China's hyperloop maglev train has achieved the fastest speed ever for a train at 623 km/h, as it prepares to test at up to 1,000 km/h in a 60km long hyperloop test tunnel.

Remember when Elon Musk used hyperloop and boring company to build nothing in the US as a way to shut down public transportation efforts?

Pepperidge Farm Remembers

It was kind of genius TBH, since the benefit of that strategy helps Tesla in a roundabout way. He's such an awful human.

Some people are skeptical this technology can ever work, but it appears CASIC's Phase 1 testing in a 2km tunnel has given them the confidence to proceed to Phase 2 testing in a 60km long tunnel.

Chinese railway engineering leads the world so I have a hunch that if any nation can pull this off, then it's China. However, lots of questions remain. A back-of-the-envelope calculation says that to achieve those speeds in the 2km test tunnel deceleration would have been about 3G. That's the same as a rocket at lift-off and not many people's idea of comfort.

The concept and technology isn't the issue. It's just not economically or technically feasible at scale.
- Well... testing is how you figure out how to make it feasible, though.
I got an acceleration of 1.5G for the test, did you forget a factor of 2 or something? Still certainly not an enjoyable experience for passengers, but I assume it would accelerate over a much longer distance if a full track was built.
- I think I'd probably be fine with 1.5Gs as long as the jerk and snap were low.
- Did you also factor in that the train needs to come to a full stop in that 2km as well?

Hyperloop? You mean a vacuum tube train. Hyperloop is Elon Musk’s name for it when he claimed to have invented it over a hundred years after it was proposed.

It's OK to use the name and laugh at his claim to have invented it
To be fair, Socrates envisioned the TV and Jules Verne hypothesized space travel, yet you don't see people giving them credit for inventing those things
- The vactrain proper was invented by Robert H. Goddard as a freshman at Worcester Polytechnic Institute in the United States in 1904. Goddard subsequently refined the idea in a 1906 short story called "The High-Speed Bet" which was summarized and published in a Scientific American editorial in 1909 called "The Limit of Rapid Transit". Esther, his wife, was granted a US patent for the vactrain in 1950, five years after his death.
I feel like I'm going fucking mental.
I was certain for about a year the idea was pneumatic tubes like in a bank but for trains. Which I though maybe, but probably too much friction.
Then it turned into a bog standard vacuum tunnel that was all over youtube and the Internet before Musk. But everyone acts like that was the original idea.
- Pneumatic tubes use a constantly generated vacuum and air pressure to move objects. It would take forever to pump out a tunnel for a single train.

After everything I've seen with tofu-dreg construction like that bridge collapsing this last week, I think I'll pass on riding a nearly supersonic Chinese train.

I think china's level of jank is a pretty broad spectrum. It might be safe, but yeah, fuck that. If that thing fails you'll be able to see that shit from space lol.

For reference, if atmospheric pressure at sea level is about 1 bar, "low vacuum" is between 0.3 and 0.001 bar.

Huh. Insane they actually build that. It's basically impossible to ever make it economical though. Just go slower, build more trains and lower prices. Way more benefit to society.

The US should be having a rail-measuring contest with China, not a hype®loop-measuring one.
- Yeah China is doing real well in that department.
  I mean if we lived in a post-scarcity utopia and build these hyperloops under ground it might be a worthwhile investment. If we had more advanced tech for tunnel digging robots and maybe 3D printing the walls out of the material we take out etc. But if you include the energy for just maintaining the vacuum against small leaks it's probably not better than airplanes. Maybe with some kind of genetically engineered bio-crete that automatically seals small cracks. But even when we'd advanced to that level of tech and automation to make it viable, it would still have to compete with a fleet of ultra cheap vertical take of electric aircraft.
It still takes the technology further, and we learn something from it that may or may not be useful in future.
The idea is to compete with planes because making them climate friendly is a damn hard problem to solve and China has a lot of domestic flights. When you put it in that context, the economic cost makes more sense.

At 1000 km/hr, it'd run out of track in less than four minutes, hope it can stop in time ... Anyway not convinced there's much point in this. China should be building more suburban rail networks to fill the gaps, instead of pouring so much concrete into crazy-wide highways and toll-roads (look on satellite image, you'll see).

sometimes proving stuff with science is still worthwhile though, right?
- Except the concept is already "proven" in that regard. What the issues are with it, are the same as with everything techy that needs to make it in the world - scaling it up.
  It's impossible to hold a vacuum in a tube that's hundreds of kilometers long. It is impossible to build a vacuum tube that doesn't suffer because of thermal expansion. It is impossible to build that long of a tube and it not have a single dent in it across the entire way. Even if you somehow ignore physics, people don't need a train like this. There is flights. Travelling at reasonable speed has been proven for hundreds of years.
  To explain it in a tldr way, I can grab a straw, put a wet tissue inside it, blow on it and in relative speeds it would go incredibly fast. Yet nobody would go for trying that with a train, since scaling it is impossible.