Why Three Prongs? (1996) - <AUTHOR> http://amasci.com/amateur/whygnd.html <comment><USER3> The obvious follow up question, then, is: why does Japan use 2-prong outlets even today? Are Japanese people dying from electrical shock at a much higher rate than the rest of the world? Is Japan full of only Perfect Electricians? Or is this not actually the significant problem that this myth (in the etiological sense, not the fictional sense) would lead us to believe?

The only 2-prong device I own is a (Japanese-made, of course) rice cooker. You'd think that if any device warranted 3-prong safety, it'd be a metal container which combines water and mains electricity.

<comment> GuB-42 \- Japan runs at 100V, the lowest and therefore safest voltage in the world. At least when it comes to electrocution. I suppose that it is also the reason why in Europe, where the standard voltage goes up to 240V, electrical safety is much more strict.

\- As it is already mentioned, Japan is backwards in several domains and that may just be one of these. That's despite their technological advance in others.

\- I have a feeling that there are more "perfect electricians" in Japan than anywhere else, because of their culture.

\- Some 2-prong devices are perfectly safe because they are double insulated. This is also called Class II and the symbol for it is a square inside another square.

<comment><USER4> _Japan runs at 100V, the lowest and therefore safest voltage in the world._

100V, 240V, if 15 amps runs through you, you're having a really bad day either way. That's another way of saying, "it ain't the volts, it's the amperage."

<comment><USER5> I was always taught "volts jolt; mills kill". i.e. high voltage will knock you across the room but a few milliamps of current across the heart will easily kill you.

A 12V car battery can kill if you're not careful.

<comment><USER6> So much misinformation in this thread. Voltage, current, and resistance are physical properties entirely dependent on each other -- increasing one affects the value of others. That's like saying that the mass of bullets kills people, without any regard for velocity.

A 12 V car battery can kill you, _if_ it has a low-resistance path that goes through your heart. Touching the terminals will do nothing. Maybe if you applied that voltage to conductive spikes inserted into specific points of the body, there would be some effect.

A voltage source, like a car battery, does not determine how much current passes through a circuit. That is determined by the circuit's resistance, and the source's upper limits (i.e. internal resistance for batteries, rated current for power supplies).

As voltage increases, so does current. High-voltage supplies will absolutely kill you, as long as they're able to supply the required current. Which, to harm a human heart, is quite low (tens to hundreds of milliamps). Aside from fringe sources like static electricity and tasers, most HV sources are entirely capable.

</comment></comment></comment></comment></comment><comment><USER7> Short form: Neutral is grounded. The "mouth" part of the plug is the ground and is isolated from the neutral to prevent inadvertent carrying of potential.

Aside: it is generally considered safer to have the outlets ("receptacles") installed with the ground at the top, but we don't tend to do this in NA because ground at the bottom makes it look like a little face and humans like faces.

Edit: Adding link to EETimes: [https://www.eetimes.com/document.asp?doc_id=1272972#](https://www.eetimes.com/document.asp?doc_id=1272972#)

<comment><USER8> I recently remodeled a house (in the US), and installed every receptacle with the ground at the top, because of that.

Every person who comes over that knows anything about electrical stuff instantly says 'your plugs are upside down'...and then I have to explain to them how/why it works :)

The inspector had no issue with it though, thankfully! In health/saftey critical installs (like hospitals), the ground MUST be on top, according to our local code. It's optional for residential.

<comment><USER9> > _I recently remodeled a house (in the US), and installed every receptacle > with the ground at the top, because of that._

Have you run into any appliances or devices that are "optimized" for a ground- down configuration?

<comment><USER10> Low profile plugs intended to have the cord exit downward at 45-degrees don't work as well with upside down receptacles.

</comment></comment></comment></comment><comment><USER11> > There is a simple solution to these problems: connect your system to the > Earth. Drive some long metal rods into the dirt, and connect them to your > wires. That way, lightning currents will be directed into the Earth rather > than spreading throughout your power lines.

I have tried and failed many times to understand the concept of "ground." Why does electricity "want to go to the ground?" What constitutes "ground?" Can I touch wire to concrete, and that counts as "ground?" No? Must I then sink it? How deep? Until it touches dirt? What about sand? Where does the electricity "go" then?

I've read plenty of articles, never got it.

<comment><USER12> There are two different mental models I find really useful when thinking about electricity. The second one will answer your question more directly, but the first one helps set the stage better.

Mental Model #1 (useful for most work with electricity):

Think of electricity moving through circuits as water going through pipes.

Electricity = water Voltage = water pressure Battery/Voltage Source = water pump Wires = Water pipes High/Low resistance = Wide/narrow water pipes

Voltage is like water pressure. You have a pump creating high water pressure is like a power source with a high voltage. The pump is always on and creating water pressure, but there's a cap placed on it that blocks the water from escaping. Similarly, in an open circuit the air acts as this cap and blocks the electricity from proceeding.

The wires in a circuit act as pipes channeling the water to different areas. Resistance in a circuit is analogous to the thickness of the pipes (low resistance == wide pipes, high resistance == thin pipes).

The above analogy sets part of the mental model. The twist is that in reality electrons want to actually travel from a place of low voltage to a place of high voltage (classical electrical diagrams show this process in reverse). Which leads us to...

Mental Model #2

Voltage sources are powerful electron vacuum cleaners trying to to _suck_ up electrons.

(You can apply this on top of mental model #1, just reverse the direction of the water flow)

Open circuits generally don't conduct electricity since within a nano-second the voltage source will suck up all the free electrons in the circuit. The negative/ground pole in circuits are where the free electrons get supplied from for the voltage source to "suck in" the electrons from.

The ground (by virtue of it being so large and having lots of moisture/materials which conduct electricity) happens to have a virtually limitless source of electrons available for the voltage source to suck into itself. This provides the circuit with all the electrons required to successfully operate.

Hope that helps :)

<comment><USER13> Here's another mental model, the balls model, which I sometimes find useful, especially in this case. Here it is in case it helps someone:

Imagine electricity as red balls, which can travel along conductors. Groups of red balls feel drawn strongly to places which have less balls, and away from places which have more balls, leading them to equalize quantities among all points in the circuit (let's assume for now cables can't store the red balls, only transport them. Points in the circuit are places that can store balls).

if you have a battery, both the sides can store balls, but assuming it's charged, the plus side might have 12 red balls and the minus side none. The difference in red balls is 12! A quite strong force pushing red balls from the + to the -. (that's the voltage). When the circuit is closed with a wire, the balls will travel quickly and end up with 6 at both the + and -. How many of them travel at once (Intensity) depends on how large the tube is (Resistance).

What if instead of 12 and 0 we have 112 at +, and a 100 balls at -? Well the force is the same as before (12), the whole circuit works the same way. 6 balls go from + to -, over the same amount of time (tubes have the same throughput), you then end up with 106 at both ends. You just have these 'residual' red balls hanging around, doing nothing special.

However, if you suddenly connect this circuit with 212 balls to the first circuit with 12, the balls will quickly flow from from the first to the second, this time with a force of a 200! (The point here is that voltage is a relative measure, unlike charge.)

You might have an isolated electronic circuit starting with 12 and 0 balls, and think all is well. You touch the circuit once to start it, the balls are flowing normally. You leave it working for a few hours and come back, it still seems to be fine. You touch it, and ZAP, a spark, burnt smell, you're wondering what happened. Well the thing is that external sources can sometimes add a red ball or two to your system. Over time, they might add up, and after a while you end up with hundreds. As soon as you touch the circuit, they all flow to somewhere that has fewer.

Ok, where does the ground come into this? A 'ground' is like the - side of your battery. It's an object that can store balls the same way. However, instead of having one 'storage point' which can be filled with balls, it has a several. So take a metallic object, and say it has, for example, 11 storage 'points'. If you connect it to a single + point containing 12 electrons, the balls spread out so that there's the same amount of balls in each point (as we explained at the beginning). So after a while your 1 and 11 points, end up with one ball at each point. (Analog to the concept of capacity)

So the natural earth turns out to behave like a huge metallic object. So big that it basically has an infinite amount of storage 'points'. You can pour red balls into it all day, and still end up at an average of zero balls per point.

So now you take your 12 to 0 circuit and connect the - side to the earth. The difference between + and - is the same as before, 12. The flow from + to - <USER2> about the same (same resistance), so the circuit behaves almost the same. If however an external red ball is randomly added, it flows from the - to the earth, meaning that you never accumulate balls in the circuit.

This allows you to set a reference amount of 0 balls in every circuit you work with. Which is great. The amount of red balls at the + can still be set to whatever you like, and they will flow nicely from + to - along whatever circuit you create (like before), but on top of that you never run the risk of having red balls jump from one circuit to another if they accidentally touch, because there is never a large difference in red balls as they all have the same reference amount.

Anything big which is conductive enough can store a lot of red balls. So what qualifies? Soil usually works, water works to an extent ([https://electronics.stackexchange.com/questions/164898/can-t...](https://electronics.stackexchange.com/questions/164898/can- the-ocean-be-used-as-ground)). When you can't connect to those a big object will have to do, like a car frame, it will have enough storage that over a short time it looks infinite, but if you really pushed and kept adding red balls at some point the reference level would change. With the earth you could pour red balls your entire life and barely make a difference to the reference level.

(So now you're thinking, the red balls are electrons, right? Well sort of, but don't tell a physicist! Otherwise they'll get angry and start talking about flow direction being this or the other way. Or they'll say something about non-rigorous representations, wave-particle equivalence, the balls actually being a 'lack of electrons' and we'll all be confused.)

</comment></comment></comment><comment><AUTHOR> > Before you "grounded" your system, the AC voltage in general acted pretty > safe for your customers. The only way they could get a shock was if they > touched both wires at the same time. This was a fairly rare occurrence. One > single wire acted as if it was "safe," and it did not deliver shocks.

I'm confused by the assertion that you could not get a shock from a single wire in an ungrounded system. If there is 120V AC between the two wires, doesn't this mean that there has to be at least 60V AC potential between at least one of the wires and earth ground? Is he depending on the "halved" voltage for safety, or depending on having an intact circuit so the other connected wire is always "better" than an earth ground, or is he right in some way that I'm not seeing?

<comment><AUTHOR> I've gotten some helpful answers, but it's apparent that I've failed make clear my actual question, which is about the relative safety of a system with an isolated ground, such as the "razors only" plugs discussed in the article. The article seems to claim that such systems are safe for any single point of contact.

Maybe I can make it clearer with a parallel more specific question. Assume I'm running an gasoline powered generator which produces 120VAC for a single outlet. As far as I can tell, this is an ungrounded isolated system analogous to the isolated transformer. If I'm barefoot and standing on wet concrete, and stick my wet finger into only one side of the plug, will I receive a dangerous shock?

The article seems to claim that as long as I touch only one of the wires of an isolated system, I am "safe". My counter intuition is that that the capacitance of the earth is such that an AC current will flow through my body and cause me harm. Am I wrong? Is the article wrong? Or is there some essential difference between my proposal and the example in the article? If I'm wrong, I'd love to have a more technical explanation of why this seemingly unsafe behavior of sticking my finger in a live socket is actually safe.

<comment><USER14> > Assume I'm running an gasoline powered generator which produces 120VAC for a > single outlet. As far as I can tell, this is an ungrounded isolated system > analogous to the isolated transformer. If I'm barefoot and standing on wet > concrete, and stick my wet finger into only one side of the plug, will I > receive a dangerous shock?

Theoretically, no. Your generator isn't going to pick up large static voltage from the atmosphere the way a power grid does, so it's theoretically safe to leave it ungrounded.

However, I would strongly advise against actually doing this experiment unless you are _absolutely_ certain that your generator is isolated from the ground, and even then I would advise against it. Some risks are not worth taking even in the name of science.

<comment><AUTHOR> > However, I would strongly advise against actually doing this experiment > unless you are absolutely certain that your generator is isolated from the > ground, and even then I would advise against it.

A safe version of the experiment would be to take a standard incandescent lightbulb and run one wire to an earth ground and one wire to one side of the plug on the generator. My guess is still (although with more doubt based on how many intelligent people here have opined otherwise) that because of the enormous capacitance of the earth, the light bulb would still light up even though no clear circuit is formed.

In my quite possibly flawed mental model, electrons will be pulled and pushed from the earth across the filament, causing it to heat up. Whether this actually works (in my mental model) depends on the frequency and the capacitance of the generator, but I'm guessing that at 60Hz whatever is inside the generator is enough to get an effect. Unless someone has already done this, I guess I'll have to get a generator and try it.

<comment><USER15> > My guess is still ... that because of the enormous capacitance of the earth, > the light bulb would still light up even though no clear circuit is formed.

Your statement implies that you are viewing the earth as a huge, perfect, capacitor. And by "perfect" I mean no series resistance.

In reality, the earth is a relatively poor electrical conductor (i.e., a high resistance [1]) and so where your mental model breaks is omitting that resistance from consideration in your model.

I.e., the equivalent circuit your 'experiment' produces would be:

       G-----bulb</comment></comment></comment></comment></comment><comment>R--C

The "R" and "C" above are the capacitance and resistance of the earth. Yes, there is an amount of C present, but there is also a quite large series "R" present as well. And it is that resistance that results in a very limited current flow from your theoretical experiment. Too low of a flow to illuminate the bulb.

[1] [https://en.wikipedia.org/wiki/Soil_resistivity](https://en.wikipedia.org/wiki/Soil_resistivity)

</comment><comment><USER16> Perhaps an ignorant question, but given that when I travel I have to bring a seemingly endless array of plug adapters, which power standard is the "best" and how do we get rid of the rest?

<comment><USER17> I may be biased, but I think British plugs are great. They have integrated fuses and are switchable too! The sockets have shutters as well to stop children sticking paperclips or forks in and electrocuting themselves.

Not great to stand on, however

<comment><USER3> BS 1363 plug has some neat safety features, but it's really big. Look at the size of a British power strip, for example. As Tom Scott observes, to get the full benefit of the safety features, they would need to make them even bigger. It's also not even close to round, so pulling it out of a nest of cables looks terrible.

I'm not convinced that a fuse belongs in a plug, either, especially if it's invisible, and the plug has to be completely disassembled with a screwdriver to access it. Put the fuse in the device, which certainly has much more space for it, and probably a mechanism to make it easy to access.

As far as the physical structure goes, BS 1363 looks like it was designed in the 1940's ... because it was designed in the 1940's. I'd much rather have something modern and ergonomic like TRUE1. It's small and round, it locks, it's basically impossible to shock yourself with it, and it's IP rated.

I'm not alone here. There's many videos on YouTube of people hacking the Edison plugs off their power tools to replace them with powerCON or TRUE1, but I have yet to find anyone in the world who wants to replace their Edison plug with BS 1363!

<comment><USER18> _> I'm not convinced that a fuse belongs in a plug, either, especially if it's invisible, and the plug has to be completely disassembled with a screwdriver to access it._

Moulded plugs generally use a clip-in fuseholder that can be opened with any pointed object; rewireable plugs can be opened to replace the fuse by loosening one captive combination Philips/flat screw. It's usually far easier than replacing a fuse in the appliance, which is often on a PCB-mounted holder buried within the guts of the appliance.

</comment></comment></comment></comment><comment><USER19> The article isn't not really on point. A two-prong system still has an earthed neutral. The third prong is purely for redundancy. If neutral happens to be disconnected, there is still a return path. It also protects against mixed up neutral and hot. If the chassis of a device is grounded to the third conductor, and that one is properly routed, then an inadvertent reverse wiring of hot/neutral is mitigated. A third conductor also makes possible ground fault detection: situations when a device is not returning all current through the neutral, because its safety ground has become energized.

How might a neutral end up disconnected? Not just by accident; for instance, someone would incorrectly wire a cold-side switch instead of hot-side (E.g. wall panel switch that controls an outlet) so that when the outlet is off, the neutral has been cut off, but hot is still live. In that situation, the third conductor would still be grounded. Nobody would mistakenly implement the switch on the ground line unless they didn't bother testing it, because the switch then wouldn't work; the ground line is implicitly protected from having switches accidentally planted on it by the fact that interrupting it does nothing, functionally.

</comment><comment><USER20> Three prongs was a good idea before the existence of ground fault interrupters, but now that they do exist, ground fault interrupters with two prongs provides a much better solution.

The problem with ground is that it's a conductor. If there's a fault on it, you don't know exactly what it's connected to, so now you have a situation where the metal chassis is connected to something. You touch the chassis and the really-grounded a sink and you have a problem.

Here's a real world example of this. The ground is bonded to neutral at the panel. But what happens when neutral between the pole and the house breaks? This happened to my neighbor. There is still 240V with neutral/ground floating somewhere in the middle. All of his appliances on the less loaded side of the 240V blew up and "ground" was very not at earth ground.

<comment><USER21> That's a problem with incorrect installation / code. In a proper TN-C-S system the combined PEN will be split up at the main panel, and PE will be local ground and pipework is typically connected to that.

</comment></comment><comment><USER22> A thread from 2012: [https://news.ycombinator.com/item?id=4058834](https://news.ycombinator.com/item?id=4058834)

</comment><comment><USER23> If GFI sockets and breakers had been widely available at the time, would the third prong have been added? Would a GFI along with the "one long slot" plugs make the ground wire obsolete?

<comment><USER24> GFI outlets are $15+, and normal outlets are $2. This adds up when you're building a house: a typical house has something on the order of 30-50 outlets, so you're looking at $400-$700 vs $60-$100. It might not seem like much in the grand scheme of things, especially to software engineers making lots of money, but if we had this approach not only for outlets, but also for everything else, building literally anything would cost 5 times as much (and in fact it does these days, to a large degree because we can afford spending 5 times as much on building).

<comment><USER25> >GFI outlets are $15+, and normal outlets are $2.

Where are you getting your prices? Last time I checked, GFCI outlets were indeed around $15, but the normal ones are less than a dollar when you buy them in bulk packs (which you would for building a house). Otherwise, your point is sound, but the price difference is even greater than you said.

Those standard outlets are really dirt-cheap, and it's annoying that builders are so cheap about installing them. New construction has gotten better though, but really there should be an outlet every 5-6 feet in my opinion, or maybe even less.

<comment><USER24> Home Depot non-bulk prices -- the only ones I'm familiar, as I haven't had a need to buy many of them at once.

Also worth noting is that you can wire your circuit in a way that the first one is GFCI outlet, and the subsequent ones are daisy-chained to it, so that all of them are protected by GFCI. Of course, there are reasons to not do it (e.g. it is then quite confusing when the GFCI trips while using some non-GFCI outlet, because it might not even occur to people to check the GFCI outlet which might not even be used), but that's also an option if you want to save money on outlets.

Also, I think the reason for few outlets in buildings is not the cost of the device, but rather labor required to put it in. Connecting wires to the outlet is quick, but you need to also install boxes, route the wire to the boxes, mark and cut the drywall to get to these boxes etc. It can all add up to significant labor time, and if you look at what electrical contractors charge, the cost of the device itself is a small part of it.

<comment><USER25> >Home Depot non-bulk prices Definitely check out the 10-packs; if you own a house that isn't new, and are already doing some wiring work, it's not a bad idea to keep some extras around and maybe replace some of the crappy older outlets when they're so cheap.

>Also worth noting is that you can wire your circuit in a way that the first one is GFCI outlet, and the subsequent ones are daisy-chained to it,

Yes, this is actually normal for kitchens, where all the counter outlets are on the same circuit. Just put the GFCI on the outlet nearest the breaker box, and all the others are then protected by it. It is really annoying, however, when people retrofit these things into old houses and you get something like a downstairs bathroom outlet that has no apparent GFCI, but then it trips, and you have to hunt around the house for the GFCI outlet only to find it in a bedroom on the upper floor. I rented a house for a while where both bathrooms and both bedrooms were _all_ on the same circuit (lights too!), and on an old GFCI outlet that would frequently trip and leave me in the dark. Extremely unsafe.

>I think the reason for few outlets in buildings is not the cost of the device, but rather labor required to put it in.

Yep, that's exactly the reason, but it's still annoying because years later, you have to move furniture around to find an outlet that your device's cord can reach because there just weren't enough installed.

<comment><USER23> > It is really annoying, however, when people retrofit these things into old > houses and you get something like a downstairs bathroom outlet that has no > apparent GFCI, but then it trips, and you have to hunt around the house for > the GFCI outlet only to find it in a bedroom on the upper floor.

Maybe easiest to just have GFI on the breakers?

<comment><USER25> They do have GFCI breakers. I'm not sure how they compare in cost, but one disadvantage is that you can't easily test them (who ever bothers going to their breaker box to test the GFCI occasionally?), nor can you easily reset them when they do trip.

</comment></comment></comment></comment></comment></comment></comment><comment><USER26> What I learned from reading every single one of the 184 comments (as of 6:28 pm ET) on this post: call an electrician for anything more complex than changing a light bulb.

</comment><comment><USER27> For some reason, this reminds me of the Laryngeal nerve. It's like a natural process repeating itself in different systems. Because re-engineering the solution from the ground up to be more efficient isn't an option, there has to be small incremental steps to arrive at a solution that works.

[https://en.wikipedia.org/wiki/Recurrent_laryngeal_nerve](https://en.wikipedia.org/wiki/Recurrent_laryngeal_nerve)

<comment><USER28> > Because of the inefficiencies of the routing the nerve takes, it's often > hailed as one of the most striking cases against intelligent design — or at > least calls into question the "intelligence".

Man, what an obnoxious way to start an article.

EDIT: link was removed, this comment no longer needed.

<comment><USER27> Oh my bad, didn't mean to suggest it was intelligently designed. I didn't read that full page and didn't pick up on that context. I'll remove that link.

<comment><USER28> My comment was a bit rude as well, I apologize. The website seems to be a little argumentative and it rubbed me the wrong way.

</comment></comment></comment></comment><comment><USER29> Excerpt:

"The sparks occur because of a little-known fact: all the world is a gigantic electrostatic generator. There is a flow of charge going on vertically everwhere on earth. Thunderstorms pump negative charge downwards, and the charge filters upwards everywhere else on earth. Depending on the height of your circuitry above the earth's surface, depending on the area covered by your wires, and depending on whether there was a thunderstorm above you at the time, there might be a fairly huge DC charge on your electrical distribution system. This charge might be several hundred volts; enough to zap computers and delicate electronics. Or... it might be many tens of thousands of volts, enough to create enormous sparks which jump across switches and leap out of wall outlets, wall switches, across transformer windings, etc. Your electric power system is acting like a sort of capacitive "antenna" which intercepts the feeble current coming from the sky and builds up a huge potential difference with respect to the earth."

</comment><comment><USER30> For those outside the US, or generally confused how US domestic power distribution works, let me explain in the context of the 3 prong plug and NFPA 70 NEC (National Electrical Code) for the lay reader. We'll start outside the house and go all the way to the plug:

0\. Before the transformer secondary on the pole outside the house, the wiring is dictated by the NESC, which is like the NEC for utilities. We'll leave that there.

1\. Most US homes have a single phase, "center tapped" transformer secondary. This gives three voltage potentials to feed the home: (Nominal) 0V - from the center tap; +120Vrms - from one "end" of the transformer; -120Vrms from the other end of the transformer. And, yes, I am glossing over the phase relationship here. All three potentials are connected through the chunky copper of the transformer, which provides a current path to complete the circuit.

2\. The three potentials feed the house meter and disconnect. The 0V potential may, or may not, be insulated on the path back to the transformer secondary, and often doubles as the mechanical support for the incoming lines (the "service"). The other two potentials will be insulated wiring.

3\. Inside the main service panel the +120V and -120V inputs are split between the breakers. Every other breaker is connected to +120V or -120V. Typically a breaker that spans multiple slots is connected from -120V to +120V. That is the "240Vrms" for ovens, hot water heaters, dryers, air conditioners, etc.

4\. Adjacent to the metal bits that fan out the +120V and -120V is a strip of metal that allows multiple connections to 0V potential. Colloquially this the "neutral bus," but in the NEC this is termed a "grounded service conductor." All of the white wires from the circuits in the house ("branch circuits") are tied to the spaces in this metal bus bar. This metal bar is also electrically connected to the 0V potential entering the house from the transformer center tap.

5\. Also inside the main service panel there is strip of metal that allows connection for a number of "grounds." It looks just like the "neutral" connection bar, but instead has a number of green wires attached to it. Colloquially these wires a called "ground," but the NEC calls them "Equiment Grounding Conductor" or EGC.

6\. Between the grounded conductor ("neutral") bar, and the EGC ("ground") bar there is a removable conductive link. In the main panel this link remains installed, but in secondary panels it is removed. The link is removed in "subpanels" to insure correct operation in the event of a fault. Fault conditions are discussed below.

7\. Also connected to the EGC and grounded conductor is a third wire. The NEC terms this the "grounding electrode conductor" or GEC. The GEC then goes to a water pipe or "grounding" rod(s). Thus the GEC is the connection between physical Earth voltage potential and the power panel. It is unfortunate that the EGC and GEC are such similar abbreviations.

In the event I'm out of characters, I'll pause and reply to myself now.

<comment><USER30> Brief recap: Three different voltage potentials in from the pole on three different conductors. And in the main panel a link between three other wires: the EGC ("ground"), GEC("earth"), and grounded service conductor ("neutral").

The next section is where people go awry, even licensed electricians I have met. But it is also the meat of the safety aspect of the three wire configuration. We will assume a house with a single electrical panel for simplicity.

8\. Three wires traverse from the main panel, down a branch circuit to the three prong "edison" outlet on the wall: One of the three prongs connects to either +120V or -120V; another connects to the EGC bar inside the panel; the last connects to the grounded service conductor bar inside the panel.

9\. The short blade on the top row of the Edison connector is +120 or -120V; the tall blade on the top row connects to the grounded service conductor (colloquial neutral). The single connector on the bottom row connects to the EGC (colloquial ground).

10\. If you plug in an item that has a three wire plug, the lower single plug prong will be longer. This is so that the item is electrically connected (i.e. "bonded") to the EGC before the other two wires. This insures the "fault current" path is connected before the item is energized.

11\. Under normal conditions, the current path is through the item plugged in between either +120 or -120V and 0V volt potentials. Crudely think of current coming "out" the short plug prong and "in" the tall plug prong. The EGC (colloquial ground green wire) doesn't do anything under normal operation.

12\. The current path is then back down the branch circuit, via the grounded service conductor (colloquial neutral). the metal bar that links all the grounded service conductors together then has a path back to 0V on the transformer by one of the three incoming conductors.

13\. Finally, the current can flow from the 0V location on the transformer to the higher potential via the wire of the secondary. Notice that the GEC (earth) connection to the ground rod was NOT a meaningful component of the current path.

14\. Returning to #11, and considering abnormal operation. Here current somehow flows outside of the correct circuitry in the powered item. The ECG is bonded (connected) to the item's chassis and provides an alternative current path. The EGC provides this connection back to the panel bar with all the green ECGs tied to it.

15\. The EGC bus bar in the panel has a conductive link back to the grounded service conductor bus bar (colloquial neutral) via the removable link that we discussed previously. The link then "brings" the current over to the grounded service conductor (0V potential from the street), and provides the current path back through the transformer secondary.

16\. Let's assume the outlet is a GFCI / RCD. It notices the current coming back on the grounded service conductor doesn't match the current going "out" into the device, and opens the circuit. That is because the fault current is "lost" to the EGC, and goes around the GFCI outlet. The outlet trips, assuming a human body is the fault current path.

17\. People commonly assume that the GEC (earth) conductor somehow matters for current path in event of a fault, but this is rarely the case. Usually the water pipe or grounding rod(s) are high impedance relative to the wire in the transformer secondary, and so the current divider formed is essentially all through the grounded service conductor.

18\. The GEC (earth) connector holds the pole transformer secondary center tap near the same relative 0V potential as the house. The GEC may also provide the lower impedance path at very high frequencies encountered during a lightning strike.

If you made it this far, I'm happy to field further questions :-)

<comment><USER31> Thanks. Really clear write up.

What issues can arise if the link between the EGC and GSC bus bars is left in place inside a subpanel?

<comment><USER30> Excellent question!

Stated rhetorically,

"If a GFCI only cares about the current imbalance, and the traditional style breaker opens to due to a big spike in current, why care about what path it takes through the building wiring back to the pole transformer?"

If a sub panel does not have the jumper removed, then the EGC and GSC between that sub panel and the main panel will form a current divider. Let's assume they are the same wire gauge, basically the same resistance, and so essentially split the return current.

This leads to a couple problems:

1\. The EGC may no longer able to carry its full rated current load, due to the baseline "normal" current that the EGC is also bearing. You want to bear as much current as possible to quickly trip a conventional breaker in event of a fault to the EGC. This is real, but relatively minor concern.

2\. All EGCs "upstream" of the bonding point have been "contaminated" by the normal neutral current that got on to the EGC at the mistaken sub panel bond. This could "put current" on the surfaces of other equipment, exposed ground wires, conductive raceway, etc. This is the more major concern, as these surfaces would have the full voltage potential available to them should there be yet an additional current path.

In the main panel the EGC, GSC, and GEC are all connected at a single point. And from this point there is only one path back to the transformer, via the 0V conductor of the GSC. The transformer side of this 0V potential conductor will match the local Earth voltage, set by the GEC, and wiggle from 0V nominal by the fluctuations caused by current (V=IR) in the GSC conductor between the panel and the pole.

Make sense?

</comment></comment></comment></comment><comment><USER32> Since this article was written, the NEC has also started requiring arc fault circuit interrupters.

[https://en.wikipedia.org/wiki/Arc- fault_circuit_interrupter](https://en.wikipedia.org/wiki/Arc- fault_circuit_interrupter)

BTW, if you have a portable generator for emergency purposes and it's connected via a transfer switch, take note of the important grounding and bonding requirements:

[https://cpower.com/PDF/InfoSheets/44.pdf](https://cpower.com/PDF/InfoSheets/44.pdf)

</comment><comment><USER33> Past posting on HN:

[https://news.ycombinator.com/item?id=4058834](https://news.ycombinator.com/item?id=4058834)

</comment><comment><USER34> Why do a majority of electronic devices has only 2 prong?

<comment><USER35> These are called CLASS II devices and they are designed with double or reinforced insulation. In plain terms it means that the current carrying components are themselves insulated AND surrounded by a second layer of insulation. That or the current carrying components are protected by reinforced insulation like a hard plastic case.

A practical example is the humble power brick or wall wart. These are class II power supplies which are enclosed in a hard plastic case which protects the user from electrical shock.

Reference: [https://www.cui.com/blog/class-2-vs-class-ii-power- supplies](https://www.cui.com/blog/class-2-vs-class-ii-power-supplies)

</comment></comment><comment><USER36> Why is the metal chassis wired at all?</comment>


Ask HN: Will programming continue to be a lucrative profession in the future? - <AUTHOR> Being a programmer right now is, in general, great. The job market is on fire and the industry is rapidly changing. Supposedly, the rate at which new jobs are created for computer scientists even outpaces the rate at which newly graduated CS majors enter the workforce.
Do you expect this trend to hold?
If so, how crazy will it get? The rumors posted on here of $300k salaries for non-famous engineers already seem unbelievable to me.
If not, what will cause it to end? The only doomsday scenario for developers in the first world that I can think of is a rise in extremely competent dev shops in developing countries.
(I realize that no one can predict the future, but I'm curious about the HN sentiment here.) <comment><USER2> The estimate is that 80% of all effort in software goes to maintenance of existing systems, of which 21% goes into bug fixing: [https://en.wikipedia.org/wiki/Software_maintenance](https://en.wikipedia.org/wiki/Software_maintenance)

With every new system successfully brought online by one programmer, they are creating a future need for four programmers to maintain that system.

Just to keep the existing body of software afloat, the existing body of programmers is dramatically insufficient. We have known this problem for decades. You will find lots of old papers raising exactly this issue.

Concerning developing countries, to an important extent they have already been absorbed into the global workforce. Certainly India is already supplying its best and its brightest. Only a limited percentage of the workforce is capable of working as a programmer. Furthermore, developing countries increasingly consume their own supply of software services. Therefore, third-world supply may already be largely exhausted.

With the world increasingly dependent on software (Has it every been increasingly dependent on lawyers?) stopping to hire programmers pretty much means scrapping systems on which organizations depend. This happens all the time already, but the net effect is still to add new systems.

<comment><USER3> The world is increasingly dependent on lawyers, the demand for which increases with the size and complexity of the economy. More economic activity means more agreements to be negotiated, disputes to be resolved, and regulations to be enforced. Moreover, this is high-end legal work, and many new lawyers will enjoy long, lucrative careers. It's not clear to me that I should advise my children to embark on a short, low-pay, low-status career in legacy software maintenance.

<comment><USER4> Who knows what the future will hold, but in the US, there are more new lawyers graduating each year than there are law jobs. Software has taken over many of the jobs the entry level lawyers used to perform.

Law (in the US) reacquires an extra, very expensive, 3 year degree, and many law school graduates are never able to find jobs as lawyers.

The market will probably eventually correct itself, but the days of law school as a sure-fire way to a high paying job are probably over.

<comment><USER3> The "more new lawyers graduating each year than there are law jobs" factoid is both stale and irrelevant. Most of those new lawyers had admissions scores well below the 50th percentile and are graduating from third and fourth tier law schools. Who cares about them? I doubt many would have had bright futures in programming, either.

Relatively modest undergraduate performance can get you into a law school like Northwestern's, where 87% of the class of 2013 "found work and reported a salary", and at least 43% of the class had a starting salary of over $160k, a very respectable ending salary for a programmer, especially outside of SFBA ([http://www.lstscorereports.com/schools/northwestern/sals/201...](http://www.lstscorereports.com/schools/northwestern/sals/2013/)).

<comment><USER4> Almost 50% of new law school graduates can't find jobs. Of course it's likely that the unemployed 50% is the bottom 50% of applicants.

Look at the distribution of lawyer income. There is a large group bunched near the bottom making 40k-60k a year, and a smaller group at the top making above 160k. You need to do really well to be in the 160k group.

>Relatively modest undergraduate performance can get you into a law school like Northwestern's

The median LSAT score for Northwestern is 168 about that's right at the 96th percentile, so about 4% of people taking the LSAT will score a 168. Even Northwestern's bottom quartile score is just below the 90th percentile. Their median undergrad GPA is 3.75. How are those numbers relatively modest?

So yes, someone who scored in the 96th percentile on the LSAT and had a 3.75 GPA in undergrad has a decent chance of spending 3 years at a top tier law school where they have a 43% chance of making over $160k a year upon graduating.

Northwestern also costs about $300k to attend.

>87% of the class of 2013 "found work and reported a salary"

I don't thinks that's really saying all that much. It doesn't say they're working in jobs requiring a law degree. Of course 87% are working at some kind of job--they owe $300k in student loans. Another way of looking at it is--13% of graduates from a top tier law school are unemployed with $300k in debt.

No one is arguing that lawyers from top tier law schools can't make a decent salary, but there are only a few thousand slots open in the top law schools each year. If you're in the top few percent of law school applicants and you think you'd enjoy practicing law, then by all means go to law school.

But looking at the averages, the median salary for a software developer is about $93k, and the median salary for a lawyer is $113k (from the bureau of labor statistics). Total cost for law school is over $150k on average, and the opportunity cost for not working as a software developer for 3 years is much more than that. Add in interest for student loans (and forgone interest on potential savings) and it will take over 2 decades before the average lawyer pulls ahead of the average software developer.

Add to that the fact that software developer jobs are expected to grow at a significantly higher rate than lawyers, and that lawyers constantly place near the bottom on job satisfaction surveys.

By the way I, initially planned to go to law school, but every lawyer I talked to was so discouraging that they eventually talked me out of it. A few of them were very successful family friends, but they absolutely hated their jobs, and they warned me that there are much easier ways of making money.

<comment><USER3> If you're a programmer who can pass algorithm interviews, you have a great chance of scoring near the 90th percentile the first time you attempt the LSAT, and the 96th percentile with practice. Scoring much below the 80th percentile on the LSAT is very poor. In Canada, few students are admitted to any law school with scores that low.

Say you spend $300k on law school. Over a 30 year career, you only have to make an average of $10k extra per year to break even.

The "Jobs Data" tab offers more details: "79.2% of graduates were known to be employed in long-term, full-time legal jobs", "93% graduates were employed in long-term jobs", etc.

The number of software jobs are expected to grow, but is the growth going to be in jobs you really want, or will they all be for 23-year-old coding bootcamp grads?

Again, who cares about the nationwide averages? The 50th percentile Northwestern law grad makes $160k right out of school, and is on track make several times that as a law firm partner, or somewhat less as in-house counsel. My impression is that most programmers struggle to hit $160k any time in their careers, at least outside of SFBA.

When someone describes the downsides of their job, I take it with a grain of salt. Often, it's a case of "the grass is always greener". Sometimes, members of high-status professions want to downplay their success. In any case, most of the lawyers I've talked to say they enjoy their work (though they do work much longer and less predictable hours than programmers).

<comment><USER4> >If you're a programmer who can pass algorithm interviews, you have a great chance of scoring near the 90th percentile the first time you attempt the LSAT, and the 96th percentile with practice.

That's probably true. But again, there are only a few thousand slots available each year at top law schools, so for the vast majority of programmers this can't work. Just a few hundred each year taking your advice would change the equation.

>Say you spend $300k on law school. Over a 30 year career, you only have to make an average of $10k extra per year to break even.

That's true, but the average is more than $300k. The average programmers makes $93k a year, since he can work 3 fewer years because of the 3 years in law school, that's $279K in lost wages + $150k for law school.

Sure the lawyer will likely eventually pull ahead, but extra money near retirement is worth less than money early on. If the programmer invests the extra money early on, the lawyer may never actually pull ahead.

>"The "Jobs Data" tab offers more details: "79.2% of graduates were known to be employed in long-term, full-time legal jobs"

Legal jobs doesn't mean working as an attorney, or jobs requiring a law degree. It could mean $15 an hour paralegal work, so that statistic isn't useful.

>The number of software jobs are expected to grow, but is the growth going to be in jobs you really want, or will they all be for 23-year-old coding bootcamp grads?

That's possible, but the new jobs for lawyers could be just as bad. From the Bureau of Labor Statistics "Some recent law school graduates who have been unable to find permanent positions are turning to the growing number of temporary staffing firms that place attorneys in short-term jobs."

Software has been eating into jobs that were traditionally done by lawyers, and it will continue to do so.

On top of this, lawyers are limited to practicing in states where they have passed the bar exam, meaning their ability to move to find jobs is much more limited.

>Again, who cares about the nationwide averages? The 50th percentile Northwestern law grad makes $160k right out of school, and is on track make several times that as a law firm partner, or somewhat less as in-house counsel.

And they admit about 200 new students per year. So yes, if you can get into Northwestern and you like law, then it's a good decision.

>(though they do work much longer and less predictable hours than programmers).

That's a _huge_ caveat. The average programmer could have been the average lawyer instead, worked more hours each week at a higher stress job so that by that he can break even in 20 years, and spend the last 10-20 years of his career making a bit more money.

If you like law and can get into a good school, then practice law. But I hardly think the extra, debt, stress, and hours worked makes it worth it for purely economic reasons.

>When someone describes the downsides of their job, I take it with a grain of salt. Often, it's a case of "the grass is always greener".

This would be the case for both programmers and lawyers, but job satisfaction surveys show that lawyers consistently rank near the bottom below programmers.

</comment></comment></comment></comment></comment></comment></comment><comment><USER5> I agree that it's impossible to predict the future. There may be some discontinuity that we haven't foreseen. That said, it hasn't happened yet.

I think the run of the mill work will get more commoditized. Building web sites is already pretty cheap. Programmers in Europe make a fraction of what their counterparts in the US make.

But the fact remains, programming is still more of an art than a science, despite all the effort that has gone into making it a repeatable technical discipline. As _smcquaid_ said, software is hard. Many new products require invention on the spot, albeit using more well understood techniques as the years go on. But as the scope of techniques continues to expand, so does the problem space within which they must be applied. Software is being used to streamline more and more of our world.

As much as we try to make it repeatable, it is still an art. Agile has gone a long way towards this goal, which is one reason we see run of the mill work being commoditized. Many people are certified in Scrum. But that will never completely solve the problem. As long as there are new challenges to be solved, those who do it well will be compensated accordingly. There's a reason good doctors and lawyers still make a good living, centuries into the advent of their professions.

<comment><USER6> Medicine and law require licenses to practice, as well as an exclusive pathway to the main game via lengthy tenure in supporting roles. This is in part to to protect their clients and patients. I want to know that the guy operating on me has relevant training and experience. But it also acts as a barrier to entry, keeping wages high in each industry.

Programming requires you to have a free account on Github and some demonstrated ability.

Keep your game up and your network current.

</comment></comment><comment><USER7> When I started programming in the '90s I thought "this is it. We are so far advanced, there's nothing left in the computing field except making slicker UIs. Hardware will get faster but computer languages are at their pinnacle." Of course I was entirely wrong, but I did believe as a result salaries for software engineers would begin to decline as more people entered the field.

Now in 2015 I believe we are only at the very beginning - a humble start. There will be things during our lifetime that change the computing landscape. Biological circuitry, quantum computers, virtual reality to name a few. Advanced technology will increase the demand for capable software engineers to solve problems we can't even dream of today.

However I don't think $300K salaries are going to be the norm for engineers solving for 140 characters or how to deliver television shows on demand.

<comment><USER8> Why not? These are the services for which there is demand.

<comment><USER7> I believe demand for engineers to solve these problems will wane as the solutions become codified into various open source projects.

Think of how difficult a problem that involved terabytes of data was to solve before the advent of Hadoop and now consider how easy it is with solutions like Spark.

Overall this is a good trend. I'm not saying that $300K engineer salaries are going away; I'm saying high salaries will pursue the engineers who are solving unique and demanding problems.

</comment></comment></comment><comment><USER9> Law of Headlines says "no".

My experience also says no. The two issues I'm facing are:

1\. Due to technology churn, after a couple years of experience, your experience loses its market value faster than you can get new experience.

2\. At 40, I'm starting to feel age discrimination. When you go on an interview and everyone else is <25, you see that you "aren't a good cultural fit". Younger programmers have started talking down to me like my experience is irrelevant. Then they ask me to debug their code for them.

As a programmer, you can make good money from 25-35. After that, it's starting to look like it's over.

<comment><USER10> I'm the youngest senior where I work at 36. Our leads are approaching or past 50. This may be a localized problem.

<comment><USER11> It is localized, the work force is aging and the population is not growing at a rate to replace those aging out. For the most part I have seen the ration of young faces to old ones lessen. It seems my generation 40 is really the generation that grew up coding and therefore the age bounds are being pushed with us. I know in certain markets that is not true, but in others it is.

</comment></comment></comment><comment><USER12> Im going to go with the in 50 years if you cant code on some level you will be seen as mildly illiterate. Coding will be core to nearly all jobs. There will still be people writing software as software engineers, but around the edges it will be specialists in a discipline writing code to extend the core software to do what they need.

Really, its just taking how many people use excel and growing that up. With technical improvements like simpler to code languages, more predictable API expectations (that is they all tend to work the same as a convention), and general maturity of software as a idea (its not old by any standard). Along with social expectations of what you need to be able to do. Today its use excel, a generation or 2 it will be basic coding.

<comment><USER3> If you're saying some jobs that today require "Excel" will require "Excel with VBA", sure. But I'm skeptical that programming will become some sort of new literacy. It seems to me that programming has narrower applicability than, say, high school math. Still, most non-programmers seem to forget their high school math, and they get by just fine in careers where numeracy would be useful from time to time, but is just not essential. No one considers them illiterate.

<comment><USER13> > _most non-programmers seem to forget their high school math_

I wrote a book to fix that: [http://noBSgui.de/to/MATHandPHYSICS/](http://noBSgui.de/to/MATHandPHYSICS/)

This book is like calling `apt-get install hs-math mech calc`.

<comment><USER14> I was not very interested in math in school or university (I suppose due to the lack of context and focus).

Now after working a few years as a web developer, a goal of mine is to revisit and study math and physics.

I've bookmarked your "No-Bullshit" Guide. Thanks for sharing.

</comment></comment></comment></comment><comment><USER15> Coding is getting much, much easier. Building an application that might have taken a team of 10 a year in the 1980s now takes a team of 2 just a few months. There's lots of reasons for this, but largely it's because programming languages are higher level, frameworks make the hard things trivial (especially UI and networking), and patching broken code is far easier so you can ship a buggy product without customers getting as annoyed. With SaaS things are even easier - essentially there's a single installation to patch and you can log every error rather than having to wait for feedback.

These changes will continue. Software will get easier and easier to build. What takes times today, say algorithm optimisation, will take a fraction of the time in a decade because we'll have better tools for doing it and hardware will be fast enough that it won't matter as much. The fact it'll be a less skilled job will exert downward pressure on wages.

Conversely though, the amount of software needed will continue to increase, so demand will keep wages up.

The question is which force will win out in the end.

<comment><USER2> > Coding is getting much, much easier.

I don't know about that one. If you want to build a compiler or a scripting engine, you will still be dealing with the one or the other variation of lex and yacc and then get bitten by the intricacies and gotchas of writing up a compilable LALR1 grammar. You should also have a reasonable command of C (or C++) but that is rather easy in comparison. Building a compiler is as hard now as in the 1970s when they first started using automated tools for that.

> Building an application that might have taken a team of 10 a year in the > 1980s now takes a team of 2 just a few months.

Yes, if you are always building a variation on the same database application, it should indeed become easier after a while. That is the essence of a "framework". You are always building the same application, with just a few variations here or there. That will indeed give the wrong impression that building software is getting easier and easier. Building such frameworks, however, is not becoming easier, and we continuously have truly new applications to build, not just variations on the same one.

<comment><USER15> To use a car analogy you're suggesting "the automotive industry still finds designing a car difficult because look at Formula 1 racing!", while ignoring everything that makes designing and building cars much easier/quicker/safer/cheaper.

There'll always be edge cases where generalisations break down but looking at them doesn't give you any insight to the bigger picture.

<comment><USER16> I think you're always going to see that. When a system is pioneered, it is very, very, very hard to get any kind of traction.

To extend the car analogy. Karl Benz spent more than 3 years trying to find an engine configuration that worked and did not blow up. Then, again, he spent years to get an engine of the correct size to provide the correct amount of force for his horseless carriage, and things like transmission, gearshifters, ... Designing the first automobile, start to finish, took one man, going through 3 companies because they wouldn't let him, from 1871 to 1885, 14 years total. And keep in mind that the 1885 version was extremely unreliable, hard to control. It got out of control during a demonstration and crashed it into a wall 3 months after it's construction. It took until late 1888 for a "usable" model to get onto the market (and this is using a flexible definition of the word usable : his wife made 3 design changes on her first trip with the car, one because the brakes didn't work downhill, another to the ignition and something about the fuel line)

But 2 things change for today : building a working car, is much easier. Anybody can do it in a week. Building a car that people might want to buy ... 2-3 years at least. Building a car with a new engine (the only way you're going to really improve performance), or any large difference (e.g. hybrid- electric) 6-10 years at least. Building a fundamentally different car like the tesla took barely less time than Karl Benz needed : 2000 (real work on Tzero started) to 2009 (working prototype presented) to late 2012 when the first model S rolled of the assembly line. This happens because the standards have gone up a lot.

Yes writing software is easier. But writing software that qualifies as "good" has much higher standards, which makes things take longer. I would argue that these 2 are in competition. Some years the tools win, and you can write software faster. Other years people introduce the web and "standard" 5 middleware layers (javascript client-side, load balancing, web server, business logic server, database server) and it takes a lot longer. Other years people demand that a local bakery's webpage is "scalable" and it takes a LOT longer.

If the car industry is a good example, the time and effort required to write software will effectively not go down by more than 20-30%, unless you compromise on quality.

</comment></comment></comment></comment><comment><USER17> It already is a bad profession. All professions are bad, if your goal is to make money.

If your goal is to maximize money in your pocket, standard employment is a bad model.

</comment><comment><USER18> What will happen to the _value_ of a programmer over time?

Do you think opportunities to make an economic impact with software are increasing, decreasing, or staying the same? (I'd say they are increasing, as the world depends more and more on software.)

If you want to earn high wages, you should probably aim for skills that are (1) in high demand, (2) in short supply, and (3) not easily replaced by substitutes. So find a niche where there will be real demand and supply is limited (because it's hard to master: think "programming" \+ electrical or mechanical engineering, or computer vision, or...).

</comment><comment><USER19> Depends how far into the future you're asking. 5 years, 10 years, 50 years? My two cents is that everything is cyclical. It's easy now to forget about the 2007 real estate crash, the 1999-2001 dotcom bust, the recession in the late 80's and early 90's. We're roughly due for another economic downturn, but the cause is anyone's guess and the software industry is not immune to external market forces. Nothing stays up forever, and nothing stays down forever either (in economics and business).

<comment><USER17> That remains to be seen. Software has been around far less time than the boom/bust cycle.

<comment><USER20> ...and yet it's already been through one iteration, two if you count the 1983 video games crash (video games are software), and more and more learned heads are starting to look uneasily at the idea that it's on the upslope of a third.

</comment></comment></comment><comment><USER21> No. Give it another few years and the fact that it's a red-hot job market will catch up and we'll end up like lawyers. The perception of high salaries and the reality of a lack thereof.

<comment><USER22> You say this like programming has never been a red-hot job market in the past. Also a lot of lawyers are still highly paid even newer ones. Being a lawyer, like being a programmer is no guarantee that you will be making 6 figures but you're a lot more likely to in either of those jobs than most others.

<comment><USER23> As a lawyer turned programmer, I've written a bit about this here: [http://www.williamha.com/economics-of-software- development-v...](http://www.williamha.com/economics-of-software-development- v-the-practice-of-law-a-rough-look/)

I also did an interview on Above the Law about how some people in the legal profession may be better off in software: [http://abovethelaw.com/2015/06/should-you-leave-law-and- lear...](http://abovethelaw.com/2015/06/should-you-leave-law-and-learn-to- code-a-conversation-with-lawyer-turned-programmer-will-ha/)

And for the record, the majority of new lawyers in the United States are paid as much if not less than an junior software developer these days.

<comment><USER22> I'm a developer, my wife is a lawyer though not in the US.

I think the assumption that you call out yourself(64 yo developer) is the main difference over a lifetime of work. How many developers are going to be finding much work over 45-50 unless they are already well positioned as an independent consultant or have a name brand? That's 15-20 years more earning potential for the lawyer.

The other thing is the startup x-factor. Because so many start ups fail studies have shown developers that go the startup career route actually make less on average than their counterparts working for larger established companies. Very few people have the drive to make partner at a large firm but even fewer people are lucky enough to be an early employee at a company that makes their equity worth more than a years salary.

<comment><USER24> I know I'm going against the normal view of things here, but as I near 50, I don't see any difficulty with people my age finding work. The group I work with would kill to find someone good with 30-40 years of experience. They are just really hard to find -- either they are already happy where they are, are a consultant, are a manager/executive, or they aren't very good.

The problem is this: If you have more than 20 years of experience and want to continue being a employee programmer you only have a few choices. You can advertise yourself as a senior programmer and try to command a senior salary. Or you can advertise yourself as a more junior programmer and ask for a low salary. If you have the ability to do the senior position, then there is not problem. If you do not... who the heck is going to hire someone with 20 years of experience who is still performing like a junior? Even if they are cheap, there is value to the employer of imagining that the employee will develop over time. Someone who flatlined 15 years ago is not someone you want on your team.

The moral of the story is: if you want to be a programmer for your whole career you _need_ to stay on the front edge of the industry. You have to work your butt off day in and day out to not only stay current but always improve yourself. There will never be a day where you "make it". You will have to justify that senior position that you are going to occupy and show that you are better than the up and coming young wolves behind you. If you are not prepared to do that, then you are better off not being a programmer.

<comment><USER22> The thing is not everyone is capable of being a senior developer or in a leadership role regardless of how much they know. I'd go so far as to say most aren't.

</comment></comment></comment></comment></comment></comment><comment><USER25> Forecasting future is obviously impossible, but we could approach your question in a structured way.

First of all, allow me to question your premise. Software engineering is a quite lucrative job in the US in general, and in Silicon Valley more specifically. But in many European countries command average salary (with variations due to seniority, obviously). In Eastern European countries, India and China it is for sure a well paid job but not nearly as lucrative as it is in the US.

Clarified this point, the drivers of such high salaries are resource scarcity and high demand.

On the demand side, there are few relevant uncertainties: basically whether the economy will sustain the growth of the software industry (or, there is no tech bubble) and, on a longer timeline, whether evolution in programming technique will outpace the growing demand for software or not.

On the supply side, the main question is whether there will be an immigration reform or not and how it will impact the tech sector. Furthermore, more people are training now in coding than before, both in universities and after university using bootcamps or similar institutions. So the critical uncertainty is whether the new trained people are enough and good enough.

My humble opinion, given all these uncertainties and their probable resolution in the long term, is that sooner or later, "software salaries" will have to adjust downward. The only question is when and how fast. Aka, it will be something in the immediate or int the far future and it will be a hard landing or a smooth erosion over time?

</comment><comment><USER26> There are a few things working against the prospect of it being lucrative and a few working for it. I think it's a safe field for 5 - 10 years, beyond that it starts becoming a bit murky. Here are three potential reasons:

1\. Influx of supply. This has been steadily happening for, well, the entirety of the life of the profession, but the prospect of big money at a lower barrier is making this feasible for a lot more people. Money attracts, which draws the parallels to the attorney drives in the past.

2\. [ Feeding #1 ] Cascading loss of professions will move people into other parts of the labor market. As automation removes entire professions, those people will be forced into other markets and will begin to tighten competition and feed the supply influx further.

Which leads to the unfortunate ...

3\. Increasing automation of developer tasks will reduce the need for humans for _some_ programming / development. Not entirely, obviously, and not in the near-term, but a lot of the functions that require humans - general problem solving scripting, testing, simple goal-based programming will begin to fall to automated agents. On a similar note, congregation of technologies and philosophies will remove a lot of the dissonance between stacks, devices and platforms.

</comment><comment><USER27> I think there will always be jobs where you get paid to write code.

If you narrow your definition, it'll look different. The jobs may not always in the Bay, they may not be using the coolest front-end framework or functional language de jour, and you may not get paid to go to 4 conferences a year. It might be maintaining custom billing software in .NET in Boise, but in the end it'll be programming and reasonably lucrative.

</comment><comment> wes-exp The whole tone of this question smacks of "gold fever". I'm guessing you're thinking about entering the field, so I'm going to tell you what someone told me during the original dot-com bubble:

Only become a programmer if you truly enjoy it.

If you're getting into programming solely because you think it's "on fire", you're going to have a bad time. It is always possible at any given moment for various reasons that VCs could collectively pull back on tech, or some major employers could downsize, and flood the market with excess talent. No one can predict this shit. There was a time post-bubble when many programmers could hardly _give away_ their skills let alone make big bucks. Not long later there was a time when it was a foregone conclusion that all software development was going to India. Now here we are talking like "is this money wagon going to go to infinity?" and I say _stop_. Just _stop_. Do it because it suits you. Do it because you like the work. Please don't do it for "the money" which may or may not deliver for you, ever.

</comment><comment><USER28> I believe the statement to be true. The rate at which new jobs are created for computer scientists even outpaces the rate at which newly graduated CS majors enter the workforce.

Meaning demand is going to increase at an increasing rate, supply will remain at a constant growth rate.

In the future, while technology may replace many things, It will never replace entertainers, engineers, designers or people who create creative things in general.

The killer fact to me is that software is hard. It is something that cannot be seen. Imagine trying to diagnose traffic problems when you can't see the cars or the roads or the traffic signals. Software is so hard that even if you build a system that accomplishes the main objective, it can be extremely hard to modify the system in the future if the quality is low. Top talent will always be in demand. Over time a few expensive talented programmers will always create a better product than hundreds of cheap mediocre ones.

</comment><comment><USER29> Eventually, sure, the trend will die down. But given that the demand has been generally increasing for decades, I don't see a reason to think that it will die down until decades from now.

Look around and you see terrible software everywhere. The medical industry, the legal industry, the insurance industry, small businesses, government entities, etc etc. Almost all of them have terrible websites, terrible internal tools, terrible uptimes, terrible everything. Billions of manhours are spent on tasks that could be better done by software. There's good money in solving those problems, the problem is that there's only so many good engineers in the world, and the hot technology companies snatch up almost all of them.

They say that software is eating the world, and it's true, but so far the world is only 5% eaten. There's plenty of work left to do.

</comment><comment><USER11> I compare it to the engineer of the industrial revolution and it will continue to be the same until there is a fundamental shift in the way we transfer instructions to computers. The biggest threat to the profession of software development is AI, when something can infer what a non-technical person means it will spell the end of the dedicated developer. Then much like the telegraph operator, the profession will disappear almost over night. That being said, a lot of professions will be gone just as quickly.

Until them I would like to offer some perspective from someone who has been in the industry for some time and to have seen the tail end of the home computing revolution, the birth of the web and all the iterations till modern day.

I had this discussion with a buddy that left software dev after the .com bust and the first wave of offshoring development jobs. He, having come from manufacturing was certain that offshoring spelled the end for US developers.

Personally, I had a different outlook, one that we should all remember when we sit at the negotiation table and that is, it is estimated that 10-20% of the population is mentally competent enough to write software and I would say that is a pretty good estimation. Probably another 5-10% border on competency so at best 30% of the population even has the capacity to code. We know the old 1 in 10 rule, that for every 10 programmers you hire 1 will be really good. So that puts us at what 3% of the population being exceptionally good developers? Probably another 6% being above average. Probably in the range of 10-15% being competent and the remainder costing companies more money than they are worth in lost time from the good developers carrying them.

So if you think about it somewhere around 9% of the world population is truly capable of good software development. And that is why despite the .com bust, the waves of offshoring and whatever will come before AI, the developer is one of the few bastions of the American middle class. It is by it's nature self limiting as far as competition goes.

</comment><comment><USER30> Nope, in fact you are going to see salaries start to retreat as more people get into the industry.

The field that will collapse the hardest is going to be data science. I speak to this as a data scientist, where most I meet don't have the knowledge to perform their duties. Eventually our salaries will decrease to those of traditional office workers/middle managers.

What is a engineer to do in this situation? The answer is to specialize, or gain exclusive access. Specialization is obvious, and exclusive access are things like clearances, certifications, and networks. Of course, this omits paths such as entrepreneurship.

<comment><USER2> > Nope, in fact you are going to see salaries start to retreat as more people > get into the industry.

That is what they said 15 years ago. Getting into the industry is not hard. It is staying that is hard. You need a respectable amount of talent and will power for that. There is an incredible amount of tourism going on in our industry. Put out an advert for a programmer and you will understand why recruiting programmers is so exceedingly costly:

[http://blog.codinghorror.com/why-cant-programmers- program/](http://blog.codinghorror.com/why-cant-programmers-program/)

 _Like me, the author is having trouble with the fact that 199 out of 200 applicants for every programming job can 't write code at all. I repeat: they can't write any code whatsoever._

<comment><USER31> Is this actually the origin of the fizz buzz? I was under the impression it had been around at least sense the 90s.

</comment></comment></comment><comment><USER32> Coding is a valuable skill because computers can do certain tasks far more efficiently than humans can, and in ways that add massive value to our lives. Every engineering industry I know has been transformed by tools created by programmers. Whether you are solving matrices or simulating aerodynamics, the cost of doing certain tasks and prototyping has reduced to almost zero thanks to computers.

And, as far as we can currently tell, there's a massive amount of untapped potential. Whether your programming trading engines or social media, the right program, even a small program, has massive transforming power.

Even more significant, if a programmer writes a piece of code that makes a 0.01% improvement to a product, it's virtually free to distribute that improvement to hundreds of millions of people . A programmer may not even need to be very good to add millions of dollars of value to a company if they are put in the right position.

As time goes forward, we are seeing substantial developments to the coding practice. Languages are getting better, compilers are getting better, theory is getting better, test suites are getting better. All of this results in programmers being that much more useful when put in the right situation. Iterating on programs is also very cheap. Rather than needing to build an entire new plane engine, you just recompile your code and throw it at the test suite again.

Will it stop? Probably not in the next few decades. As simulations and other tools get better, we may see other engineering industries catching up, but right now programming is unique in how accessible it is, how quickly you can iterate on a design, and how easily you can distribute improvements/products to millions and even billions of people.

Even if the supply of programmers expands dramatically, I can't imagine running out of things to throw them at. There's always another feature, or another product idea, or some other project that would take a substantial amount of programming resources to complete.

High salary programmers are here to stay. I don't know where the ceiling is, but as the tools continue to improve, so will the justification of the salary. Even if we are in a bubble right now, the bubble bursting will still leave programmers in a very comfortable position.

</comment><comment><USER33> I believe that people who can work as part of team to solve difficult problems using computational tools will continue to be highly paid.

I doubt whether people will continue paying high salaries for hacking up crud apps.

Concretely, I expect the peak salaries for people who program for a living to continue to increase more or less monotonically. However, I also expect the _average_ salary in the field to fluctuate, and I believe that in 40 years from now, these past few years will stand out on an inflation-adjusted graph as "the good years".

</comment><comment><USER34> No.

\- Risk of loosening of immigration restrictions

\- Large and increasing supply of skilled workers from East and South-East Asia, who are willing to work for lower wages.

\- Skill based work is hard to defend and retain in the presence of significant competition.

\- Tech companies may create and make widely available training programs to become a software engineer, also increasing supply. (I don't understand why this hasn't become the main purpose of MOOCs).

Chamath Phalipapitya (sp?) called programming the "blue collar work of the 21st century".

<comment><USER35> MOOC's have been shown to be ineffective most people dropout, and if you learn from an MOOC its unlikely you will hit most of the concepts, I think I have seen that when I worked as a tech recruiter for a year, there were tonnes and tonnes of iOS "Developers" who learned from coding shoppes and mooc they never make it past fizz buzz or even building anything more sophisticated then a twitter api call app.

</comment></comment><comment><USER36> The job market in CS is cyclical, with a roughly 20 year cycle; we are now at the point where supply will start to catch up with demand; 'everybody' will study CS, and in 4-5 years we will have a glut of beginners and bad programmers.

But, having experienced the bust of 2001-2002, I expect that, even at the bust, it will not be that bad. Also, programming trains you to think mathematically and analytically, so it is easy to move to a slightly different function.

</comment><comment><USER37> The best place to be, will be in a position to leverage automation and artificial intelligence as a multiplier effect of your labor and income potential. Instead of competing with those things, instead of going against them.

The ability to run massive Internet services with very small teams, will continue to increase. The spoils will perpetually increase for those teams. Ride that trend, rather than having it ride you.

<comment><USER38> And then people make lots of money maintaining COBOL and Java code. Or securing custom PHP applications...

</comment></comment><comment><USER39> I think in the future, there will be programs to write 50% of the code for you in some way and (if DARPA get this right) you may have code that lasts a lot longer and does not need to be rewritten. So like programmers are making jobs in other professions irrelevant now, they will likely make jobs of other programmers irrelevant in the future.

<comment><USER8> I don't really understand the thing about computers writing code and this resulting in less demand for programmers. Don't computers already write a lot of code in the form of compilers, frameworks, preprocessors etc.? Seems that these technologies only make demand go up.

If anything, code generation is the worst option out of any form of code reuse and results in code that is entirely unmaintainable. Code generation is often a sign of a language that handles abstraction badly, like Java.

I can imagine some form of ai that instead o being trained to recognize images etc., is trained to present an interface. However this will likely be deathly slow and require custom code for anything custom anyway.

</comment></comment><comment><USER40> People like Chris Granger are making programming more accessible:

[http://www.chris-granger.com/2015/01/26/coding-is-not-the- ne...](http://www.chris-granger.com/2015/01/26/coding-is-not-the-new- literacy/)

</comment><comment><USER41> The necessity of the human practice of software development doesn't end until the onset of general artificial intelligence. In the time between then and now it will increasingly be the hammer that is used for humanity's nails.

</comment><comment><USER42> As long as technology exist will always be a need for programmers. We can't progress without new technology.

</comment><comment><USER43> xyz will be a lucrative profession if and only if 1\. xyz is gated 2\. xyz is intrinsically hard 3\. fewer people attempt to get into xyz over time 4\. xyz yields higher wages per hour relative to other professions.

I don't see programming fitting any of these axes, let alone all of them.

<comment><USER44> I don't think the presented axes are correct (#3 I'd argue isn't necessary, though there may be a different supply factor that is, and #4 itself is _equivalent_ to being a currently lucrative profession, it isn't a separate consideration that is necessary), and programming certainly _currently_ meets 4, and arguably meets 2, at least for some significant subfields of programming.

</comment></comment><comment><USER45> In the far future? No, of course not. It depends when computers can program themselves (aka hard AI or, if you will, the "singularity"), which is either 10 years, 20 years, or 100 years from now. It is difficult to predict when programming will end as a profession, but it will be one of the last ones to go if you even believe in the end of work.

</comment><comment><USER46> I think the hype right now is overblown.

</comment><comment><USER47> Yes, the wages will go down, but so will everyone else's even more.

Computers, AI and automation are eating all jobs it makes sense to me by the time programmers are redundant everyone else will be long screwed.

PS IT enrolments are down, not up ATM

</comment><comment><USER48> Yes.

</comment><comment><USER49> I'm 34 years old, and I don't think this question matters at all. As someone who's been professionally programming since well before YC existed, I fall into a strange category: I'm really young.

To anyone even close to my age or older? Be very worried. To everyone else? Be worried about the non-programmers. If you can hack it at hacking, then you have nothing to fear in any economic environment.

Any individual might see a downturn because the overall economy sucks, or because the dominant culture doesn't recognize them as fully human. We live in far stranger times than that. Don't worry about the upper $300k tier, rather worry about the bottom falling out of the $60k tier market. (That's still triple the poverty line.)

If you are worried about anything else, you should literally die.

<comment><USER50> > To anyone even close to my age or older? Be very worried.

Huh? Why do you say this?

<comment><USER49> I don't know. I got downvoted on this post a lot.

Technology jobs are far less secure for the humans older than me with more experience. Ageism wasn't the only reason I posted this, but I'm guessing nobody that downvoted me was older than me. (eager to be wrong)</comment></comment></comment>


Ask HN: Best books/resources on running a lean/bootstrapped company? - <AUTHOR>

<comment><USER2> The Single Founder Handbook - [http://www.singlefounderhandbook.com/](http://www.singlefounderhandbook.com/) ?

</comment><comment><USER3> The obvious ones: The Lean Startup - Eric Ries, Rework - Jason Fried & DHH, Getting Real - Jason Fried

</comment><comment><USER4> Traction is also good book</comment>


Ask HN: Do you know any fun science/maths books for a casual read? - <AUTHOR> I am looking for books related to maths/science which can be read in bed without a need to take notes or work on proofs. <comment><USER2> The first author that comes to mind is :

[https://en.wikipedia.org/wiki/John_Allen_Paulos](https://en.wikipedia.org/wiki/John_Allen_Paulos)

His most famous book is Innumeracy:

[https://en.wikipedia.org/wiki/Innumeracy_(book)](https://en.wikipedia.org/wiki/Innumeracy_\(book\))

but all his books are nice.

Maybe they are too simple/basic?

</comment><comment><USER3> Faster Than the Speed of Light: The Story of a Scientific Speculation

Blurb from Amazon: "Nothing travels faster than the speed of light, and light travels at one fixed speed. This idea is considered a foundation of modern physics, but what if it is wrong? Theoretical physicist Magueijo presents the idea that light traveled faster in the early universe than it does today. The varying speed of light theory solves some of the most intractable problems in cosmology, and could have major implications for the study of physics."

</comment><comment><USER4> There are a lot! What kind of math or science do you like? Any books you've liked before, so you're looking for "more like this"?

</comment><comment><USER5> Perhaps something like Godel, Escher, Bach?</comment>


Silicon Valley has a new vision for the pizzeria. It involves lots of robots - <AUTHOR> http://www.latimes.com/business/technology/la-fi-tn-zume-pizza-automation-20170706-story.html <comment><USER2> Sounds like a really, really over-engineered solution. Especially since, as the article states, people want hand-crafted food nowadays.

The pizzerias that are thriving right now are the ones making neapolitan style pizza in wood ovens, Pizza Hut and Little Caesars barely exist around here anymore.

<comment><USER3> "Around here" being the operative words. For those of us that choose to not live in urban environments, hand-crafted foods are much more scarce. I think there's a pretty large market for these guys to pop up stores in cities that aren't close to large cities.

And if they can get their costs down with automation I'm sure they'd find a way to make a profit in urban areas as well. After some time at the brewery, a $3.50 pizza is pretty attractive.

<comment><USER2> Not sure how much food costs are where you live, but a $3.50 pizza isn't possible here. The ingredient cost is too high.

<comment><USER4> In the NYC area there are a few bars that give you a free small pizza with every $5 pint all day every day. Pretty decent too.

</comment></comment></comment></comment><comment><USER5> Wait a second... these guys make supermarket-grade pizza using "Jira and Kanban"?! This world has some serious problems.

<comment><USER6> I got a good laugh seeing them using a $100,000+ 6-axis automotive assembly- line robot to move a pizza 90 degrees from a conveyor to an oven. Overkill to say the least. This is laughably overengineered.

<comment><USER7> Especially since most chain pizza places use a conveyor oven to cook the thing.

</comment></comment></comment><comment><USER8> At the Stern school, first term part time MBA students were told to go to the streets and observe pizza places (so many in the city). Come back and build a business plan.

Wasn't long before students saw how much there was to be made on a slice and that cheese is the most expensive part of the pie.

Personally, perhaps because of the population of Italian heritage near me, I simply avoid pizza places that seem like a business, not a life vocation.

</comment><comment><USER9> At least around me, the small Pizzerias don't have much turnover. It's the same two or three guys running the place year in and out (but that's in the Hudson Valley/NYC area).

I guess this would be attractive to Dominos or Pizza Hut.

</comment><comment><USER10> This seems like an overengineered problem for food. I don't get how all of the capital expense can be justified for the ever slimming margins of food production? Do they plan to scale it up? Others have mentioned pizza factories and wouldn't that be their competition? I don't get it.

<comment><USER11> I never understood why minimum wage labor was so expensive for fast food or pizza places, and that's pretty much what they're eliminating here.

Maybe the answer is that margins are so slim in the food business that any significant reduction in cost is bigger than it appears?

<comment><USER12> >Maybe the answer is that margins are so slim in the food business that any significant reduction in cost is bigger than it appears?

Seems so. We've got people saying labor is the biggest cost for a restaurant or pizzeria, but that necessitates asking: holy shit, how can the value-add of a fresh, hot pizza over its unprepared ingredients be _so low_ that it's worth cutting wages to below $8/hour by robotizing the work? If pizza really takes that much value as input, why does it have so little value as output?

<comment><USER13> > We've got people saying labor is the biggest cost for a restaurant or > pizzeria, but that necessitates asking: holy shit, how can the value-add of > a fresh, hot pizza over its unprepared ingredients be so low that it's worth > cutting wages to below $8/hour by robotizing the work?

In a competitive market, it's always worth reducing the cost of inputs. The restaurant business is generally a competitive market (it's actually a bit _worse_ than an ideal competitive market for participants, because there are usually lots of unsustainable competitors selling below cost and losing money.)

<comment><USER12> >(it's actually a bit worse than an ideal competitive market for participants, because there are usually lots of unsustainable competitors selling below cost and losing money.)

 _This_ sounds like the problem. Shouldn't the government do something about these anticompetitive practices? I don't think a good economy involves "charities" driving the restaurant business to extinction.

<comment><USER14> There are many Walter Mittys out "playing restauranteur" and no, I don't think the government should be in the business of telling people they're bad at business and stopping them from doing it. It's not like the local restaurant of the day is going to dump food on the market in mass quantities hoping to create and exploit a monopoly later.

</comment></comment></comment></comment></comment></comment><comment><USER15> This already exists in vending machine form, saw one of these in a supermarket in Greece [https://www.youtube.com/watch?v=j7_lxiU8eLM](https://www.youtube.com/watch?v=j7_lxiU8eLM)

<comment><USER16> This is pretty awesome. As someone who makes pizza at home about once a week I have a few minor observations:

1\. Only flour and water in the dough? What about yeast and salt?

2\. Whenever I make pizza the dough is rather sticky. I wonder how they keep the parks from being clogged up by sticky dough.

As a complete aside, having tried both Italian pizza in Italy and americanized pizza I actually prefer American style with it's more cheese, more sauce, and diced meets instead of whole slices. But I'm sure it is also way more calories.

</comment></comment><comment><USER17> Now I wonder if there would be a business in just putting frozen pizzas in the oven and having those delivered.

Could put the oven on the back of the delivery scooters they use around here for fresh-out-the-oven pizza.

</comment><comment><USER18> How does this compare to pizza factories?

<comment><USER19> I would guess they could borrow a few ideas from the frozen pizza industry. But the scale is very different, and frozen pizza factories don't have the oven to deal with.

</comment></comment><comment><USER20> This is a submarine article ([http://www.paulgraham.com/submarine.html](http://www.paulgraham.com/submarine.html)), an ad for zume pizza. Food manufacturers already have frozen pizza down to a precise science, and automate more than this startup. I've been watching the food technology space for some time, and this companys only innovation is putting pizza ovens in delivery trucks.

<comment><USER21> If you think frozen pizza is a replacement for freshly made pizza (regardless of what makes it), then you must not have any taste buds.

A fresh pizza has qualities in the dough and especially in the meats that just don't carry over to a frozen pizza. One is a proper dinner, the other is a backup plan.

<comment><USER22> Still, like sex, even bad pizza is good.

</comment></comment></comment><comment><USER23> anyone here ever had a cappuccino from a machine? if they can't get that right, doubt that robopizza is coming any time soon, at least in any big way.

</comment><comment><USER24> Get back to me when robots have the same level of sass as my goto pie place. Not to mention kitchen bs-ing.

Technically, it sounds like it's a pain in the but.

How much better is a machine made pizza if it's not been frozen?</comment>


GNU Hurd 0.8, GNU Mach 1.7, GNU MIG 1.7 Released - <AUTHOR> http://www.gnu.org/software/hurd/news/2016-05-18-releases.html <comment><USER2> Is there a simple and easy to follow guide to running Hurh/Mach in a virtualisation environment? Virtualbox? KVM?

<comment><USER3> [http://www.gnu.org/software/hurd/hurd/running/debian.html](http://www.gnu.org/software/hurd/hurd/running/debian.html) has a QEMU image link and instructions.

</comment></comment><comment><USER4> > The Hurd is firstly a collection of protocols formalizing how different > components may interact. The protocols are designed to reduce the mutual > trust requirements of the actors thereby permitting a more extensible > system.

This is great, but what protection do I have against _on silicon_ trust?</comment>