It's true that energy density of batteries is a lot lower than gasoline, but electric motors are a lot more efficient. It doesn't make up the whole difference, but it does make up some of it. Also, battery technology is improving pretty rapidly.
Electric aviation is not yet viable commercially, but it will be soon. I'm working at a company building electric aircraft, and one of our prototypes has done a flight of more than 380 miles. Note that this is a prototype, in ideal conditions, with a tailwind, last few miles were circling the airport within the glide cone, etc. The actual production vehicle range, with all of the safety margins, seats for passengers, passenger weight, etc, will be a lot less; but still, 150 miles is enough for many commercially viable trips, especially in dense areas like the BosWash corridor, or getting from suburbs to a long haul airport, or many others.
Electrification can also make viable new architectures, like VTOL, and the extra efficiency and longer maintenance intervals can drastically drive down operating costs; so there will be many trips that are economically viable in an eVTOL that wouldn't be in conventional airplanes (due to needing an airport) or helicopter (due to high fuel and maintenance costs).
Beta ALIA-250, an eVTOL, and CX300, a conventional takeoff and landing aircraft that's basically the ALIA 250 with the lift motors and supporting structure deleted to get through certification sooner, and serve a few markets that don't need VTOL.
We're a little bit quieter than some of the other players, as we're still a private company and are focusing more on engineering than marketing right now.
edit: Oh, hey, just checked your profile and I guess your firm is one of our investors, so I guess you already know about us.
I'm a big proponent of EVs, I drive an EV car and work on EV aircraft, but they aren't yet ready to replace every segment of the market.
Electric motorcycles are only just becoming viable, and are a lot more limiting compared to electric cars.
And an ICE motorcycle can be a lot more fuel efficient, and is also lower carbon impact to manufacture, and takes up less space on the street and to park. For a single occupancy vehicle, an ICE motorcycle is a lot cooler than an ICE car; and depending on the use, could even be better than an EV car.
I am hopeful that within about 5-10 years, battery technology and prices will improve to the point that electric motorcycles actually become viable. But for now, buying a gas sipping Honda Monkey and commuting to work on it could be a big step up over a car.
Growing crops for biofuel is more land intensive, and thus involves cutting down more forest and removing carbon sinks, than the equivalent solar power.
Yes, bioruels are better than fossil fuels, but worse than clean electricity.
Anyhow, it's not an either/or. ICE vehicles will be with us for a while, so it's better to use more efficient ones, but we also need to be replacing as many as possible with electric.
Biofuels are better than fossil fuels, but most ICE engines run on gasoline, and can't run on 100% biofuels efficiently and cleanly.
I wasn't referring to biofuels. I was referring to pure synthetics like in the HN link I provided. Those require no crop land. Essentially conversion of solar energy into chemical batteries. ICE is treated as equivalent to fossil fuel because that's our main current method of producing the fuel, but it's just a really reliable, high energy density, chemical "battery". What matters is finding clean ways to replace that. Or other options. Aluminium/Air say...
Also, if it turns out biofuels is the answer (and IMO synthetic fuel production seems way more efficient in the long run), there are ways to reduce the externalities. Using land that wouldn't be used for crops, growing the plants or algae without use of fossil fuels. And of course if you're going for externalities, most forms of green energy have them too...
Ah, sorry, I'd missed that you were discussing completely synthetic fuels. Yeah, those are a possibility, but a lot further out; those are not going to be showing up in production quantities in the next 5-10 years. And an ICE engine is already way less energy efficient than an electric motor, it's hard to imagine that the entire cycle of synthetic fuel production to useful energy at the vehicle could ever compete on efficiency with current green energy production and battery electric vehicles.
These kinds of solutions are useful to do research and development on for cases where we're not sure if battery electric vehicles will ever have a path to replace, like long haul aviation.
But for surface transport, it's really hard to see much being competitive with battery electric vehicles; they are already commercially viable, and can be powered with 100% green energy, and green energy prices are already lower than fossil fuel. My EV is charged with 100% carbon neutral power when I charge at home or work. Sure, the mix of sources varies across the grid, but given how cost effective renewable energy is, and incentives, the share of renewables is growing fast.
The infrastructure and production capacity are rapidly developing. And while energy density and specific energy of batteries are a bit limiting now, there are a lot of developments that are nearly ready for mass production that will get rid of many of the remaining limitations of battery electric vehicles for all but the most demanding of applications (like long haul air transport).
I think you might be surprised by how fast ICE vehicles become obsolete for all but niche use cases. As infrastructure develops, production ramps up, and battery technology improves, it won't be long before EVs start to outsell ICE vehicles. EVs already outsell ICE vehicles in Norway, in China they're at about 25% of new car sales, and worldwide they're at about 12% of new car sales; and these numbers are growing rapidly, they may already be out of date by now. Once they are outselling ICE vehicles, it will only be about a decade before EVs are the majority on the road.
I would find it hard to imagine a way in which synthetic fuel would ramp up to production readiness and be cost-effective in the same kind of time scale.
You could be right. Right now we're having still a hard time with the densities. Which is why I brought up aluminium/air. You did bring up air as a situation where ICE would still be needed.
In any case none of what you brought up above contradicts my general point that ICE does not automatically mean evil.
Don't forget walking, bicycles, e-bikes, electric motorcycles, working from home, buses, etc.
Yes, we are behind schedule, and we can't get there just by replacing ICE cars one for one with electric cars, but there is plenty more we can do.
Living in walkable neighborhoods. Demanding better infrastructure for more than just cars. Working from home if you have a desk job.
And of course personal transport is only part of it. Electricity generation. Industrial precesses like steelmaking, and concrete will need to go carbon neutral as well.
Electric cars will be part of it, though. Those infrastructure changes won't happen overnight, we need all possible options at our disposal, it's not either/or, it's "yes, and."
From my narrow viewpoint in the US mountain west I think the future will look like increase in all those green technologies you mention alongside a legacy of ICE vehicles still in use. There are numerous reasons, some more valid than others, that will stop people transitioning away from ICE. So we'll need tech to counteract that effect. A complete transition to EV is naively optimistic in my opinion.
JWTs are the poster child of fragile signature design. If something is like JWTs, you should reconsider. Many implementations allowed JWTs with a null signature scheme, completely bypassing any security!
The assertion was that allowing signatures for sub-parts of the information is extremely fragile. Your example of null signatures being allowed would equally affect sub-part signing and whole document signing, so doesn't really show that sub-part signing is a problem.
It’s also difficult to actually get people on board with the idea of supplying a user-specific signing key instead of relying on a global one.
Instead they’ll end up persisted in a data store, making them stateful, because there’s no reliable way to invalidate such a token simply by rotating the signing key. Or using a cookie-backed session.
And it sucked. The drivers could never find where I was, or wanted to go. It took a lot longer for them to arrive when they could find me. I had to carry cash, because half of them claimed their credit card readers were broken.
There are problems with Uber and Lyft, but they were both such a huge improvement over traditional cabs that it's not surprising that they quickly became popular.
Their app was the only differentiator. My local Scottish towns taxi company has an app that is feature complete for everything needed (granular location on me and driver, call through to driver or visa-versa, auto payment, specify private or business (auto generate receipt if business) etc etc.
That doesn't and has never required a multi $billion wedge driven into gap in the market.
The whole idea that it needed a single monolith to spark change was a nonsense.
So, as someone learning to fly, I can say that the METAR format is actually pretty quick to learn and the standardization does make it pretty quick to read, effectively acting as a shorthand. I'm not going to say it couldn't be improved, but it's standardized enough, and contains information that's immediately relevant to everything you're doing, so it's something you pick up quick.
The same is not really true of the NOTAMs, at least as far as I can tell. They're much less standardized, being mostly just plain text with weird awkward abbreviations and all caps that make them slower to scan. There's all kinds of mostly irrelevant metadata; and a lot of the time there are so many of them, most of them not really relevant, that it's really easy to lose track of what is important.
So, I don't think there's much pressing reason to change the METAR format, but oh god do they need to reform the NOTAM system, both the format and better filtering for actual relevance.
Note that this is coming from a student pilot, but I've also seen more experienced pilots express similar frustration with NOTAMs.
Electric aviation is not yet viable commercially, but it will be soon. I'm working at a company building electric aircraft, and one of our prototypes has done a flight of more than 380 miles. Note that this is a prototype, in ideal conditions, with a tailwind, last few miles were circling the airport within the glide cone, etc. The actual production vehicle range, with all of the safety margins, seats for passengers, passenger weight, etc, will be a lot less; but still, 150 miles is enough for many commercially viable trips, especially in dense areas like the BosWash corridor, or getting from suburbs to a long haul airport, or many others.
Electrification can also make viable new architectures, like VTOL, and the extra efficiency and longer maintenance intervals can drastically drive down operating costs; so there will be many trips that are economically viable in an eVTOL that wouldn't be in conventional airplanes (due to needing an airport) or helicopter (due to high fuel and maintenance costs).