what God has to say about it.

Thursday, May 24, 2018

Blame where it's due

I can't say I'm even a little bit surprised that the summit with North Korea has fallen through.  I wouldn't even bother blogging about this except that back in April I expressed some cautious optimism that maybe, just maybe, Trump's bull-in-the-china-shop tactics could be working.  Nothing makes me happier than having my pessimistic prophecies be proven wrong, but alas, Donald Trump seems to be every bit as catastrophically incompetent and destructive as I feared.

Let's take stock: a year and half into his presidency the number of foreign policy deals closed by this supposed master negotiator is... zero.  But he has, however, apparently succeeded in strong-arming the NFL into joining him in his perversion of patriotism and evisceration of the first amendment.

I would say that Trump is all hat and no cattle, except that in this case it would be an insult to hats.

[UPDATE] Have I changed my mind now that the on-again off-again summit is (apparently) on again?  No, I have not.  Why?  Because by keeping his cool, not throwing a temper tantrum, and not offering any major concessions, Kim called Trump's bluff.  And Trump, by reinstating the summit without extracting any major concessions from Kim, folded like a cheap suit.  Now Kim knows that Trump desperately wants a deal.  (If Obama got a Peace Prize, Trump has to have one too!)  That gives Kim the upper hand in the negotiations (to put it mildly).

Trump has apparently completely lost sight of the fact that simply being in the same room with the President of the United States is a huge win for Kim.  Trump, the master negotiator, is handing Kim that win with nothing at all to show for it.  So no, I am not impressed.

Thursday, May 10, 2018

A quantum mechanics puzzle, part drei

[This post is the third part of a series.  You should read parts one and two before reading this or it won't make any sense.]

So we have two more cases to consider:

Case 3: we pulse the laser with very short pulses, emitting only one photon at a time.  This is actually not possible with a laser, but it is possible with something like this single-photon-emitting light source (which was actually case 5 when I first made up the list).

Before analyzing this case I have to hedge: I'm pretty sure I know the right answer, but not 100%.  I have actually asked one of the authors of that paper to confirm my suspicions but he's busy and so it will be a while before I expect to get an answer.  If his answer turns out to be substantially different from what I say here I will definitely let you all know.

So with that disclaimer in mind, I'm quite confident that this case will turn out to have the same behavior as the case where we have a laser dimmed by a filter, and the photon emissions post-filter detected using a parametric down-converter, i.e. there will be no (first-order) interference (with one exception, which will arrive at in case 4).  The reason I'm confident is that this case is structurally the same as that one: we have made a modification to the experiment that allows us to know when the photon was emitted, which allows us to determine which path the photon took by comparing departure and arrival times, and so there can be no interference.  Please note that I have taken pains not to say that our (potential) knowledge of the emission time causes the interference to go away.  It doesn't.  What causes the loss of interference is the entanglement of the photon with something else.  Entanglement is a pre-requisite for measurement, which is a pre-requisite for knowledge, so it is true that if there is (potential) knowledge that there can be no interference, but the knowledge bit is a red herring.  The only reason I'm using that phraseology is that it is, sadly, ubiquitous in QM pedagogy.

So, with that out of the way, let us proceed to the interesting case:  We turn the laser on and off with a duty cycle of 50% and a period that is long enough that the pulses actually do produce interference.  The lengths of the arms of the interferometer are adjusted so that the Nth pulse coming from the long arm exactly coincides at the detector with the N+Kth pulse coming from the short arm for some integer K>=1.

Before I go into detail on this I want to say a word about how practical such an experiment might be. To make this work, the period of the pulses has to be long enough that the individual pulses are coherent, but short enough that we can "store" at least one them "in flight" while waiting for the next one without losing coherence.  Can this actually be done?  Yes, it can, at least if you believe Wikipedia.  There is says that fiber lasers can be built with coherence lengths exceeding 100km.  That's about 300 microseconds, which is essentially forever by the standards of quantum optics.  You could actually do this experiment with a regular semiconductor laser with a coherence length of "merely" 100m.  It's pretty straightforward to power-cycle a laser, produce time delays, and measure the results with events happening at nanosecond/meter scales.  So this would not even push the boundaries of the state of the art.

There is no doubt what would happen in this case: you would see interference, but (and this is really important) only after the Kth cycle.  Before that we know that all of the light at the detector arrived via the short arm, so there is no interference.  After the Kth cycle, light is arriving from both arms, so we do get interference.  There would be some transient effects at the beginning and end of each pulse, but at steady-state the interference would be easily detectable.  This is predicted both by quantum theory and classical E-M theory.  There is absolutely nothing interesting going on here, until, that is, you make one more little modification: in addition to a 50% duty cycle, you also dim the laser with a filter.

The outcome predicted by QM is clear: dimming the laser with a filter makes no difference.  Whatever we saw when the laser was bright we should also see when the laser is dim, namely, for the first K cycles of the laser we get no interference.

How is this possible?  The dramatic narrative of interference usually goes something like this: interference happens when a photon (or some other particle, it doesn't really matter) is placed in a quantum superposition, usually a quantum superposition of physical locations.  The usual slogan is "the photon goes both ways".  The two paths are then brought together in such a way that no which-way information is available in the final state.  The result is interference.

But can this possibly be happening in this case?  The two paths that the photon can take are separated by an enormous amount of time, big enough that we are able to turn the laser off and back on while we are waiting for it to travel the long way 'round through our interferometer.  It's already enough of a mind bender to say that we cannot know when a particular photon was emitted when the laser is on continuously, but now we seem to be going a step further: in order to have interference, we cannot even know which power cycle a detected photon was produced by!  Is it really possible for a laser to produce a photon that is in a quantum superposition across power cycles?  That seems extremely improbable.  Surely once you turn the laser off, the universe is committed: there's a batch of photons flying through space at the speed of light in some particular quantum mechanical configuration.  Surely that configuration can't be changed by something that happens (or not -- we could choose at any time not to turn the laser back on!) in the future?

There is another possibility.  Maybe the interference we see is not created by one photon interfering with itself, but rather interfering with another photon produced in a different cycle.  This seems a lot more plausible, but is it actually possible?  Paul Dirac, one of the founders of quantum theory, once famously wrote “...each photon then interferes only with itself.  Interference between different photons never occurs.”  Interestingly, while I can find this quote all over the internet, and it is invariably attributed to Dirac, I cannot locate its original source.  So it's possible that this quote is apocryphal.  But it doesn't matter.  What matters is that this sentiment was taken seriously for decades until an experiment by Magyar and Mandel debunked it in 1963.  There have been books written about, and even entitled, multi-photon interference.  So it's definitely a thing.

The experiment as we have described it to this point is an interesting variant on the Magyar and Mandel experiment.  There they used two different lasers (actually they were masers, but it doesn't matter) to generate their photons, whereas we are using one laser and separating the production of the two photons by time using power cycles and bringing them back together using delay lines.  But it amounts to the same thing.  The key is that we're bring the photons back together at the same time.  That's the reason that the delay time in the interferometer is an integer multiple of the cycle time on the laser, otherwise it doesn't work.

So this might be a mildly interesting but not earth-shattering result.  Maybe someone has even done it, I don't know.

But there is one thing that should make us a little queasy about this line of thought, and that is that we cannot actually control how many photons enter the interferometer on any given cycle.  We can attenuate the beam so that on average we get one photon per cycle, but that will only be an average.  Some cycles we will get more than one, some cycles we will get none.  If we're depending on photons to interfere with each other then we need the same number of photons each cycle, otherwise some photons won't have partners to interfere with.

In fact, we can actually completely eliminate the possibility that what we see is multi-photon interference simply by making the laser even dimmer.  Let's attenuate the laser to the point where, rather than of one photon every cycle, we instead get one photon every 2K cycles (or more).  In other words, most of the time the interferometer is totally dark.  Every now and then we will get a photon.  The temporal separation between photons is now much more than the coherence time of the laser, much more than the cycle time of the laser, much more than the travel time through the long arm of the interferometer.  We can make it an hour or more between photons.  Theory predicts that we will still see interference!  Not only that, but it will be the exact same interference pattern that we saw when the interferometer was fully illuminated.

How are we to account for that? In particular: remember how above we noted that we only saw interference after the Kth cycle? How would any given photon know whether the index of the cycle that produced it was more or less than K?

Note well that this is in no way intended to highlight a problem with QM.  The outcome predicted by QM is very clear, and I would give you very long odds that this prediction is correct.  The problem is only in trying to tell a story about what the fleep is going on here that involves photons being emitted by the laser.  I don't see any way to do it.

In fact, I'll go one step further: AFAICT, this is a strong argument for the following remarkable conclusion (and if this holds up I think it really could be earth-shattering): the quantum wave function must be physically real because that is the only thing that could account for the K-cycle delay in the onset of interference.  If anyone can see a flaw in my reasoning I would really appreciate it if you would point it out.

Tuesday, May 08, 2018

A quantum mechanics puzzle, part deux

This post is (part of) the answer to a puzzle I posed here.  Read that first if you haven't already.

To make this discussion concrete, let's call the time it takes for light to traverse the short (or Small) arm of the interferometer Ts, the long (or Big) arm Tb (because Tl looks too much like T1).

So there are five interesting cases here.  Let's start with the easy one: we illuminate the interferometer with a laser which we turn on and leave on.  In that case it's a no-brainer: the photons arrive at the business end of the interferometer first from the short path Ts seconds after turning the laser on.  At this point we know (because timing) which way the photons went so there is no interference.  Then at time Tb the photons arrive from the long path.  All the photons are identical, so we no longer know which path they took.  So interference.

Case 2 (the one the original puzzle was about): the laser is turned on and stays on, but the power is modulated (or filters are put in place) so that the light level is very low, so low that the average time of arrival between individual photons at the detector is much larger than Tb.

There are two plausible-sounding answers in this case.  Plausible-sounding answer #1 is that the result is exactly the same as before: after Tb we still get interference.  The equations of quantum mechanics are independent of brightness, so wherever we get interference when the light is bright, we still get interference when the light is dim.

Plausible-sounding answer #2 is that when the light is dim we can tell which way the photon went by looking at the timing.  Whenever we get a detection there are two possibilities: either the photon was emitted Ts seconds earlier and took the short path, or the photon was emitted Tb seconds earlier and took the long path.  So if we can tell when the photon was emitted, then there will be no interference.

But can we tell?  Well (and this is the answer I was originally looking for when I composed the puzzle) it depends on exactly how we make the laser dim!  There are at least two ways, and they produce different results.

The first is to put some sort of shutter in front of the laser that only lets through one photon through at a time. This is equivalent to turning the laser on only for very short periods of time.  If we do it this way we will get no interference.

The other way is to do nothing to the laser itself, but rather to put a filter between the laser and the interferometer that blocks (or reflects) most of the photons.  The photons are blocked by the filter at random, so there is no way to tell when a particular photon got through the filter.  Hence: interference.

But suppose we tweak our setup slightly so that we can tell when a photon was transmitted by the filter.  How can we do this?  It is this exploration that leads to (IMHO) a profound insight.

Think about it: how do you detect a photon without destroying it?  You can't!  The only way to detect a photon is to have some atom absorb it, and that process destroys the photon.  But there is a sneaky trick we can do: we can run the photons through a parametric down-converter (PDC).  A PDC is a crystal made of some material (typically some stuff called beta-barium borate or BBO) whose atoms absorb photons at one wavelength and then re-emit them as two photons at different wavelengths.  The key is that these two emissions happen at more or less the same time.  So we can send one of these photons into the interferometer and use the other one to tell us when this event happened.  Experimental physicists actually do experiments like this routinely.  To distinguish between the two photons, the one that goes into the apparatus is called the signal photon, while the other that is measured to figure out the timing is called the idler.  By measuring (and hence destroying) the idler photon we can tell when the signal photon entered the interferometer, and so we can tell which way the signal photon went (by comparing the timing of entry and exit).  So we cannot have interference.

Here is the profound insight: this setup will not produce interference even if we don't actually measure the idler photon!  Why?  (You might want to think about that for a moment before proceeding.)  Because if it did, then we could use that fact to transmit information faster than light!

Here is how we would do it: instead of measuring the idlers, we send them off (via mirrors) to some distant location (let's call it L1)  At the same time, we take our interferometer and move it away from the PDC by the same distance but in the opposite direction to a location we will call L2.  The distance between L1 and L2 is much greater than the length of the long arm of the interferometer.

If we could produce interference by choosing not to perform any measurements on the idlers then we could use this setup to communicate faster than light by selectively measuring the idlers or not.  When we measured the idlers at L1, the interference would be destroyed at L2.  And this effect would have to happen instantaneously because if it didn't then we could measure idlers at L1 and still have interference at L2, and that is impossible.

The profound conclusion is that photons emitted by a parametric down-converter do not produce interference!  [1]

Those of you who have read my paper on the EPRG paradox will find this all to be familiar territory.  In fact, this is the exact same conclusion that was reached in that paper, and for the exact same reason: the photons emitted by a PDC are entangled, and entangled photons do not self-interfere.  The reason they don't self-interfere is that entanglement is the first step of the measurement process, and it, not measurement per se, is what destroys (first-order) interference.

This is all old news (at least 17 years old).  So why is this (IMHO) cool?  Because we could reach this conclusion without knowing anything about entanglement!  We didn't need to invoke EPR or Bell's theorem or polarization or anything like that.  All we needed was the principle that which-way information destroys interference to reach the conclusion that if there is any physical process that reliably produces multiple photons at the same time, then those photons cannot self-interfere.  We have shown, without doing any math, only from elementary first principles, that entangled particles are different in some deep and profound way from non-entangled ones.

I think that's cool.

That's probably enough for one post.  I'll finish up the other three cases later.


[1]  This is not quite true.  The strictly correct statement is that entangled photons do not produce first-order interference.  They can and do produce second-order interference, which can only be detected by transmitting classical information from L1 to L2.

Friday, May 04, 2018

In your face, liberal haters!

The New York Times reports that California is now world's 5th largest economy.  Only the U.S. as a whole, China, Japan and Germany are bigger.  On top of that the vast majority of that growth came from the coastal areas, where the liberals live.

Meanwhile, in Kansas, the Republican experiment in stimulating economic growth by cutting taxes has gone down in screaming flames:
The experiment with tax policy [in Kansas] was such a failure that a Republican controlled legislature not only voted to raise taxes, but did so over the veto of the governor.
So: in your face all you who say that high taxes and regulation kill economic growth!  In fact it is, and has always been, the exact opposite.  Taxes fund government and infrastructure, both of which are essential components of a robust economy.

Thursday, May 03, 2018

I don't know where I'm a gonna go when the volcano blows

Hawaii's Kilauea volcano is erupting.  So is one in Vanuatu.  And there is increased activity in Yellowstone.  Hang on to your hats, folks, Jesus's return must be imminent.

(In case you didn't know, the title is a line from a Jimmy Buffet song.)

A quantum mechanics puzzle

Time to take a break from politics and sociology and geek out about quantum mechanics for a while.

Consider a riff on a Michelson-style interferometer that looks like this:

A source of laser light shines on a half-silvered mirror angled at 45 degrees (the grey rectangle).  This splits the beam in two.  The two beams are in actuality the same color as the original, but I've drawn them in two different colors to make the two paths easier to follow.  The red beam is reflected up, the green beam passes through the mirror and continues to the right.  Both beams are reflected back from whence they came by a pair of regular mirrors (the white rectangles) also mounted at 45 degree angles relative to the beams.  They return to the half-silvered mirror where they are recombined and sent to a detector, which registers the presence of absence of interference.  (In reality it's a tad more complicated than that, but that's a sufficiently accurate description for this thought experiment.)

What distinguishes this "riff" on a traditional Michelson interferometer is that the mirrors that reflect one of the beams (the one drawn in green) are mounted on a trolley that allows them to be moved as a unit to an arbitrary distance.  We use this capability to make the distance traversed by the photons on the green path be much larger than those on the red path, large enough that there is an easily measured difference in the travel time between the two paths.

Let's call the time it takes to traverse the red path T1 and the time it takes to traverse the green path T2, with T1 much smaller than T2.

So we turn on the laser.  What can we expect to see?  Well, the laser beam is emitted at the speed of light (obviously).  After time T1 the red-path photons arrive, but the green-path photons are still en-route, so we should see no interference.  Then at time T2 the green-path photons arrive.  What happens then?

From a purely electromagnetic point of view we would now expect to see interference.  But do we?  Here is an argument that this cannot be the case: whether we see interference or not should be independent of the brightness of the beam.  So turn the brightness down to the point where the time between the emission of individual photons from the laser (and hence the arrival of photons at the detector) is much greater than T2.  (Of course, the actual arrival times will be random, but we can make the average time between photons be large enough that the probability of having two photons in the interferometer at the same time is indistinguishable from zero.)

If we do this with a standard interferometer (or two-slit experiment) where the path-lengths are very nearly the same, we still see interference even when the photons go through one at a time.  This is the famous and mysterious phenomenon of quantum superposition, where each individual photon "goes both ways" and interferes with itself.  But with this setup, "interfering with itself" would seem to be impossible.  Yes, the photon goes both ways, but how can it possibly interfere with itself when the differences in travel times between the two paths are so large?  By the time the red-path-part of the photon arrives at the detector, the green-path part is still en-route to the distant mirror.  Likewise, by the time the green-path-part of the photon arrives at the detector, the red-path part is long gone.  So individual photons can't possibly interfere with themselves in this setup, and so large numbers of photons should not be able to produce interference either.

So there are three possibilities:

1.  There is no interference after T2 (in violation of standard electromagnetic theory)

2.  There is interference after T2, but it goes away if the laser is dim enough (in violation of standard QM theory), or

3.  There is interference after T2 even when the laser is dim.  In which case the question becomes: how?

The answer next time.  It turns out that this thought experiment has some pretty profound implications with respect to the interpretation of quantum mechanics.  As far as I can tell from a cursory search, I'm the first to propose it, though I would be surprised if that actually holds up to scrutiny.  If anyone knows where this has been analyzed in the literature I'd appreciate a pointer.

Wednesday, May 02, 2018

This is inspiring

The Washington Post reports that:
Two African American men arrested at a Philadelphia Starbucks last month have reached a settlement with the city and secured its commitment to a pilot program for young entrepreneurs. 
Rashon Nelson and Donte Robinson chose not to pursue a lawsuit against the city, Mike Dunn, a spokesman from the Mayor’s Office, told The Washington Post. Instead, they agreed to a symbolic payment of $1 each and asked the city to fund $200,000 for a grant program for high school students aspiring to become entrepreneurs.
Wow.  I doff my hat, raise a glass, and salute you, Rashon Nelson and Donte Robinson.  You took a thoroughly sucky situation and turned it into something positive.  You've restored my faith in humanity.

Friday, April 27, 2018

Credit where it's due

Richard Nixon is rightfully remembered as one of the great villains of American democracy.  But he wasn't all bad.  He opened relations with China, appointed four mostly sane Supreme Court justices, and oversaw the establishment of the EPA among many other accomplishments.  Likewise, I believe that Donald Trump will eventually go down in history as one of the worst (if not the worst) president the U.S. has ever had, but I think he deserves some kudos for some of the recent developments in Korea:
The leaders of North and South Korea have pledged to jointly eliminate the risk of war and work together to achieve complete denuclearization of the Korean Peninsula. 
The joint statement Friday, from the border truce village of Panmunjom, concluded a historic one-day bilateral summit aimed at achieving peace between the longtime adversaries for the first time in more than sixty years. The meeting of the Korean leaders was the first in more than a decade.
Whether this actually leads anywhere remains to be seen, but the mere fact that this announcement happened at all is astonishing to me.   I thought a hot war in Korea was much more likely than peace overtures.  Just the change in rhetorical tone from Kim Jong Un is borderline miraculous.  A week ago I'd have given long odds against any of this happening in my lifetime.

I have no idea whether all this is happening because of or despite (or is completely indifferent to) anything Donald Trump has done.  But it happened on his watch.  If war had broken out I surely would have given him the blame, so he deserves some of the credit regardless of what his actual influence might have been.  I have a very hard time believing that the "little rocket man" rhetoric was helpful, but Mike Pompeo's visit certainly seems not to have set things back.

I still want to see Donald Trump go down in screaming flames because he is such an asshole, and I don't like to see assholes win.  But I grudgingly concede that he seems to have made more progress in North Korea than any of his predecessors.