grrgyle ,
@grrgyle@slrpnk.net avatar

I want transitions lenses so bad, but the women in my life won't let me 😔

Guest_User ,

Why not? I thought they were pretty popular.

grrgyle ,
@grrgyle@slrpnk.net avatar

I don't know. I think it's because they're practical?

Spur4383 ,

It's because they are not practical. They do not work inside cars, they transition super slow in winter, they are clear when you need sun glasses and dark when you need to see.

captain_aggravated ,
@captain_aggravated@sh.itjust.works avatar

They worked pretty well when I was in high school marching band. I didn't drive yet so I didn't need road vision, they darkened while out at practice and were clear elsewhen. Got an actual pair of prescription sunglasses in flight school though.

BearOfaTime ,

They transition just fine in winter, even down to 10f or lower.

They have a version that works in cars now. But that's an issue with the car windshield blocking UV. So leave a magnetic "clip on" shades in the car. They look exactly like your frames, with them attached you can't tell they just stick on from the front - they look just like your glasses.

Crozekiel ,

Then just use the clip-ons all the time and not pay for mediocre sunglasses? I'm not a fan, I've tried them and hated them. Super slow to go back to clear and unreliable. I don't want my lenses deciding when I need tinted lenses or not when I can just carry around either clip-ons or a complete second pair of prescription sunglasses. IMO Transitions are a bad solution to the problem.

BearOfaTime , (edited )

Because I don't have to carry the sunglasses with me all the time?

98% of my time I'm not in a car, and my not mediocre sunglasses work better than the clipons, since I prefer the color, they already block UV and aren't too dark.

Why should I carry something else?

As it is, I put my glasses on when I wake up, and most days only take them off to clean them or go to bed. They're almost hassle free, unlike carrying around sunglasses, putting them on, taking them off, yada yada , like I did for 10 years before I got transitions.

Why do you carry a smartphone, instead of a laptop, tablet, feature phone, GPS, mobile access point, multiple credit cards, rolodex, checkbook, etc?

It's funny you trying to tell me that I'm wrong to choose what works for me.

Crozekiel ,

Calm down and quit shilling for "big-transitions".

limelight79 ,

Yeah, I've used mine while cycling in freezing temperatures without an issue.

Takumidesh ,

So the scenario is
A) you have transitions that work 90% of the time and a pair of prescription sunglasses for the times they don't
Or
B) you have regular glasses, and still have prescription sunglasses.

Option a means 90% of the time you don't need to carry an additional pair of glasses with you.

I used transition lenses for a decade, they are great.

stebo02 ,
@stebo02@lemmy.dbzer0.com avatar

why is it considered a bad idea?

grrgyle ,
@grrgyle@slrpnk.net avatar

I could never get a straight answer. I think it's fashion.

EncryptKeeper ,

If it’s the women in your life, then yes. They are the epitome of turbo-dork when it comes to eyewear.

grrgyle ,
@grrgyle@slrpnk.net avatar

You know, we're generalising, but you've got a point. None of my male friends have glasses in any kinds of shapes other than "boring grey ovoid."

Obi ,
@Obi@sopuli.xyz avatar

I have to wear them every day with any outfit at any occasion, it sounds silly to choose something flashy.

EncryptKeeper ,

It’s not the shape, it’s just the transitions themselves. Aesthetically, sunglasses have a handful of popular styles. Whatever frames you have for your regular vision correction, most likely aren’t one of those styles.

Spur4383 ,

They work based on UV light. So they will not transition inside cars. They also will not transition in cold weather, so you'll walk in snow with clear glasses and have dark ones for 5 minutes once you go inside.

BearOfaTime ,

Never had them not work in cold. They change even during heavy snowfall when it's well below freezing and well, no sun, heavy clouds. It's great because they help with the glare from snow.

pineapplelover ,

What's wrong with Transitions lenses. I like mine

BearOfaTime , (edited )

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 left right corner. Sounds bad and is bad.

limelight79 ,

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.

dependencyinjection ,

You can get them to work in the car. You just need to break all your windows.

Easy.

limelight79 ,

I prefer to cut the top off.

AdrianTheFrog ,
@AdrianTheFrog@lemmy.world avatar

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.

EncryptKeeper ,

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.

spikespaz ,

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.

Clbull ,

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.

RenBiv ,
@RenBiv@lemmy.ml avatar

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!

pineapplelover ,

They transition very quickly though. Takes like a minute

RenBiv ,
@RenBiv@lemmy.ml avatar

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.

pineapplelover ,

Interesting, yeah, I don't mind them as much I guess. Now I'm considering just getting prescription sunglasses to wear all the time

mightyfoolish ,

If anyone else is also curious on why "putting mold on infections" is more good than crumple zones:

They [molds] also play important roles in biotechnology and food science in the production of various pigments, foods, beverages, antibiotics, pharmaceuticals and enzymes. - Wikipedia

grue ,

My beef with the placement of that item is that it isn't even further down the "actually a good idea" axis. Penicillin -- perhaps the most important medical innovation of the 20^th^ century -- rated less "actually good" than mere laser eye surgery and fecal transplants?! C'mon, Randall!

Wild_Mastic ,

So, about Project Orion from Wikipedia

In August 1955, Ulam co-authored a classified paper proposing the use of nuclear fission bombs, "ejected and detonated at a considerable distance," for propelling a vehicle in outer space.https://en.m.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)

Excuse me what the fuck

ours ,

Read "Footfall" for a hard scifi story featuring such a ship.

Wild_Mastic ,

Will do! Thanks

Crackhappy ,
@Crackhappy@lemmy.world avatar

I like Footfall, but it's also a little over the top for me.

ours ,

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.

Shurimal ,

Not worse than a fusion torch. Or open-cycle nuclear propulsion. Or an antimatter drive.

You know, the Kzinti lesson😉

Wild_Mastic ,

Never heard of those, but if they are on par with project Orion I have some nice readings to do today.

MightBeAlpharius ,

If you're into hard sci-fi and you're looking for a good read, they actually dropped a pretty good recommendation with that reference at the end - Larry Niven does a great job of blending real-world theories like Dyson spheres and advanced propulsion drives, with some of the more far-flung standards of the genre like an intra-planetary teleportation grid.

Cethin ,

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.

Wild_Mastic ,

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.

notabot ,

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.

Promethiel ,
@Promethiel@lemmy.world avatar

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

SonnyVabitch ,

It's not uncommon in scifi. Netflix's Three Body Problem also explores such a solution in quite some depth.

jballs ,
@jballs@sh.itjust.works avatar

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.

SonnyVabitch ,

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.

jballs ,
@jballs@sh.itjust.works avatar

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.

jol ,

Ah the 50s, when everything atomic was rad.

GratefullyGodless ,
@GratefullyGodless@lemmy.world avatar

::Fallout theme starts playing::

TomAwsm ,

"I don't want to set the world on fire...."

frezik ,

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.

Silentiea ,
@Silentiea@lemmy.blahaj.zone avatar

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.

frezik , (edited )

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.

szczuroarturo ,

But then how would you launch nukes on orbit without the risk of accudental nuclear explosion?

frezik ,

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.

MonkderDritte ,

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?

Silentiea ,
@Silentiea@lemmy.blahaj.zone avatar

Don't forget the mass of whatever ablates from your shield!

GBU_28 ,

They spoke to that and found it manageable. The ablation isn't there deal breaker

Badabinski , (edited )

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
  • 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
  • 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!
  • 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.

MonkderDritte ,

I'm more with VASIMIR though, maybe with a nuclear reactor for power, since it's variable.

sagrotan ,
@sagrotan@lemmy.world avatar

Combo washer dryer are never as good as two decent machines. Empiric fact.

angrystego ,

This graph is rather discutable.

Omgboom ,

How dare they put heelies in the bad section

Bread_And_Buried ,

For real, all credibility lost.

Sorgan71 ,

project orion was awsome and the nuclear panic ended it.

witty_username , (edited )

I don't get the diverging diamond interchanges one

Lux ,

Diverging diamond interchanges are a type of road intersection that appears very chaotic from the outside, but are actually pretty simple and safe to navigate

Silentiea ,
@Silentiea@lemmy.blahaj.zone avatar

Significantly safer to navigate in practice than traditional intersections, and very straightforward to navigate, if not quite as easy as a normal intersection you've seen all your life.

waz , (edited )

Never heard of or seen that, but it makes me think of the ‘magic roundabout’ concept

https://feddit.uk/pictrs/image/90fa7c4b-9992-4e09-a447-f52006a0a703.jpeg

https://feddit.uk/pictrs/image/2e2f47f3-9220-4b73-aea9-4736e597eabf.jpeg

eksb ,
@eksb@programming.dev avatar

Diverging diamonds are great if your only consideration is car throughput.

If you are considering people walking or riding bicycles, they are shit.

Lux ,

I hadn't considered that. I was still pretty car-brained when i watched the cgp grey video on them, but now that you mention it, i definitely agree

eksb , (edited )
@eksb@programming.dev avatar

This is expensive to address because you have to separate cyclists out to the right before the right car lane splits for right turns before the crossover. And then you have to build a bridge or tunnel for cyclists and pedestrians. On each side.

Really, any road busy enough to justify a diverging diamond probably already needed separated bike lanes. But in America (motto: "If you aren't in a car, you don't matter"), there almost certainly was not any cycling infrastructure there before.

There is one of these near me. Their solution for pedestrians is to make them cross the high speed outer lanes four times (where drivers are encouraged to not slow down). Their solution for cyclists is take the lane and pray or get off and do what the pedestrians have to do.

Edited for clarity: pedestrians cross four times, not drivers are encouraged to not slow down four times.

Lux ,

where drivers are encouraged to not slow down FOUR times

Wtf, thats insane

eksb ,
@eksb@programming.dev avatar

To be clear, it is four times that pedestrians have to cross, not four times that drivers are encouraged to not slow down. Drivers are not explicitly encouraged to not slow down, but the point of the diverging diamond is to make drivers not have to slow down.

Lux ,

Ohhh, thanks for the clarification 😅

Oinks ,
@Oinks@lemmy.blahaj.zone avatar

It doesn't help that US diverging diamonds seem to insist on having pedestrians walk through the median.

But honestly all interchanges are varying degrees of horrible and if you want your city to be bearable to navigate as a pedestrian/cyclist you just really don't want to do urban highways, or roads above a certain size in general.

stebo02 ,
@stebo02@lemmy.dbzer0.com avatar

https://lemmy.dbzer0.com/pictrs/image/c4994008-cf46-4d04-b89b-794ad8271354.jpeg

Having to stop for a stoplight twice just to go straight? No thx.

Badabinski ,

There are many of these where I live. The lights are usually timed so that you just go straight through without having to stop. They're much better than the traditional intersections that came before.

I will absolutely concede that they're shitty for pedestrians or cyclists, however.

BearOfaTime ,

The ones I've used time the pedestrian lights with the traffic, so it's safer for them. Still tricky for peds going across turn lanes.

Silentiea ,
@Silentiea@lemmy.blahaj.zone avatar

They're usually built over a motorway where there was already two stoplights just to go straight, so ...

yamanii ,
@yamanii@lemmy.world avatar

Every single glasses of mine have had transition lenses, I can't imagine my life without them anymore.

DragonOracleIX ,

Same. Although mine became a lot less useful after becoming a night owl.

Death_Equity ,

I love transitions lenses. I have transitions contacts and they are fantastic.

BearOfaTime ,

Holy cow-had no idea they made those.

Death_Equity ,

They kind of released under the radar because a comedy skit about them came out and gaslighted people into believing they were not a real thing.

I only found them because I went to order contacts and saw the product category.

They aren't as good as sunglasses(but are really awesome) and they don't work much in the car so you will still want sunglasses.

Grandwolf319 ,

Omg, does that mean your “eye color” changes in the sun?

Death_Equity ,

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.

Lizardking27 ,

An extension cord with 2 male ends is useful for powering your home with a generator.

Wizzard ,

Yeah, if you want to electrocute some poor linesman outside.
If you have considered purchasing a generator for emergencies, get the transfer switch installed and be prepared so when you do it, you do it safely.

rekabis ,

I’m hardly an electrician and even I know to have some sort of a cutoff switch that can isolate the home if I want to power it separately.

Lizardking27 ,

Obviously you shut off the main breaker so as not to backfeed. Didn't think anyone would be pedantic enough to make me say it. I wasn't writing out a tutorial.

Point being, there exists a purpose for the allegedly purposeless thing.

De_Narm ,

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.

tiredofsametab ,

For some types of bread, the machine can do it much more uniformly and without crushing. This can be difficult for humans.

onion ,

You can buy your own bread slicer

https://deerbe.com/imgs/a/b/d/g/o/restaurierte_antike_brotschneidemaschine__lauterjung_1940iger_jahre_5_lgw.jpg

Gieselbrecht ,

My appartment is too small for this kind of stuft. Buying sliced bread is fine.

onion ,

Of course

BennyHill ,
@BennyHill@lemmy.ml avatar

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.

MonkderDritte ,

Thanks, i laughed. ^^

leftzero ,

Those aren't good types of bread, though.

Rai ,

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!

tiredofsametab ,

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).

biddy ,

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.

De_Narm ,

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.

deegeese ,
@deegeese@sopuli.xyz avatar

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.

PiratePanPan ,
@PiratePanPan@lemmy.dbzer0.com avatar

I'm sorry, what transplants?

Woovie ,

people with certain medical issues in their bowels can be cured of them by a fecal transplant from someone who is a good donor. It usually means a family member. The purpose is to treat bowel infections. Pretty neat shit.

PrettyFlyForAFatGuy ,

neat shit

Actually i think it's usually pretty diluted

ReeferPirate ,

South park aired an episode about it with a Dune twist.

feedum_sneedson ,

Still the best adaptation.

barsoap ,

It's about the microbiome, lots of critters living in your bowels breaking down stuff for you. Some conditions or treatments (e.g. chemo) can fuck with that severely up to completely obliterate everything so you need a donor to get it started up again.

rekabis ,

Most of your body’s mass does not have a human genome, it represents other living things existing in symbiosis with your body. And your digestive tract is nearly 100% reliant on these microbiota to break down food and provide it to the small intestine. If you don’t have the right mix/balance or you have too many of the wrong species, you can suffer extremely deleterious health effects. If you have none at all, you starve pretty quickly regardless of how much food you eat.

Fun facts:

  1. Almost all of your excrement that isn’t visible remnants of unchewed food are the remains of gut bacteria that died.
  2. Scientists have recently confirmed that your appendix acts as a “safe room” for your good, beneficial gut biome to retreat to when the rest of the intestinal tract is suffering from catastrophic environmental issues or another bug is running rampant and dominating in a destructive manner. Once things calm down, the intestines are re-colonized by good bacteria from the appendix.
raynethackery ,

They demolished that room when I was 5.

hactar42 ,

Wouldn't a fake prank fire extinguisher just be a normal fire extinguisher?

Wiz ,

I wonder why solar cars are bad?

LodeMike ,

Not enough power. A car is not a 1500 watt appliance.

Viking_Hippie ,

A car is not a 1500 watt appliance

[Citation needed]

massive_bereavement ,
@massive_bereavement@kbin.social avatar

The Sinclair C5 had a 250W engine:
https://en.wikipedia.org/wiki/Sinclair_C5

Viking_Hippie ,

Wasn't really a car, though, rather

a small one-person battery electric recumbent tricycle, technically an "electrically assisted pedal cycle".

LodeMike , (edited )

And a micro car wouldn't be able to have even a 750 watt panel on it.

ours ,

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

Viking_Hippie ,

unless your car is a drone on some remote planet

Which is about as ineffective as personal transport gets. And also not a car.

Silentiea ,
@Silentiea@lemmy.blahaj.zone avatar

I mean, maybe the muskrat is considering the car to take to Mars with him?

Viking_Hippie ,

Should have strapped him into the Tesla he stuck on one of his penis compensators rockets when we had the chance..

Shurimal ,

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.

biddy ,

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.

rtxn ,

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.

frezik ,

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.

There's some possibilities for RVs, which have a lot of roof space for panels, tend to sit in one spot for days or weeks, and have other power usages that are a lot less than driving. Otherwise, put the solar panels over the parking places and roadways, not on the cars.

jmiller ,

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.

https://aptera.us

frezik ,

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.

Fenrisulfir ,

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.

frezik ,

I'm not sure you can haul more. Cargo e-bikes can do a lot more than you think.

Fenrisulfir ,

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.

jmiller ,

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.

frezik ,

You know how the Internet made fun of Stockton Rush for using carbon fiber in a sub, which is a compression structure? Similar thing going on here. Carbon fiber is a great material for tensile strength and lightweight. It can be used in compression structures, but it needs more careful engineering to pull it off. The benefits do not always outweigh the costs.

As a more general issue, if a car the size of a Geo Metro or smaller can't be safe on roads, then motorcycles and bikes can't be, either.

jmiller ,

Well, I just said carbon fiber, but to be more exact it is forged carbon SMC, so yeah, careful engineering involved. Same stuff Lamborghini is using for some structural components, so probably fairly fit to purpose.

https://en.m.wikipedia.org/wiki/Forged_composite

zeekaran ,

The energy one can get from a panel the size of a car roof is tiny and not worth the added weight.

daltotron ,

They're not. If you make your car light enough, and potentially aerodynamic enough (things which should already be done to electric cars/cars in general), it makes sense, especially for the real life practical application of people who don't have outlets they can run to their car. Aerodynamics is mostly just an efficiency increase, but decreasing weight gives a myriad of benefits, potentially including increased power to weight ratio, decreased road wear, decreased road noise at speed, increased efficiency, improved crash safety as a result of decreasing the total amount of weight you have to stop, which can actually improve the efficiency of the interior space as you can now make things like roof pillars less thick. Could also lead to increased parking space, better maneuverability, and better visibility, if you make the car itself smaller as a result of decreased weight.

Cars should be like1/3rd of their current size. Clown cars ftw.

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