hyperloopone

I've got this one. I have watched the video, and made copious notes. Thunderf00t is a well known youtube science commentator, best known for debunking religious fundamentalists and understanding the surface-maximization of liquid alkali metals, published in Nature last year.

That aside, both hyperloop videos show a complete reluctance to engage with the real arguments. Sorry, but highlighting some semi-literate comments by your critics does not amount to engaging in a useful discussion. I would like to levitate this video into the sun.

Here are some specific points and rebuttals: -Thunderf00t primarily makes reference to the Hyperloop alpha whitepaper, written by some SpaceX employees in 2013. I saw no evidence of engagement with subsequent press releases by any of the hyperloop companies. In particular, TF doesn't seem to be aware that there is more than one hyperloop company. FYI, we are Hyperloop One, the company that has raised ~$10⁸ and built the world's most powerful linear motor in 5 months. -Thunderf00t talks a good game about aerodynamics, but shows no evidence of even having read the wikipedia article on choked flow, duct flow, the Kantrowitz limit, or knowing any of the other 'first day on the job' level detail for our aero team. -One of Thunderf00t's technical gotchas was 'expansion joints are difficult', despite the fact that hydraulic cylinders exist, most steel rails are thermally pretensioned, and thermal expansion is probably something we thought of already. -Thunderf00t could have easily looked up our people on LinkedIn, checked their google scholar bona fides, whatever, but seemed more keen on a cheap take down than actually engaging with interesting and ongoing engineering challenges. -One symptom of the level of technical effort that went into TF's video is his careless assumption that 1g = 1m/s/s, as though Hyperloop was being built on some tiny moon of Jupiter. As a fellow academic, I was disappointed by TF's lack of intellectual humility in an area in which he is obviously not an expert. One would wonder why TF would put such hastily produced, easily debunked rubbish on his Patreon feed - people actually pay for that!

-Casey

we are always interested in better ways to get good tacos faster. -HD

Ours exists

Giegel

Well.

-IU

Our tubes are constructed out of thick, strong steel and are very difficult to puncture or buckle. We’re designing and constructing the tube and pods explicitly to handle down to 100 Pa of pressure or more (equivalent to air pressure at 200,000 feet above sea level), changes in air pressure, and to safely tolerate small leaks, holes, and even breaches without suffering from a vacuum collapse.

If there was a leak or breach in our tube in an operational system air would leak into the tube. The affected vehicles would slow down due to the additional air pressure, or require a power boost to get them to the next station. The pods will be built to withstand even sudden air pressure changes safely. We will also have the ability to section off parts of the route and re-pressurize sections in the case of a significant emergency. Every pod will have emergency exits if needed, but mostly pods will glide safely to the next portal (station) or egress point in the event of an emergency. Additionally, we are building sensors throughout the system to notify of any leaks or breaches and we would be able to identify and perform maintenance to resolve any leaks quickly.