Friday, August 31, 2012

Ghost Photos and Invisible Gorillas

This post was triggered by a couple of recent claims that something paranormal -- probably a ghost! -- was photographed.  

The first case concerns a photograph taken by "paranormal researcher" David Bennett.  It shows a woman sitting on a gazebo, only we are told that it could not just be a woman on the gazebo, because "there were four of us present and no one saw anyone there with our physical eyes. If she had been an actual physical presence, someone would have noticed her."

In the second case, a woman took a photo of her pool.  Near the center of the photograph is a small pool house, in the window of which is what might be a face peeping out.  "She assures us there was no one in there. 'I was all by myself sitting by the pool. My husband wasn't home and my son was across the street with his friend.'"

In the first case, it is obviously suspicious that the person who took the photograph for no apparent reason is a self-described "paranormal researcher"; maybe this is simply a lie.  In the second case, what looks like a face is very blurry, poorly lit, and seems to be partially obscured; it could easily be a case of pareidolia.  However, if we take the two photographers at their words, what they're saying boils down to, "It is more likely that this is a ghost than that there was a flesh-and-blood human here whom I did not notice."

How reasonable is that assertion?   Probably not as reasonable as one might think.  It turns out that we perceive a good deal less than we think we do.  In much the same way that the mind "covers over" the blind spots in our vision with "good guesses" based on the surrounding image, so that we don't notice the blind spots, it uses good guesses about what's going on to decide what is important for our attention and what is not.

Take a look at The Invisible Gorilla for some surprising demonstrations.  (I think some of these are a little unfair; after all, we have been trained by movies and TV to "see" what they mean, not necessarily what is shown, but the demonstrations are still quite striking.)  

On a more serious topic than alleged paranormal photographs, this research has some disturbing implications for the reliability of eyewitness testimony and the need to be extra careful when supervising children.

Life Near White Dwarfs?

Planetary nebula & white dwarf formation

There has been recent speculation that a good place to look for life might actually be near a white dwarf.  This possibility had been rejected before, mostly because it is hard to see how a planet could get into the right spot.  For example, in about 4 billion years the sun will expand into a red giant that will engulf Mercury and Venus and probably the Earth -- if Earth is not swallowed, it will at least be thoroughly roasted, with the atmosphere and oceans all boiled off.  Then the sun will throw off its outer layers as a planetary nebula and shrink down to a white dwarf about the size the Earth is today.  The nearest surviving planet will be Mars, but the sun will be only a very bright pinprick -- it will look a bit smaller from Mars than it currently looks from Pluto.

The reason the new research has caused some excitement is it has shown that there can be a "habitable zone" suitable for liquid water that would last for billions of years -- depending on the mass of the white dwarf, potentially much longer than the current age of the Earth.  Since many stars will end up as white dwarfs, maybe they are a good place for life to take hold in the future.  Maybe some of them have life even now!

There are at least three main problems with this idea.  The first is the size of the habitable zone:  the planet must be almost as close to the white dwarf as the moon is to the Earth, and remember, in the red giant phase the star will have cleared out the area around it.  Probably the only way to get a planet there would be to have a Jupiter-sized planet engulfed by the star during its red giant phase.  Most of the planet would be boiled off, but maybe, if it was engulfed only at the end of that phase, the planets core would survive.  Drag in the star's atmosphere would cause the planet's core to spiral inward.  Having the core both survive and get that close to the core of the star (which becomes the white dwarf) without hitting it seems very unlikely.

Or, maybe, there would be some debris in the neighborhood of the white dwarf from which a new planet could form.  Since the white dwarf forms by blowing off the outer layers of the star, I'm doubtful. 

The second problem is related to the first.  If the planet was engulfed by the star's outer layers, all the volatile elements should be expected to boil off, even it some core survives.  You might have iron and silicon, but probably no water.  If, on the other hand, the planet is somehow captured, tidal forces will quickly circularize the orbit and synchronize its rotation with its orbit.  This will not be a gentle process; orbital and rotational energy will have to be shed in the process, and this will dramatically heat the planet.  The best analogy is probably Jupiter's moon Io; tidal flexing from Jupiter has made Io the most volcanic body in the solar system, and it has already blown off all its water.  For our proposed planet, the situation would be even worse.

Comet SOHO-6

My last concern may be a positive, may be a negative, or may not matter at all!  It is star-grazing comets.  Each year many comets are discovered near the sun, which after all is the bottom of the solar system's gravitational well.  Many actually fall into the sun, and of course that is the end of them.  Something similar should happen with other stars, and it would be barely affected by the red giant and white dwarf stages. 

A planet in a white dwarf's habitable zone is still a tiny target, and almost all comets would miss it, regardless of where it might be -- but near the white dwarf, it would have an enhanced likelihood of cometary impacts.  Furthermore, those impacts would be at a higher velocity, since the comet would pick up speed as it falls in toward the white dwarf.

This might make the planet unfavorable to life, since it would be in the middle of a shooting gallery.  On the other hand, maybe the comets could deliver water that was lost in the process of bringing the planet so close to the white dwarf.

Wednesday, August 29, 2012

Opening Monolog for Star Trek: The Next Generation

At the beginning of "Next Generation", Picard gives an "updated" version of Kirk's monolog from the Original Series:
Space... The final frontier...
These are the voyages of the Starship Enterprise.
Its continuing mission:
To explore strange new worlds...
To seek out new life; new civilisations...
To boldly go where no one has gone before!
But of course, they NEVER go where "no one has gone before".  They always find people in the places they go -- often humans, but at least Romulans, Klingons, Cardassians, Ferengi, somebody!

This was not a problem in the original monolog:  "... To boldly go where no man has gone before!"  The problem, of course, was that it was so terribly un-PC to use "man" as it always has been used, to mean all mankind -- err, "humankind".  So in order to avoid saying something a bit un-PC, an obvious falsehood is substituted. 

This is all the uglier in the real world, of course.  A present-day Neil Armstrong would have to say, "That's one small step for a human, one giant leap for humankind."  If you think that's anything like as poetic as what the real Neil Armstrong said, you have no feel for the English language.  Another example would be NASA's discontinuation of the term "manned" for the manned space program, since that sounds sexist to some people.  Now they talk about "crewed" space flight, which inevitably sounds like "crude" space flight.

Monday, August 27, 2012

Voting for the Lesser Evil

People who think the way to bring about positive political change is to vote for the lesser evil must think the way to house-train two dogs is to give the treat to the one that pees closest to the door.

Sunday, August 26, 2012

You know how to help your child if they're choking ...

... but do you know how to help them if they're having trouble making pronouns agree in number with their antecedents?

Saturday, August 25, 2012

Neil Armstrong, R.I.P.

It's ironic that Neil Armstrong dies just as I am trying to organize a student group dedicated to space exploration.

Sadly, I don't think there is anything really worthwhile we can do with manned space exploration for several decades now.  

Mars is the obvious next goal, but the technical problems are no joke -- especially radiation shielding.  Also, we really need to be sure there is no life on Mars before we send people there; I'm less worried about bringing Martian bugs back here than I am about contaminating Mars with Earth bugs.  It will probably take at least 30 years to test the most likely niches for life, especially underground aquifers, where there will be liquid water and protection from radiation, and the neighborhood of Olympus Mons, where there has been recent geological activity and where there may still be geothermal energy that could be tapped. 

The idea of visiting a near-Earth asteroid sounds good, but the reality is that they are moving fast when they pass by, so there would be no room for delays, for example due to weather.  The low gravity of an asteroid would mean astronauts would not really be able to walk on the asteroid; most likely, the best way to get around would be to treat it like a shuttle EVA and rocket everywhere.

As for the Moon, there's nothing much there.  There may be a little ice in the perpetual shadow of craters near the poles, but we should not waste that until we know what our plans for the Moon will be.  Even when we decide to exploit that resource, it will take many tons of industrial equipment to do so.  

In the meantime, we should not be standing still.  We are still in the golden age of planetary exploration, with fantastic results being returned from robotic probes to all the planets -- including, in about 2 years, Pluto.  When we are ready to go to Mars, we will know whether the planet has life, and if so how to protect it.  We will know where we are going, what it's like, what we will do there, and how we will do it. 

In other words, when we are ready to send manned missions again into deep space, it won't be as explorers, but as settlers.


Son, defraud not the poor of alms, and turn not away thy eyes from the poor.  Despise not the hungry soul: and provoke not the poor in his want.  Afflict not the heart of the needy, and defer not to give to him that is in distress.  Reject not the petition of the afflicted: and turn not away thy face from the needy.  Turn not away thy eyes from the poor for fear of anger: and leave not to them that ask of thee to curse thee behind thy back.  For the prayer of him that curseth thee in the bitterness of his soul, shall be heard, for He that made him will hear him.  -- Sirach 4:1-6
I feel torn by panhandlers.  God has been exceptionally good to me, and I know I have a responsibility to help those in need when I can.  On the other hand, I know that giving cash may in many cases be quite the opposite of giving help.  When I can, I prefer to give a gift card to a supermarket (but that may be used to buy alcohol around here) or a fast-food restaurant.  I'm not ultimately responsible for making sure the alms are spent wisely, let alone in a Spartan fashion, but I think I should use some sense.  Any other suggestions?

Friday, August 24, 2012

Historical Revisionism

When did the Red Sox lift the "Curse of the Bambino"?  In 2004, when they won the World Series for the first time since 1918.  

Well, at least for now they won the title back in 2004, and again in 2007.  But for those who remember seeing the Red Sox win the World Series in 2004, remember that others saw Penn State win 4 games and USC win the BCS Championship game that year; we are now told those never happened.  Also that year, Lance Armstrong was seen becoming the first man to win 6 Tours de France, but again, we must have been hallucinating.  

I've just about had it with vacating games and voiding titles, which seems to be getting out of hand.  Look:  I'm used to the fact that a touchdown I see scored on the field may be called back for an illegal block, even if that illegal block did nothing to contribute to the success of the play.  However, for the points to be taken off the board, the flag has to be thrown right after the play -- not sometime in the middle of the next quarter.  Also, the referee has authority only over what happens on the field.  If, for example, it turns out that the wide receiver who made the touchdown catch was involved in a hit-and-run accident on his way to the game, that is a matter for the courts, not the referees.  He may go to jail, but his touchdown should still stand. 

What Sandusky did at Penn State was certainly a hideous crime, and for that crime he has been sentence to essentially life in prison.  What other people did and did not do in relation to this may also have been crimes, but that is a matter for the courts to decide.  It had no more to do with football than the hypothetical hit-and-run mentioned above.  These matters are above the pay grade of the NCAA. 

In the case of Lance Armstrong:  yes, I think he was doping.  It seems too unlikely that such remarkable, even suspicious, success should come to maybe the only pro cyclist who was not cheating.  At the same time, before stripping him of titles, I would want physical proof, not merely testimony, let alone suspicions, and I would want it in a timely manner.

So what coach in major college football now has the record for most wins?  Bobby Bowden.  Assuming, that is, that no ugly charges arise in the next few decades and change the past yet again.  

I have a rule for science fiction:  Except for Doctor Who (where it is the main conceit and has usually been handled adroitly), each series may use time travel only once.  Most of them violate this rule at least to some extent, but what can't be allowed is what happened in Eureka, where at least once a season a major time-travel incident meant that 90% of the episodes you had seen before had now never happened.  Unsurprisingly, Eureka has been cancelled.

Sports is beginning to look too much like Eureka.

Thursday, August 23, 2012

Seismometer to Go to Mars!

Just the other day, I was complaining about the fact that there are no seismometers currently on Mars.  Well, the good news is that NASA has decided to send a probe with a seismometer.  This is a real step in the right direction; it will be the first probe to punch significantly beneath the Martian surface (to a depth of about 5 meters).  Presumably, this means it will be able to drill through rock, since there is no guarantee that the InSight probe will land on a deep and stone-free patch of soil. 

This will be an important step; although the InSight probe will be concentrating on heat flow, at some point there will be a need to drill into an aquifer and take a sample of the water -- if there is any life on Mars, that might be the most likely place to find it.

MarsTopoMap-PIA02031 modest

My next wish for Mars is for a rover that will plant a grid of electrical probes and perform electrical resistance tomography to look for an aquifer and see if it is in motion.

Wednesday, August 22, 2012

Have You Ever Died in a Dream?

A blog posting by Simcha Fisher got me thinking about this.

Of course, everyone has heard the old saw that if you die in a dream, you die in real life.  The thing is, I actually did die in a dream; I was fighting in Italy in World War II, and I was killed by a hand grenade.  I woke up just after dying, not just before.  I don't really remember anything else from that dream, though.

F1 grenade

Interestingly enough, though, I had another WW2 in Italy dream that I remember in much more detail.

We were fighting in a city just a little south of Rome, and had made it into a building that the German army was using as a local headquarters.  The building had long halls, and the rooms off the halls had deeply recessed doorways, which both the Germans and we used for cover.  However, most of the Germans in this building were little more than clerks with side arms, and we made pretty short work of them. 

Then, from around a corner, came a pretty blond young woman, wearing the feldgrau uniform of the German army and carrying a pistol in her left hand (she seemed to be left-handed) and a box in her right hand.  (It was quite significant to me that she was in the German army, not the SS.) 

At this point, the dream got sort of fuzzy.  I'm pretty sure that I dreamed and re-dreamed the next few seconds until I got an acceptable outcome, because on the one hand my upbringing really ingrained into me not to hurt a woman, but on the other hand she had a gun.  My shot hit her in the shoulder, and she had to drop her pistol.

I took her in custody back to our headquarters, which were unrealistically nearby.  She was taken away to be processed as a POW, but I knew the box was probably important.  It was about one foot square and six inches high, with a fastener through the center.  In the dream I knew that this was a message box, designed to protect important papers; once it was locked, anyone opening it the wrong way would set off explosive charges, destroying both the papers and the person trying to get to them.  I strongly suspected that this was what we were looking for:  information about tanks in Yugoslavia that were being brought up to support German positions in Italy.

Back in our headquarters, though, there was a serious problem.  There was a general in nominal command, but his mind was not in the game; he expected to be given a high position in the OSS and thought of nothing but the politics.  The man effectively in command was both a colonel and an idiot. 

"Now, you see how this thing fastens through the top?  They don't want us to just force it open.  That tells me it's what we should do,"  he said.   

I was unconvinced.  "I don't think so.  Maybe we should send for the girl who was carrying it?  She might know how to get it open." 

"Son," he said, "Do you think I got all this rank without knowing how to defuse a Nazi bomb?"  (He pronounced it "Nazzy".)

When I heard that and saw he was about to pry the lid off, I started running.  I just made it out of the building when the charges blew.

Then I woke up.

Tuesday, August 21, 2012

The More Pro-Liver Beverage

Uncle Sam is like a man who, after a lifetime of hard drinking, now has a serious liver problem.  Tonight he has a choice of beverages:  a bottle of whiskey, a six-pack of beer, or a bottle of ginger ale. 

6pack Duff Beer

I am told that it is unrealistic to ask him to drink the ginger ale.  He hasn't touched the stuff in well over a hundred years, drinking only whiskey and beer.  If I ask him to drink the ginger ale, I am one fewer voice asking him to drink beer; they tell me this is "just like" asking him to drink whiskey.

Our uncle didn't get his liver disorder overnight, and he has plenty of other things wrong with him that might kill him before his liver completely fails, but still:  the beer might kill him more slowly than the whiskey would, and it might be the most "pro-liver" beverage he is likely to agree to drink, but it still contains the same poison as the whiskey, and it will also kill him.

Saturday, August 18, 2012

Music from Looney Tunes

One of the great things about classic cartoons is the music.  Some of the music comes from easily identifiable classical sources, such as Strauss waltzes, from traditional American songs -- Stephen Foster is heavily used -- or from popular songs of the day.  

Here are two pieces you should recognize from cartoons, but which you might have trouble putting a name to.  

The first is "The Dance of the Comedians" from Smetana's The Bartered Bride.
This is most often heard in Road Runner cartoons, such as this one:

Incidentally, Smetana is probably best known for his tone poem "The Moldau", which is part of a series called "Ma Vlast", or "My Fatherland".  If you're not familiar with it, give it a listen -- it's one of the most beautiful pieces of music around.  

The second piece is "Powerhouse" by Raymond Scott.  
You hear this in LOTS of cartoons.  Here's a good one (with lots of popular songs, too!).

Friday, August 17, 2012

How Important (in the Presidential Race) Is My Vote?

Only once have I voted in the fall for a major-party presidential candidate.  That was for George H. W. Bush in 1988, the first major election in which I could vote.  I came to regret having given him support.  Since then, I have voted for only 3rd-party candidates.  I will not vote for a Democrat, because they actively support intrinsic evils like abortion, but I have not found a Republican candidate with the right priorities to earn my vote, either. 

2008 Presidential Election by County

As a socially conservative Catholic, I get tired of comments like these:
bernadette says:  So what exactly does this mean? Romney supposedly is pro-abortion which I deplore. But I don’t want to hand over a victory to Obama to have four more years to destroy what is left of our country. This is what will happen if serious Catholics vote for a third candidate. I am really torn about this.
wmeyer says:  bernadette, this is precisely the point I try to make to those who think they can abstain, or vote for a 3rd party candidate. History shows that the result will be against us. And though I am not a Romney fan, I shall vote to remove O.
As an aside, what wmeyer really means is that if a lot of people refuse to vote for the Republican, the result will be against the Republicans, not that if a lot of people refuse to vote for the Constitution Party, the result will be against the Constitution Party.  Both statements are obviously true.  His first mistake is thinking that people who vote for the Constitution Party, as I have for as long as I have known it existed, are really Republicans, and that they will be happy if a Republican is elected.  His second mistake is thinking that a Catholic who takes the Catholic teachings on, for example, abortion seriously is morally obligated to support a party -- the Republicans -- who consider abortion a very serious matter when raising money, a very serious matter when turning out the vote, and the least important item on their agenda when it comes to governing.

For the sake of argument, though, let's pretend that it is indeed a grave sin for me to cast my vote in a way that helps a Democrat into the Oval Office.  Has that ever actually happened?
  • In 1992, I was a resident of Florida.  George H. W. Bush won the state and all of its electoral votes.  Obviously, changing my vote would not have changed anything. 
  • In 1996, however, while I was still a resident of Florida, Bill Clinton won the state with 2,546,870 votes to Dole's 2,244,536. Let's further pretend, though, that if I had changed my vote to Dole, so would more than 300,000 other Floridians, so that the GOP would then have won the state.  Even then, Bill Clinton would have easily won in the Electoral College, 354 to 184.
  • In 2000 and 2004, I was a resident of Texas.  In both elections, George W. Bush won the state of Texas easily and went on to win the elections. 
  • In 2008, I was a resident of West Virginia.  McCain won West Virginia by a large margin, but with only 5 electoral votes, it made no difference, and Obama won the national election by a wide margin in the Electoral College.
In other words, my vote has never had an impact on the presidency.  

The one thing my vote represents is my choice.  That is the only thing it means.  And I choose not to support an evil just because I have passed up on the opportunity to support a greater evil.  


"But what if everyone voted the way you did?"  Then both the Democrats and Republicans would be swept out of office, and the country would be better off for the change.

"Oh.  But I won't change my vote to your party.  That means you have to change your vote to my party, otherwise our votes will be divided and the greater evil will win!!!" 
  1. First of all, see everything I've written above.  
  2. Secondly, if you were convinced that being politically undivided is a moral requirement, you wouldn't be playing electoral chicken and assuming that I will flinch first. 
  3. Finally, why should the Republican Party buy the cow (actually govern to eliminate abortions) when they can get the milk (pro-life votes) for free?  Other groups understand this.  The pro-abortion and pro-gay-rights crowds won control of the Democratic Party by playing hardball.  It's long past time social conservatives learned to do the same.

Wednesday, August 15, 2012

Modern Views from Plutarch

Several years ago, I read The City of God by St. Augustine.  It is a fascinating book on many levels, but it made me realize I needed to learn more about Roman history to better understand it.  One of the books I read was a translation of Plutarch's The Makers of Rome (though this title reflects a reorganizing of the material, which had originally been a series of parallel Roman and Greek biographies). Over the past few days I've been re-reading it at a slow and casual manner -- just a paragraph or two before bed.

Marcus Porcius Cato

I've made it now to the life of Cato the Elder.  A couple of quotes took me a bit by surprise.
However, for my part, I regard his treatment of his slaves like beasts of burden, using them to the uttermost, and then, when they were old, driving them off and selling them, as the mark of a very mean nature, which recognizes no tie between man and man but that of necessity.
This is a proper attitude, one which I might expect to find in any Christian.  Such expectations, however, would be perpetually disappointed.  It was insufficiently widespread in the slaveholding ancient world, insufficiently widespread in the revived slaveholding after the "Renaissance", and is insufficiently widespread in today's corporate world, where employees are all too often treated exactly as "beasts of burden". 
We should not treat living creatures like shoes or pots and pans, casting them aside when they are bruised and worn out with service, but, if for no other reason, for the sake of practice in kindness to our fellow men, we should accustom ourselves to mildness and gentleness in our dealings with other creatures.
This sums up in a nutshell why Michael Vick's dogfighting was so wrong:  how we treat animals is practice for either kindness or cruelty to our fellow men.

Saturday, August 11, 2012

No Syrup on Mac and Cheese Pancakes!

OK, I can see the basic idea of Macaroni and Cheese Pancakes as working.  I have to strongly object, though, to the idea of putting maple syrup (or even cane pancake gravy!) or any other sweet syrup on them.  That is simply barbaric, like putting maple syrup on potato pancakes; next they will be putting ketchup on them.  I haven't tried the recipe, but if the idea is pulled off right, no sauce should be necessary.  If you simply must have a sauce, I would think something like Alfredo sauce would work better.

Friday, August 10, 2012

Is It Possible to Add Too Much Cayenne Pepper to Soup?

Yes.  It is. 

I made "Bretzenheim soup" today.  This is something I made when I was a postdoc in Germany -- Bretzenheim is a suburb of Mainz.  The soup is just dried or frozen tortellini (I used cheese ravioli because I could not find the tortellini at the supermarket I was in yesterday) boiled until done in about 2 quarts of water with one package of onion soup mix.  A couple of minutes before it's done, add a few cups of frozen peas.  (Note that I'm not really adhering to a detailed recipe or detailed measurements.  This is bachelor cooking, for crying out loud!)

The last important touch is a dash of cayenne pepper.  Originally, I had planned to add paprika, but I grabbed the wrong spice by mistake, and I liked it having a bit more of a kick.  

That said, there is such a thing as too much of a good thing.

Thursday, August 9, 2012

Is Mars Geologically Alive?

On Earth, life has been found deep underground, particularly in the form of bacteria that extract energy from minerals or chemicals created by geologic processes.  This has led a number of researchers to hope that similar life may exist on Mars.  There is evidence of underground water on Mars, and deep underground the problems of the low temperatures and radiation of the surface would be irrelevant.  Also, Mars has a number of (extinct? dormant?) volcanoes, including Olympus Mons, the largest volcano in the solar system. 

However, for life to persist on Mars, some kind of ongoing geological activity is probably necessary -- otherwise the minerals and chemicals produced early in the history of Mars would presumably be exhausted by now, and any subsurface bacteria would have starved.  This is a big problem; the heavily cratered surface of Mars clearly shows that Mars has had neither significant rain nor robust plate tectonics for billions of years.  The standard thinking has been that Mars has never had plate tectonics and that the volcanoes are extinct. 

Maybe it's not that bad, though.  Images from the Mars Express spacecraft imply that Olympus Mons may have erupted as recently as 2.4 million years ago.  That may sound like a long time ago -- and it is, certainly by Earth standards -- but given that the volcano is at least 100 million years old, it would be odd if it died just before we could observe it.  It was certainly erupting while sauropods (the long-necked dinosaurs like "Brontosaurus") walked the Earth. 

On top of that, there is new evidence that Mars may have limited, much slower, but perhaps still ongoing plate tectonics driving processes similar to some of those on Earth.

In light of all this, wouldn't you expect each Mars lander to contain a seismometer?  After all, it is seismometers that have allowed us to determine the existence, depth, and composition of Earth's inner and outer cores; they should be able to provide similar information about Mars, as well as determining more precisely how active Mars is today -- with all the implications that has for the existence of Martian life.  As far as I have been able to find, though, there are no seismometers on Mars at all.

Tuesday, August 7, 2012

Saint Augustine of Hippo on Witchcraft

I recently read an article at Crisis Magazine refuting the absurd claims made by some modern groups (mostly neo-pagans and those who simply enjoy bashing the Church) that nine million people have been executed as witches over the centuries.  The article makes some good points, but it misses the boat with a few others.  Notably, it rather casually dismissed the existence of witches, so that by definition all those executed for witchcraft were falsely accused.

Odds nipperkins

This is accomplished mostly in this passage:
Many cultures around the world believed for millennia — and still believe — in witches. In typical folklore, past and present, witches are night-flying evildoers who inflict harm on others by supernatural means, such as curses, the evil eye, and magic substances. Witchcraft is usually thought of as an innate power, unlike sorcery, whose magical spells must be learned.

The example to keep in mind here is Circe, who bewitched and seduced Odysseus.  She was supposed to be the daughter of the sun god Helios, so she would indeed have certain innate powers.  In more modern terms, think of Samantha and her family from the TV show Bewitched.  Somehow they were born with the inherent capacity for magic, only using incantations for the more dramatic spells. 

It is only in the light of such examples that any sense can be made of the assertion 
But to St. Augustine, concrete witchcraft consisted of idolatry and illusion rather than harm to others. Following Augustine, an anonymous ninth-century text, Canon Episcopi, became part of the Church’s canon law, declaring that belief in the reality of night-flying witches was heresy because there was no such thing as an actual witch.

In other words, to the extent that this is true, it is true only for a definition of witch that no one really uses today -- notably including modern adherents of Wicca, who are all humans, not literally demigods. 

In fact, though, the assertion that the term "witch" means only a being like Circe or Samantha is not historically true; it has usually been taken to be synonymous with "sorcerer" or "sorceress".  This is how it was used in Exodus 22:18:
Thou shalt not suffer a witch to live.
Related passages include Leviticus 19:31:
Regard not them that have familiar spirits, neither seek after wizards, to be defiled by them: I am the Lord your God.
and Deuteronomy 18:9-12:
When thou art come into the land which the Lord thy God giveth thee, thou shalt not learn to do after the abominations of those nations. There shall not be found among you any one that maketh his son or his daughter to pass through the fire, or that useth divination, or an observer of times, or an enchanter, or a witch.  Or a charmer, or a consulter with familiar spirits, or a wizard, or a necromancer.  For all that do these things are an abomination unto the Lord: and because of these abominations the Lord thy God doth drive them out from before thee.
Witchcraft is clearly listed as an abomination that may be learned, not an inborn ability; it is, in other words, either identical to sorcery or the same basic thing with minor variations.  Needless to say, St. Augustine would have been well aware of these passages, and St. Augustine never casually dismissed Scripture.

As for sorcery itself, here is what St. Augustine said about it in City of God, Book XXI, Chapter 6:
For to this inextinguishable lamp we add a host of marvels wrought by men, or by magic,— that is, by men under the influence of devils, or by the devils directly—for such marvels we cannot deny without impugning the truth of the sacred Scriptures we believe. That lamp, therefore, was either by some mechanical and human device fitted with asbestos, or it was arranged by magical art in order that the worshippers might be astonished, or some devil under the name of Venus so signally manifested himself that this prodigy both began and became permanent. Now devils are attracted to dwell in certain temples by means of the creatures (God's creatures, not theirs), who present to them what suits their various tastes. They are attracted not by food like animals, but, like spirits, by such symbols as suit their taste, various kinds of stones, woods, plants, animals, songs, rites. And that men may provide these attractions, the devils first of all cunningly seduce them, either by imbuing their hearts with a secret poison, or by revealing themselves under a friendly guise, and thus make a few of them their disciples, who become the instructors of the multitude. For unless they first instructed men, it were impossible to know what each of them desires, what they shrink from, by what name they should be invoked or constrained to be present. Hence the origin of magic and magicians.

Were there people wrongly convicted and executed for sorcery?  Certainly.  Also for treason, murder, and quite a few other crimes which used to be punished by death.  But it is every bit as possible to be a witch as to be a traitor or an assassin.  It is misleading to imply that St. Augustine thought otherwise.