Alt text:
While it seemed like a fun prank at the time, I realize my prank fire extinguishers full of leaded gasoline were a mistake.
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All chemical propulsion is just controlled explosions that we use to push a thing forward. It’s not that different, as long as you don’t use it in the atmosphere or near humans.
Yeah I know, it’s the same principle behind modern fuel engines. Still, using nukes for propelling something forward is a bit of a stretch.
Not just nukes, but nuclear shaped charges, at a rate of maybe one per second for a manned vehicle or even more for a faster cargo only mission.
If you can trust the human monkeys with the “shaping” of a rock that got us here, how you gonna distrust the widdle trivial matter of taking little bits of something and splitting them.
It’s shaped charges, it’s totally fine and sane. I’d happily get on the 1,000th Orion flight*.
*Only if that’s a fresh hull
Ah the 50s, when everything atomic was rad.
::Fallout theme starts playing::
It’s not uncommon in scifi. Netflix’s Three Body Problem also explores such a solution in quite some depth.
I love The Three Body Problem, both the books and the show. But it bothered me to no end to read Netflix’s Three Body Problem.
I’m not familiar with the books, and the plot summary of their Wikipedia article does not mention nuclear propulsion whereas the article for the series does, so I went with that.
Unless what bothers you is the x followed by the apostrophe and the s, which I never know when to omit the s, so it is what it is.
Ah gotcha. Yeah you should check out the books if you’re liking the show! The books go into a ton more detail and the Staircase Project is pretty cool. Seeing it on the screen is cool too, but if you really wanna nerd out I highly recommend the books.
Read “Footfall” for a hard scifi story featuring such a ship.
Will do! Thanks
I like Footfall, but it’s also a little over the top for me.
Co-written by the guy who tried to sell the US military the concept of “rods from god” (orbital kinetic weapon). I wouldn’t expect anything less.
It would probably work just fine, but it needs a huge ship. It could get up to a few percent of the speed of light.
FWIW, nuclear test ban treaties are considered to outlaw it. I think we’re more likely to solve the technical difficulties of antimatter propulsion than we are to get over the political difficulties of nuclear bomb propulsion.
It could get up to a few percent of the speed of light.
So could a person sticking their head out and blowing, but it’s still a terrible idea.
Just as an observation, there was a time when everyone on the Internet was gaga over the idea of Project Orion, and you didn’t dare speak out against it lest you get a hail of downvotes.
It’d work fine in deep space. It’s not a good idea to launch from Earth this way. But again, we’ll probably find something better once we’re at the stage of needing it.
But then how would you launch nukes on orbit without the risk of accudental nuclear explosion?
Implosion-type nukes are all but impossible to make go off that way. They need a whole bunch of small explosives to go off very precisely to squeeze the core in just the right way. A short circuit or a crash won’t have the necessary precision. This isn’t entirely safe, either–it can still cause a small explosion with a flash of fallout and radiation–but it’s a manageable problem.
Gun-types (Little Boy was one) are easier to go off on accident, but the US retired its last gun-type design decades ago. I don’t think Russia used them much, either. They’re only good for smaller bombs, and their safety issues make them questionable for any use. Smaller nuclear powers aren’t bothering with them.
Not worse than a fusion torch. Or open-cycle nuclear propulsion. Or an antimatter drive.
You know, the Kzinti lesson😉
Never heard of those, but if they are on par with project Orion I have some nice readings to do today.
Aren’t there plans again?
Considering that you need huge shields and dampening and you only have the mass of the bomb itself as propelant, is it still as effective as controlled propulsion?
Don’t forget the mass of whatever ablates from your shield!
They spoke to that and found it manageable. The ablation isn’t there deal breaker
I think you may be mixing up Project Orion (let’s chuck bombs out of the back to make us go zoom) with NERVA (a nuclear thermal rocket engine where the heat from chemical reactions is replaced with heat from a nuclear reactor to generate gas expansion out of a nozzle). Something like NERVA is actually a great idea. Let me tell you why!
-
It’s completely clean (unlike Orion and fission-fragment rockets)
- the reactor and fuel never touch, the fuel goes through a heat exchanger and is not radioactive
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it provides extremely high efficiency
- chemical rockets top out at ~400-500 isp in vacuum
- NERVA tests in 1978 gave a vacuum isp of 841
- ion thrusters like NEXT has an isp of 4170
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it provides lots of thrust
- NERVA had 246kN of thrust
- NEXT (which was used on the DART mission) is 237 millinewtons
- That’s 6 orders of magnitude more thrust!
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No oxidizer is needed
- All you need is reaction mass, just like ion thrusters
For automated probes, the extreme efficiency and low thrust of ion thrusters makes perfect sense. If we ever want to send squishy humans further afield, we need something with more thrust so we can have shorter transit times (radiation is a bastard). Musk is supposedly going to Mars with Starship, and the Raptor engine is a marvel of engineering. I don’t like the man and I’m not confident that he’ll actually follow through with his plan, but the engineers at SpaceX are doing some crazy shit that might make it happen.
Just think though, if the engine was literally twice as efficient and they didn’t need to lug around a tank of oxidizer, how much time could they shave off their transit? How much more could they send to Mars? Plus, they could potentially reduce the number of big-ass rockets they have to launch from Earth to refuel. If you can ISRU methane, then I imagine you could probably get hydrogen.
There are problems that still need to be resolved (the first that comes to mind is how to deal with cryogenic hydrogen boiling off), but like, the US had a nuclear thermal engine in the 70s. It was approved for use in space, but congress cut funding after the space race concluded so it never flew.
I’m happy to see that NASA is once again researching nuclear thermal rockets. Maybe we’ll get somewhere this time.
I’m more with VASIMIR though, maybe with a nuclear reactor for power, since it’s variable.
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I was under the impression that bloodletting could in some cases actually be beneficial.
Yeah, for people with hemochromatosis (too much iron in the blood) the main treatment is still bloodletting.
Or go piss off Magneto
Yeah, it’s still practiced. But the whole four humors thing is a bit old hat.
I think there’s a few of these misplaced. Heelys>transition lens.
Heelys>transition lens.
I dunno, seems kinda unrelated…
And also often in such cases, blood donation is suggested instead.
Yeah it can reduce PFAS levels in your system. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2790905
Though better to just donate that blood than let it go to waste.
Also leeches are used to help veins heal after reattaching fingers/ears/other dangly bits, which is a form of bloodletting
What is this transition lense slander
I know right, I recently replaced my glasses with transition lenses and it’s pretty nice.
Who doesn’t want automated sunglasses? Not seeing any downsides yet. Only thing I know they don’t work in cars, but I don’t generally drive so it’s ok
The technology has come a long way since the 90s
In the cold they take too long to transition to clear. So you end up taking them off for a few seconds when you go inside. It’s only minorly annoying.
To be fair, regular glasses mist up anyway when going inside from the cold, so you take them off anyway
Can confirm, it’s all positives with the only downside being that it costs a little more.
I find that they don’t “un-tint” when going inside fast enough for my liking, personally.
Creates kind of the opposite effect of going from a dim room into a bright space. Instead of evrything seeming extra bright, it just dimmed everything and made it more difficult to see.
One problem my mom did not anticipate was that she would be stuck effectively wearing sunglasses for my brother’s outdoor wedding, where was sitting up with the bride and groom for the whole thing (Indian wedding). She just looked like an asshole, and continues to look like an asshole in the just about every photo of the ceremony. Oops.
Why would wearing sunglasses outdoors make someone look like an asshole?
They have different varieties, some do work in the car
But then they would probably work in a well lit office too.
No, they don’t change inside (I’ve had them). They do have a slight tint all the time though, which isn’t a big deal.
Was it long ago? Mine have no tint
So soup sounds like an idea and is actually an idea. Checks out.
I dont know, soup has always been a better idea than it first seemed to me
Depends on the soup I find.
At least when you make soup yourself it good
Canned french onion soup? meh.
Homemade french onion soup? Yeah!
What’s wrong with Transitions lenses. I like mine
Transitions are game changing. Sounds like someone who doesn’t wear glasses all the time. I even had transition sunglasses before I needed glasses - got tired of taking them off going in/out all day.
Not sure who created this (I kkow, XKCD), but it’s mediocre.
Double-ended extension cords belongs in the top
leftright corner. Sounds bad and is bad.I’ve worn glasses my entire adult life and I had to get rid of them because being half blind every time I transition from outside to inside was interfering with my job.
This. I worked in a hardware store as a floater (I’m good at things, they ask me to do random) and often found myself irritated at how often I need to go outside for a minute to meet a customer or something, and then come back in and all the fucking lights are off.
Double-ended extension cords belongs in the top left right corner. Sounds bad and is bad.
Remember, you’re probably more technical than the average person. Double ended extension chords sound fine if you haven’t heard of them before until you think about it for five seconds.
It might just be a joke. I use transitions in my cycling glasses, where I might be in shade or when it starts to get dark (but I’ll still have something protecting my eyes). I use regular sunglasses in the car, as transitions generally won’t work there.
You can get them to work in the car. You just need to break all your windows.
Easy.
I prefer to cut the top off.
My only gripe with them is that if I spend any amount of time outdoors, even if it’s not actually sunny, my glasses quickly turn to shades.
Coming inside and not being able to see a lot.
I specifically got rid of them having had them in my last pair. Too annoying!
They transition very quickly though. Takes like a minute
I work from home in an office garden. The walk from the house to house to the office was enough to transition the lenses and then you’re wearing sunglasses for 5 mins and they slowly change back. Definitely takes longer than 1 minute.
Interesting, yeah, I don’t mind them as much I guess. Now I’m considering just getting prescription sunglasses to wear all the time
Replying to spammers sound like a good idea at first, should be top left.
I think sliced bread is overrated as fuck. It used to be nice back when people couldn’t just buy knives for cheap, but nowadays it just means getting stale bread faster.
For some types of bread, the machine can do it much more uniformly and without crushing. This can be difficult for humans.
You can buy your own bread slicer
My appartment is too small for this kind of stuft. Buying sliced bread is fine.
i got a like 30 year old electric bread slicer, never sharpened the blade, still cuts like brand new, sometimes the crust gets stuck when its a super fresh super crispy crusted bread, but its amazing.
Thanks, i laughed. ^^
Those aren’t good types of bread, though.
I recommend a very nice bread knife! I have a mediocre bread knife that was like 15USD like 15 years ago and it still saws solid slices of soft bread without schmushing the bread!
I’m mostly just commenting on why it was such a big deal in the time that it happened rather than today. Today, we do have more machines, easier access to knives, and generally less domestic work to do than was the case in this era. I do own a breadknife, though I rarely eat bread and it’s mostly denser loaves when I do (a kind of sandwich bread the wife prefers or something like Baurenbrot for my tastes).
For pan loaves, people store it in a plastic bag to keep the crust soft.
Pan loaves should be presliced, stone baked loaves with thick crust should not.
But sliced bread has become something else that doesn’t exist with loaves. You can’t buy an unsliced loaf of ultra-processed white bread.
You can get a wide variety of both sliced and unsliced loaves in pretty much every supermarket in my area. The ultra-processed american type bread is something else entirely and it’s also a bad idea too, like pretty much all ultra-processed foods. Can that stuff even get stale? I remember it staying exactly the same up until it grows mold.
Every single glasses of mine have had transition lenses, I can’t imagine my life without them anymore.
I love transitions lenses. I have transitions contacts and they are fantastic.
Omg, does that mean your “eye color” changes in the sun?
If you keep one eye closed and expose the other to sunlight, you can see the difference. The lenses tint a dark shade of purple. I have dark brown eyes, so you can’t really notice the difference easily. There is a purple ring that is most noticeable outside of the limbal ring. They don’t turn your eyes black like you had the tint of sunglasses or transitions glasses, which would be cool.
I would imagine someone with lighter color eyes, like really light blue, would have a very noticeable difference.
Something I did notice as the wearer is when the lenses are tinted there is like a contrast filter on your vision so colors look better.
Same. Although mine became a lot less useful after becoming a night owl.
Excuse me, what about pizza in squares?
I guess because there is no crust to grab. Gotta get grease and maybe sauce on your hands to eat the inner squares.
But square pizza is the sort you eat with fork and knive tho?
Not necesarilly. I fear we have to face it: This is one of the rare cases where xkcd fucked it up.
Not at all, they are probably talking about horrible Dayton Style pizza. For when you want pizza but it needs to be thin, unsatisfying, greasy, and difficult to eat.
https://en.wikipedia.org/wiki/Dayton-style_pizza
Fucking heathens, if it weren’t for them keeping keeping the alien technology from area 51 at Wright Patterson AFB I’d have them wiped off the map.
This is the superior thin crust style of pizza. Cut in squares, which is a totally fine and legitimate thing to do.
Do people actually eat this?
https://upload.wikimedia.org/wikipedia/commons/0/04/Marion%27s_Supreme.JPG
People who eat Dayton-style pizza are like the city of Dayton itself—smelly inside and bereft of true purpose. Those of us in the US who haven’t been so psychically damaged wouldn’t eat that shit.
(I’m only just learning about the disgusting gutter pizza. I don’t like Dayton because my last company was slowly destroyed over several years by a company that was headquartered in Dayton. I associate the city with the asshole who was CEO. Fuck you, Chris! I’ve heard Dayton is, at worst, not great, so take my comment as the joke it is.)
Hard to believe but they do. Note the blackened edges to make it even worse. It isn’t a nice char like you get with Neapolitan, or even the seared cheese you get with a good Detroit or Pan, it’s just burnt.
There are many American pizzas that are great, Chicago deep dish, NY, Detroit, on and on, Dayton style is not one of them.
There is no pizza acceptable to eat with fork and knife.
<Chicago pizza has entered the chat>
That’s a misnamed quiche.
Tomato soup in a bread bowl, with cheese. Not quiche, the filling isn’t egg-based.
It’s delicious. And since the Italians call just about any round bread with toppings pizza (e.g. Bartolomeo Scappi’s pizza was cake with powdered sugar & saffron toppings) it’s pizza. As is New England clam chowder in a bread bowl!
Pizza with zucchini and champignons. Vegetables pizza in short.
Any pizza that requires utensils is not pizza.
This can be solved by using a napkin
(Or just not caring about the problem anyhow)
As a fork-and-knife pizza eater, I have come around to pizza squares.
That said, PIZZA BELONGS IN A TRIANGLE
If the pizza is a square or rectangle (like Detroit deep dish or a flatbread) it is on, but round pizza cut in squares is just bad
The only correct way to cut (not too gigantic) round pizza is into six parts so you get equilateral triangles (well, modulo a curved section) which is ideal for holding.
Home-made pizza rarely if ever is round, though, in which you probably don’t want to go for squares but eyeball some appropriately-sized rectangles.
oh lord that alt text
Pizza is way too right and too high on this graph.
I wonder why solar cars are bad?
It’s way more effective to collect the solar energy from a station to charge batteries than to cary the whole thing around unless your car is a drone on some remote planet
unless your car is a drone on some remote planet
Which is about as ineffective as personal transport gets. And also not a car.
I mean, maybe the muskrat is considering the car to take to Mars with him?
The sun gives you around 1500W per m2. If sun shines at maximum brightness for 24 hours, you get 36kwh per day. That’s enough to fully charge a small EV every day. That’s a spherical chicken estimate.
Bringing this to numbers that exist in the real world, the sun will only give you about 20% of that over the course of the day, and the panels are around 20% efficient. You’ll get more like 1.4kwh per day per m2. You can double or triple that, depending on how much surface area you can cover. An EV can get around 3 miles per kwh, so tripling that number will get you 12 miles. Considering the extra costs involved (both in buying the panels and adding weight), it’s not even worth it as a supplementary source.
Put the solar panels over the parking places and roadways, not on the cars.
The benefits increase as the efficiency of the car increases though, check out Aptera. They say they get 10 miles per kwh, and they have a lot of surface area for panels. Enough that in ideal conditions they say they get 40 miles per day from solar. It is a bit different looking though.
It’s also a three-wheeler, which gets around US safety regulations. It gets registered as a motorcycle or autocycle (depending on how your state handles it). However, it’s still an enclosed metal box. There’s not a lot of good data, but it’s arguably better to be sitting loose on a motorcycle with a helmet and safety gear as opposed to being crushed inside a sardine can.
There’s a certain point of shrinking cars where you have to ask “why not use an e-bike?”, and this is that point.
Cuz you can haul more, camp inside of it with the tent mod, travel further and faster.
They’re planning 250, 400 and 1000 mile versions. I’m also not taking an e-bike on the highway.
I’m not sure you can haul more. Cargo e-bikes can do a lot more than you think.
Ya I saw that cybertruck to cargo bike comparison. I automatically went to the mountain bikes. We don’t have the same cargo bikes the Dutch have but there is a guy around here with a cargo e-trike. I bet it’d be close. But the car can also take a second passenger not in the cargo space.
Well, it has a carbon fiber frame with a crumple zone in the front. They are going to put it through 3rd party safety testing. It won’t be as safe as a big SUV, sure, but I think it will be safer than an ebike. It also protects you from weather and has 35 cubic feet of storage in the back. I think ebikes are great too, but this does have more of the advantages of a car.
They’re not—as long as the PV cells are a supplementary charging solution, in addition to wall charging, to the batteries. You’ll get a bit more range out while driving, especially when the car is a lightweight low drag design and PV cells may be the only thing needed to keep the constant 90 km/h speed in a sunny day. And when not driving the cells might be enough to get the 10…20 km or so commuting range back over your 8-hour workday.
But putting PV cells on a 3 ton electric SUV or pickup truck is stupid, it won’t do jack all due to the inherent inefficiency of such vehicles.
Let’s worry about the inefficiency of SUVs and pickup trucks for transporting one person to work. Compared to that solar panels are a drop in the bucket.
Not enough power. A car is not a 1500 watt appliance.
A car is not a 1500 watt appliance
[Citation needed]
And a micro car wouldn’t be able tohave even a 750 watt panel on it.
The Sinclair C5 had a 250W engine:
https://en.wikipedia.org/wiki/Sinclair_C5Wasn’t really a car, though, rather
a small one-person battery electric recumbent tricycle, technically an “electrically assisted pedal cycle”.
Solar cells of comparable scale don’t provide nearly enough power to propel any kind of useful mass, and their output is only a trickle compared to even the slow-charging current of a classical EV. A solar-powered car would have to save mass everywhere, including safety devices (goodbye, crumple zones), backup propulsion, and batteries. No batteries means that the car would be limited by weather, time of day, and day of the year (winter -> sun at lower angle -> reduced solar cell power). Solar cells would have to be flush with the car’s body lest they turn into sails/wings/airbrakes, which makes tracking the sun for better efficiency impossible. Driving through a city, a wooded area, or inside a tunnel would cast shadows on the car, especially at dawn/dusk.
I could go on.
The energy one can get from a panel the size of a car roof is tiny and not worth the added weight.
Hmm, I had never thought of it…but soup is absolutely a neutral experience. Even a good soup on a cold, winter day is still slightly above neutral, and is improved by non-soup add-ins.
Combo washer dryer are never as good as two decent machines. Empiric fact.
