Cool. So you'd be fine with me coming over and spray painting something of my choice on your house, assuming I assured you (with absolutely no supporting evidence) that it would go away over some unspecified period of time?
I do not think so.
Anyone who's been around small children knows that some food dyes do NOT disappear when washed, even with detergent.
Indeed. I had a professor in undergrad named Kanapathipillai Thirugnanasambanthan. He might've been from Sri Lanka rather than India proper, though.
He went by "Sam Thiru".
When I first began I asked a friend if he knew anything about this "Professor Thiru". He said "Well, that's not really his name. His real name wouldn't fit in the schedule." :-)
Later, a different professor used him as an example of why it was a bad idea to hard-code the length of name fields.
Great guy, and one of the best instructors I've ever had.
Lots of people from Andhra/Telugu people have many names, and are known by initials or drop them if they come to the US. That sometimes includes optional caste names or titular names that come at the end, with the family name leading (as in China and Japan). My uncle, for example, had a four-word given name, formally introduced his given name in India or in temples as the latter two, and then dropped the first of the two, and swapped family-first for first-family when he came to the states.
For example, if you ever fly into Bangalore or Mumbai, you'll see GVK on their airports. That's for Gunapati Venkata Krishna Reddy, who goes by GVK. Gunapati is the family name, Venkata Krishna is his given name, and Reddy is the caste name.
Other examples are NT Rama Rao, P.V. Narasimha Rao, and my favorite, is a person I know of who went by KRKVNS Sharma.
True enough. However, you also need to consider that customers are much more likely to hand their card number over to Apple than to some random website they've never heard of before. In fact, Apple probably already has it.
70% of something is more than 100% of nothing (especially when the product is software or something else that has a marginal cost of production of essentially zero).
How is requiring the user to open a completely different application a better "user experience" than installing it from the web page they're already on?
Yes, I know that installing a PWA is confusing (especially on Apple's systems), but there no reason it has to be that way.
PWA (if it were implemented properly): "Click here to install app". Click. Confirmation dialog. App is installed. App opens in the same window.
App store: "Click here to install app". Click. An entirely different application opens. Confirmation dialog. App is installed. You open it, but now you're in a different context.
> PWA (if it were implemented properly): "Click here to install app". Click. Confirmation dialog. App is installed. App opens in the same window.
> App store: "Click here to install app". Click. An entirely different application opens. Confirmation dialog. App is installed. You open it, but now you're in a different context.
You’re unfortunately oversimplifying the PWA installation. Say a user has heard of a new service called “Florb” which has a PWA and a native app. To install natively:
1. Open the App Store
2. Tap the search button (optional, might already be selected)
3. Search “Florb”
4. Tap Get
5. Confirm download
For the PWA:
1. Open Safari
2. Search for Florb using your chosen search engine
3. Open Florb homepage
4. Tap “share”
5. Hunt and scroll for “Add to Home Screen”
6. Tap “Add to Home Screen”
7. Give the app a name
8. Tap Add
This is ignoring the possibility that searching Florb returns other sites first (maybe news articles about the neat service, or a wiki page), nor that there are usually enough ads on google pages to completely obscure the first real results from the screen on page load. Yes, the App Store also shows an ad, and it’s possible for other similarly named apps to appear first in the list, but it’s generally less of a problem than relying on google searches.
Even ignoring the fact that the average user doesn’t know or care that PWAs exist, the first option is simply easier and more reliable. There’s no getting around that. And that’s also ignoring that PWAs are, to an average user, “installing a website” rather than “installing an app,” which just feels wrong.
“Add to Home Screen” has been available on iOS since at least iOS 4 (that’s the first time I remember seeing it, but it may have been around longer). If people don’t care about it yet, I have a hard time believing they will any time soon unless it is substantially and objectively better than the App Store.
This is an idiotic way of breaking it down. How does the user even know Florb exists? They're already on the web at this stage. You're also being totally disingenuous with your break down. Why does the user have to "hunt and scroll" for the app on the PWA side but not the app store? Go ahead, search for "fastmail" on your Android app store and tell me what the first and most prominent result is.
And when I click "add to home" in my browser's menu I don't need to name the app. The app has a name. What are you talking about?
They can hear it from a TV/radio ad, they can see it on a billboard, they can hear it from a friend. Exploring that an app exists doesn't happen only on the product website.
> How is requiring the user to open a completely different application a better "user experience" than installing it from the web page they're already on?
Because it is strange and different. If Web apps were standard going to the iOS App Store would be weird. It’s not so PWAs are weird. Just give them an app, don’t make them work to install it.
Bingo. Defenders of the app store have severe stockholm syndrome. Apple ruins the PWA experience intentionally, so they blame people who use PWAs, instead of Apple.
Definitely a good rule of thumb, though there are exceptions.
I gather that surströmming, a type of canned fermented herring popular in Sweden, is considered to be at its best when the can starts to bulge (for some value of "best").
Apparently the key difference is that it has enough salt in it that botulism and other nasty bacteria can't survive.
Opening a can of this stuff is memorable. Even the Swedes generally open it outdoors.
>now that solar energy is far cheaper than coal ever was
I'm sorry, this is simply not true. Usually such claims are the result of ignoring two basic facts:
First, solar is only online 50% of the time, at most (in most regions, considerably less than 50%). That means that you need at a minimum twice the nameplate capacity for a solar plant than for a coal one.
Second, being offline half the time means that you also need sufficient (very expensive!) storage capacity to cover the half the time that the solar plant is not working at all.
In other words, to replace a 2GW conventional plant you're going to need at least 4GW worth of solar cells, plus 24 megawatt-hours of storage.
If you have a source for reliable figures that take these factors into account, and still show solar being "far cheaper", please provide it.
Edit: oh, and no woo-woo battery or solar cell technology that's not currently in mass production. Your statement was that it's "far cheaper" right now, not using future fantasy batteries or solar cells that may (or may not) be on the market in the future.
You nailed it. What do you do when you have cloud cover for two weeks in a row? It’s not unheard of when some areas have 200+ days of at least some cloud coverage.
Nuclear is essential to avoid using coal and not having regional rolling blackouts due to weather. Solar alone is not realistic anytime soon in all regions of the US.
Nuclear is a horrible complement to cheap intermittent renewables. Running it as a peaker multiples your costs and running it as base loads means selling power for negative prices when the sun is shining.
Solar/wind plus batteries for short term storage and pumped hydro for long term storage is the cheapest way to get zero carbon energy. Pumped hydro is more expensive than fossil peakera so build out of that hasn't happened yet.
How do you scale up to producing far more energy in that approach? What about the efficiency to produce large amounts of energy on large spacecraft and other planets and in the ocean?
are you asking how you scale up to producing far more energy with solar panels? world marketed energy consumption is about 18 terawatts, total terrestrial insolation is about 128000 terawatts, and current mainstream panels are about 23% efficient, so if you put solar panels on 50% of the earth's surface, you get 15000 terawatts, which is almost 1000 times more than the humans are using now. on the bottom of the ocean you probably need a different approach, maybe nuclear, or egs geothermal, or maybe running a cable up to the surface, or periodically receiving shipments of thermite in a submarine. some other planets will have no trouble with solar panels; others will need nuclear reactors
Getting only 1,000 times more than humans are using now but requiring 50% of the earth's surface seems like an awful deal. Not only do you need much more of the earth's surface, taking away from trees and habitats and other uses, but you need to significantly increase mining activities to produce the panels and their associated infrastructure. Whereas to get 15,000 additional terawawtts from more nuclear reactors, you could do that with 1,200 - 1,900 additional nuclear reactors occupying just the size of Rhode Island.
mostly you'd be floating them on the oceans (ideally the currently-nutrient-depleted parts of the oceans that aren't teeming with algae), but yeah, that's roughly the limit for solar, and as you're approaching that limit, you need to be thinking about space-based solar power, nuclear power, geothermal power, etc. maybe when you're at 64× of current energy consumption, say
probably we should think of this as a lower bound, though; adoption is likely to slow down as solar moves into application areas that are not already electrified or indeed yet done at all by humans, and the last 24 years have been, historically speaking, unusually peaceful
That depends on how much more efficient solar panels get and what future energy requirements are, but in any case it'll be worse to scale energy creation with solar than with nuclear.
i would instead say that as long as nuclear energy is horrendously expensive, it won't scale. but nuclear energy is not inherently horrendously expensive; it's just that human technology is very primitive still
Costs are high because gas peakers exist and pumped storage generally doesn't. For rarely used long term storage, capital costs dominate, and already built sites don't incur additional capital costs.
All you need is a hill and some water for pumped storage. Those sites are very plentiful.
no place has as high a capacity factor for solar pv as 50%; the world average is 14% (i.e., 14 watts average output per 100 watts nameplate output) and the country with the highest is egypt at 35%
(this doesn't mean that you get zero power for 65% or 86% of the day. it means that you get lower than max power at all times except noon. to a great extent you can compensate by that by just installing more panels, but at night you need a better strategy)
but the capacity factor is irrelevant to the fact that solar energy on the power grid generally sells for about half the price that coal-generated electricity sells for, on the same grid, when storage capacity is insufficient. in fact, prices used to go negative at night (to avoid shutting down slow-ramping baseload plants) and now they go negative in the day
https://pv-magazine-usa.com/2020/05/28/record-low-solar-ppas... is an article from four years ago giving some specific prices: a solar ppa had just been signed for 15 dollars per megawatt hour, while the cost of production with coal at the san juan generating station was 44.90 dollars per megawatt hour, even though it was built right on top of a coal mine to save on shipping costs. that's why the san juan generating station has been decommissioned. if you look, you'll find stories like this all over the place, and solar panels now cost half of what they did when that story was written
now, it's true that a ppa that includes battery storage will be more expensive than the 1.5¢ per kilowatt-hour ppa in that article. (https://emp.lbl.gov/pv-ppa-prices has a queryable database of all the ppas signed in the usa, although the usa is less reliable as an indicator of true costs because of how its prices are artificially inflated by protectionist tariffs.) how much more expensive depends on how much utility-scale storage is needed; you suggest 12 hours, but a much more typical number in practice is 3–4 hours, partly because there are still coal plants and partly because electrical demand drops a lot at night
also, you are incorrectly assuming that 'conventional' plants have a capacity factor of 100%, when a more typical capacity factor for a coal plant is 60%
so let's consider a kind of worst case: replacing your suggested 2 gigawatts (nameplate) of coal plants in the usa, where construction costs are ridiculously inflated. before we swung the wrecking ball, those coal plants were generating 1.2 gigawatts (real) of power (10.5 billion kilowatt hours per year), so we need 1.2 gigawatts (real) of solar panels. in the usa the average capacity factor is 21% (the article i linked above is from an area with more sun than average) so that's 5.7 gigawatts peak. typical costs for utility-scale fixed-tilt solar plants in q1 02024 were 98¢ per peak watt https://www.seia.org/research-resources/solar-market-insight... including costs like permitting, design and engineering, etc. so that's 5.6 billion dollars. utility bond yields in the usa are currently at 4.35%, and often these things are amortized over 25 years. i think the amortization calculation is that you have to pay 372 million dollars a year, which works out to 3.5¢ per kilowatt hour or 35 dollars per megawatt hour. definitely too cheap for coal to compete with, but still a lot more expensive than the price that ppa came in at
so, suppose we need 4 hours of storage for our 1.2 gigawatts. that's 4800 megawatt hours. six months ago lithium-ion batteries have fallen precipitously to 139 dollars per kilowatt hour https://about.bnef.com/blog/lithium-ion-battery-pack-prices-... so we need to spend another 670 million dollars on the batteries, which adds about 12% to the cost of the project. except that in real life you need more than just a pile of batteries, you need to pour concrete and run wires and connect inverters and so on. and the batteries won't last 25 years, maybe 8, so you have to amortize this capex over a much shorter period. but it should be clear that this is not a crushing cost that dwarfs the cost of the solar farm
(theoretically lead-acid might be cheaper by a factor of 1.5 or 2 or so, but lithium-ion's advantages seem to have driven it out of the utility-scale market)
aha, here we go.
https://atb.nrel.gov/electricity/2023/utility-scale_battery_... says that a 4-hour 60-megawatt lithium-ion battery system costs 446 dollars per kilowatt hour and has 240 megawatt hours of storage. so our required 4800 megawatt hours cost 2 billion dollars. that's about three times the cost estimate above for just the batteries, but that's an estimate from before the batteries dropped in cost by half, so 1.3 billion dollars is a better estimate. this plus the 5.6 billion dollars for the solar plant gives us a total up-front cost of 6.9 billion dollars
the main reason for the difference seems to be how sunny the location is; the technical brief explains:
> Aided by the ITC, most recent PPAs in our sample are priced around $20/MWh
(on a levelized basis, expressed in real 2021 dollars, and including bundled energy, capacity, and RECs) for
plants located in the West, and $30-$40/MWh for plants elsewhere in the continental United States.
the itc is a subsidy, so the real cost is a bit higher (due to the tariffs)
> when a more typical capacity factor for a coal plant is 60%
This is, of course, patent nonsense. "Not producing maximum power because it isn't needed at the moment" is an entirely different thing from "not producing maximum power because you can't".
A coal or nuclear plant that's producing less than its maximum output because the power isn't needed at the moment can be ramped up if needed (not super quickly, hence the need for peaker plants, but it can be done).
A solar plant that's producing less than its maximum output because it's night, or because it's cloudy, cannot.
> https://pv-magazine-usa.com/2020/05/28/record-low-solar-ppas... is an article from four years ago giving some specific prices: a solar ppa had just been signed for 15 dollars per megawatt hour, while the cost of production with coal at the san juan generating station
1) No storage costs are mentioned.
2) Most places are not New Mexico.
3) I'd bet money that there's some heavy government subsidization involved here. Ah, yes: "EPE will also receive the associated renewable energy credits (“RECs”) bundled with the purchased energy."
> you suggest 12 hours, but a much more typical number in practice is 3–4 hours, partly because there are still coal plants and partly because electrical demand drops a lot at night
Wait: you're claiming that the nighttime zero production from solar plants doesn't matter because there are still coal plants?
I'm sorry, that is a benefit of the coal plants, not the solar plants.
What happens in your scenario when there aren't any more coal or nuclear plants? Again, that might work in New Mexico, but in most regions people would prefer not to freeze in the dark.
for someone who started out demanding that people 'please provide' a 'source for reliable figures', your comment is astoundingly devoid of any sources or indeed factual information. you are very much not living up to the standards of debate i was hoping for; please try to do better
> "Not producing maximum power because it isn't needed at the moment" is an entirely different thing from "not producing maximum power because you can't".
your replacement solar plant also doesn't have to produce the un-needed power, so you have to take the capacity factor into account when you're calculating the replacement size
> No storage costs are mentioned [in the article about the palo verde trading hub prices]
yes, that's why other parts of my comment explore storage costs in great detail
> Most places are not New Mexico
most places that people live are sunnier than new mexico or close enough to someplace that is
> there's some heavy government subsidization involved here
yes, you may note that the comment that you're replying to discusses those subsidies and actually names another one and computes what the unsubsidized cost would be for your suggested 2/4/1.2 gigawatts. as i mentioned, there's also some heavy government taxation involved here; solar panels in the usa cost twice what they cost in the rest of the world. also, as i mentioned, the price of solar panels has dropped by half since the article was written
> you're claiming ... because there are still coal plants
technically what i claimed was that the typical number in practice was 3–4 hours not 'because there are still coal plants' but 'partly because there are still coal plants and partly because electrical demand drops a lot at night'. probably i should also mention wind power, nuclear plants, hydroelectric power, gas peakers, and distributed storage such as car batteries, all of which currently play a role in compensating for the intermittency of solar
the current average is about 3 hours; that will presumably increase as solar becomes a larger fraction of the grid. to estimate how much it increases, we need to start by understanding the current situation, but we also need to predict how extensive demand response will be. you posit that the storage requirement will increase to 12 hours, but that seems unlikely to me. if it did increase to 12 hours, that would make the battery system cost as much as the solar farm. unless batteries somehow got cheaper
what's at issue is not 'freezing in the dark'. people generally do want it to be dark most of the night, because they're asleep, so not being in the dark only requires storing about 40 watt-hours per person, which is a single usb power bank. and you can reliably avoid freezing with a so-called 'sand battery'; 12 hours of 6000 watt heating can be provided by a tonne of sand heated up to 250° when the sun is shining. that's about fifty bucks of sand and a few meters of nichrome wire. if you live in a normal sized house with maybe some insulation you need a lot less than that
so relax, you're not going to freeze in the dark
a mean man scared you with a scary story, but it's not real
rather, what's at issue is industrial process plants like blast furnaces and haber–bosch nitrogen fixation, which are traditionally pretty intolerant of being shut down; it takes a long time to bring them back to steady state after a perturbation. in some cases there are alternative batch processes that compete with continuous-flow processes, which have conventionally been economically uncompetitive, though there are exceptions such as electric arc furnaces. in other cases, it may be possible to design continuous-flow process plants in such a way that they can ramp up and down efficiently, so that they can take advantage of the unprecedented abundance of free energy during the daytime
> road infrastructure (eg bus lanes) so they not stuck in traffic
Bus lanes aren't going to do anything to help with the real bottleneck in city bus transport: having to stop every couple of blocks to let people on and off.
> It's trivially obvious that some kinds of stem cell can become any type of cell, given that we all had our beginnings as a single cell.
It’s not that obvious, as the brain grows, certain kind of cells die off and never come back. For example at 4-5 years of age being able to speak different phonenes is lost due to mass die off of a certain type of brain cell.
Could be the same for the pair of cells that start a human life. Once their purpose is served they may never exist again.
Do you have a source on the phonemes situation? First time I hear of it, and I'm pretty sure I've seen people learn them past that point. I know they struggle with it, but, as an example, even japanese people can learn the effective difference between l and r given enough effort.
It’s why certain ethnicities cannot pronounce words in their non-native language. Like people from the US not being able to make certain consonant sounds in German or Chinese being unable to pronounce the R consonant. So go look it up yourself.
You are referring to the critical period [1] of (second) language acquisition, which is generally thought to end with the onset of puberty [2].
Neurodevelopmentally, this period coincides with extensive synaptic and dendritic pruning and increased myelination (of axons) [3], which result in the loss of some connections and the strengthening and acceleration of others. Cell loss is not thought to be a major driver of brain maturation, nor is it thought to occur more frequently during this time window.
> It’s not that obvious, as the brain grows, certain kind of cells die off and never come back.
I'm not sure what difference that would make. Those brain cells (and all the other brain cells that don't die off) were still formed by successive divisions of the single cell that resulted from sperm meeting egg. Therefore, that original cell is capable of producing any cell type found in the body.
Your evidence for it "washing away with the next rain" would be?
Ever see what a child can do with a glass of "cherry" Koolaid?
A dye being labeled as "food grade" has essentially no correlation with its permanence.
> Does sidewalk chalk count as vandalism?
Sidewalks aren't 4,500 year old World Heritage Sites.