It's perhaps not obvious but there is no such thing as perfect consonance in music:

- Tone C3 is an exact second harmonic of C2 and a fourth harmonic of C1. That's why the sound so nice together.

- Tone G2 is a third harmonic of C1, but (surprise) not an exact one. That's because if you take 13 third harmonics (C G D A E B F# C# G# D# A# F C') you are supposed to arrive at the same tone. But you don't, there is a slight frequency offset. In practice, this offset is distributed among all 13 intervals so we are generally unable to notice it.

- The fifth harmonic tone (C1 -> E3') is also inexact. It is fairly close to the sound (here E) obtained from the scale above but again there is a slight frequency offset.

- The sixth harmonic (C1 -> G3) is 2*3 times the fundamental frequency, so is as (in)exact as the third harmonic.

- The seventh harmonic (C1 -> ~A#3, noticeably lower) is not on the (twelve tone) scale but it still sounds nice.

- The eight harmonic is exact (2*2*2, C1 -> C4). And so on...

The twelve tone scale is a rather clever invention, it manages to approximate a rather large number of harmonics with a small number of tones. But it is still only an approximation - a perfect consonance can only be obtained for octaves.

I agree. A comment section with a scoring system would be fantastic.

Nope, strong inductive coupling is efficient and reliable. But it only works at a short distance and requires coils to be aligned. That's perfect for recharging buses at bus stops, but too cumbersome for other uses.

Resonant coupling can still be efficient at larger distances but: it stores a huge amount of energy in LC tanks (currents and voltages roughly 100 times larger than in non-resonant coupling), produces proportionally stronger magnetic field, is very sensitive to losses in the environment (paddles, metal objects), and is not suitable for high power recharging (think more of 100W-order trickle charging).

So, we are talking about an expensive, difficult to install, weak, inefficient, unreliable, interfering and dangerous solution to a very pressing problem, which is sticking a plug into a socket. I can see (inductive) wireless charging being deployed in fixed-route buses but other than that this technology is only a distraction from solving truly important problems (batteries, specialized range extending ICEs etc.).

Hey, but wireless charging is much better than that. By "much better" I mean "at least 2x more efficient".

BTW, haven't you noticed how everybody complains about these damn gas nozzles? Screw larger and cheaper batteries, we want wireless charging.

Except that it takes a lot of electricity to make and transport gas. You could pretty much use this electricity directly and skip the whole pointless cycle of producing, distributing and burning gas.

Lower efficiency means not only about getting less energy in the battery but also getting more energy outside of it. Would be nice if the losses were just heat but they are not.

Consumption drives economy. Savings or (in unsustainable manner) loans drive consumption. It is really as simple as that.

Japanese do spend a lot of money, which is a *problem* because they are not getting anything near to what they have paid. They reached the stage where keeping cash is a natural defense from what government policies gave them (risky or unavailable savings/loans and inflated prices).

To answer that we'd first need a working graphene transistor, and the one described in the TFA is not.

The issue currently limiting performance/watt is transistor transconductance (gain), which for bipolar transistors (at room temperature) is 1decade of output current per 60mV of input voltage change, for MOS (in subthreshold) 1decade/(80~120mV) and significantly less in saturation modes. Considering that you need ~5 decades to get ON/OFF behavior that sets the supply voltage at min. 0.5V, in practice twice as much because of variability and lower conductance in saturation. So, at least for high performance circuit, we are stuck with ~1V supply voltage and that's pretty much the end of (fast) performance scaling in CMOS.

To get better performance/watt we'd need a device that has some sort of a positive feedback based switching mechanism (breakdown, avalanche etc), which could exceed the 1decade/60mV limit. I'm not sure if we'd get that from graphene. Sure, low conductivity of graphene (ON resistance) helps too, as we could make the transistors smaller and that would reduce their gate capacitance but since energy is proportional to C*V^2, capacitance has much less effect than the voltage.

It looks like a SiC MOS transistor, with electrodes (D, G, S) made out of graphene rather than metal or polysilicon. Does it really make that much difference in performance over regular MOS transistors? If so, how much of the performance gain comes from the semiconductor material (SiC vs. Si) and how much from the interconnections? How multiple layers of interconnections are handled, if at all?

Sort of.

Yes, Li-ion cells supplying consumer electronics are mass produced and we are incredibly blessed to have them around (as well as research, engineering and production capacity going into them). Without that we wouldn't be able to bootstrap the EV market.

No, their form factor isn't suitable for a car (we really need larger cells for lower cost/capacity and better thermal balancing), and their chemistry is designed for short-lived high energy density products. You can get them fairly cheaply (per unit, at least) but then you spend a lot on battery assembly. If you want cells designed for EVs prepare to pay at least twice as much (per capacity, per unit that's even more). So, even with today's technology we could see ~3 times lower prices if the EV market was as developed as the consumer electronics one.

Another issue is that in a growing market production capacity lags behind the demand, producing some inertia. That's why LCDs didn't replace CRTs "overnight" - for a while LCDs were priced at premium and CRTs were dirt cheap. But that's only a transient phenomenon (it was the market *growth* that was slowing things down), the fate of CRTs was set long time ago.

I agree, and I am really surprised Nissan doesn't offer one, at least for hire. This alone could boost their sales several times.

Perhaps the problem with the trailer is that it implies a small range extender of the type I was writing about above. You simply can't take a Volt's ICE and put it on a trailer.

Honestly, if there was an electric car with 100 miles range and (detachable or not) range extender *extending* the range 3x, I would buy it tomorrow. I don't even care about efficiency of the range extender, as long as it is cheap, small and quiet.

Batteries are already good enough (see Tesla S). It is their price that hinders the market. Luckily batteries are much easier to produce at mass scale than, say, Diesel engines, so the market *will* grow exponentially (more customers -> larger scale of production -> cheaper batteries -> more customers).

Performance of batteries will improve as well but it won't make or break the deal. In a worst case you can just add a cheap 600cc range extender and make the car go 300+ miles on a full charge.

With a disruptive technology like this it is *very* unlikely we will see a 50% adoption for an extended period of time. Either EVs will catch on and it will be highly uncool to drive a gas fueled car, or they will not and the market share will settle at single digits. Sure, to go from 0% to 99% you have to pass that 50% but at this level we can expect the highest rate of growth, so I wouldn't bet on the time it will happen.

Simple, just use electricity we currently waste on drilling, refining and transportation of oil.

The need wasn't strong enough to justify a purchase of a dedicated reader. Especially that there is a critical mass effect involved.