You pay for someone (another rail company operating at that railyard) to move it for you into storage, where you pay the storage costs. If you need that railcar somewhere else, you pay someone to transport it somewhere else, same as how cargo rail would work.

Amtrak doesn’t actually own most of the rails, and pays the rail owners like CSX for access to those routes.

the admittedly gross food car.

Is it gross to other people? Seems like an ordinary bare bones cafe to me: a few snacks, including some basic hot food, coffee/tea/soft drinks, beer, wine.

Boom Supersonic is a private company working on it, with an eye towards better fuel efficiency than the Concorde. They’re still in the early stages, though, so who knows if they’ll actually be able to finish a design, much less manufacture a working model.

And NASA has been doing some research on sonic boom characteristics, to see if a plane can be designed to fly faster than the speed of sound without causing a sonic boom.

That’s one of my pet peeves, when people use relative comparisons to overstate things that have very small absolute differences.

55g of CO2 is basically nothing. A gallon of gasoline represents about 2400g of CO2 emissions when burned. So for a typical vehicle that gets 30 miles per gallon, 55g of CO2 is basically the equivalent of driving 0.6875 miles (1.1km).

It’s less than the carbon footprint of a cup of coffee (60g).

Or, alternatively, eating a single quarter pound hamburger would be about 3 kg of CO2, or 55 hours of video viewing at this rate.