Super-linear disk cost back when disks were already atrociously slow compared to the rest of the machine have largely gone away with SSD's hitting huge capacities and tech like NVMe, solid state RAM modules, and Intel's upcoming Optane tech ensuring that more than ever, scaling horizontally can be put off way more than used to be possible.

If you look at scale-out vs scale-up for any applications that were disk limited, disk performance is now ridiculous - > 1GB/s and IOP's measured in 100's of thousands. I'm expecting a bit of a comeback for HA over HP. More than likely, your app can be served well by a single big machine that is well within the linear scaling regime, and you need several for durability and geo-availability.

A consumer to operate a small gas turbine and store their energy in the form of hydrocarbons. If this is to be sensible, then 43MJ/kg would have to be enough, because that's what they're going to get with kerosene/jet fuel.

Now let's consider lithium. The problem with metal-air batteries has mostly been poisoning by unwanted gases. Let's assume for a moment that a membrane material is developed that only allows high purity oxygen through, but suffers low throughput. This is no problem for our off-grid solution because we're talking about large storage relative to power, similar to some flow battery applications. Using some method of specific ion or biological style solution, such a membrane is not implausible.

Lithium-air weighs in at 40MJ/kg specific energy. How much does it cost? Given that a metal-air battery uses lithium oxide, the lithium carbonate and lithium hydroxide prices are not quite valid guides, but the price of $7/kg is obtainable for the carbonate of "battery grade." If the pure oxide can be the material used in manufacture, then possibly the $7 value is in the ballpark.

Jet-A is $0.45 per kilogram. 1.41 $/gal / 3.78541 l/gal / 0.820 kg/l

Higher efficiency must be allowed because even with combined cycle at high latitudes where it's cold, we're looking at 90% round-trip for a battery vs ~75% for our Brayton cycle + home heating.

There are external costs to a large tank of kerosene and a pile of lithium carbonate. One requires a gas turbine and the other requires a battery & significant manufacturing. Excepting those two things, we're left with a roughly 7:1 factor of cost for the raw material, so a seven year payoff it is.

Lithium might not be the cheapest rechargeable precursor. It might be great for EV's (high power output is a requirement) and maybe something else will show up as the cheapest energy storage without requiring off-grid people to rely on ARES gravity trains.

Perovskites (new paper just suggested that hot-carrier phonons can be used to raise theoretical efficiency to 66%) throw yet another wrinkle into solar. Both energy storage and generation could become quite a bit cheaper.

All hypothetical, yes, but my napkin does tell me not to rule out off-grid, not that I'm sympathetic to off-grid, anti-social Ayn Rand acolytes =D Whatever matters for off-grid matters for a ton of settings, such as places where there is no grid still. It's tough to say definitively that a straight-renewable energy source won't become cost-competitive even in grid areas of high latitude within the decade.

Source on Jet A specific heat: http://www.exxonmobil.com/AviationGlobal/Files/WorldJetFuelS...

Source on Lithum Air theoretical specific energy: https://en.wikipedia.org/wiki/Lithium%E2%80%93air_battery

Jet A price: http://www.indexmundi.com/commodities/?commodity=jet-fuel

Lithium Carbonate Price (ev grade): http://www.globalstrategicmetalsnl.com/_content/documents/40...

To start though you need multiple inheritance likely to get this to work idiomatically. C would also do fine, as would Java, except the Java would look like C because of the lack of multiple inheritance/mix-in, while the C code could result in some type insanity -- although components can be implemented as simple structs in structs for entities, except the whole construction/destruction phase of life.

As an outsider looking in, C++ seems filthily well-suited to game development.

Reducing a task graph is exactly the role that I'd expect a UX Engineer to be perfect at, and yet the article is titled "Engineers Build Ugly Products" while going on to state exactly the expected benefit of having a UX Engineer deeply involved with the product team -- reduced tasks, focused functionality.

Where this kind of thinking blows back on real decisions is when someone says, "Look, I know how you engineers think..." suffixed by some opinion completely drawn from the realm of speculation. Subscribe to such thinking if you want to arbitrarily override the work of your best modelers.

The absolute worst kinds of push-back are fueled by identity politics statements like these bait into. You wake up in a conversation about prioritizing core value and someone pushes on wanting to change the color of the drapes and calls the entire engineering team anti-design like we don't get anything outside of text-highlighting in our code editors. It's infuriating.

Getting that correctness to propagate because of the strictness of all the tools involved and accuracy of their construction is the issue, which leaves us with needing to either automate proofs with Coq or prove things in more general ways that lead to undecidable problems etc. Still, the fact that one function can be written bug-free and known to be bug-free does indicate that it's not an inevitability of probability playing out as code grows.

We have null-pointer exceptions and no maybe type. The API's that emit nulls sometimes make me expect sewage to leak from light sockets. It's possible to do better. We just don't, and none of us love it. Rust and Kotlin are at least very exciting. I'd like to understand some Coq more in the context of x86. What routines are strictly necessary to even do Coq? A response based on some statement about how the Y-combinator enables X where X leads to Y would not surprise me.

I asked myself, "Are we going to see a wave of startups figuring out how to phrase their late-stage capital raising in terms of other old-school financial instruments?" What are some other typical Wall Street machinations startup world might not know as well?

In the case of huge capital requirements, stating ones growth plan as a bond seems quite an enabler for previously untouchable product concepts that would never make it out of early stage to access the late-stage private equity that's the only usual alternative for raising huge sums. Is this even the right way to look at the situation with Solar City? What other companies are doing or have tried to do something like this?

Comments URL: https://news.ycombinator.com/item?id=10343967

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"Facebook, this whole internet thing, hasn't really..."

"...worked out"

"Yeah, this isn't what we thought it was gonna be. Let's just... "

"...turn it off"

There was a belief implicit in the idea of every human on Earth being connected. Many of the phenomenon that came about have made that belief look vulnerable to a certain cynicism, a cynicism about humanity, that we fear in each other, that we hold towards ourselves. A currency that bound us together face to face became fiat and then failed at scale. It is within the vacuum painted by this fear that the organizing effects of the old-world economy have been fallen back on, but I do not presently fear this cynicism, and I save my currency wherever I can earn it.

There are too many people willing to seed a decent product to go all-in with anything except time and soul.

Chris Sacca has a pretty damned interesting tale: https://www.youtube.com/watch?v=6VOQnK7O2To

Second novice Java programmer reads title, wants to pass objects into functions, wants to avoid expensive stack copy and writes &myObject, gets compiler error, Googles "Java pointer," and curses author of the title.

Lesson learned: author of title is either unaware of the consequences such an interpretation will cause or seeks cursing as a source of attention.