"What a computer is to me is it's the most remarkable tool that we've ever come up with, and it's the equivalent of a bicycle for our minds." — Steve Jobs.
I'm much less optimistic. Even when factoring in the poor thermal efficiency of gas turbines (~30-40%) compared to electric (>90%), the usable specific energy gap remains immense. Jet-A still delivers roughly 14 times more useful work per kilogram than modern batteries. Removing fuel plumbing and tweaking airframes won't overcome that fundamental physics. Also the issue with the high-altitude efficiency argument is that batteries, unlike liquid fuel, don't lose mass during flight meaning the aircraft to haul its maximum takeoff weight from departure to arrival. It's a double whammy.
Well, in this case, we don’t need to argue about theory. The Joby has a tested range of 150 miles. They also tested it with hydrogen fuel cells and got >500.
Right, so when you factor in the legally required reserve flight time the battery powered Joby is only capable of very short hops. And that's fine, it's still potentially useful on a few routes and newer models will improve over time.
This isn’t meant to slot into the role of other planes, though, it’s meant for rideshare. It can take off and land on my suburban lawn. There’s a lot to figure out before we can get to that point, so they’re just displace helicopters for the moment, but it can be a lot more. It’s basically the long awaited flying car, in nascent form.
No, it can't take off and land on your suburban lawn. The wires and trees overhead would make that ridiculously dangerous, a last resort only for emergencies. Plus they need to recharge for the next flight. These e-VTOL aircraft will operate from dedicated pads.
Just talking about what they've talked about as goals in interviews. And I'm surprised you're willing to make definitive statements about my lawn, we have a large enough area with none of those obstructions you're talking about, we live on a few acres. And if it's running 20 miles here and there, it can do a few trips before it needs to go somewhere to charge or battery swap. That would cover our trip to our nearest international airport.
If these e-VTOL aircraft get used for air taxi service at all it's going to be for short hops in denser urban areas. Not in rural areas where people have acres of open land.
Go watch one of JoeBen's interviews. His original inspiration for the company was making something that could make where he grew up in the redwoods of the Santa Cruz mountains more accessible. His stated long term vision is vertiports embedded in communities. In the short term, I agree that they're going to start in denser areas.
Heh it doesn't have to be literally on one's own lawn, it could just be a little helipad per community. And my understanding is that the vast majority of private helipads don't have air traffic control - your hospital's roof doesn't have its own air traffic control. Pilots operate under "see and avoid" rules.
Use your imagination a little. So much status quo bias here.
Who would want to privately own a community helipad? Sounds like an insurance and liability nightmare.
This is an impressive enough achievement, but let's not kid ourselves this is going to revolutionaise suburban or semi-rural transport. Its maximum payload weight (450kg) barely covers 5 passengers with no baggage. It's for hopping from the country club to the golf course.
I don't really have a problem with this - the designs look nice and don't have any of the hallmarks of AI slop. My issue is when the AI generated product is just bad, not merely the fact it was AI generated.
Nice! It would be fun to include some of the other sounds on the tube like the door closing chimes or the sounds the doors make when opening and closing.
That has not been my experience with them at all. I've done nearly quarter of a million miles in various Teslas and never had a serious issue. My service experience with them has also been lightyears ahead of the traditional manufacturers.
Nothing immediately - Teslas have a both a High Voltage system for the traction battery and a Low Voltage system powered by a separate 12-15V battery. The HV system keeps the LV system charged and most critical safety related functions run on the 12V system. The booster, ABS/ESP, airbags, and steering assist are all designed to remain functional long enough for a controlled stop after an HV disconnection.
You obviously wouldn't be able to speed up again, which depending on the situation, would be where the danger lies.
Not only is the majority of an EV the exact same components as an ICE car, but the electric car industry has been using off the shelf components for decades.
Tesla buys plenty of products from them, including things like electric steering assist.
Bosch wants to stay relevant for longer than ICE cars after all, and a lot of these components were developed for ICE cars anyway.
Tesla have done a lot of vertical integration, but for other manufacturers there's a lot of common electronic components. Stuff like headlamps (even if it's a different plastic housing the board will be the same basic design), door locks, infotainment, dashboard displays where there's little reason to significantly reengineer them for an EV.
I don't think it would have to be only electric cars, if you're building a hybrid where the 12V battery is kept charged by the high voltage battery, you've got basically the same situation.
Availability of accessories seems like it would be inconvenient for any early adopters, e.g. you can readily get USB chargers, portable generators, coolers, tire inflators, battery boosters, etc. that run off 12V... if you get a 48V vehicle today, you'd either need a 110V->12V adapter to run accessories, or you'd be limited to 48V RV accessories.
Virtually all electronics need a step down (buck) converters as they run at lower voltages 5, 3.3, 1.8. 12V > 3.3- 1V would a single step. 48V ones would likely require an intermediate step. The only exception would be running some power systems where it'd require less current.
You're going to need the expensive bits of a power supply anyway to meet transient requirements, so it's not much of a savings to run at native voltage and it gives a lot of design freedom/reusability to have one voltage for everything.
The main savings is current though, because the wiring harness is one of the most expensive parts of a car.
The move to 48v is very much about efficiency within the harness backbone. For the same wattage, less amperage is needed in a higher voltage system, meaning the wires can be smaller and they produce less waste heat.
There are a few different topologies for a 48v harness, but somewhere in the line there's a 12V DC/DC converter in there somewhere.
The wiring for 48V can be a lot thinner than it is for 12V. As there is a square law involved for resistive heating it turns out that wiring for 48V can use 1/16th of the weight of copper as that for 12V.
A switchmode converter can be designed for 48V just as easily as 12V.
It's far cheaper and easier to just pluck a readily available 12V power supply off the shelf than it is to design one that will have limited applications outside of a single manufacturer.
Because all of the IC's that are attached to the battery are designed for 12V. Things like solid state relays (BTS7008 for exammple) and the 5/3.3 volt regulators.
Ok? So you've never lived anywhere that isn't relatively central and walkable. Many people do (even in Europe!). I am one of them. And on a night when I am working late being able to order a hot pizza to my front door is a godsend.
So you do understand food delivery. Is it a stretch then to imagine why a service that expands the delivery market from a handful of pizza and chinese restaurants to ~every restaurant in the city (that wants to opt in without hiring its own fleet of drivers) is successful?
Yes. The quality of a delivered pizza is higher than the quality of other delivered foods relative to the quality of getting them for dine in at the restaurant.
I live in NYC and 9 out of 10 meals I have delivered are hot, fresh and show up on a bicycle in about 25 minutes. I know that not the norm, but a good 20-30 million Americans live in areas with an astounding number of fast and diverse delivery options and it should confuse no one as to why people take great advantage of it.
And those same urban-dwellers are far less likely to own a car, and far more likely to have a tiny kitchen.
Reminds me of the fact that for 500 years everyone graduating with a BA from Oxford had to swear that they would never agree to the reconciliation of Henry Symeonis, despite no one having any idea who he was for most of that time.
Yes! I was disappointed to learn when I graduated with my BA that this oath was no longer required. However, I continue refuse to reconcile with Henry Symeonis. It's only been 800 years, you never know when it might be important. After all, the Anglo-Portuguese is still in force 650 years on!
Looks like it was removed in 1827. I don't actually remember having to say anything at any of my graduation ceremonies there (BA, MA, DPhil), just walking on to the stage. I do wonder if at matriculation we all had to make some oath together but I think I would have remembered if that had been the case. I have a strong feeling though I might have had to make an oath when I became a scholar - there was definitely a ceremony we had to go to - but that would have been college-dependent.
You'll have collectively said "do fidem". The rest is read by the official at the table, not the graduands.
The question as to whether this constitutes swearing an oath or making a simple promise was an interesting one for me as Quakers traditionally refuse to do the former.
"i give my trust". i believe that would be a promise or affirmation as it does not invoke a god. Unless it's the accusative of the goddess of faith (unlikely).
I was reading some stories and notes made by my grandfather, they where written sometime in the 1980s. He's recalling stories and people in the area where we lived, out in the country side. Apparently my family has feud with a priest from the late 1700 hundreds. The priest complained that people (my family included) wouldn't travel the 7 - 8 kilometers to the church during the fall and winter. The area is in between would flood and freeze, becoming dangerous to travel. The priests refusal to understand the danger (and long travel time, during the winter), caused the feud, which apparently lasted at least until the 1920s.
Had to look this one up. Apparently the answer is he was a rich *hole who murdered a student, got fined £80 (which might have been a lot of money, but he was rich), stayed away from Oxford a few years and then The Powers That Be told everyone to get over it.
The fine was against multiple men. That makes me speculate the death was part of a drunkin bar fight and the victim was comnected but the King was neutral and only banned him until the King returned. Ahew, what a nest of rabbit holes to follow.
Thanks for that, looked it up and was a interesting rabbit hole:
Basically, that oath was Oxford University saying "fuck you" to a request of the King (1200s England) officially after he effectively tried to order them to break their collective line and accept a rich fuck who murdered a scholar in the past. Feels kinda like a proto-union-action to me
https://blogs.bodleian.ox.ac.uk/archivesandmanuscripts/2023/...
Which reminds me of The Cagots were a persecuted minority who lived in the west of France and northern Spain [0]
The origins of the Cagots remain uncertain . . . . Despite the varied and
often mythical explanations for their origins, the only consistent aspect of
the Cagots was their societal exclusion and the lack of any distinct physical
or cultural traits differentiating them from the general population.
The man cannot be living, ergo there can be no reconciliation, ergo the promise/oath can only exist because nobody bothers to remove it; not because we don’t know the reasons for its existence.
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