If you want a fusion power reactor, by far the most viable fuel is D+T. You'd need orders of magnitude more tritium than is could ever be extracted from trace fission byproducts.

The idea to obtain this much tritium is to use the extra neutrons from the fusion reactor itself to breed it from lithium. This is supposedly a demonstration of that process.

ED: Last time I looked (when the tech was brand new) I couldn't find any studies on plants, but there apparently are now, and... yeah, it's what I expected. In fact, it's even worse than I expected: because all the energy is absorbed in such a short distance (the (living) epidermal layer), it does a lot more damage in that (critical) layer.

That said, apparently at lower doses you can still kill fungal pathogens without hurting the plants, and is much more effective at doing so, there is that.

I wonder if we should be exploring even shorter frequencies for plants. If you go shorter, bacteria are going to be able to escape harm, but you'll still be able to kill viruses and maybe still kill e.g. fungal condia.

Hmm. New thought (re: 222 / 233nm): as a pesticide.

Insect exoskeletons tend to be proportional to the insect's size. A big beetle's exoskeleton might be up to a couple hundred microns thick, while an aphid's only a several microns, and a spider mite's cuticle is just like 1-2 microns thick. And even with insects with exoskeletons too thick to kill, they typically moult, and after moulting, the new soft cuticle is initially far thinner. Also, with winged pets, the cuticle is often far thinner than on body regions (to keep them light and enable fast movement).

I bet far-UV would really do a number on small pests & winged pests. And... hmm... I guess that means we can go back away from the world of plants and back to the world of humans: surely it will kill skin mites, lice, etc... anything not hidden by clothes / hair / etc.

(And that's without fuel)

I went searching trying to figure out where you managed to find a 3241 lb Camry. Seems the 2020 ones were that light, but were non-hybrid, while the current ones are now all hybrid. Of course, it has an even more anemic performance of 7,6s 0-60, and is once again, still smaller than the 3.

To repeat, from the top: actual class competitors of the Model 3 are cars like: BMW 3-series (330i for the SR, 340i for the LR), Mercedes C-Class, Audi A4 & S4, Acura TLX, Infiniti Q50, Volvo S60, Jaguar XE, etc. And class competitors for the Model Y are cars like: BMW X3, Mercedes GLC, Audi Q5 & SQ5, Volkswagen Tiguan, Lexus NX, Acura RDX, Infiniti QX50.

Either compare apples to apples, or expect nobody to take you seriously. You might as well just say "BUT MY MOPED IS ONLY 200 POUNDS!!!".

Why on Earth are you comparing a SUV to a small sedan? Don't get me wrong, Model Y isn't exactly a GMC Yukon or anything, but it's much bigger than a Camry, with over double the cargo space (971L vs. 428L).The Camry has only 71% the cargo space of the Model 3. 7cm less front headroom / 5cm less rear headroom than the Y, and 4cm / 3cm less than the 3. And it's in an utterly different performance class. Are you, like, *trying* to be dishonest, or are you just this ignorant?

And even then, here's a stats table (US units for you). Tesla mass here and here and Camry here and here, for your disbelief.

Toyota Camry 2025 LE (FWD): 3,594 lbs, 6.9s 0-60
Toyota Camry 2025 XSE (AWD): 3,774 lbs, 6.8s 0-60

Tesla Model 3 2025 SR (RWD): 3,880 lbs, 4.6s 0-60
Tesla Model 3 2025 LR (AWD): 4,019 lbs, 4.2s 0-60
Tesla Model 3 2025 Performance (AWD): 4,080 lbs, 2.8s 0-60

Tesla Model Y 2025 LR (RWD): 4,235 lbs, 5.6s 0-60
Tesla Model Y 2025 LR (AWD): 4,392 lbs, 4.6s 0-60
Tesla Model Y 2025 Performance (AWD): 4,392 lbs, 3.5s 0-60

Explain to me how you think these numbers are somehow out of line with each other, given that even the 3 is larger than the Camry, and both are in an entirely different performance class?

Can't speak for them, but I've never gotten COVID and thus my risk for the much more severe, more common COVID-related myocarditis is zero.

"Processed" usually means smoked, cured, or other means of preservation. Cured meats commonly have nitrates or nitrites (carcinogenic) and tons of sodium. Smoked meats have carcinogenic PAHs and HCAs.

Well, your buying power would be crippled.

So clueless.

The fact is that the trade imbalance is the largest single factor that makes the US dollar the world currency -- and also helps to keep the federal debt cheap. All of those countries that have a trade surplus with us send us lots of goods and in exchange they get lots of dollars. What do they do with them? They buy US-denominated securities, including treasury bonds. So many people and organizations around the world holding large reserves of US-denominated securities is what makes the dollar the world's default currency.

To the extent that he succeeds at "correcting" the trade imbalance, he'll undermine the dollar's status. And trying to bully countries into sticking with the dollar by threatening action that will make the dollar worth less to them is just... clueless. And that's assuming his actions to explode the debt while escalating financing costs doesn't result in enormous devaluation of the dollar, which would make it worthless rather than just worth less.

On balance I think I'm mostly glad that Trump is a moron, because if he weren't he would be really dangerous. On the other hand, if he had either a brain or the humility to listen to people who do, he might understand that he's trying to destroy what he's trying to control, and that winning that sort of game is losing. Probably not, though. He's amoral enough to be okay with ruling over a relative wasteland, because he and his will be better off.

You are talking nonsense. A Tesla Model Y battery is 1700 pounds, whereas a full gastank of a typical sedan is less than 150 pounds

SIGH.

First off, none of the battery packs in the 3/Y are 1700 pounds. The SR pack is 350kg / 772 lbs, while the LR pack is 480kg / 1058 lbs. This includes the charge cabling.

Secondly, unless you drive around in a vehicle that is nothing more than a gas tank or a battery pack, you're kind of forgetting a few things. Let's help you out.

ICE engines typically weigh 150-300kg (~330–660 lbs), and high-performance engines can exceed this. On top of this, the transmission usually adds another 70-115kg (150-250lbs). EV powertrains are light. An entire Model 3 drive unit, including gearbox, oil pump, filter, etc is ~80kg / ~175lbs. And actually this plays it down, because except in the performance Model 3 - which matches up against quite powerful / heavy ICE powertrains - they're software locked, so they're actually well oversized relative to what they're allowed to deliver.

ICE exhaust systems add ~25-45kg / ~50-100 lbs. Obviously absent in EVs.

ICE fuel systems (pumps, lines, etc) add another ~15-20 kg or so (maybe 30-50 lbs)

ICE vehicles, due to their inefficiency, require much larger radiators, coolant reservoirs, hoses, etc (again, another ~15-20kg extra over EVs).

The battery pack in an EV makes up the floor pan. Again, that cuts mass by a couple dozen kg.

The battery pack is a stiffening element, and eliminates the need for many dozens of kg of extra stiffening mass.

The needs of an engine block impose a lot more difficult design constraints on an ICE car, including a larger front end, a higher centre of gravity, a less compressible front end in an accident, etc. The need to compensate for these things also adds significant mass.

ICE vehicles have all accessories driven by the engine, and all electrics on low voltage (heavy wiring). EVs do it either with a DC-DC converter or direct HV, saving many kg again here. New EVs are also ditching the low-voltage battery altogether.

I could go on and on. The simple fact is, while EVs add (significant mass) in the form of one part, ICEs nickle and dime the car for mass all over the place. ICEs still win out mass-wise, but on a class-and-performance comparison, like-to-like, the mass differences just aren't that much (again, unless the designer is just bad at their job or doesn't care - *grumbles again in Hummer*).

(Also, re: serviscope_minor above: You don't compare vehicles by length; it's not a very useful metric. For size, you can compare by interior space specs - trunk / frunk volume, driver/front passenger head/leg/shoulder/hip room, rear passenger head/leg/shoulder/hip room. Length isn't a good proxy because it ignores packaging; a 1960 Chevy Corvette might be "long", but has very little interior space. Interior space and overall profile are often included as part of the category of "class" (for example, the Model 3 and BMW 3-series both have very similar interior space metrics and profiles). Also part of "class" is perceived / marketed luxury, though people differ over what counts as luxury, so it's not a very clear-cut metric. Performance is another axis, as higher performance cars tend to be heavier and/or have less interior space relative to their footprint (though EVs suffer a lot less on this than ICEs).

You can't get sunburned from far-UV like you can with normal UVC. It doesn't penetrate deep enough to reach living skin cells (e.g. the (dead) stratum corneum is 10-40 microns on most skin, up to hundreds on e.g. palms and soles) - in human tissue, 222nm penetrates only a few microns, with most of the energy deposited in the first micron; the deepest any degradation was seen in one study was 4,6 microns (for 233nm, it's 16,8 microns). As mentioned earlier, the only cells it can kill are the outermost layer of cells in the eye (corneal epithelium), but they're constantly being shed regardless (the entire corneal epithelium is 5-7 cells thick and has a ~1 week turnover, so on average just over 1 day per cell on the surface).

The comments about material degradation probably are also not true with far-UV. It's certainly ionizing, but again it doesn't penetrate deeply into surfaces . Paint is generally many dozens of microns thick (a typical two coats of interior paint is ~100 microns), while epoxy is typically millimeters or more, so you're only going to be affecting the extreme outermost surface. I doubt you could even tell.

Also, contrary to popular myth (and indeed, our pre-COVID medical understanding), most common communicable diseases (influenza, COVID, most cold viruses, etc) spread by direct airborne transmission, not fomites (surface transmission). So how well surfaces are cleaned has no bearing on this primary means of transmission. That's not that surfaces don't matter - said diseases still *can* be transmitted from fomites, and some other diseases (esp. fecal-oral route ones like norovirus) are still believed to be primarily transmitted via fomites.

Again, honestly, the only thing I would have concerns about are plants. Most plant cuticles are only like 0,1-1 micron thick. Xeriphytes (desert plants) can be thicker, though, like 1-20 microns, and are in general adapted to more UV exposure, so might be able to deal with it. But I'd think a plant with only a 0,1 micron thick cuticle and a 0,1-0,3 micron thick cell wall will get its leaves pretty badly burned by far-UV. I'd expect any epidermis and stomata exposed to the light to be almost entirely killed. But if you had a cactus or plant with really waxy leaves, it might be fine.

That we should be cool with them blowing through billions of our taxpayer dollars so that they can throw shit at a wall and see what sticks.

SpaceX has saved the US government an immense amount of money. What are you even talking about? Falcon 9 / Falcon Heavy is by far the cheapest launch system out there, and is also, FYI, the most reliable launch system out there. And it go that way by exactly the process above. And that process cost far less than NASA spends to develop its super-expensive launch systems.

Tesla has been at approximately mass parity with its closest class/performance competitors from BMW (with a full tank of petrol) since 2017 (the 330i vs. the SR, the 340i vs. the LR, etc). This "EVs are super-heavy thing" is a myth. I mean, sure, if you're terrible at your job you can design a really heavy EV (*grumbles in Hummer*). But usually, if the designers did their job right, the weight difference is small when matched up on class/performance competitors.

And beyond what others pointed out - that PM emissions are only a fraction of pollutants, and that they come from both brakes and tyres, and EVs have far lower brake emissions - it should also be pointed out that tyre PM tends to be mainly *coarse PM*, not fine PM. Both are harmful, but fine PM is significantly more harmful per amount produced. Brakes have a higher ratio of fine to coarse than tyres do, exhaust is higher still.

Cars also have air filters which capture PM. Generally well less than is produced, but I've seen a proof of concept where they amped up the air filtration so that the car was net negative. If you really wanted to, nothing is stopping you from mandating that. Still, economically your best bet is surely on taxing tyres (esp. studded ones) to incentivize people to choose durable ones and ones that don't wear down the roads, to limit hard accel / braking, etc.

Sure, itâ(TM)s quite possible for two people to exchange offhand remarks about the local weather apropos of nothing, with no broader point in mind. It happens all the time, even, I suppose, right in the middle of a discussion of the impact of climate change on the very parameters they were discussing.

It occurs to me that this is a good use of massive solar plants. It wouldn't cost much to idle your oxygen-separation equipment when the sun isn't shining, so you wouldn't need much in the way of battery storage. Grid scale solar without battery backup in a sunny area (like south Texas) can cost as little as $0.03/kWh, which would give you a separation cost of $4.5 to $24 per ton of LOX. Obviously, if you were producing LOX at a scale needed to fuel a fleet of Starships, you'd work to get that towards the bottom of the scale -- so the LOX loadout for a ship could cost on the order of 3500 * 4.5 = $15,750. To launch 150 tons to orbit. Of course you still need methane.

Could you make "green" methane (i.e. without using fossil fuels) with a big solar farm, and what would that cost? You'd do it with the Sabatier reaction to combine CO2 and H2 to get CH4. To make a ton of CH4 you need 2.75 tons of CO2 and 0.5 tons of H2 (stochiometry, dawg). To get a ton of CO2 with direct air capture takes about 2000 kWh of electricity, so 5500 kWh for the CO2. At $0.03/kWh that's $165 for the CO2. However, producing the half-ton of H2 with electrolysis would take 25,000 kWh, so $750. This puts the raw materials cost of green CH4 at around $915. The Sabatier reaction would add a little more, call it $930 in all.

So... Starship could be entirely solar-powered at a cost of around 3500 * 4.5 + 1000 * 930 = ~$946k, assuming $.03/kWh, ignoring equipment and storage overhead. It turns out that the cost is utterly dominated by the cost of methane production; LOX is all but free. But the cost of solar will likely continue to go down so... fuel costs could indeed get really, really low, even with a zero-carbon strategy. Perhaps as low as $2/kg to LEO.

The thing to understand is we're talking about sixth tenths of a degree warming since 1990, when averaged over *the entire globe* for the *entire year*. If the change were actually distributed that way -- evenly everywhere over the whole year -- nobody would notice any change whatsoever; there would be no natural system disruption. The temperature rise would be nearly impossible to detect against the natural background variation.

That's the thinking of people who point out that the weather outside their doors is unusually cool despite global warming. And if that was what climate change models actually predicted, they'd be right. But that's not what the models predict. They predict a patchwork of some places experiencing unusual heat while others experience unusual coolness, a patchwork that is constantly shifting over time. Only when you do the massive statistical work of averaging *everywhere, all the time* out over the course of the year does it manifest unambiguously as "warming".

In the short term -- over the course of the coming decade for example, -- it's less misleading to think of the troposphere becoming more *energetic*. When you consider six tenths of a degree increase across the roughly 10^18 kg of the troposphere, that is as vast, almost unthinkable amount of energy increase. Note that this also accompanied by a *cooling* of the stratosphere. Together these produce a a series of extreme weather events, both extreme heat *and* extreme cold, that aggregated into an average increase that's meaningless as a predictor of what any location experiences at any point in time.