As I suspect most of my readers know, Elon Musk unveiled a proposal yesterday for the “Hyperloop”, a new concept for high-speed transportation. The response shows how easily ignorance takes on the color of knowledge. (See updates below for more of this.)
For example, the top Google hit for “Hyperloop” at the moment is a BBC news article, “Is Elon Musk’s Hyperloop just a pipe dream?”, and the article offers the world the opinions of a seemingly knowledgeable critic:
This is by no means a new idea,” says Rod Muttram, formerly of Bombardier Transportation and Railtrack…It [sic] has been previously suggested as a possible transatlantic transport system. The only novel feature I see is the proposal to put the tubes above existing roads.
Rubbish. The Hyperloop is very much a new idea, but Mr. Muttram hasn’t bothered to skim the proposal [pdf, >50 pages] before telling us the features he claims to sees in it.
And here is the evidence:
From personal experience of high-vacuum systems,” says Mr Muttram, “maintaining a high vacuum…. [is difficult]
Elon Musk, however, cites this difficulty as one reason why the Hyperloop does not employ high vacuum. Indeed, the vehicles glide on air bearings in a low pressure — but not evacuated — tube. Even the slightest effort to understand the idea trashes the idea that high vacuum has anything to do with it.
The other criticisms on the BBC article are mostly generic: Lots of ideas don’t work out, costs can be higher than expected, and things take time. These are truisms worth keeping in mind, but one should also keep in mind that Elon Musk is a remarkably creative engineer with a track record of developing demonstrably practical concepts — witness the success of both Tesla Motors and SpaceX.
I don’t expect to see a Hyperloop, but at the moment, only for the most generic of reasons. The concept itself is sweet and worth taking further, as it will be — Musk has open-sourced the engineering.
Update, 14 August: In the Atlantic (Pneumatic Tubes: A Brief History) we read that “Elon Musk is not the first inventor to put his hopes into vacuums. Respect to the Hyperloop, but pneumatic tubes have a centuries-long history…”. There’s one problem: The hyperloop is not a pneumatic tube technology, because the air doesn’t push the vehicle.
A bunch of work went into elaborating the facts in the Atlantic article, but not enough work to check whether the facts have anything to do with the proposal.
— It’s an old idea and requires high vacuum!
— No, it’s an old idea and works by air pressure!
But hey, criticism is criticism, regardless of its relevance… Why am I reminded of chatter about swarms of dancing, atom-juggling nanobots?
Update #2, 14 August: The Telegraph (The Hyperloop: flawed fantasy or achievable challenge) finds an expert who (without quoting numbers) speculates that rocket engine designer Elon Musk may have bungled calculations involving air compressors and heat exchangers (“All that air compression creates an enormous amount of heat, which can damage the pod and its machinery”).
Nonetheless, this article is, on the whole, of much better quality than two mentioned above: It is, for example, a critical review of the actual proposal, and cites genuine engineering and economic challenges.
And an editorial in the New Scientist: Breathing new life into the pneumatic dream.
Scanning a bunch of other articles: Most are not too bad — they are predominantly reality based.