Tuesday, April 23, 2019

What if Democrats Understood Economics?

The last few days have been full or statements of idiocy from the 623 announced Democratic presidential candidates, and made me think of how even an undergrad econ student should understand where they're wrong.

Since I only have time to focus on one, Elizabeth Warren, Fauxcahontas, proposed to pay off $1.25 trillion in total student debt over ten years, and also called for a $100 billion increase in federal student aid that does not have to be paid back.  She also proposed that public two and four-year universities be completely tuition-free by way of a "state/Federal partnership".  And a new, super duper, ultra tax for billionaires that I need better numbers on to see if that's remotely realistic. 

This article will emphasize the free college.  I feel bad about writing about stuff that's so blatantly obvious - you, dear Reader, are far too smart to believe Democratic primary promises - but I hope I can add a piece of information or two that might be helpful for you.

First off what's wrong with higher education in one word?  Government.  Too short?  How about this?
  1. Colleges and well meaning parents have created the narrative that the only way to get a good job is college.  That creates an almost total demand - virtually every child in that generation thinks they need college.
  2. The number of real seats in classrooms to put equally real student butts into is far smaller than the number of said butts.  There's no quick fix for this imbalance because the number of qualified teachers is too small to embark on a grand plan to add thousands of other colleges to drive prices down.  This means demand is far beyond supply and is going to stay that way.
  3. When demand vastly outpaces supply, prices go up.  In a free market, with people spending their own money, some percentage would say, "that's too expensive" and find a way around the problem.  But it doesn't matter what the price is, because government has guaranteed that grants, scholarships, and loans are available to pay for those seats regardless of the costs.  
  4. The politicians can't ration or cut money for college loans and grants because they would be called mean, haters, or the old standby, racist.  Not providing infinite student loans would deprive some poor underprivileged student of their chance - their chance to take out an enormous loan while betting they'll be able to pay it back and not go bankrupt.
  5. In order to appear "concerned about rising costs", government imposes more costs for more administrators and more hoops for the colleges to jump through.  The colleges couldn't care less because the cost just raises tuition so it gets stuck onto the student's loan.  But the politicians can say they're doing financial oversight of the colleges.
Everything wrong with education comes from government screwing it up by supplying lots of money.  Warren's answer?  "Let's do it again, only harder!!"

Let's be honest here.  There's more evidence of simply stunning economic idiocy.  A college degree is valuable - to the extent that it still is valuable - because not everyone has one.  Not everyone can master the work.  If everyone has an Associates or Bachelor's degree (depending on which candidate is promising), it will become equivalent to today's High School diploma.  You can actually see this already happening in that the only degrees that help graduates to get hired are the ones with strong skills imparted.  There simply aren't many jobs for holders of degrees in Philosophy, Literature, or Offended Minority Studies.  Any 12th grader wanting to major in those things needs to know they're going to go deeply in debt and have a meager life when they graduate. 

If college becomes "14th grade", the perks and higher pay will go to the Master's Degree holders, the Ph.D.s or some degree that doesn't exist yet.

But you don't have to take my word for it.  What we predict with simple application of econ 101, "Supply and Demand" is already true in South Korea where college attendance is almost 100%.
Seongho Lee, a professor of education at Chung-Ang University, criticizes what he calls "college education inflation." Not all students are suited for college, he says, and across institutions, their experience can be inconsistent. "It’s not higher education anymore," he says. "It’s just an extension of high school." And subpar institutions leave graduates ill prepared for the job market.

A 2013 McKinsey study found that lifetime earnings for graduates of Korean private colleges were less than for workers with just a high-school diploma. The unemployment rate for new graduates has topped 30 percent.
I've used the following graph several times.  As I said the last time, it's kind of old but searching for updates wasn't fruitful.  It shows the inflation of college tuition (top) vs. medical care (mid) and the official cost of living (bottom).  This is the effect of the unlimited loans and other free money. 


From John Uebersax on Creative Commons (Wikimedia).

Here's the hard question.  Does Warren actually know this?  Does she actually know her ideas can't work and will just destroy colleges and force more people into the pursuit of higher degrees?  Back during the Obamanation, Bamster did an end run around the law and appointed her to "staff up" the just-created Consumer Financial Protection Bureau, which she did and that apparently involved economics.  But I also found some criticism of her work by one of her professors back at Rutgers, before she did the affirmative action gig at Harvard.  He didn't think too much of her intellectual prowess. 

It could be that she just thinks Democrat primary voters are complete idiots and will vote for her because of this idea. Or it could be she's a big enough idiot to believe it herself. 


Monday, April 22, 2019

Happy Erf Day!

It's time for our annual bacchanalia of the made-up holiday they call Earth Day.

Earth Day, as most of you know, was made up in the late 1960s at the start of the national environmental movement.  Ira Einhorn is one of the main founders of Earth Day, if not the guy who started it.  Ira practiced what he preached: he murdered his girlfriend (less stress on the planet, ya know) and composted her body in his closet.  (Hey - reduce, re-use, recycle!)  And that was before people started worrying about their carbon footprints.  What a leader!
You won't find Ira Einhorn's name listed in any of the Earth Day promotional literature, as the organizers have taken great pains to distance themselves from this man, at least since he became better known for composting his girlfriend in a trunk in his closet for a couple of years in the late 1970s.
The movement led to the creation of the Environmental Protection Agency, the High Priests of Junk Science, probably the single best example of an agency that has outlived its usefulness. 

Over the years, I've wasted far too many minutes writing about Earth Day.  It's too long to sort through and pretty much all curmudgeonly, so I'll just say I hope you had a nice day.  Still, there are a a couple of good things to remember about the modern environmental movement.  If you'll just remember that nature wants you dead and most environmentalists prefer the wild animals over you (look at how they respond to wolf attacks on cattle or people), you'll have a pretty good start.  In fact, it's probably easier just to say that mainstream environmentalists want you dead. 
  • CNN Founder Ted Turner: "A total population of 250-300 million people, a 95% decline from present levels, would be ideal."
  • Dave Foreman, Earth First Co-Founder: "My three main goals would be to reduce human population to about 100 million worldwide, destroy the industrial infrastructure and see wilderness, with it’s full complement of species, returning throughout the world."
  • Maurice Strong: "Isn’t the only hope for the planet that the industrialized civilizations collapse? Isn’t it our responsibility to bring that about?"
Gee, the moderate guy only wants to kill off more than 95% of the human race.  See the current world population is around 7 .7 billion people.  For Dave Foreman, 100 million out of 7 billion is 100 out of 7700 or 1.3 %.  At 300 million, Ted Turner would generously let 3.9 % live.

Unfortunately, between Erf Day and Easter falling so closely together this year, plus spending lots of time helping the still-on-a-cane Mrs. Graybeard, I forgot to get the tires for my celebratory tire fire.  I'll have to turn on all the lights in the house and both air conditioners to make up for it.  If you have your tires, just remember your tire fire should be visible from Proxima Centauri; and if you don't have tires to burn, your house should be visible from that star system.


More seriously, the environmentalist predictions have been so consistently wrong, Borepatch has a few (and only a few), if you could find a place that takes bets, bet against the greens every time.  If they think I shouldn't be having a tire fire, it's a safe bet I should.



Sunday, April 21, 2019

Happy Easter!



I thought it was time to re-dress my annual Easter post and drop some of the links that are over five years old.  Part of my usual posting is hard to drop, because it's part of my personal conversion story, so parts of that will still be here.

Coming from my background, it was a large change.  I had studied biochemistry and microbiology in college through my third year before life imposed some detours, eventually getting my degree and starting to ply my trade as an engineer.  I had been an amateur astronomer, so between them I was deeply marinated in the standard model of Cosmology as well as conventional biological evolutionary theory.  Frankly, I wasn't giving it much thought any longer, but my wife had re-affirmed her faith (she had first accepted Christ as child) and I was having all of my mental models disrupted.  She had started a subscription to Bibical Archaeology Review and the constant refrain from archaeologists, not religiously motivated, along the lines of "we thought this was old Jewish folklore, but here it is" got me thinking "if that's true, maybe there's more that's true."  Strobel's The Case for Christ, played a role in filling in the gaps in my historical knowledge. 

Easter is the most important day in Christianity and far more important than Christmas because of the resurrection.  Everyone has a birthday, but only one man in history has been resurrected.  So since virtually everyone, including honest atheists, agrees Jesus was a real man in history (Jesus' existence is better attested in ancient sources than that of Julius Caesar - but no one claims Julius was not a real person) and died on the cross, the question becomes whether or not it can be verified that Christ was seen after the resurrection by someone other than the closest circle of disciples. Strobel says:
Did anyone see Jesus alive again? I have identified at least eight ancient sources, both inside and outside the New Testament, that in my view confirm the apostles’ conviction that they encountered the resurrected Christ. Repeatedly, these sources stood strong when I tried to discredit them.

Could these encounters have been hallucinations? No way, experts told me. Hallucinations occur in individual brains, like dreams, yet, according to the Bible, Jesus appeared to groups of people on three different occasions – including 500 at once!

In the end, after I had thoroughly investigated the matter, I reached an unexpected conclusion: it would actually take more faith to maintain my atheism than to become a follower of Jesus.
For a great examination of this, see the 2016 post "Five Confounding Facts About Jesus' Resurrection" at Sense of Events. Donald Sensing put together an excellent piece; simply put, it's preposterous to reconcile the events of that time without saying Jesus rose from the dead that Sunday.  This year, Sensing has outdone himself with several days worth of posts on the historical Jesus, including a rather long piece on exactly why Pontius Pilate executed Jesus.  This is followed by articles put together by working scientists, "Can A Scientist Believe in the Resurrection?" and "Is Belief in the Resurrection Unscientific?"

The other religions of the world are about ritual and ultimately about self, about proving yourself worthy; Christianity is about grace.  You're not worthy on your best day; you're saved by Grace.  No other religion teaches Grace.  Islam teaches that Allah is unknowable.  Christianity teaches that not only is God knowable, he wants us to know him.  Islam doesn't teach salvation, it teaches servitude to a fickle, arbitrary, distant Allah.  Christianity teaches forgiveness by Grace; that you're given a gift you don't deserve by a God who wants a close personal relationship with us.  I like the way the Message translation talks about being saved by Grace (Ephesians 2: 8)
It's God's gift from start to finish! We don't play the major role. If we did, we'd probably go around bragging that we'd done the whole thing! No, we neither make nor save ourselves. God does both the making and saving. 
Evolution vs. creation? I believe people pay way too much attention to this.  There's no mention of evolution in the bible, but there's no mention of the laws of thermodynamics, Avogadro's number,  relativity or thousands of other such things.  The bible isn't a science book.  Look at it this way: the creation story, how we got here, takes up a page.  The next thousand pages (or more, depending on font size, paper size, and so on) are concerned with how we treat each other while we're here; how we create and maintain a civil society.  Creation is clearly not the emphasis of the book, the other 99.999% is. 

Saying a fluctuation in the quantum vacuum exploded creating everything sounds remarkably like "Let there be light", especially if someone were trying to explain the standard model of cosmology to people who were mathematically at the level of today's preschoolers.  You got a better way to explain modern physics to kindergartners? 

Enjoy your day.  Enjoy your families. As usual there's a pork butt in the smoker but with the added experiment of seeing how doing most of it in the ultra-controlled sous vide cooker does.  Pulled pork tonight.



Saturday, April 20, 2019

Radio Sunday #4 - Modulation Basics

This post will be Saturday instead of Sunday - because Easter, of course. 

We've covered the development of radio receivers up until the end of the 19-teens, but have never talked about what the receivers are actually receiving.  That requires a side track into transmitters that had to wait for us to get past the development of the triode and superheterodyne because modern transmitters use the same basic superheterodyne approach.  Suffice it to say that radios were being used for communications long before the advent of modern architecture (superheterodyne) transmitters and receivers.

Single radio frequency generation would rely on the development of the vacuum tube triode oscillator, a circuit that deliberately creates that “microphone in front of the speaker”, positive feedback effect by tapping some of the output and sending it through a circuit back to the input, which tunes the frequency of oscillation.  The invention of the oscillator is another of those things credited to Edwin Armstrong.  These circuits are most often an inductor/capacitor from output to input.  (Since the schematic symbol for an inductor is usually called “L” and a capacitor is called “C”, these are referred to as LC oscillators)  All that is needed is a gain of 1 and this positive feedback to ensure the generation of an output at the frequency of the LC circuit.  By varying either component, a Variable Frequency Oscillator or VFO could be obtained, and that allowed tuning many frequencies, not just one. 

Modulation is the process of adding intelligence to a signal, called the carrier, to communicate over a distance.  In its simplest form, a transmitter's output can be keyed on and off, giving the Morse code we hear today (called Continuous Wave modulation or CW), but the goal was to transmit sound – voice and music.  Turning the signal on and off is the most extreme form of changing its amplitude, but what if we could vary the amplitude of the transmitter signal with the amplitude of the speech?  Of course, this is Amplitude Modulation or AM (and sometimes referred to as “Ancient Modulation” by hams).  I'm going to spend a bit of time here on AM and then FM because they're the modes people are most familiar with. 

AM modulation can be done at low power levels in the transmitter, but was typically done in the final amplifier stage.  Why?  If the modulation is done at a low power level, the amplifiers that produce the transmit power can distort the modulation, unless they're run to be “linear”, so that the output signal is an enlarged version of the input.  This is an inefficient mode, or "class"  – the tube has to run considerably more power than if it's just setup to amplify as much as it can – so designers typically run everything as “wide open” (highest gain) as they can and modulate the output.


A generic low level modulated versus high level (plate modulated) AM transmitter.  The block diagrams are very sparse on details; that box labeled “VFO & LO” can be several pages of schematics.  In older models, that might be a VFO tuning half or one MHz in the low HF spectrum, say from 5.00 to 6.00 MHz, and a host of crystals to mix with that to generate the desired HF bands.  Today, that box might be a single chip Direct Digital Synthesizer for casual use, or a complex Phase Locked Loop synthesizer for the highest performance.  On the left, those two RF amplifiers might be four or more stages, all “Class A”, high linearity stages.  On the right, there might be more than two stages, but they all would be higher gain, “Class C” stages.



AM as seen on an oscilloscope. The carrier is so much higher in frequency than the audio that we see what looks like an audio frequency envelope filled with lighter color that's the many cycles of the carrier.  The amount of AM is measured in percentage and that can be calculated by measuring the amplitude of the peaks and valleys of the signal, my rough guess is this is about 80% modulated.

Any portion of the transmitter's power amplifier circuit can be used to modulate the output amplifier: the cathode, grid or the output (plate); modulators are referred to by what they modulate. I don't follow AM enough to say what the most common mode is, but since plate modulation is running the RF circuits in the most efficient mode possible (class C), I always thought the industry would have used that. A high voltage transformer is used to apply the modulation to the plate circuitry.


Mathematically, AM modulation is mixing: multiplying the carrier times the audio frequency.  If the audio includes a DC value of the proper voltage, the output of the circuit is the carrier (the DC term) along with the sum and difference frequencies – the carrier plus the audio and the carrier minus the audio.  The sum is referred to as the upper sideband and the difference as the lower sideband.  If you think about it a minute, if all the information is in the sidebands, and the same information is in either sideband, the logical conclusion is if you only transmit one sideband you transmit 100% of the information, at a tremendous saving in power.  The only thing sending full AM does is make the receiver easier.  Bell Labs was researching this in the early 1920s.

As anyone who has listened to an AM radio can tell you, AM is prone to noise pickup.  This is because static, electrical sparks, and so much more, cause noise spikes of high amplitude at the receiver frequency and this unwanted AM gets “stuck onto” the desired signal.  While Frequency Modulation was experimented with for noise improvement before Armstrong's work, this was work done on narrowband FM and that legitimately doesn't provide as much immunity to noise as the wideband FM that Armstrong patented in 1933.  Wideband FM (WBFM) hadn't been properly analyzed by others and they hadn't foreseen some of the benefits of WBFM.  Today's Broadcast FM stations are the WBFM that Armstrong originally developed (with the addition of stereo).  Because FM detectors are designed to detect changes in frequency rather than amplitude, they are much less affected by AM noise like lightning static, powerline noise and so on.  Part of the protection is the use of VHF frequencies for FM broadcast – the sources I just mentioned are naturally reduced in amplitude as the radio frequency goes up.

The amount of modulation in an FM signal is referred to as deviation, expressed as how far the carrier deviates during use.  NBFM is used in amateur handheld radios, with a typical deviation of 5kHz peak; the WBFM which broadcasters use is 75 kHz peak, 15 times greater. 

In practice, it's impossible to distinguish Frequency Modulation from Phase Modulation, and many typical FM radios are actually phase modulated.  If the audio goes through an RC integrator before being modulated, the result is FM (pdf warning).  Often, the amount of modulation is calculated to be a fraction of the desired and frequency multiplication increases the deviation.


Frequency multiplication increases the amount of deviation by the multiplication ratio.

Dispensing with more of the details of the historical steps, it is possible to put intelligence on a radio signal by modulating amplitude, frequency, carrier phase or any combination of those.  We can control every characteristic of a radio frequency signal and every characteristic can be used to get information from one person to another. 

Today, we've developed general purpose modulators that can produce whatever form of modulation is required.  These require signals with a 90 degree phase difference between them, referred to as I and Q signals for In-phase and Quadrature-phase signals.  Any form of modulation (pdf warning) can be created with the right waveforms on those two signals.  Virtually all of these transmitters are done with the low level modulation scheme used on the left in the figure comparing AM transmitters above.

The most common forms of modulation used commercially are probably Bi-Phase Shift Keying and Quad-Phase Shift Keying, BPSK and QPSK respectively, but higher number of phase shifts like 8PSK are common in places.   When you hear of a mode like 64 QAM – quadrature AM – this is combination of both phase and amplitude modulation. 

If there are general purpose modulators, there are general purpose demodulators.


This takes in an RF or IF signal and an LO, splits the LO so that one side is 90 degrees behind the phase of the other side.  These are then multiplied by the RF, which is simply equally power split with both legs in phase with each other.  The result is it strips off the I and Q modulations.  If the LO equals the tuned RF, this becomes a Zero IF receiver and in most of what's on the market, the I&Q data streams go into Analog to Digital Converters.

If the input is on the right, as I and Q signals, the radio frequency output is on the left, this circuit becomes your general purpose modulator. These are commodity components made and sold by the tens of thousands - or more.  And that's just one supplier.  They're made in a variety of technologies with the same block diagram. 

It might be helpful for you to know that in receivers this circuit is called an image reject mixer, or image reject front end.  Last week, during the brief introduction to the Direct Conversion (Zero IF) receiver, I mentioned its drawback of hearing anything on the image frequency at the same level as the desired station.  While this won't give unlimited suppression of the image, it can reduce the image 30 to perhaps 45 dB, not shabby at all.



Friday, April 19, 2019

Citibank Questioned at Shareholders' Meeting - Come up BSing

It's almost unfolding as you'd expect.  According to TTAG - The Truth About Guns - at Citicorp's annual shareholder meeting, they had their feet held to the fire for the way they impose on gun businesses.
Justin Danhof, General Counsel for the National Center [for] Public Policy Research and Free Enterprise Project posed a simple question. “Can you tell us – your investors – exactly how much money we stand to lose because of this decision, and explain why you have this right while Warren Buffet has this wrong?”
I say "almost as you'd expect" because Justin Danhof isn't from one of the mutual fund companies who are actively managing money for millions of Americans; his letterhead says, he's the General Counsel and Free Enterprise Project Director for The National Center for Public Policy Research.  He's interested, but it's not his job to be optimizing return on every penny.  Still, he's asking the right question: what makes you think you'll get me better returns on my investments than Warren Buffet and Berkshire Hathaway - who have made lots of millionaires over the years?  Buffet famously said,
“I don’t believe in imposing my political opinions on the activities of our businesses,” he said. It was the second time he stated his position. Earlier in 2018, he stated it just as clearly. “I don’t believe in imposing my views on 370,000 employees and a million shareholders. I’m not their nanny on that.”
Unfortunately, Citibank CEO Michael Corbat is either a moron or liar (not that he can't be both) because he really gave some stupidity for his answers.
Corbat said Citigroup’s policy to discriminate against firearms manufacturers and retailers who refuse to abide by their policy of instituting age-based gun bans – deny a right to keep and bear arms by a legal adult – wasn’t a Second Amendment threat, rather a “good practice.”

Corbat tried to couch it that they would only do business with retailers who conduct full background checks and no financing for companies who use loans to convert legal firearms into illegal firearms.

If it sounds confusing, it’s because Corbat purposefully was aiming to do so.
Since the readership here is generally quite aware of the laws for buying and selling guns, I don't need to quote the next paragraph from TTAG - but I will, with emphasis added.  The important point is that Corbat is either lying about what their practices are or he's too stupid to know he's asking them to do what they already do.  Again, not that he can't be both lying and stupid.
All federally licensed firearms retailers are required by federal law to conduct an FBI background check at the point-of-sale before they can transfer a firearm to a consumer. This is done each and every time. This is not a “best practice,” it’s the law which the industry supports.  Also, no firearms manufacturers use any money – lent, invested or earned – to convert legal firearms into illegal ones. It’s a quick way lose a manufacturing license and head to prison.
In Danhof's letter (pdf warning), he accuses Corbat of not meeting his fiduciary duties to shareholders, but merely following the lead of the liberal media:
The company joins a list of corporations following the liberal whim of the moment and not looking out for the best interests of long-term shareholders. CNBC talking head Andrew Ross Sorkin has been pressuring banks and credit cards to take a stand against gun rights. But you don’t work for the interests of a liberal journalist. 
Corbat wouldn't commit to how much money this policy has cost Citibank, merely saying, it hasn't “cost us a meaningful amount of money.”  This is debatable, and there are details at the original article.  

Like the rest of us, CEOs are never 100% right or wrong.  This is a wrong decision on the part of Corbat, or the Board of Directors.  Is it the only wrong decision?  Doubtful, but I don't know.  Citibank stands out especially because they're only in business today due to taxpayers bailing them out in 2008.  As their way of thanking taxpayers, Citi is making sure to deny 2nd amendment rights to taxpayers that are "too young" in their view.  It's none of their Citi's damned business.  If the gun store is following all applicable state and federal laws, that's all they need to know.  

You know I'm dedicated to free market principles, and the right principle here is for the Mutual Funds and other Citi stockholders to hold Corbat responsible for a stupid decision.  Hopefully, word of this will get around and increase the chance they get rid of Corbat and get a saner CEO in place.  Which is why I'm passing the word around.



Thursday, April 18, 2019

NASA to Open Lunar Samples Untouched Since Collection

Frankly, this article shocked me, but according to a news article from Machine Design, NASA and the Lawrence Livermore National Laboratory will soon be opening some lunar samples that have not been touched since Apollo 17 at the very end of 1972.  The samples were sealed while on the moon to keep them "vacuum packed" and have never been opened.
Nine “special samples” were collected during the Apollo 15, 16, and 17 missions and stored in containers with indium knife-edge seals to maintain a lunar-like vacuum. Apollo mission planners devised these special sample containers to meticulously preserve fragile and transitory sample characteristics (e.g., solar wind volatiles and volatile coatings). Three of these samples have remained sealed in their original Apollo containers until today.

Cosmochemists at Lawrence Livermore National Laboratory will get a chance to analyze these Apollo 17 relics to study the geologic history of the site where the rocks were collected, a geologic cold trap where water may have been able to freeze. This marks the first time a sample will be studied in detail since the end of the Apollo program.
The surface of the moon is covered by a fine, powdery, dust called regolith created by meteoritic bombardment of the Moon’s surface over the past 4.5 billion years.  Volatile elements, such as those from coronal mass ejections from the sun, can get trapped in the powdery regolith and the techniques for finding, identifying, and determining quantities of these volatiles have improved in the intervening 50 years. 

One of the neatest aspects of this new analysis is that the guy who collected some of these samples, Geologist Harrison Schmitt, 83, will be part of the LLNL team doing the studies.


(Harrison Schmitt on the lunar surface during Apollo 17 - his only space flight.  It's only when you look at device in the right foreground that you realize you're looking at a color photograph, the scene is so monochromatic - NASA photo)
A new NASA program, the Apollo Next Generation Sample Analysis, has selected nine teams to extend the science legacy of the Apollo missions by studying pieces of the Moon that have been carefully stored and remained untouched for nearly 50 years. LLNL is part of the University of New Mexico team of scientists that will look at the vacuum-sealed samples to study both the volatile element record and the geologic history of the Apollo 17 site.

The teams were selected by NASA’s Planetary Science Div. and will be funded by the space agency’s Lunar Discovery and Exploration Program. The goal is to get the most data possible from these samples in preparation for future lunar missions anticipated in the 2020s and beyond.

LLNL will conduct the measurement of noble gasses, as well as analyze major and trace elements and chronology on large clasts. Specifically, they will determine how noble gases were modified by meteorite impacts on the regolith, define the source of hydrogen in hydrogen-bearing minerals in the regolith, and investigate the origin of meteorites that hit the Moon through its history. The group will also determine the ages of samples in the regolith using a variety of dating techniques to better understand the timing of crust formation on the Moon.
One would have to consider these specimens to be essentially priceless and irreplaceable, at least for now.  Naturally nobody is just going to pop open the vacuum container and say, "now what?"  That's going to be decided long in advance.  Before that happens, the teams will meet at NASA's Johnson Space Flight Center in Houston for planning sessions to determine the best way to open the samples to avoid contaminating them or destroying opportunities to learn something from them.


Wednesday, April 17, 2019

Question for Fellow Google Bloggers

Is anyone else seeing a big increase in Spam comments?  A couple of weeks ago, I woke up to something like 10 comments to 10 different posts - like the last 10 posts I put up.  They all contained links to some commercial site.  Deleting Spam is "all in a day's work" as they say.

This is different.

It may be the way I have things set up that makes them standout to me, but lately I've been getting about a half dozen to a dozen Spam comments every day.  They're always to old posts, and this is the strange part, they will comment repeatedly to the same post over a period of days.  I've had posts from 2010 or 2014 that just get commented to over and over again.  It's like they latch onto that post and keep trying to get through.

The way I have the blog configured is that comments to posts over 14 days old go into moderation.  I do this for a couple of reasons: first, to know that comments to old posts have been made.  The blog displays about the last 30 posts, about a month, and I don't go watch comments on posts more than a few days old.  When they show up in my Gmail inbox, I can go read and react if necessary.  The second main reason is that older posts tend to be found by whatever mechanisms the spammers use and it's best to delete those comments rather than clog up the reading for people who come across the post later.  Occasionally, though, I get comments on old posts that are valid and related to the post.  I approve those and let them post.  My twin posts on getting ripped off by Ian Sinclair Design for their credit card knives are an easy, good, example.  Between the two posts, they got 128 comments over more than two years.   

These latest Spam comments have all sounded like they're either auto generated, or left by non-English speakers.  They alternate between random words, flattering comments on how wonderful the blog looks, or ask questions about things that seem designed to get me to respond.  It might be an AI system learning or just a simple SpamBot. 

My assumption is that if I post them, that will tell the spammers that they can post their ads or other things they're posting.  Or get their credit for whatever they're doing.

Anyone else seeing this?





(Spambot image source)


Tuesday, April 16, 2019

SpaceX's Falcon Heavy Wasn't A Perfect Day After All

News was released yesterday that the center booster of the Falcon Heavy was lost at the drone ship due to sea conditions.
"Over the weekend, due to rough sea conditions, SpaceX's recovery team was unable to secure the center core booster for its return trip to Port Canaveral," SpaceX representatives said in an emailed statement. "As conditions worsened with 8- to 10-foot swells, the booster began to shift and ultimately was unable to remain upright. While we had hoped to bring the booster back intact, the safety of our team always takes precedence. We do not expect future missions to be impacted."
This is the time of year when it's very common for the area around the Cape to get strong winds off the ocean and those winds bring rough seas.  While it's a shame to see them lose the booster, reality is the system has to be designed for these seas.  Balanced all the while against the cost of a ship that much bigger and more stable than the ones they're using.

It's widely reported that the ships are autonomous, and the crews are relocated onto another ship that stands back well away from the drone ship while the landing attempt is made.  The first step is for a crew to return to the ship and secure the booster to the deck by welding hold down brackets to the landing feet on the Falcon 9, according to the Wikipedia entry.  The statement from SpaceX makes it sound as if they viewed it too dangerous to deploy the welders onto the drone - or to leave them there if they were already aboard.

When you look at the feet of the booster, remember these things are a lot bigger than you might think.


The same view with some workers near the legs adds perspective.  Those hold downs aren't standard U-bolts you're going to find at Ace Hardware.  


And the Atlantic off the Florida east coast gains another stretch of artificial reef a bit over 225 feet long and 12 feet across.


Monday, April 15, 2019

Monday Odds and Ends - Peak Florida

Two stories that are short and don't belong together.

Peak Florida

You're probably thinking of more Florida man/woman stories.  This time it's a Florida Reptile.

You may know we have a problem with Burmese Pythons taking over the ecosystem in the Florida Everglades.  I know I've done a few stories on these (cool photo or useful map of python range).  Our local paper carried a story that shows even a bad python may have a silver lining (?)  It seems the pythons are killing off rattlesnakes by carrying a parasite that is decimating the pygmy rattlesnake population.
Now, Burmese pythons are killing — although indirectly — one of their own ilk, the pygmy rattler.

A new study, led by researchers at Stetson University, shows that parasitic worms spread by invasive Burmese pythons are killing native Florida pygmy snakes.

The researchers found the invasive worms in Central Florida, more than 100 miles away from where the Burmese pythons reside in the southern portion of the state. But that doesn't mean the pythons are there. The parasite is getting that far north by other means, hitching rides in reptiles and other host critters that Florida snakes eat, with risk of spreading far beyond the Sunshine State.
Yes, I know that rattlesnakes can be important predators in the ecosystem, but I don't mind a few less pygmy rattlers.  While I know people who have encountered very large eastern diamondback rattlers, pygmy rattlers are more likely to brush up against the people in suburbs and more rural areas.  

OTOH, this being Florida, Australia of the northern hemisphere, the pygmy rattlesnakes are probably keeping something even worse under control.



Back on the first Sunday of March, I posted about Mrs. Graybeard's painful trip over the hose while setting up to wash the cars.  For the rest of March and into last week, she was confined to a walker with instructions to not put any weight on that foot, along with lots of other restrictions.  We did x-rays every week to ensure the part of her thigh bone that broke off didn't displace but started to attach to the rest of her femur.  

Last Monday, week 5, the doctor cleared her to start putting more weight on that, and to get around on a cane instead of the walker.  We have both the cane and the walker from earlier "adventures" so it was easy to transition. She pretty much re-achieves some extra motion and extra ability daily, getting a bit more back to normal a little at a time. 

Today we did what we probably would have done a month ago, and went to our local multi theater to catch Captain Marvel.  Unless you pay no attention to the Marvel Cinematic Universe (MCU) you'll know that calling for Captain Marvel was Nicky Fury's last act at the end of Avengers Infinity War and there are scenes in the trailers showing her working with the remaining Avengers for Endgame.  It was originally rumored she was the only Avenger strong enough to take on Thanos.

Let me start out by saying this is a good movie that belongs in the MCU; it's not stuck on like they didn't know where else to put the character.  Both Mrs. Graybeard and I were dreading that it was going to be too full of "Grrrl Powerrr" stuff and it wasn't.  Captain Marvel is played by Brie Larsen, and back in 2017, when I wrote about Kong: Skull Island, I referred to her as "the designated pretty girl" part.  I didn't think much of her because she was really a background character playing a stereotype role in a comic book movie.  In this movie, she shows quite a bit more acting range and is actually quite good. 

The movie is Captain Marvel's backstory to help setup Avengers Endgame.  I don't really want to do paragraphs explaining the plot - go see it.  In using this movie to do Captain Marvel's story, they devote the full two hours to her story which makes much more sense than a half hour tacked onto Avengers Endgame.  This way, I'll bet Marvel makes both movies more watchable and gives a more complete storytelling than, say, the first half of Wonder Woman doing her backstory.

If Thor Ragnarok is my favorite of the MCU movies, I can't rate this one higher than that, but this was a good, fun movie.  Better than Black Panther, not as funny as Ant Man or Ragnarok, and better than I expected.  Good solid 4 and some change out of 5.  The movie starts with a modified opening that replaces the familiar flipping comic book pages with a tribute to Stan Lee.  Stan appears in this one in a cameo, and I understand he appears in Endgame, too.  The usual Marvel previews during and after the credits are worth waiting for. 

Oh, and watch for the cat, Goose. 



Sunday, April 14, 2019

Radio Sunday #3 - The Birth of the Modern Receiver

The Superheterodyne – Part 1

Now we're back where we started, before the look at earlier architectures for receivers. The most common receiver design is the superheterodyne, developed by Edwin Armstrong in 1918 – during World War I – and just after the Tuned RF design. Undoubtedly both men were working on the same problems and Armstrong found a way to overcome many of the problems of the TRF design along with other competing ideas. The superheterodyne principle of operation is followed in virtually every modern radio; whether or not that design is implemented in hardware or software.

So what does superheterodyne mean? It is essentially a buzzword; an advertising line. The best explanation I've read is that super was a big advertising word, hetero came from the word for “different” referring to different frequencies and dyne from power. Heterodyne has come to mean to combine two signals by multiplication, which produces the sum and difference of the two signals. This process is widely used, but it's usually called mixing, so that the components that do this on purpose are called mixers. Multiplication? Like light, if you put two radio signals through a medium like the air, or (for radio) a wire, they stay as their separate frequencies and don't affect each other. Only if you combine them in a circuit that affects their amplitudes nonlinearly will you get the sum and difference frequencies.

Let me present a block diagram of a superheterodyne (superhet) receiver that looks more conventional to hams and others who have studied some electronics than the one I posted in the Receiver Hunting story.



The big X in the mixer is to signify that it's multiplying two signals times each other; due to a property of math, when we multiply two sine waves, we get the sum and difference of the two frequencies.  Real mixer circuits put out four frequencies: the RF, LO, and the sum and difference frequencies.  From a circuit performance standpoint, the best mixers are called double balanced mixers; others exist but thousands or millions of double balanced mixers are sold every year.  The balance refers to electrical currents being balanced in the mixer to help with various performance measures I'll get to later. 

Without the demodulator and audio amplifier, this is a frequency converter.  Back around 1981, I made a shortwave converter for my car.  The local oscillator was two crystals in an oscillator set so one was switched on at a time.  They were set to 9.000 and 14.000 MHz.  The filter took the difference of the input minus the crystal.  That meant that with the 9.000 MHz crystal, 10.000 MHz WWV (time and frequency standard) came out at 1.000 MHz so I could listen to it on my pickup truck's AM radio.  Likewise with the 14.000 MHz crystal, 15.000 MHz WWV came out at 1.000.  I could listen to the “31 meter” and “19 meter” shortwave bands; 9.55 to 9.95 MHz and 15.1 to 15.4 MHz. 

This approach is universally used for frequency converters like this.  Some years later, I designed a two meter transverter for my ham radio station (transverters work for transmitting and receiving).  This took low level transmitter signals and mixed it with a crystal, taking the sum, not the difference.  For the oscillator, I used a 116.000 MHz crystal.  When I set to transmit at 28.000 MHz, the transverter output 144.000.  On the receive side, the system went the other way; it took in 144.000 MHz, subtracted off 116.000 and put 28.000 into the radio. 

There's problem lurking here.  All superheterodyne receivers will receive the undesired mixing product just as strong as the desired.  It's called the Image frequency.  In the case of my shortwave converter, I wanted to receive LO + IF.  My receiver would put out just as strong a response at LO – IF.   That would be at 8.000 or 13.000 MHz depending one which crystal I turned on.  That's why the block diagram has that RF filter at the input – to reduce the strength of anything on the image frequency.


(This image is based on the common IF of 455 kHz, mentioned below)

Mixers can be made in many different ways; Armstrong used vacuum tubes, and as transistors and FETs appeared, those were adopted into service.  The following picture shows what's called a Double Balanced Mixer: a four diode bridge with the Local Oscillator applied on the left, the Radio Frequency applied on the right and the Intermediate Frequency taken out of the tap at the lower right.  These also work “the other way”.  If you apply a low frequency to the IF, perhaps your modulated audio for a transmitter, the RF port becomes an output, not an input.



So why do we do this?  Why do we build an oscillator into the radio, and add the mixer stage?  The architecture buys you some important things
  • It allows you to spread out the gain between RF, IF and audio.  For ordinary use, you might need gain of over a billion.  That would surely oscillate if the radio was all one frequency.  If you spread the gain out intelligently, the chance of a problem goes to zero.  
  • You only tune two circuits: the RF filter and the Local Oscillator.  In practical radios, your RF filter may be switched from a bank of similar circuits as you change bands, and the LO will have components switched so it can tune several bands.  Most of the fussiness of tuning wide frequency ranges in the TRF approach goes away.  
  • You have most of the receiver working on one frequency.  Amplifiers and filters change performance as you tune across your frequencies of interest.  Typically, the higher you tune, the lower the gain goes.  Now you have one stage to be concerned about.  Ordinarily, the IF filter is where the ultimate channel selectivity is obtained; with this approach it stays the same whichever RF band you tune. 
This architecture is universal.  It can mix a low frequency signal up to a higher IF or mix a higher signal down to a lower IF (appropriately called upconversion or downconversion).  Cheap AM radios (remember them?) settled on an IF just below the bottom of the AM broadcast band, 455 kHz, long ago.  Multiband radios with shortwave coverage sometimes upconvert to another IF, usually because there's a filter they want to use first, then downconvert to 455 kHz, in an architecture called dual conversion.  Microwave receivers downconvert, sometimes a dual conversion, to get to a frequency where the signals are processed. 

The block diagram above is single conversion.  High performance receivers in the vacuum tube era went to double and sometimes triple conversion (I haven't personally seen quad conversion, but they might be out there).  Double conversion is still very common.  A very common technique today is to convert the entire receive spectrum, from 0.5 to 30 MHz up to around 70 MHz, filter and amplify, then downconvert to a lower frequency, sometimes in the low kHz.  For example, an Icom 7600, their last superheterodyne HF radio, upconverts to a “roofing filter” (no signal wider than that gets into the rest of the receiver) at 64.455 MHz then downconverts that to 36 kHz where the signal is digitized and all the signal processing is done digitally.

There's an application of the superheterodyne principle that has become widely adopted among hams and is now a frequently used architecture in commercial wireless systems.  Hams call it direct conversion, and the novelty of this architecture is that the IF is 0 Hertz – DC.  The architecture could be the same as previously shown, but in most ham uses, the mixer is the detector. 


In modern radios, the audio filter will usually amplify was well, so it's not a big change.  

So how does this work?  A common example might help: consider you want to make an amateur receiver with minimal power drain, and small enough to fit in a tiny package for backpacking or camping.  You want 40meters (7.0 to 7.35 MHz).  The local oscillator tunes that range (usually called a VFO for Variable Frequency Oscillator).  We know the mixer will give us the sum and difference frequencies, and we want to tune in someone transmitting Morse Code (CW) on 7.025 MHz.  If we tune to exactly 7.025, the receiver would hear nothing.  At this point, you could be using a multi-thousand dollar receiver.  Most of those  receivers offset the display from where you're tuned so that when the display reads 7.025 the LO is really offset from that, and the tone you hear in the speaker is from that offset.  They have a separate product detector, which is a mixer and Beat Frequency Oscillator, BFO.

Instead, we tune the VFO slightly off the exact frequency by tuning it to make a Morse code tone we like.  We've made our demodulator into a product detector and our LO is their BFO.  The problem is that you also hear the image frequency if someone is transmitting on it - the signal that's the same offset as the desired on the other side of the LO.  If your LO is at 7.024, you'll hear someone on 7.023; if your LO is at 7.026, you'll hear someone at 7.027.

In effect, you double the number of potential interfering signals.  This is called the Single Signal problem with direct conversion.  There are ways to reduce it, but it's always there.

The main drawback of the superheterodyne architecture is the complexity of having more parts in more circuits, so cost and complexity.  As a rule, whenever we introduce new circuit blocks and complexity, we have a tendency to fix some problems and introduce others.  In the vacuum tube era, receivers used crystal oscillators and VFOs as their LOs to change bands.  Starting primarily in the 1970s, with digital integrated circuits, those began to be replaced by frequency synthesizers (Phase-locked loops or PLLs).  When those were introduced, problems the existing circuits didn't have started to show up, and radios took a giant leap backwards until that was understood.  Similarly, when transistors replaced vacuum tubes, problems with strong signal handling surfaced that the high standing voltages or currents of vacuum tubes masked, and it took years to understand that, too.

A less obvious problem is that mixers, being the only deliberately nonlinear component in the radio, can introduce problems with hearing signals that aren't really there.  The image is not considered one of these.  The details are probably more of interest to designers than people just trying to learn about how receivers work but makers of mixers sometimes provide charts of all the undesired products their mixers will receive.  Double balanced mixers are better in this regard (better suppression of undesired) than single balanced, or unbalanced mixers, but the "spur table" has to be designed for.   Here's where I get to wave my hands and say, "that's beyond the scope of this article". 


Saturday, April 13, 2019

A Hundred Years of Food Prices Compared

From the Foundation for Economic Education, author Marian Tupy got motivated by a quote from Twit of the Year, Alexandria Occasionally Coherent, to compare food prices after a century of largely free market forces working in American agriculture.   It was the famous quote in which she babbled:
Capitalism is an ideology of capital—the most important thing is the concentration of capital and to seek and maximize profit... we’re reckoning with the consequences of putting profit above everything else in society. And what that means is people can’t afford to live.

“Capitalism is irredeemable,” she concluded.
I'm not sure if this is the talk where she said unemployment was low because everyone had two jobs.

I'm not sure how obvious this is, but it's tricky to try to compare prices from a hundred years apart.  We know, for example, that inflation has decimated the dollar, but that's hard to separate from that other price trends.  Appliances and electronics have gotten cheaper, for example, but everything where the market has been broken by the government has gotten more expensive; things like education and health care, and then products that are highly regulated, such as automobiles, homes and aircraft.  A 2019 car might cost far more than a 1969 car, but it has been regulated extensively in terms of gas mileage, crash safety, and a host of other things.

His bottom line conclusion is that food in America has become almost eight times cheaper relative to unskilled labor over the last 100 years.

Here's what he did.  First, he obtained a report called:
Retail Prices, 1913 to December 1919: Bulletin of the United States Bureau of Labor Statistics, No. 270, which was published in 1921. On pages 176-183, we encounter nominal prices of 42 food items—ranging from a pound of sirloin steak to a dozen oranges—as registered in the city of Detroit in 1919. Those can be seen in the second column of the attached graphic.


The next step was to derive the hourly wage for unskilled labor in 1919, using a 1774 to 2016 scale at www.measuringworth.com and re-indexing it to 1919.  This gave a pay rate of 25cents/hr for unskilled labor in 1919.  Finally, 2019 prices for items as comparable as could be determined were obtained from www.walmart.com - chosen because it was believed to be a place many unskilled laborers shop. For reference, the 2019 pay rate for unskilled workers calculated to be $12.70 per hour.

Their conclusions:
  1. The time price (i.e. nominal price divided by nominal hourly wage) of our basket of commodities fell from 47 hours of work to ten, 21.2 %, (see the Totals line in column five).
  2. The unweighted average time price fell by 79 percent (see the Totals line in column six).
  3. Put differently, for the same amount of work that allowed an unskilled laborer to purchase one basket of the 42 commodities in 1919, he or she could buy 7.6 baskets in 2019 (see the Totals line in column seven).
  4. The compounded rate of “affordability” of our basket of commodities rose at 2.05 percent per year (see the Totals line in column eight).
  5. Put differently, an unskilled laborer saw his or her purchasing power double every 34 years (see the Totals line in column nine).
I know that "Big Ag" gets its criticisms around the web, Bayou Renaissance Man ran one just nine days ago, but the results of this century long change in agriculture has led to quality of life improvements for all of us, here measured by the poorest among us.  Add in that American agriculture has brought food as foreign aid to many places around the world.  An average time price decline of 79% is a big improvement in life.  It means, picking one item from the second chart, that a pound of sliced ham went from costing 2.27 hours (2 hours, 16.2 minutes) in 1919 to costing 0.24 hours (14.4 minutes), so a full two hours of pay is freed.  It means that there's more money at the end of the week for other things.

What "factory farms" buy us consumers is the "Iron Law of Production", which says that as quantity doubles, price comes down by roughly 25 to 30%.  Larger farms can economically justify techniques that smaller farms can't.  Yes, I'm aware of the general protests against living conditions for livestock on these farms, and I'm sympathetic to some of it, but I see that as a first world problem.  Look at it this way: if you were a starving Venezuelan eating out of garbage can, because there are no zoo animals or pets left, do you eat the "factory farmed" ham or do you keep starving?   I think modern small farm techniques for raising livestock more humanely while keeping total costs down have a lot of room in the market.

That's getting lost in the weeds, though.  The bottom line is that the system AOC loves to hate has done very well for Americans, while the system she loves produces Venezuelans eating out of garbage cans.  Her quote that "...people can’t afford to live," due to capitalism is proven, demonstrably false.  People today have it much better than they did a hundred years ago.

I think author Marian Tupy hits it out of the park with his closing quote:
Joseph Schumpeter, the famous economist who served as Austrian minister of finance in 1919, observed that the
capitalist engine is first and last an engine of mass production which unavoidably also means production for the masses … It is the cheap cloth, the cheap cotton and rayon fabric, boots, motorcars and so on that are the typical achievements of capitalist production, and not as a rule improvements that would mean much to the rich man. Queen Elizabeth owned silk stockings. The capitalist achievement does not typically consist in providing more silk stockings for queens but in bringing them within reach of factory girls.
To those silk stockings we can now add food.

EDIT 2202 EDT 4/13/19: to add the Walter Williams image I forgot.



Friday, April 12, 2019

Use By Date Approaching

Ran into this cartoon Tuesday and better use it before its "Use By" date gets here.


(Steven Breen)

Read those as Dr. Seuss prose, it works better. Unfortunately, I was unable to find a referenced story, but the list of ideas California's state legislature is contemplating was discussed in a few places as recently as last weekend, IIRC.

I did find a couple of interesting stories that illustrate the problem.  At Town Hall, Austin Hill writes about a proposal to implement a "third income tax" to pay for education.  The existing two are their California state income tax and the Federal Income tax. 
But now California, with an average statewide unemployment rate of over 12% (in some regions the rate is over 20%) and a budget deficit of somewhere between $10 and $15 billion, is considering the imposition of a third income tax. The additional income tax rate would vary, according to which region of the state one lives in, and would be imposed directly by school districts and county governments.
See, back in 1978, California voters passed a thing called "Proposition 13" which capped the amount that property tax could be raised year over year.  That means California school districts are broke just like the state.  They can't do what many other school districts in America do, and just raise property taxes by leaps and bounds every year.  Under the proposal, school districts will gain the right to decide on their own income tax levels to charge people living in their district. 

Do you find it surprising that they're getting legislative support for this idea?  If so, are you considering the government employee unions, long since joined at the hip with the Democrat party would like some of that sweet taxpayer money, too?

To add a little more context, Victor Davis Hansen, writing in the Daily Signal points out a couple of things to note.
For over six years, California has had a top marginal income tax rate of 13.3%, the highest in the nation.

About 150,000 households in a state of 40 million people now pay nearly half of the total annual state income tax.
That last one is astounding.  That means 0.375% of tax payers pay half of the state's income tax revenue.  No wonder ordinary Californians keep electing the people they do.  Everything they vote for comes with the fact that someone else is paying for it.  It's OPM - Other People's Money - the most addictive substance in the world.  In addition:
  • California recently raised gas taxes by 40% and now has the second-highest gas taxes in the United States.
  • The state has the ninth-highest combined state and local sales taxes in the country, but its state sales tax of 7.3% is America’s highest.  As of April 1st, that sales tax is applied to any purchases from out of state merchants.  
  • Scott Wiener, a Democratic state senator from San Francisco, has introduced a bill that would create a new state estate tax. Wiener outlined a death tax of 40% on estates worth more than $3.5 million for single Californians or more than $7 million for married couples.  Since $3.5 million will essentially buy a cardboard box to live in in San Francisco, that will impact families who have passed a home down generation to generation.  The current owners will lose those houses.
  • In January, new governor Gavin Newsome proposed a tax on drinking water.  I'm sure that's an additional tax on water because I can't imagine people aren't already paying at least one tax on their water, if not several.   
It's no surprise that middle class Californians are moving out of the state.  I found it surprising that the rich are moving to California.  They're moving to the expensive cities and driving up housing prices which help force the lower income Californians out of state. 

I think California is working toward the Venezuela model of having a few rich people, mostly people living on handouts, and no middle class. 



Thursday, April 11, 2019

I Don't Care Who You Are - That Was Cool!

Mrs. Graybeard and I just enjoyed watching the second launch of a Falcon Heavy (FH) from historic pad 39A on the Kennedy Space Center.  There has been a great deal of buzz about this launch with some local sources saying they expected a couple of hundred thousand visitors to the immediate area around the KSC. 

You know, there's only a handful of places on Earth where you can see launches like this, and no other place to see a launch quite like this one.  The FH is the most powerful rocket at liftoff on Earth, but not the most powerful ever, at over 5 million pounds of thrust - the Saturn V that took our crews to the moon had a liftoff thrust of over 7 million pounds.  For every other launch besides a FH, you see a rocket lift off and disappear in the distance.  From a practical standpoint, once it's a minute or two into flight, you don't get a better view of a launch from as close as you can get to the pad as you do from anywhere along the coast.  With the FH, though, you can get this if you get close:


This view of the two side rockets from the Heavy landing is, of course, from the SpaceX video feed, but soon you'll be able to see somebody's home video from nearby.  (I just checked, no videos of tonight's launch yet, just one from a year ago).  The landing site isn't very close to anyplace tourists can get, but is closest (straight line) to Port Canaveral Jetty Park.  I've seen videos taken from Playalinda Beach at the north end of the KSC and they're not terrible.  

Unlike their test flight last February, this time SpaceX got the center booster recovered, too.  Due to the way the flight is structured, the center core doesn't shut down until the first two boosters have dropped, and the remainder of the rocket stack is too far down range for the center booster to make it back to the land.  This is why they have their autonomous recovery drone, and they stuck the landing this time.


The drone ship is so far off the coast that it's way below the horizon, so there's no chance of seeing that.  The booster landing area can be seen from nearby, but the only time we've ever seen the return burn was during the night launch for the Crew Dragon test.  We can hear the sonic booms of the returning boosters, though, and heard them tonight. 

Mrs. Graybeard and I settled on the "Space Coast" in the early days of the Shuttle program, 1982, and I had always wished that I had taken the few hundred mile trip from where I grew up in north Miami to see a Saturn V launch.  Stories I've heard from locals who were on the cape for one of those launches have only turned that into a haunting want.  We seem to be entering a new renaissance of space with plans on the book to get back to the moon relatively soon - whether that's on NASA's SLS, a private sector rocket or some combination is a decision that's still a long way out.  Maybe I'll get a chance to see a moon rocket after all.



Wednesday, April 10, 2019

One of the Oldest Electronics Jokes Sorta Comes to Life

In the early days of my life in electronics, today's ubiquitous Light Emitting Diodes (LEDs) were not very common; in fact, they were somewhat exotic.  Every April Fools Day, someone would pass around a joke about the new invention called the Dark Emitting Diode or DED.  I guess some jokes  never die

That's a long introduction to a story in Electronic Design magazine about a using an LED backwards to absorb light.  Light absorbing is sort of like Dark Emitting.  Sort of.  Making it either a DED or a LAD, but they start the story with "This is not an April Fools joke". 
Researchers at the University of Michigan (Ann Arbor) have used an infrared light-emitting diode (IR LED) with its electrodes reversed to cool another device just nanometers away.
The reverse biased IR LED is held 55 nanometers, about 2 millionths of an inch, from the device they intend to cool.


Linxiao Zhu shows the experimental platform that housed the calorimeter and photodiode. This system can damp vibrations from the room and building, steadily holding the two nanoscale objects 55 nm apart. (Source: Joseph Xu)
Reversing the positive and negative electrical connections on the IR LED makes it behave as if it’s at a cooler temperature than the ambient. The reverse connection not only keeps it from emitting light, but also can induce the LED to suppress the thermal radiation that it would be emitting.
ED makes it clear that the physics behind this is well established, and in use in other laboratory techniques.  They describe the very intricately crafted experiment that was needed to verify the effect, which depended on creating a tiny calorimeter (80 microns in diameter - .00315").  The source of heat and the LAD were separated by "a subwavelength nanometer-size gap", which is ambiguous, but earlier in the story mentioned a separation of 55nm, so assume around that.  
The researchers showed that when the calorimeter and reverse-biased LED are in each other’s near-field, with a vacuum gap between them of just tens of nanometers, this evanescent cooling occurs via two mechanisms. One is photon tunneling (which enhances the transport of photons across nanoscale gaps), while the second is suppression of photon emission from the photodiode (due to a change in the chemical potential of the photons under an applied reverse bias).
So what?  One of the pernicious problems in electronics is getting rid of the heat generated in small components.  One possibility for this cooling is to have coolers built into packaged components.  I can envision photonic cooling systems being built into more complex parts, perhaps going 3D in the package, like some memory chips are now doing.  In the published Nature article, they claim heat removal of 6 Watts per square meter.  Unfortunately - that number means nothing to me in terms of how effective this solid state cooling could be at cooling practical processors, memory chips, and other components.  It sounds awfully small though. 

The thing about the DED joke, though, as that in those days this would have seemed like something from Star Trek (The Original Series), like Spock himself had given it to us.  It would have been unimaginable. 



Tuesday, April 9, 2019

The Story of the Chinese Woman At Mar-a-Lago Takes a Nasty Turn

The story of the Chinese woman who was apprehended at Mar-a-Lago with, shall we say, suspicious items in her possession took a turn for the more sinister Monday.  Ars Technica brings a detail I've seen nowhere else.  First, some necessary background info for those not fully familiar with the story.
The already suspicious account of a Chinese national who allegedly carried four cellphones, a thumb drive containing malware, and other electronics as she breached security at President Trump's private Florida club just grew even more fishy.

The possessions in Zhang's hotel included five SIM cards, nine USB drives, yet another cell phone, and a signal detector that could scan an area for hidden cameras, according to reports widely circulated Monday. In addition to the electronics, Zhang's hotel room also contained more than $8,000, with $7,500 of it in US $100 bills and $663 in Chinese currency, The Miami Herald reported.
Zhang was in court Monday to decide if she gets bail.  The Feds argue that she's a flight risk because she has no ties to the US and (direct quote), "She lies to everyone she encounters."  None of this seem particularly weird.

The first thing that seems weird is that in addition to the "signal detector that could scan an area for hidden cameras" (probably something like the eBay "bug detectors" that receive on frequencies common cameras use) is the sheer volume of hardware she was carrying.  When she was first stopped, she was carrying two Chinese passports, four cellphones, a laptop computer, an external hard drive, and a thumb drive.  Back at the hotel where she was staying they found a fifth cellphone, five SIM cards, and nine more thumb drives.  $7500 in $100 bills and another $663 in Chinese currency seems like expense money.  The thing that stands out as really unusual is the particularly nasty malware on that thumb drive they grabbed a Mar-a-Lago.  According to Ars, quoting the transcript from the hearing:
Secret Service agent Samuel Ivanovich, who interviewed Zhang on the day of her arrest, testified at the hearing. He stated that when another agent put Zhang's thumb-drive into his computer, it immediately began to install files, a "very out-of-the-ordinary" event that he had never seen happen before during this kind of analysis. The agent had to immediately stop the analysis to halt any further corruption of his computer, Ivanovich said. The analysis is ongoing but still inconclusive, he testified.
I'm nowhere near expert on tradecraft and I couldn't tell you if this seems like she's a Chinese agent, a freelancer, or working for a domestic Democratic candidate.   It does seem like this is a bit more than casual.  A noteworthy exchange during the bond hearing went like this
Adler, Zhang’s attorney, pushed back during the hearing on the idea that she was a spy.

“She did not have the type of devices that can be associated with espionage activities,” he said.

Garcia, the prosecutor, replied that “there is no allegation [in the criminal complaint] she was involved in espionage ...”
Adler's line is stupid.  A pencil can be "associated with espionage activities".  Garcia saying, "we never said she was a spy" is also stupid.  Especially because he also said he wouldn't rule out charging her with that later, or "more serious charges."

This is the very beginning of the beginning; think page 2 of a 400 page novel.  I wanted to believe that agent Ivanovich's partner, the one who plugged the USB stick into a laptop, wasn't using just a regular agency laptop, but rather one that was air gapped to any other SS machine, and was to be used for this purpose.  However, he specifically said, "... had to immediately stop the analysis to halt any further corruption of his computer" and that quote doesn't go together with using a special computer designed for forensic examinations.

I'd like to think the Secret Service is not so dumb they're going to plug a piece of irreplaceable evidence that could contain anything into a plain agency laptop, but it seems like they did.  Jake Williams, a former hacker for the National Security Agency who is now a cofounder of Rendition Infosec, said on Twitter,  "As a taxpayer, I'm very concerned about where Agent Ivanovich's laptop is and where it's been since he plugged a malicious USB into it. If this was the Secret Service quick reaction playbook, perhaps Zhang planned to get caught all along (not joking)."
A Secret Service official speaking on background told Ars that the agency has strict policies over what devices can be connected to computers inside its network and that all of those policies were followed in the analysis of the malware carried by Zhang.

"No outside devices, hard drives, thumbdrives, et cetera would ever be plugged into, or could ever be plugged into, a secret service network," the official said. Instead, devices being analyzed are connected exclusively to forensic computers that are segregated from the agency network. Referring to the thumb drive confiscated from Zhang, the official said: "The agent didn’t pick it up and stick it into a Secret Service network computer to see what was on it." The agent didn't know why Ivanovich testified that the analysis was quickly halted when the connected computer became corrupted.
I've never seen a word about any computers being compromised at Mar-a-Lago, although I seriously doubt they would tell us.   Oh, and "they say" that the head of the Secret Service, Randolph ‘Tex’ Alles, stepping down has nothing to do with this. 

Again, it's very early in the story.  Everything we think we know is probably wrong.


Mar-a-Lago, White House Photo


Monday, April 8, 2019

NASA-Funded Mission Fires Two Rockets into Aurora, Injects Tracers

Late Friday night, two sounding rockets launched from a small spaceport in northern Norway.  The two small rockets soared to an altitude of  200 miles (320 km), and each released a visible gas intended to disperse through and illuminate conditions inside the aurora borealis. Some of the resulting images of the blue gas from the rockets interacting with the green auroras  were stunning.

The two rockets each had four capsules that released the gas in an impressive light show.  At 2226 UTC the first rocket had dropped is blue gas:


Five minutes later, at 2231 both rockets' clouds were reaching full density.


This was the AZURE mission:
This NASA-funded AZURE mission, which stands for Auroral Zone Upwelling Rocket Experiment, is one of a series of sounding rocket missions launching over the next two years as part of an international collaboration known as "The Grand Challenge Initiative – Cusp." The goal of these flights is to study the region where Earth's magnetic field lines bend down into the atmosphere, and particles from space mix with those from the planet.
...
After their launch, the two rockets ascended into space while onboard instrumentation measured the atmospheric density and temperature in order to determine the ideal time to release visible tracers—trimethyl aluminum and a barium/strontium mixture. These gas tracers were released at altitudes varying from 115 to 250km.
ARS Technica included this time lapse video of the experiment made by a guy who just stumbled across the experiment going on.  It's 18 seconds - watch it.  Then I bet you watch it again. 



I would have loved to have seen this!  Seeing the auroras has been on my bucket list for as long as I can remember.