Monday, January 30, 2017

Tricks A Dumb Grid Can Play


Inauguration Day in Brookville, Pennsylvania arrived with a bang. Within minutes after Donald Trump swore to preserve, protect, and defend the constitution of the United States, the 911 calls began.  In one house, light bulbs were exploding.  Another resident reported that a power strip was smoking.  At another house, the siding was on fire, and at yet another the electric meter was engulfed in flames.  The main radio transmitter at the police station tripped out, so the 911 call center was unable to contact them until the dispatcher used his battery-powered radio to make contact.  In all, about 400 residents of the small western Pennsylvania town of 3800 suffered some type of damage, ranging from singed carpets to fried computers and exploding fluorescent light fixtures.

The power surge had nothing directly to do with Donald Trump.  A quick investigation by Penelec, the local electric utility, revealed that an insulator on a power line had failed.  What follows here is my extrapolation from the limited details in the Associated Press wire story, but represents what I think is a good guess.

Electric power networks are divided into transmission lines and distribution lines.  The transmission lines are the tall steel-framed towers that span many miles across the countryside, and are the interstate highways of the electric grid, transmitting megawatts of power from generating plants to substations many miles away.  To transmit this much power efficiently, the voltage of these lines is generally above 100,000 volts (100 kV).  For example, there is a 138-kV transmission line that connects Brookville with the rest of the power grid in western Pennsylvania, and there may be others at even higher voltages.
           
Once power arrives at a substation, it is stepped down in voltage with large, expensive units called transformers to a lower voltage suitable for distribution locally.  Distribution lines, the neighborhood streets of the network, carry voltages in the range of 12 kV to 35 kV, or occasionally higher in rural areas.  My guess is that Brookville has at least two or three separate distribution circuits with voltages in the 25-kV range.  The familiar wooden power poles that carry telephone and cable TV lines also support power-distribution cables, always suspended on the highest point of the poles.  Every few hundred feet, a "pole pig" (distribution transformer), usually a metal can a couple of feet tall, lowers the voltage still more to 240 V or less for delivery to commercial and residential customers. 

What probably happened was this.  One of the high-voltage insulators on a transmission line carrying in excess of 100,000 volts failed mechanically, dropping its conductor on or near enough to one of the town's distribution lines to allow a flashover (an arc) to jump from the 100+ kV transmission line to a 25-kV distribution line.  All power-line insulators are built with a safety margin.  That is, an insulator for a 25-kV line may be able to withstand 50 or even 100 kV, which can happen during situations such as lightning surges and so on.  This is good in normal circumstances, but in this case it backfired.

The insulation of the 25-kV distribution line held just long enough for the high voltage, four or five times normal, to get into the distribution transformers and ultimately the houses of about ten percent of the town.  So for a few seconds or maybe even longer, equipment designed for 120 V was receiving, say, 500 or 600 V. 

There are kooks on YouTube who delight in taking innocent electric appliances such as razors, clocks, toasters, light bulbs, and so on, and connecting them to high-voltage power sources just to see what happens.  They are never pretty.  Every electric appliance has a maximum rated voltage, and when you exceed it by 500% you either blow a fuse or, in the case of equipment that doesn't have fuses such as light bulbs, the excess heating makes something melt or vaporize or explode. 

Many power strips have surge-arresting devices in them meant to absorb fast transient surges caused by lightning.  But those surges usually last only milliseconds, and a surge of several seconds overheats such a device, making it smoke, which explains the reports of smoking power strips. 

Why didn't all the protective devices that a utility normally uses, such as fuses and circuit breakers, operate right away?  Because they are designed primarily for lightning strikes, not an overvoltage that lasts many seconds.  And the fuses probably didn't blow right away because a fuse only slightly over its rated current takes a considerable time to melt. 

Penelec has announced that they will compensate those who have suffered losses as a result of the surge.  Fortunately, no one was injured, but a considerable amount of property was damaged and the mess will take weeks or months to clean up. 

The "dumb grid" in the title refers to the fact that most electric utilities still use protective technology that was developed prior to World War I, for the most part:  fuses and electromechanical relays.  Innovative "smart grid" technology connecting the power grid to the Internet and replacing many electromechanical controls with faster-acting solid-state devices promises a number of good things, mainly pertaining to increased efficiency and reliability.  But it's also possible that if Brookville's grid was smarter—that is, if it could have figured out within milliseconds what happened and cut off the surge then—none of the bizarre damage might have occurred.

Admittedly, situations in which a transmission line arcs over to a distribution line are rare.  But as Brookville shows, they can happen.  If the new Trump administration wants to improve America's infrastructure, encouraging utilities to take the smart-grid path is one way to do it.  Whatever Washington does about it, though, it's too late for a few hundred residents of Brookville, who are still replacing siding, light bulbs, and computers as a result of a freak accident that shows we still have a ways to go in improving electric utility safety and reliability.

Sources:  The Associated Press report on the Brookville incident of Jan. 20, 2017 was carried by a number of news outlets, including  PressFrom.com at http://us.pressfrom.com/news/us/-21781-tiny-towns-power-surge-fries-computers-appliances-siding/ on Jan. 28, 2017.

Monday, January 23, 2017

Radiation: The Unsolved Problem of Space Travel


These appear to be great times for future space travelers.  Commercial rocket outfits such as SpaceX are thriving, the Dutch organization Mars One is still refining their pool of potential Martian astronauts for a flight presently scheduled for 2032, and National Geographic's "Mars" docu-drama TV series has intermingled interviews with space experts and a dramatic portrayal of what an actual flight to Mars might be like, complete with death-defying crises. 

Then along comes Charles L. Limoli, a radiation biologist at UC Irvine, with his mouse brains shot full of holes, as he describes in an article published in the February 2017 issue of Scientific American.  They're not holes you can see with the naked eye—just tracks of ionization damage caused by nuclear particles intended to simulate the damage caused by cosmic rays and solar particle radiation that a typical years-long round trip to Mars would involve.  The bad news Limoli has is that when you take smart mice and shoot their brains with that much radiation, it damages certain fragile parts of the nerve cells:  the dendritic spines.  And they don't grow back.  So even high-IQ mice who get zapped in a NASA particle accelerator designed to simulate the type of radiation that astronauts will be exposed to, end up with what amounts to a mouse form of Alzheimer's.  The performance of these mice in certain mouse intelligence tests (don't ask me how they figured out how to do that) fell to only 10% of what it was before the zapping.  And the damage seems to be permanent, at least in mice.

So what, you say?  We'll just shield the space capsule.  Think again.

The more energetic a particle is—the faster it's going and the heavier it is—the harder it is to shield against.  Turns out that galactic cosmic rays, which are one of the two main kinds of radiation astronauts on deep-space missions will encounter, are the highest-energy particles known, with many of them having more energy than the most powerful earth-bound particle accelerators can produce.  The only practical radiation shielding presently used involves putting a lot of heavy stuff—concrete, steel, lead—between you and the radiation.  On earth, this isn't such a problem if you happen to have a disused salt mine handy—you just go underground.  But weight is the enemy of space travel, and a rocket that was shielded well enough to reduce cosmic-ray fluxes to something comparable to what we encounter on earth (shielded as it is by its magnetic field and atmosphere) would be prohibitively heavy.  We are talking shield thicknesses of many feet, all around the living areas of the vehicle. 

So at present, all these nice dreams of people spending years in deep space are still only that—dreams.  Based on the work of Limoli and others, sending astronauts on an unshielded rocket to spend a year or more in deep space would likely turn their brains into Swiss cheese, radiation-wise, with dire consequences that would affect everyone on board.  I don't know about you, but I can't think of a more depressing end to a space flight than to have everybody turn into candidates for assisted living in a matter of months.  And that's just if we try to get to Mars.  If the astronauts somehow manage to get there without losing their minds, the first thing they'd have to do would be to dig a deep burrow to shield themselves, or apply whatever unknown shielding technology they used on the trip to the newly established colony as well.

Space optimists look at this problem as just another speed bump on the road to Mars.  There may be medical ways of alleviating some of the damage that radiation causes to neurons.  But any such treatment is far in the future, and prospective space travelers need it now.  There is even less likelihood of finding a lightweight way of shielding against high-energy cosmic rays.  The physics of the problem has been well understood for decades.  In principle, you could use magnetic fields to create a shield, but the field intensity to deflect such particles is absurdly high—even the superconducting magnets in  today's MRI machines, which have to be carefully isolated from any ferrous object, probably wouldn't do the job.  And if you don't do something, you're condemning your space travelers to virtually certain mental decline.  Of course, some may think that this is just a risk we have to take.

Having watched the entire National Geographic "Mars" series over the Christmas holidays, I noted a disturbing tendency on the part of some enthusiasts for what I would term secular millennialism.  The religious millennialists called the Millerites were followers of William Miller, who convinced both himself and many others that he had figured out when the second coming of Christ would occur:  Oct. 22, 1844, about ten years ahead of when he was writing.  In the years leading up to 1844 he accumulated a large following who sold their farms, businesses, and houses and gathered in small groups, waiting for the big day.  In what became known as the Great Disappointment, nothing unusual happened, either then or later.

Secular millennial movements such as classical Marxism exact arduous and even painful sacrifices today for a promised millennial paradise tomorrow—and somehow, tomorrow never comes.  Some present-day promoters of deep-space travel have convinced themselves that the future of the human race lies not on Earth, but on Mars or other places where we'll be able to start over again and do it right.  If you really believe this, it's going to affect your attitude toward life on Earth.  After all, if we're just going to move soon, why paint the walls? 

It's not clear at this point whether radiation will pose a "deal-breaker" problem to deep-space travel.  I suppose if we get clever enough about orbital assembly stations, we could eventually manage to build a rocket that could carry enough conventional shielding to protect astronauts on their way to Mars.  But that does not seem to be in the current plans of many space enterprises. 

If somebody started calling for volunteers, or even offered lots of money, for people to jump off a thousand-foot cliff without parachutes "just for the experience," I hope we would find a way to shut them down.  That hasn't happened so far with Mars One, the Dutch outfit that is currently selecting people to go on a one-way trip to Mars.  But if by the time astronauts gets to Mars, their brains are so fried that they don't know where they are, it would be a shame for everybody—especially the astronauts and those who put them knowingly into a situation that was going to end badly. 

Maybe we'll figure this one out, but in the meantime, any time I see someone promoting manned deep-space flight, I'll be wondering what they plan to do about radiation.  And so far, I don't see anyone taking it seriously enough.

Sources:  Charles L. Limoli's article "Deep-Space Deal Breaker" is on pp. 54-59 of the Feb. 2017 edition of Scientific American.

Monday, January 16, 2017

No Airbags for Takata's Crash


The story of Takata Corporation's defective air-bag inflators is one we've been following for the last couple of years.  Last Friday, Jan. 13, Takata itself received what amounts to a corporate deathblow by admitting guilt in a single criminal charge brought by a Federal grand jury in Detroit.  In the agreement, Takata will pay a total of $1 billion which will go to fines, to compensation for individuals who were killed or injured by defective inflators, and mostly to car companies who bought the bad inflators, and who are now facing the world's largest recall headache.  Takata is expected to file for bankruptcy and be sold or liquidated shortly thereafter. 

First, some background.  Air bags are safety devices which demonstrably save lives.  An older friend of ours who was driving her pickup truck when it was hit by a delivery van a few months ago is alive today, thanks in part to the airbags that went off in her truck cab.  But when a safety device turns into a deadly weapon, as a certain fraction of Takata air-bag inflators do, you have the automotive equivalent of razor blades in Halloween candy.  That's not what's supposed to be going on.

By admitting guilt, Takata has implicitly endorsed the findings of the Federal indictment that charges three managers in particular with covering up the defects in the air-bag inflators for over a decade.  As we discussed in an earlier blog on this matter, air bags work by setting off a propellant chemical that is supposed to burn in a controlled way, releasing lots of gas rapidly to inflate the air bags.  But a controlled burn is not an explosion, and if the propellant detonates instead, the spike in pressure can rupture the metal container, sending shrapnel toward the vehicle's occupants.  This has happened worldwide hundreds of times with Takata inflators, resulting in over a hundred injuries and sixteen deaths. 

The requirement for controlled burning is tricky, and various chemicals have been used over the years.  One of the main challenges with airbag inflators is to make sure they'll work when needed after years of changing temperatures and humidity inside a car body.  This calls for chemically stable propellants, which tend to be expensive.

Takata had the notion years ago of using one of the cheapest propellants around:  ammonium nitrate.  It can be made to burn controllably, but it is sensitive to humidity and can turn into a highly explosive state unless protected from moisture.  Internal Takata tests showed that their ammonium-nitrate inflators tended to leak, leading to instability of the chemical and the possibility of an explosion when triggered. 

What the indictment shows is that the Takata executives intentionally and repeatedly falsified test data as long ago as 2005, calling it "XX-ing" the data, in order to keep selling the inflators to automakers.  When problems with the Takata inflators began to surface, the company first ascribed them to isolated manufacturing issues.  But investigations have revealed the truth:  Takata executives have known there was a systematic problem for years, and concealed it from their customers and the public. 

As a result, although many Takata inflators worked properly, over a dozen people died and hundreds were injured by defective ones.  And millions of drivers (including yours truly) are wondering whether a minor fender-bender in their Honda or Toyota will set off a Takata inflator and turn the incident into a deadly encounter with a time bomb. 

It's probably pointless to speculate, but I wonder if any of the Takata executives involved in this sordid mess ever took an engineering course that mentioned ethics.  When I discuss ethics in my engineering classes, one of the standard case studies I trot out is the (hypothetical) situation in which some engineering test results come out negative, and your boss tells you to fake the results so it looks like the product passed anyway.  It's one thing to sit in a classroom as an impoverished engineering student and say, "Oh, sure, I'd never do anything like that."  And I suppose it's another thing altogether to be in charge of a large American division of a firm whose profit margins depend on sales of a product that you know to be defective. 

There are limits to the ability of education to influence behavior.  The most that educators can do is to alert students to the moral implications of their work, to urge them to be aware that such situations can arise, and to think carefully about how they would respond before being caught up in the heat of the moment when an ethical dilemma arises.  Even if the Takata managers took some such class way back when they were students, in their case the workplace pressures overwhelmed whatever inclinations they had to do the right thing. 

It's unusual that an ethical lapse ends up basically destroying a firm, but it has happened before—think Enron—and the Takata story shows that it can happen again.  Even if Takata manages to liquidate itself to the extent of paying the full $1 billion (which is dubious), I don't think it will help the wronged automakers much in their attempts to replace the millions of airbag inflators that are now under a cloud of suspicion.

As far as the three individuals who were personally charged in the indictment, the U. S. government is attempting extradition, but the final decision is up to the government of Japan.  Assigning blame for such situations on an individual level is complicated, simply because one has to have a good enough understanding of the management structure that prevailed at the time of the wrongdoing to figure out who was really doing the coverup and how it was managed.  Should the janitor in the lab where the tests were falsified go to jail?  Probably not.  Should both the technician who falsified the reports, and his boss who ordered him to, be jailed?  That is a judgment call that I'm certainly not qualified to make, but complexities like these will arise in the denouement of this sad tale.

In the meantime, if you're like me and have received a recall notice about defective airbags, either don't sit in the seat next to the airbag, or if you can't help but sit there, drive really carefully.

Sources:  The Associated Press report of Takata's guilty plea and fine were carried by numerous outlets, including the Los Angeles Times on Jan. 13 at http://www.latimes.com/business/la-fi-hy-takata-charges-20170113-story.html.  I also referred to an ABC News story at http://abcnews.go.com/Business/wireStory/justice-department-announce-takata-criminal-penalty-44759439.  I previously blogged on the Takata inflator problems on Oct. 27, 2014 (http://engineeringethicsblog.blogspot.com/2014/10/do-not-sit-here-exploding-airbag-recall.html), and on Sept. 19, 2016 (http://engineeringethicsblog.blogspot.com/2016/09/time-to-make-airbags-optional.html).

Monday, January 09, 2017

Californians Talk To Their Cars


The citizens of the U. S.'s most populous state have long had a love affair with the automobile.  Life in Los Angeles is well-nigh impossible without wheels of some kind, and many commuters spend almost as much time in their cars as they do on the job.  As of Jan. 1, it is illegal in the state of California to use your mobile phone while driving unless you use hands-free technology.  Fortunately for the millions who will now have to find some other way to communicate from their cars, the automakers are rushing to integrate voice-recognition systems such as Amazon's Alexa into their products so that you can simply ask for directions or ask to talk to a friend, and the system will do the rest.

As reported in a recent  New York Times article, Ford announced that Alexa will soon be a feature of its newest hybrid models later this year.  A mobile Internet connection is vital to the new service, which counts on using cloud computing for the often computationally-intensive task of voice recognition.  The same Internet connection will be used for many of the services accessed by the software:  online purchases, remote control of "Internet-of-Things" devices, and many other uses besides the obvious ones of telephone service and GPS guidance. 

The new law is a step forward in the struggle to reduce traffic accidents caused by distracted driving.  But we have yet to see what the effects of a well-functioning voice-recognition system in a car may be in terms of safety. 

Studies have shown that visual distractions can be deadly to drivers, while sounds are much less so.  Most people can carry on an animated conversation with a passenger without being too distracted from driving, and it's reasonable to assume that conversations with voice-recognition software will not be much more distracting than having a live passenger beside you.  Still, depending on the usefulness and accuracy of the system and the number and complexity of features, things could get complicated.

Your scribe here lives such a sheltered life that the closest I've come to an Alexa is seeing the ad for it every time I click onto Amazon.com.  So I am not in a position to pass judgment personally on how well they work.  Apparently they work well enough to have made Amazon a lot richer in the past year or so, and the quality trend as more artificial-intelligence resources are applied to these things will only be upward.  Like many other new technologies, the real challenge in growing the market won't be so much technical as it will be changing peoples' habits.  And the California law is a powerful incentive to do so.

Consumers lie on a spectrum with regard to the adoption of new technologies.  Some folks—often younger ones—are early adopters who are the ones who wait in line all night long to be the first to buy a new iPhone or what have you.  The bulk of us don't rush out right away to get every latest thing, but when friends or acquaintances tell us about the item and how pleased they are with it, we go ahead and buy one when our old one wears out or when some business or personal need makes it better to buy than not.  And then, bringing up the rear of the bell curve, there are late adopters such as myself, who cling to old technologies with a grip that often takes legal force to loosen. 

There's no need to spend much marketing effort on early adopters—they often turn out to be a product's best informal salespeople as they show off their new purchases to others.  The major challenge is getting the average person to change their ways in the face of a new technology.  And California has done the automakers and the voice-recognition people a big favor in passing their hands-off-the-phone law.

Casual observation shows that a large fraction, if not a majority, of people who drive also like to talk on the phone at the same time.  If they haven't already adopted hands-free technology, as of this month, in California at least, they'll have to do something in order to avoid the threat of getting a ticket.  Enforcement is going to be lax at first, but the understanding is that this is just a grace period to give people time to adopt a new way of phoning while driving, and eventually you'll have to be using some kind of voice-recognition system, whether it's in your phone or installed in your vehicle. 

For people such as real-estate agents, maintenance providers, and others who drive around all day and have to be in touch with customers, the new law is just part of having to do business, and they will either buy a car with a built-in system or achieve their goal some other way, if they haven't already. 

For others who have not made a habit of talking on the phone while driving, the law will mean either pulling off the road when their hands-on phone goes off, or ignoring it until reaching one's destination.

Eventually, though, such actions will seem as quaint as hunting around for a pay phone to make a phone call.  The last time I saw a working pay phone was last summer on a drive through a small Nebraska town.  If I recall correctly, the same town also had a small operating movie theater in the middle of town, and a factory near the edge of town that made lawnmowers.  I didn't see any signs saying "Caution — Entering the Twilight Zone" but it gave me that feeling. 

The California law, and the automotive voice-recognition systems that will allow people to abide by it, are all part of the push to make us constantly connected whether we're at home, at work, or in between.  It's what people seem to want, or at least think they want.  Why they think they want it is another question, but one best left for another time.
Sources:  The New York Times article "Coming From Automakers: Voice Control That Understands You Better" by Neal F. Boudette and Nick Wingfield appeared on Jan. 5, 2017 at http://www.nytimes.com/2017/01/05/automobiles/automakers-voice-control-amazon-alexa.html. 

Monday, January 02, 2017

What Are the Rules of Cyberwarfare?


We are now well into the era of cyberwarfare—the use of computers and computer networks in military, terrorist, and diplomatic conflicts.  But to judge by the recent tiff between President Obama and Russian President Vladimir Putin, neither the U. S. nor Russia has figured out exactly how to use these new weapons, or how to defend against them effectively.

Last July, Wikileaks unleashed a flood of embarrassing emails hacked from the Democratic National Committee, leading to the resignation of that organization's chairwoman Debbie Wassermann Schultz and undoubtedly influencing the Presidential selection process, though to what degree it is impossible to say.  In December, the CIA announced that they were confident that Russian hackers were responsible for stealing the emails and giving them to Wikileaks.  And on Dec. 23, President Obama announced that he was retaliating for the hacks by sending home 35 Russian diplomats and taking other actions against the Russian diplomatic corps in the U. S.  After initial talk by Russian officials of retaliation against the retaliation, Russian President Vladimir Putin surprised many by saying he would suspend any actions against U. S. diplomats in Russia, at least until the Trump administration takes office. 

Retaliation against diplomats has been around ever since there have been diplomats.  Over the decades, countries have developed traditional ways of treating official representatives from foreign lands with policies such as diplomatic immunity from routine prosecution, the suspension of normal customs inspection for diplomatic materials, special diplomatic zones around embassies, and other perks.  But one reason for all these special privileges is that they can be revoked at any time. 

This writer is old enough to recall some of the many times that the old Soviet Union (USSR) engaged in these kinds of games with the U. S. on any pretext or sometimes no pretext at all.  It was all part of the Cold War chess game, and watched closely for indications that the Soviets might be wanting to warm up the war a little.  Everyone agrees that sending a diplomat packing is a lot better than throwing bombs, so while tensions are raised by such incidents, it's usually a sign that serious conflicts are not in the immediate offing.

Still, there are a couple of notable and disturbing aspects of the DNC hacks and their consequences.  One concerns the identity of the hackers, and the other concerns what constitutes a truly effective response to such attacks.

It took nearly six months for the CIA to be confident enough to announce publicly that Russians were in fact responsible.  In that aspect, hacking and other hard-to-trace cyberattacks resemble terrorism, in that the identity of the terrorists responsible for a given attack is usually not immediately known, and may not ever be discovered.  Although good detective and investigative work often uncovers the perpetrators eventually, the delay between the attack and the discovery of who did it allows for uncertainty to dominate the situation, leading to general confusion, controversy, and other problems that are usually exactly what the attacker wants to achieve in the enemy camp.  It's possible that the CIA made its announcement when it did not because it took all that long to figure out who did it, but for other diplomatic or political reasons.  Still, it's hard to fight back against an enemy if you don't know who he is.

Identifying the source of a cyberattack is only the first step in an effective response.  As in conventional warfare, one doesn't want to overreact, but on the other hand, just letting an enemy get away with anything isn't good either.  An important factor in these not-yet-open-warfare conflicts is how the public perceives them.  Both the U. S. and the Russian presidents do everything with an eye to their constituents, so things done in secret which have secret effects are not that useful.  Instead of using the hacked emails for their own purposes, whoever hacked them (probably the Russians) gave them maximum publicity, and to the extent that the DNC was hampered in its operations, the attack was a success. 

What's new and disturbing about this particular incident is that it represents a significant intrusion into the domestic electoral process by a foreign power which overtly favored a particular candidate—one who will take office on Jan. 20, barring unforeseen circumstances.  What makes the situation worse is that the President-elect does not seem to be all that troubled about it.  Four years in office is a long time, though, and it's likely that Trump and Putin will at some point fail to agree on something, after which it's anyone's guess what will happen.

Part of what makes it so hard to defend against cyberattacks is the global nature of the Internet environment—Moscow or Paris or Adelaide is just as close to my Internet connection as the neighbor down the street.  Traditional military defenses were geographically fixed and you could draw contours of safety within them—here, you have to be concerned about ground attacks, there you are subject to air bombings, and way back behind the front lines, there was almost nothing to worry about.  But cyberattacks can go anywhere there's an Internet connection, and the targets are often only as well-defended as the private organizations and their IT people can make them.  As we know, these defenses range from the almost impregnable to the nearly nonexistent, and so many attractive cyber-targets are almost defenseless against a concerted attack by well-resourced agents of a foreign power.

It's not clear that the best defense is a good offense either, especially when it's not immediately clear who is doing the attacking.  And when many thefts of data are not discovered until months or years after the damage is done, it's even harder to mount an effective response.

It looks like international cyberwarfare will muddle along in this confused state unless and until such a major attack occurs that we get serious about some sort of national defense policy against foreign cyberwarfare.  There are serious concerns being voiced these days about the hacking of power grids and other vital infrastructure systems such as air-traffic control and the domestic Internet itself.  Our best defense for these systems right now is that nobody has a strong reason to attack them, but that could change at any time.  And if it does, I just hope we're ready for what comes afterwards.

Sources:  I referred to a report on President Obama's retaliatory actions against Russia carried by CNN on Dec. 29 at http://www.cnn.com/2016/12/29/politics/russia-sanctions-announced-by-white-house/, and also a report on Putin's non-response at https://www.washingtonpost.com/world/russia-plans-retaliation-and-serious-discomfortoverus-hacking-sanctions/2016/12/30/4efd3650-ce12-11e6-85cd-e66532e35a44_story.html.