crazy2be

Thermal masses are a super cool way (ha!) to store energy, and I'm surprised they don't get more attention, both in the media, and in terms of research / investment. Heating and cooling accounts for somewhere around half(!) of residential energy use [1], which could be easily time-shifted with some very cheap thermal mass and some economic incentive to do so.

This is actually used in some commercial buildings in places where energy is cheaper at certain times of the day (for example, at night) [2], by freezing ice when energy is cheap, and thawing it when it isn't.

That being said, although this is a super cool project (I have the same inverter, and I made a similar control board ;)), this thermal mass doesn't seem like it would be particularly practical in most cases. Water has a relatively high specific heat capacity of 4.186J/gC, but given the narrow range of temperatures acceptable for a fridge, this doesn't end up being very much - only 79Wh per degree Celsius that the fridge is allowed to swing. If you consider 1C - 6C "acceptable", you only end up storing 395Wh. This is about 30-40% of the capacity of a $100-$200 "deep discharge" lead-acid battery, and is also a much wider range than most consumers would be used to (and may result in frozen veggies, for example).

In order to make this more practical, you really want something that can freeze around fridge temperature. For the same amount of water used above, freezing and thawing the water would store 6,308Wh(!), around 16x as much. If you could get something that freezes at 3C/4C with a similar heat of fusion to water, you could have a much smaller thermal battery that lasts _much_ longer, without the substantial temperature swings you see with your current design.

[1] https://www.eia.gov/tools/faqs/faq.php?id=96&t=3 [2] https://en.wikipedia.org/wiki/Ice_storage_air_conditioning

the shady part was that they charged him for a full year after he forgot to cancel, despite quoting the price on a monthly basis when he signed up.

(Also, "free" auto-renew trials like this without refunds are by themselves shady imo)

Huh, interesting. I read the whole thing and understood at least half of it ;).

Are the damages primarily thermal? I couldn't figure it out from that report, although it seemed to somewhat hint that they were. I.e. if you could keep the cells warm (with more insulation or otherwise), would they still get damaged by the shutdown?

Yes, but aluminium smelting has certain constraints - namely, the molten metal cannot solidify[1]. This restricts your ability to quickly spin up and down smelters, but they are still potentially a very useful part of an energy smoothing strategy.

[1] https://en.wikipedia.org/wiki/Aluminium_smelting

NAT has not solved the IP address problem, it has merely postponed it slightly. Multi-level NATs are a hell far beyond the single-level NATs that most consumers see (and single-level NATs already cause all sorts of problems for even moderately advanced network usage). So most people only have single-level NATs, which practically only extends the address space by a small multiple - 8 bits at most, in practice ~2-3 bits.

128 bits allows routing tables to be super small and fast. While RAM has gotten cheaper, it is still slow, and smaller routing tables are way more important than smaller addresses.

However, I agree with your central point - IPv4 was "good enough" that IPv6 is going to be a tougher battle than it ought to be. However, IPv6 is winning that battle already. 15% of google's users use IPv6, and it's increasing sigmoidally. [1]

[1] https://en.wikipedia.org/wiki/IPv6_deployment

This is at best a tangential point. If the wind farm is 114MW with a 10% capacity factor, his point is still correct.

Yes, they still rely on coal and natural gas to smooth the load, but his point was that by subsidizing the wind power, they still reduce emissions the same amount as if they didn't.

Obviously, this strategy only works when renewable penetration is fairly low, once you start having oversupplies then you no longer have 100% efficiency with this strategy.

Example: https://github.com/urbit/urbit/blob/master/noun/vortex.c#L23...

I can confirm this is roughly what the intentional source code looked like.

Personally I found it a huge pain and an unnecessary difficulty, but opinions differed :). The bigger problem was a lot of the code was crap (yay research code!). The lack of english names only made this more difficult because it removed valuable clues as to what the intention of the author might have been.

NO. Do not buy factorio. You will lose sleep. You will lose your job. You will sell your children just for a few more speed modules.

The first time I played factorio I played for 24 hours straight, and I am not normally someone who finds games any fun at all.

But seriously, Factorio is a great game. A game I imagine myself still playing 10 years from now.

Where are you getting $15,000 for the powerwall? It's $5,500 for 13.5kWh, which should be enough for nighttime loads in many houses (but may require some inconveniences, like not running the dryer at night).

You are right that it does not yet work out, it's $0.17/kWh for the powerwall (assuming you fully charge/discharge it each night) + cost for panels. Given that grid-disconnected users would want some buffer, an off-grid system probably works out to ~$0.40/kWh all in for battery-stored electricity

You could save a big chunk of this by some habit changes, most of the cost comes from the batteries, so scheduling energy intensive activities to run during the day reduces your cost for them to $0.10/kWh or so.

Honestly I am surprised how close these numbers are. I initially was sure the grid would survive in cities, but now I am not so sure. In 10 years these numbers will likely be half what they are now (batteries in particular will be way cheaper). It might all be enough to kill the grid in many places.

Out of reach for your local dentist? Huh? Dentists make more than most people here, $159k/yr average[1]. Software developers make a little over half that on average, depending on which sub occupation they work in. [2].

[1] https://www.bls.gov/ooh/healthcare/dentists.htm [2] https://www.bls.gov/ooh/computer-and-information-technology/...

VGA is still the most common connector type I see on projectors and in conference rooms. It's being slowly replaced by HDMI, they might be about even now.

Ethernet is still the premier PHY layer for people who want their shit to work. Wifi is still flaky as crap these days in many places. Thus, there is no Ethernet replacement yet.

As chriswarbo says, the age of the tech is completely irrelevant. Instead, it's the utility / cost tradeoff that matters. A floppy drive would be expensive in terms of weight/size, and would be useful to approximately 100 people (10 if it's 5"). VGA and Ethernet adaptors would be useful to probably 1/2 to 1/4 of the users, and cost almost nothing to have.

Also, VGA specifically is one of those ports that's still really nice to have, just in case. Last thing you want is to show up at a conference room and not be able to plug in your laptop.

You can do both. My point is that most of the ports and features they removed really cost nothing in terms of weight, and so aren't really engineering tradeoffs in a sense, but rather design tradeoffs (i.e. thinner). In the feature/weight space, they are not even close to the pareto optimum.

Personally I find wireless anything to be a persistent pain and not worth the trouble, but since it costs almost nothing to add, I'm totally cool with adding it. Maybe in 10 years it won't suck.

By perfectly fine, do you mean:

- Wifi is flaky (ier than on windows)

- Battery life is shit (ier than on windows)

- Sleep mode has one of the following problems

* Does not properly suspend (i.e. wakes up immediately when suspending, shuts down instead of suspending)

* Does not properly resume (i.e. kernel crash on resume)

* Sometimes does not properly resume (even more annoying to debug)

* Resumes randomly, when you don't want, often turning your backpack into a forge.

- Hibernate mode doesn't work (at all, your hardware has been blacklisted).

- Plugging in an external monitor occasionally causes everything to crash (but sometimes just compiz).

These are the most annoying problems I have on my Linux laptop. Admittedly, mine is not Thinkpad, but looking at reviews on the latest Thinkpad, at least the battery life issue seems to be ever present. These are pretty much the same problems I've had for the 10 or so years I've been running Linux on laptops. I would have thought they'd been fixed by now. 10 years ago, Windows had a bunch of these problems too, so it was excusable. Now, it's just embarrassing.

I still run Linux on my laptop because I like the dev environment and tools so very very much, but I would pay serious money for hardware that was guaranteed to just work (tm) with Linux, with all of the above solved by the vendor rather than by me. I used to enjoy these little problems, but now they just annoy.

The sleep mode problems are the most annoying to me, the most elusive to solve, and the most impossible to predict from reviews :/

Fallacy of the excluded middle. They can do something more than Apple (i.e. not just USB-C ports), but less than others. The Apple design doesn't end up being small or light, because to actually use it you need a plethora of connectors.

At a minimum, I would expect standard USB, headphone, sd card reader, standard HDMI, mini displayport.

You're going to have a hard time convincing me that an HDMI connector adds more than a few grams of weight. Thickness, maybe. But even then.

VGA and ethernet could be nice too, but wouldn't see much use in my case.

The battery could be removable (i.e. half internal half external, like the thinkpads).

Optical drive is obviously not much use in a laptop anymore and should be external. (this one actually adds weight and not just thickness)

I'm not convinced having fewer children will help anything and I wish people would stop repeating this. People emit very few greenhouse gasses as a virtue of their existence, the extreme majority of them are emitted by lifestyle choices.

Even in developed countries the differences are stark. Qatar emits 54.7 tons of CO2 equivalent per capita, the United States 24.3 tons, Germany 12.3 tons, Switzerland 7.2 tons. A difference of almost 10x, with countries that all have similar standards of living! In a relatively undeveloped country like Burundi, the emissions are a mere 0.4 tons per capita[0]. A difference of literally 100x!

The best fix is a revenue-neutral carbon tax, with import tariffs on goods from countries that do not have such taxes (i.e. China). This internalizes the externalized costs of CO2 emissions, automatically encouraging development of more energy-efficient everything.

[0] Data from 2000, unfortunately, but the numbers have not changed in magnitude since then. https://en.wikipedia.org/wiki/List_of_countries_by_greenhous...

Well, I guess it all depends on what you mean by do poorly in life.

High school valedictorians and child prodigies (especially the former) are disproportionately likely to hold positions of societal power. Just read the bio of any president of the IMF or the World Bank or the Federal Reserve. Essentially all of them graduate university summa cum laude or magna cum laude.

Innovative scientists and people who move the world forward? Perhaps less likely to come from this group, for a variety of reasons.

Actually, this is a good point.

Uber subsidizes fares ~20% or so currently. Assuming they didn't used to do this, the payout to drivers seems like it would be about the same:

3.75 / 0.8 => 4.6875 (vs $4.90 originally)

The per-minute fees are still quite a bit lower, admittedly:

0.65 / 0.8 => 0.8125 (vs $1.25 originally)

Well, a flight from SFO to LAX is $70 if you book at least a couple weeks in advance. If you assume parity for the ticket price, you need to sell an average of 100,000 tickers/day. With 100 passengers per car and 10 cars per train, you would need 100 trains/day, full, in order to make the math work.

I agree that seems pretty dubious. Why on earth is infrastructure so expensive in the US?

It does come up?

In the case of pensions and royalties, it is wealth from prior work, so it's not really in the same category morally (for a culture that believes in the virtue of work).

Social security and inherited wealth definately do have a sort of stigma attached to them though, precisely because of the lifestyles that "trust fund children" tend to live, and because the poor are already stigmatized in general. The structure of social security makes real problems here too, where people can't get jobs without losing their social security.

The average new vehicle purchased in the United States is $33,560[0]. The Tesla Model 3 is $35,000, PLUS $7,500 in government tax credit[1]. This puts the effective cost at $27,500. The Honda Civic, widely considered a cheap car, is $20,415 MSRP[2]. Once you factor in gas and maintenance savings, around $1,200 per year[3], the Tesla is cheaper after just over 6 years. Since most cars are kept for 20 years, that is a good deal.

Given that, I would say that calling it a "cheap" car is pretty accurate for most Americans. Obviously it is not in the range of used cars or the ultracheaps ($10-15K), but it's really amazingly cheap for an electric if they can make it happen.

[1] Note this is likely to be halved or a quartered for new orders as Telsa reaches the 200,000 vehicle mark [2] https://www.truecar.com/prices-new/honda/civic-sedan-pricing... [3] Rough estimate based on $150/mo in gas -> $50/mo in electricity

That does not match the scientific consensus [1]. You'll have to do better than a single study, summarized in a Forbes article, if you want to make that claim.

[1] https://en.wikipedia.org/wiki/Passive_smoking

Zim[0] (open source) has a lot of these features. It saves your notes as plain markdown files, but has a WYSIWYG editor. You can link between notes. Add pictures, formatting, etc.

There is also a huge number of extensions, back when I was doing math stuff I used the LaTeX one pretty often. Another useful one is the calculator extension, which can evaluate simple expressions like 3 * 5 =.

Since it's just plain markdown files, you can save to Dropbox, git, NFS, or anything else really. There's even a built-in plugin to automatically commit to git periodically (useful for standalone notebooks, since you don't really want to be opening git manually).

I've yet to find anything better, although I do wish it had better support for "anonymous" notes. That is, notes that I don't really feel like organizing or naming.

[0] http://www.zim-wiki.org/index.html

"multi-story" => "two stories tall maximum, and half of ground space is parking lot"

Places like Paris are entirely (or nearly entirely) 4-5 stories tall, with no parking lots. This allows incredible density simultaneously with great livability (especially for pedestrians). (See [1])

So technically the gp was incorrect, but I would posit there are few (any?) places in Mountain View, or even most of the bay, with a floor area ratio (FAR) > 1.0.

[1] https://en.wikipedia.org/wiki/Paris#Cityscape

You mean NaN != NaN. null == null is true, and null != null is false.

NaN != NaN is surprising, but is not unique to JavaScript. As far as I know, this is the case in every language, and is mandated by the IEEE 754 specification.

However, it does come up in JavaScript more often than other places, since NaN is really easy to get (+{} => NaN, 1 - '' => NaN, etc, etc).

You can install adobe reader on Linux. On Ubuntu it's acroread from package adobereader-enu.

Although sometimes you can use Chrome (or evince, or okular), occasionally Adobe Reader is the only one that can fill forms properly.

"Quantum computing and consciousness are both weird and therefore equivalent" -- Scott Aaronson

I agree in principle, but given the huge proportion of energy which comes from fossil fuels, a carbon tax would have to be huge (and hence unpopular) if it were to match the market competitiveness of subsidies.

That is, to subsidize solar 33% (our current subsidy in the US), you would have to make a carbon tax equivalent to 50% of the current price of fossil fuels, or about $1.50/gal. This is obviously politically untenable in the United States.

The happy medium is probably to do a bit of both, and work toward the middle. Smart, targeted subsidies for carbon-neutral sources, and small, gradually increasing carbon taxes.

Of course, you could have a separate pull-out track for train stations, and interleave the trains. Then you would be able to double your utilization :).

I can't really think of any reason why one technology is inherently higher-capacity than the other, it's mostly that private cars are very inefficient, not rubber tyres.

That may be true, but is irrelevant.

Mathematics is not patentable either, and there are many "significantly new" innovations there.

The position of whether software should be patentable depends mostly if you think of it like math, or like pharmaceuticals. The former requires mostly just a lot of thinking, and very little money. The latter requires massive quantities of cash, expensive equipment, trials, lawyers, etc.

A large number of software patents don't even require a lot of thinking- the majority of the work goes into writing the patent, rather than the creating the system to be patented.

Short patents on truly new software inventions could be overall a benefit to the software industry. But the crappy ones are unquestionably a significant drag.

I don't know, I can't see any way that the read: protocol is any more vulnerable than the file: protocol (standard on all browsers), other than the fact that the code is probably less battle-tested.