There's a limitation to the bootstrapping analogy here, if you think of it in the sense of a computer boot(strap). Yes; when a complex system is totally disabled (ie, the computer is shut off), then there is a reliance on the lower-level system(s) to bootstrap back into an operating mode. In this case, roughly, BIOS->Bootloader->Operating System.
Similarlty, turbine aircraft (jets, etc) require a small power unit to start up first, which then enables the full engine systems to start and run. A "bootstrap".

However, the analogy to computer systems falls down when we're talking about the overall technology base. When you already have the tools, building replacement tools doesn't have to rely on older (lesser) tools; a steel hammer can forge another steel hammer, you don't need to drop back to iron, bronze, or stone. In this case, the "bootstrap" is using older tools (iron) to build newer tools (steel), which then *does* allow you to eliminate use of the older system --as the new tools can replace it. We would only need to "bootstrap" again in the event of a total throwback to the stone age.

Similarly, to the parent's note; we (as a global society) absolutely can leverage so-called fossil fuels to enable future energy technologies, with a planned eye to remove fossil fuel use once the new technologies can replace the work required. This "bootstrap" is a once-only requirement; the older technology can vanish, because we don't need to keep re-bootstrapping to work with the newer once the newer can create/build/maintain itself. It's not necessarily going to be a fast "boot", or a quick dissolution of the older technology -- and we may be too late -- but in this case, yes, a bootstrap *can* result in the elimination of the older system. In fact, it's a requirement; we cannot get off of fossil fuels without a replacement energy source, and we cannot get a replacement energy source without using fossil fuels to move us along the path. Once we've moved along the path enough for the replacement energy source to *keep* us on the path, fossil fuels become non-required, and can be left in the dustbin of history.

Assuming, of course, we have the willpower as a society.... and the last 50 years isn't very positive on that note.

This... if I had points, I'd be +1(informative) you here.

As the parent stated; the odds of 1:4200 is that *someone*, *somewhere*, gets harmed. In 4199 cases, anything reaching ground/sea level misses humanity entirely. Not remotely the same to say 1:4200 chance that any *one individual*, specifically, gets harmed; then we'd be looking at rougly 2M people expected to be harmed; hardly a negligible concern!

A quick search says that 20-25% of the world's population lives within 10 degrees of the equator (thanks White Yeti's response to parent for the latitude range); call that about 2 billion people. So there's a 1/4200 chance than 1/2,000,000,000 people would get hurt... or about 1/8,400,000,000,000 (1 in 8.4 trillion) chance for a given person in that latitude range. Maybe a little higher on the chance that the impact is in a crowded area. And as you move out of that latitude... the chance of harm moves to zero, for the other ~6B people on the planet.

Ok.
So let's look at the numbers here, again.

For a solar farm, per the earlier calculations -- the fee to be split would be on the order of $0.04/hour, per satellite tasked to the farm. For someone wanting lighting, per the article, Reflect Orbital wants to charge $5000/hour/satellite (on contracts of 1000 hours or more), with higher amounts to one-time users. If I were Reflect Orbital, I would never bother tasking to solar farms --- I could make orders of magnitude more revenue providing lighting at even a fraction of my stated price.
On the lighting side; $5K/hour at $0.18/kWH means ~27.8 MWH worth of electrical grid power, -vs- "100 moons" worth of light -- which a quick AI search indicates is *significantly less* light than a single, 100W-equivalent bulb -- which would require about 0.1 kWH of power, costing perhaps $0.018/hour. So a lighting user would be paying a crazy amount for very little light, against simply using terrestrial-powered artificial lighting.

So: the point is that, whether someone is looking at running a solar farm *or* "buying" reflected sunlight for nightttime illumination, the cost-per-unit to pay Reflect Orbital for this is insanely high for the return.

So I saw this, and the numbers person in me wanted to check... you're right (their pricing is insane).

My first thought; 60ft is the *test* satellite. 180ft for the production model, and thanks to squaring space, much more coverage. However;
180x180ft; call that about 3000 square meters. Using your estimate, that would scale to ~1,125kW after panel losses... so about $200/hour at the $0.18. Still ridiculously low compared to the nominal $5K/hour charges.

However it gets worse! The panel is supposed to reflect light "equivalent to 100 full moons" -- rather less than full sunlight.

A quick AI search indicates that moonlight peak power is about 0.3W per square meter... so 3000 square meters, about 900 watts for 100 "moons". Allow for ~25% panel efficiency, and we're down to ~225 watts -- not kilowatts, watts. At $0.18/kWH -- this is about $0.04 in theoretical electrical output per hour from a single satellite's reflected light.

As a way to keep solar farms running, this is insanely expensive. And that doesn't even start to think about the stationkeeping requirements of what amounts to a large solar sail trying to stay in a stable orbit *and* reflect sunlight in a tightly controlled manner...

Triple capacity in the next 25 years? Good luck, even with the $trillions those companies could in theory throw at it.

A quick look at OurWorldInData indicates that total capacity has gone from ~2,540 TWh in 2000 to ~2,700 in the 2020-2023 window (jagged but roughly flat). So, about a 6.3% increase over the last 25 years, globally. Now, in the next 25 years, they want to see a 300% increase, in deployment of systems that take on the order of 6-8 years each, globally (thanks Google). With a little over 400 plants operating (per Google, 2023) globally, that means a net build of ~1200 equivalent plants, not accounting for rebuilds or decomissionings. Then further, all those reactors need the associated transmission capability and grid capacity, wheresoever they may be built.

All of this build needs to involve fairly rare, specialized skill sets and fabrication capabilities, which would need to be expanded to handle the volume (and then, perhaps, be mothballed? Or would the pace continue afterwards?) -- and over 25 years, we're talking about people who are starting *today* being potentially ready for retirement at completion, so entire generations of skilled workforce being involved.

Can it be done? Potentially. Personnel,manufacturing, and materials availability becomes a concern, but those might be worked through. Realistically? Not even close.

Statistics, and damned statistics.

Per the article, someone named "Moorhead" (and CNBC forgot to reference who that is!) is thinking of seeing "up to" 5% increase in feature phone sales, over the next 5 years. The article also indicates that HMD Global is selling "10s of thousands" such phones, in 2022.

So, first; 5% of 90000 (the highest "10s of thousands" number) would be less than 5000 additional phones.

Given some numbers about the American market; 97% of people have a cell phone. 12% are "non smart", the remainder smart. That means, on a population of about 335M, there are about 40M non-smart phones out there, and about 285M smart phones.
5000 incremental phones per month, presuming the 2022 increase isn't related to covid-delayed purchasing, if totally due to people switching off smartphones, would make all of a 1% dip in the relative smartphone ownership over the course of...about 570 months, by my math. Or, about 47 years.

Given the iPhone was first released in 2007, and calling that the first "smartphone" -- it's taken 15 years for smartphones to reach the ~85% saturation level. It'll take 3x that (or more) for feature phones to increase another 1% from the current level... and I'm ignoring population changes.

"up to" 5% growth in 5 years is... up to 1% per year, which is not efficiently off flatline, and generally below inflation levels. This doesn't smell like "on the rise" so much as "maybe falling slower" to me.

Interesting thought.
I can't begin to measure against the yield tonnes (precooked? cooked? hulled?) , but cooked, rice seems to be about 100Cal / 100grams, and wheat closer to 340/100grams (thanks again, google)

So, from a caloric view, even the ~50% lower yield by weight would seem to indicate a ~50% higher caloric yield for the wheat, per unit area being farmed.
With the earlier comment indicating that wheat is also a lower-carbon crop to farm, would seem to indicate a move towards wheat would be a good idea.

Carbon footprint may not be the driving piece, or may depend on how you're measuring.

Low-tech farming (and, in fact, all farming) pays more attention to output per space (acre or hectare); on a quick set of searches, it looks like China, for instance, puts out about 7 tonnes of rice per hectare, or about 3.5 tonnes of wheat. Rice is therefore more efficient for the land use, which may be one of the drivers.

There are also challenges around space - rice needs water, and can be grown in tiered hilltops, but wheat prefers wide flatlands, for instance - that may drive interest in particular grains.

And all that ignores what the local consumers want, too...

Thanks for sharing this.

One key point in the video (4:45-4:52) notes that Dragon splashdown is at about.... 16mph. So both NASA and SpaceX seem to think that a splashdown landing at 16mph is valid.
Soyuz, which shares a parachute-based landing, has a landing zone area of about 25 miles in width. The same page notes that minimum speed under parachute is 24 feet per second... which translates to 16.4mph. Soyuz, with a hard landing (not water), has retrorockets to reduce speed further at the last moment; Dragon and Orion use the water to soften that landing.

Soyuz spends about 15 minutes under parachute; that's a 4-mile vertical travel window with zero horizontal control. In the video linked by bws111, Dragon was under main chutes for about 3 minutes prior to touchdown; about 0.8 mile vertical drop. With a crosswind of just 10 mph, Soyuz would have a ~2.5 mile variance in landing from the direct fall; Dragon would be down to about 0.5mile with the same crosswind.

Neither is remotely close to "pinpoint" landings, as seen with a glide-entry vehicle like the STS, the Dragon boosters, or what SpaceX is trying with Starship.

Orion apparently pops chutes at about 24000 feet, or about 4.5 miles up. That means accuracy from that stage can only be similar to Soyuz -- about 2.5miles with a 10mph crosswind -- and presumes that the capsule was dead on course at the moment the chutes opened.

Take into account that wind speeds at 24000 feet can routinely be 150+mph, typically decreasing with altitude. At 100mph average over the descent, we're now at a +/-25 mile radius from where the parachutes deploy to where the capsule comes to rest.

Suddenly a ~6mile radius as a target is actually really, really tight plotting, at least in my mind.

All true... I think my point is that there is nobody required to take the other side of my "bet". If I think a stock will go up, I buy some; if I think it will go down I can short sell; all I need is someone who is willing to sell or buy the stock at the given rate, either way. Their sale or purchase either starts or ends their own 'bet'; how they did isn't relevant to my own.

But, absolutely; the market as designed allows for 'bets' on both positions, for and against success of the company behind the stock.

Shorting stocks is an odd one, I'll grant.

Contrary to someone a couple posts up, one does not need anyone to take the other side of a bet; if I invest in a stock, expecting success, then I'm looking for the stock value to rise, and potentially for dividend income from ownership in the business. If my "bet" fails, then the stock value falls, and perhaps there is no (or not as much) dividend income. I "lost"; *nobody won because if it*.

For a short sell, as I've had it described to me; the "bet" is that the company's stock value will decline over a given period of time. So, as a short seller, I go to a existing shareholder, and write up an agreement; you (as the existing shareholder) let me sell your stock today, and in two weeks I'll give it back to you for today's value plus something. Meanwhile, since I sold it today for $X, I plan to buy it back next week for $X--. I use the difference as my gain (and to add the plus something to the loan of the stock).

So; sell a stock today for $100, buy it next week for $80 -- still have all the stock, plus $20. Give it back to the original person, add in their cut of $5 - I'm still up $15. That's a successful short sell. On a failure, sell this week for $100, buy back for $120 -- and still have to give the stock and an extra few bucks back to the original owner. Now out $20+; that's a failed short sell.

Short sells don't require that the company "fail"; only that the seller can take advantage of a (potentially short-term) decline in stock price by leveraging timely sell and buy orders.

Or put one more way; "classic" stock market is "buy low, sell high". "Short" selling is "sell high, then buy back low".

The metric indeed.... number of houses or total quare footage built per employee.

One of the other changes over the last ~50 years? Death of the generalist construction worker. It takes several people to build a house, sure; but a great deal more people when each one employee has only one role - Framer, Roofer, electrician, drywaller, taper, mudder (yup, 3 people/roles for the drywall alone!), plumber, finish carpenter, window installer, painter, masonry, soffit/faschia installer... the list undoubtedly goes on.

A house might only have 2-5 people on site at a given time... but roll through over 40 different employees to finish the work.all the way from digging the foundation hole through final touchups.

A different metric would be to look at the person-hours involved per sqft, as compared over the timeline. Is the work "more" efficient (less person-hours)? Or has the multiplication of required job roles increased the total person-hour count required? In the first case, we might have situations where individual tradespeople are underutilized. In the second, we could be dealing with true productivity stagnation or loss (the workers in question, on average, can't do as much) or we could be looking at impacts of complexity or regulation increasing the total workload, as others have pointed out in these threads.

"Efficiency" is a funny number to work with, mathematically. Choosing what to measure efficiency against is almost more of an art than a science...

As an ebike owner... one of the tricky things with ebikes is that, if you pedal much (or ever use the throttle), they *will* take you up to their top speed, fairly easily (on the flat). For me, that means 32kph (~20MPH) -- holding to a lower speed requires a great deal of attention to (usually reducing) pedaling power, or changing the limiter settings. My ebike is legal (in Canada, in Ontario) for road work, but not in for some dedicated bike paths or parks, depending on the city. Limiting the maximum (powered) speed for the device simply makes it easier to confirm that the rider, not the device, is the one running too fast.

Here, I'm 100% behind getting rid of this limit. Similarly, my 500W motor has a real challenge on heavy hills. Personally, I'd rather see a restriction around maximum powered acceleration (say, 0-max in 10 seconds) than on absolute power, to facilitate hilly riding. That said, I'm *not* in favour of increasing maximum powered speeds; 32kph already puts me well over the average cyclist's flat road speed, and bike helmets are not built to handle crash scenarios much faster. Classifying faster (powered) bikes as motorcycles or mopeds, with the inherent rule changes, makes sense to me.

Almost precisely.
From the article;

There's a lovely webcomic by XKCD that shows the general timeline. Look for the swoop at the bottom... that's what the climate folks want to bend back closer to a straight line.

I think this is where we differ.
Locally? Sure. One US state; one European country, or a couple of such, near each other. I'll totally agree here; happens regularly, particularly with smaller geographies. Again, the wider grid should help.
But *Continent wide*? That's the entire US, Canada, and Mexico, for mainland North America; or every country in Europe, simultaneously; or Russia, China, India, and a host of others for Asia, all having the same zero-wind, low-sun scenario. Far, far more likely that the south of France has power to feed north to Belgium; or that the Carolinas can feed to Vermont; or that India could feed power to part or all of China to reduce that battery load requirement.

Regions without an integrated grid? Yeah, they're going to need other sources. Texas, island nations like Cuba, and remote spots with insufficient hydro capability may well be using fossil fuels for a while, at least for their power backup requirements.

Probably doesn't help that I first read the 28 hours as *48*. Quite a climb down from that to 18, too...