As all engines are. A Trent 1000 engine (e.g. on the dreamliner) is about 20 million dollar and a lot in maintenance.

Most long haul flights I've been on the past years basically had the windows closed for most of the flight anyway. And in a 10 abreast most people don't have window access right now. However, there are also solutions for that, like fake windows with screens or ceiling windows that let in some sunlight.

> Most of your passengers wind up in the middle of the plane, far from any windows

As they do now, but now we have personal inflight entertainment and on long haul you often got the shades closed almost all flight so not that big of a deal any more.

I agree that there are also challenges, but I wouldn't assume in 50 years planes will look the same

Again, distances. Easy to electrify a large and heavily used part of the network in Germany or France and then use diesel on the lesser used lines where it doesn't make sense to build the infrastructure. Of course you will then operate a mix of diesel, electric, or hybrid.

If you have distances like in Canada it's not easy to electrify a decent percentage of your rail network and then it makes more sense to just stick primarily to diesel.

yes, but if you burn normal fuel you'll also create a lot of water.

Rolls Royce is one of the most successful engineering companies there is. They are building aircraft engines for over 100 years now. If you are on a long haul flight on a wide body airplane, the chances are about 1 in 3 the plane uses Rolls Royce engines.

I mean beryllium would be slightly better, but everything is worse than hydrogen. Hydrogen has the highest (useable) electron to weight ratio.

Distances in Canada are much longer, and once most of it runs on diesel there's not really a point to electrifying small parts of it since all the equipment is not made for it anyway.

> commercial aircraft store most of their fuel in the wing structure.

I wouldn't expect planes to look like they do now. There are a lot of different concepts of planes, look at Airbus Maveric. That blended design would create a lot of volume that can be used.