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Comment He's totally wrong. (Score 1) 292

When Bill Gates says:

"There's no battery technology that's even close to allowing us to take all of our energy from renewables and be able to use battery storage in order to deal not only with the 24-hour cycle but also with long periods of time where it's cloudy and you don't have sun or you don't have wind."

he's totally wrong.

For starters, there's Vanadium Redox. A flow battery (pumped electrolyte): Power limited by the size of the reaction device's electrode and membrane assembly. Energy storage limited by the size of the tanks. It's mainly used for utility-level energy storage down under (Oz or Nz, I think), because the patents are still fresh and the little startup doesn't want to license it to others. Vanadium is some substantial percentage of the Earth's crust so there's no shortage. Using the same element (in different sets of oxidation states - vanadium has (at least) 6 of 'em) for BOTH electrodes means leakage of small amounts of the element through the dilectric membrane doesn't poison the battery.

Lithum cells are already good enough to run laptops, cars, and houses, and are improving at a Moore's Law like rate. The elements are also not rare and the use of several nanotech techniques on the electrodes have drastically increased the lifetime and other useful properties. (We just had reports of yet another breakthrough within the last day or so, doubling the capacity and extending the life.) The fast-charge/discharge cells are also extremely efficient. (They have to be, because every horsepower is 3/4 kW, so even a few percent of loss would translate to enormous heat in an automotive application.) The main problem is to get companies to "pull the trigger" on deploying them - and risk their new production line being rendered obsolete before the product hits the market by NEXT month's breakthroughs.

Lead-acids need to be replaced once or twice per decade. But they have been the workhorses for off-grid since Edison's and Nikola Tesla's days, and still are today (though not for long, if Elon Musk and the five billion dollars of investments in his lithium battery plant have anything to say about it).

Nickel-Iron wet cells are a technology developed by Edison. They have more loss than lead-acids. But they literally last for centuries. If you have a moderately steady renewable source (like some combination of enough wind and a big enough windmill, enough sun and a big enough solar array, or a stream and a big enough hydro system) you'll have enough more power than you need to keep them topped off. They're just fine for covering days, or even a couple weeks, of bad generation weather, or down-for-maintenance situations. That IS what they were in at least one hydro plant I know of. (The problem is finding them: They last so long you only need to buy them ONCE, so there aren't many plants.)

That's just four FAMILIES of entirely adequate solutions. There ARE more.

So Bill is either uninformed, talking through his hat, or starting on the "embrace" stage of yet another:
  - Embrace
  - Extend
  - Extinguish
  - PROFIT!

Comment Second law of thermodynamics. (Score 2) 292

we have a way to turn electricity directly into heat. But there is no direct way to turn heat into electricity. It has to go thru a second step of mechanical energy to spin a magnet to create electricity.

You can go from electricity directly to heat because that increases entropy. You can't go from heat to anything useful because that decreases entropy, and entropy of a closed system only increases. The best you can do is a heat engine, working off a temperature DIFFERENCE. (Some of them also work backward as heat pumps, to go from electricity to heat more effectively, by also grabbing some heat from elsewhere to include in the hot end output.)

There ARE at least two major forms of electronic heat engines - direct from temperature differences to electricity, with only charge carriers as the moving parts: Thermoelectrics (thermocouples, peltier junctions, and thermopiles of them) and thermionics (both heat-driven vacuum diode generators and a FET-like semiconductor analog of them). Both are discussed in other responses to the parent post.

Comment Thermionics (Score 3, Interesting) 292

TEs are ridiculously inefficient and aren't looking to be much better anytime soon

Because thermoelectric effect devices leak heat big time.

However there's also thermionics. The vacuum-tube version is currently inefficient - about as inefficient as slightly behind-the-curve solar cells - due to space charge accumulation discouraging current, but I've seen reports of a semiconductor close analog of it (as an FET is a semiconductor close analog of a vacuum triode) that IS efficient, encouraging the space charge to propagate through the drift region by doping tricks (that I don't recall offhand). The semiconductor version beats the problems that plague thermoelectrics because the only charge carriers crossing the temperature gradient are the ones doing so in an efficient manner, so the bulk of the thermal leakage is mechanical rather than electrical, and the drift region can be long enough to keep that fraction down.

Comment Re: Cool (Score 1) 191

It was pretty clear what he meant, you were just being a dick.

If you're following the comments, why didn't you log in?

It was clear that the original poster didn't understand how the technology worked.

Also, if my comment to him is considered "being a dick" then my goodness he must have a thin skin. He'd better be careful on the internet. What specifically about it is me "being a dick"?

Comment Re:Cool (Score 1) 191

You don't get it.
What vux984 is saying is that he set up the magic trackpad so that he only has to touch the trackpad to click, and he does not have to exert a force on it.

I personally got rid of everything that requires to exert an additional vertical force on the trackpad the day I tried to use it on my laps. I'm talking about a wireless magic trackpad of course. I replaced everything with two and three fingers gestures, and it feels so confortable that I setup my laptop the same way, and never looked back. So force touch for me doesn't make sense, but I have to admit that I have not tried a force touch enabled magic trackpad.

I do get it. He is saying that he has never used the force touch feature when that's literally impossible, even if he taps it lightly enough to just register his finger - the cap sensor and the strain gauges work together on the new trackpad. Je just didn't understand that.

Comment Re:Cool (Score 2) 191

No, it really doesn't.

It really doesn't MATTER.

There are two thresholds where it clicks - the fact that its haptic vs mechanical is irreelevent. I never ever touch it with enough force to engage either click threshold.

So any additional functionality mapped to touching with greater force; I'm not ever using. So it may as well not be there.

Ah, so you're changing your argument. Fair enough.

I was just pointing out that you were factually incorrect and based an argument on it. Next time you say that you don't use any part of a technology that you literally have to (because that's how the trackpad works in its entirety) you'll know a little more about it.

Comment Then again. (Score 1) 62

I got the impression from the (sketchy) article that repeater AMPLIFIERS were still needed but repeater REGENERATORS were not.

Then again - another part of the article makes it look like an additional result was that they could boost this less-subject-to-degradation-by-nonlinear-distortions signal at the start until the fibre itself was acting non-linearly, in order to get a signal strong enough to survive a much longer hop.

So it's not clear to me whether the distance was achieved by:
  - long hops enabled by strong signals, and NO amplifiers
  - longer propagation without regenaration using JUST amplifers
  - a combination of the two: Both getting long total length without regeneration AND being able to use stronger signals and thus use larger space between the amplifier-type repeaters.

Comment but not amplifiers (Score 1) 62

Since the diameter of the earth is 7 926.3352 miles, this could conceivably remove any need for repeaters.

I got the impression from the (sketchy) article that repeater AMPLIFIERS were still needed but repeater REGENERATORS were not.

I.e. you still needed to boost the strength of the signal to make up for the losses. But the progressive degradation of the quality of the signal - with data from different frequency bands bleeding into other bands (especially in the amplifiers themselves) due to nonlinear "mixing" processes - had been headed off, by synchronizing the frequencies of all the carriers to exact multiples of a common basic difference-between-the-carriers frequency.

This apparently sets up a situation where the distortion products of each carrier's interaction with nonlinear processes cancel out with respect to trying to recover the signals on another carrier - much the way the modulation products do in OFDM modulation schemes. In OFDM it allows you to make essentially total use of the bandwidth. In this system it lets you use simple, cheap, amplifiers to get your signal boost, rather than ending the fibre before things get too intertwingled, demodulating all the signals back to data streams and recovered clocking, then generating a fresh set of modulated light streams for the next hop - MUCH more expensive and power hungry.

Comment Re:Congratulations Apple! (Score 5, Insightful) 191

You have finally realized that your touchscreen controller actually provides a pressure strength and are able to hype it up like it's revolutionary.

Not even if we realize the limitations of pressure sensing of a standard capacitive controller and add additional sensors to make the detection less granular is this something new. I don't know how long Synaptics (touchpad manufacturer) have had their capacitive+force sensor combination available but it is at least two years, but even ignoring that the idea and implementation isn't anything new.

Bah.

Err, no.

Apple's implementation of force touch on the Macbook Pro trackpad (where it is current used, not counting this rumour that it will be on the iPhone) uses a set of strain gauges to measure the applied pressure. It doesn't use the touchscreen controller.

You might want to actually look up how it works before trying to score a "sick burn" (is that what the kids call it these days?) from your armchair quarterback position.

I also don't see where Apple are hyping it up to make it seem like a revolution. They are advertising that the MBPr and MB have it, but I fail to see how their advertising materials claim it's revolutionary. Unless you think the term "whole new way to experience a trackpad" means that, and not "this trackpad works differently than the old ones due to the numerous new ways you can use it due to the force sensors"

Apple is frequently guilty of hyperbole when it comes to advertising, but on the force touch it's pretty understated. Did you just assume they would claim it was a revolution that had never been seen before? Given that you don't understand how Apple's implementation works I have to assume you've done zero research on it. Google (a popular search engine) can tell you quite a lot about it if you're interested.

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