13 ms·
Hyperloop: Not so fast
- skj 13y agoDespite the headline, which I'm going to assume was added by an editor, the article is positive about the hyperloop prospects.
- jasallen 13y agoIt's a pun, not actually a 'negative' headline.
- JTon 13y agoTo me, it's read as both a pun and a negative headline. I'm surprised others don't see it that way as well
- protomyth 13y ago"not so fast" is generally a nice way of telling someone to stop and consider what they are doing because they are about to do something unwise. I do believe you are correct to take the headline as negative.
- diydsp 13y agoIt's purposeful ambiguity to create drama, elicit an emotional reaction, creating a slightly tenser situation in the brain, and hence divert resources from baseline functioning to a heightened start of awareness. So, we react to the fear, find there's nothing to worry about and move on. Ultimately, though, gathering attention this way is counterproductive because it inhibits the brain from taking in new information. If we were invited to collaborate in the thought in a more relaxed matter, there would be fewer "stress-clicks" and more worthwhile, creative contributions. The main purpose of the article is of course to promote the product of his organization through making a community contribution, so what do I expect. Maybe I'm just in a more serious mood on this day. We should be grateful to this person for pointing out this info to us :)
- pbreit 13y agoThat's what I thought initially but I don't think it was meant to be that negative but more reflective of the content of the post which had to do specifically with how fast the hyperloop could go in certain areas.
- dangerlibrary 13y agoArticle assumes that the hyperloop can/would follow existing highways. Considering the cost of diverting traffic during construction, it seems unlikely you could build it for anything close to the advertised $6 billion while following existing highways. Also, the structure would need to be tall (or short) enough to bypass highway bridges and overpasses...
- sargun 13y agoThe Hyperloop design paper states that it would be along existing highways.
- dangerlibrary 13y agoI missed that! Thank you.
- dasil003 13y agoDid you change your original comment because this thread makes no sense.
- dangerlibrary 13y agoI did not change anything. I was nitpicking about something implied in the linked article, without realizing it was in Musk's original spec/budget.
- blackjack48 13y agoThe paper also included a map that showed the route running between Hayward and Burbank, not city centers. That may be how Musk proposes to solve the curve radius problem.
- cju 13y agoAnother article of the blog is about the modelisation of the Hyperloop vehicule (+environment): http://blogs.mathworks.com/seth/2013/11/07/hyperloop-model-architecture-we-want-your-feedback/ http://blogs.mathworks.com/seth/2013/11/07/hyperloop-model-a... It can be read as an introduction to Model Based Design. It shows for instance the interest of handling variants to test either different hardware concepts or different level of representativity.
- kinofcain 13y agoPassengers are much more sensitive to vertical acceleration than horizontal. Repeated 1g swings from -0.5 to 0.5 g would make this thing a vomit comet. Would be interesting to see this analysis done with normal limits for high speed rail design, instead of Elon's chosen 0.5g limit. Edit: HS2 in Britain, for instance, is being designed with a maximum of around 0.01g vertical acceleration. If Elon's has figured out how to get passengers to handle 50x that much, he could save them a lot of money.
- morsch 13y agoVertical acceleration refers to acceleration in the direction of the tracks, right? Some other figures I could find: Shinkansen: 2.6 km/h/s = 0.07g ICE (German HSR): 0.5 m/s2 = 0.05g S-Bahn (metro transport): 1 m/s2 = 0.1g Makes sense that metro transport has higher acceleration, as high speed rail spends a lot of time "cruising" at certain speeds, while metro transport is basically always either accelerating or decelerating. I'd guess subways also feature relatively high g-forces. Also interesting: http://en.wikipedia.org/wiki/Orders_of_magnitude_%28acceleration%29 http://en.wikipedia.org/wiki/Orders_of_magnitude_%28accelera...
- melling 13y agoMaybe someone can convince China to develop the technology. They already have 6,200 miles of high-speed rail, on their way to 10,000 miles. http://en.wikipedia.org/wiki/High-speed_rail_in_China http://en.wikipedia.org/wiki/High-speed_rail_in_China Their Shanghai Maglev only cost $1.2 billion. http://en.wikipedia.org/wiki/Shanghai_Maglev_Train http://en.wikipedia.org/wiki/Shanghai_Maglev_Train China is clearly interested in building a 21st century transportation infrastructure. Beijing to Shangai is 800 miles. Perfect for 700 mph hyperloop.
- us0r 13y agoShanghai does not have the prevailing wages CA has.
- stcredzero 13y agoIt might be worth their while to fund the development just as PR.
- melling 13y agoI'm not sure why that matters in this discussion. If China can build a hyperloop then the technology is proven. The United States can then follow.
- illumen 13y agoShanghai is extremely wealthy... even if you don't account for the accounting tricks played by china with their currency. Have you ever been? It's like being transported into the future. Apparently 20-30% cheaper than places in CA for most things, but to buy an apartment it's more expensive. Wages are 75% or so cheaper in Shanghai, but purchasing power is 66.36% lower too... http://www.numbeo.com/cost-of-living/compare_cities.jsp?country1=United+States&country2=China&city1=Oakland%2C+CA&city2=Shanghai http://www.numbeo.com/cost-of-living/compare_cities.jsp?coun...
- throwaway_yy2Di 13y ago"Shanghai is extremely wealthy..." Seriously? The mean household income is US$4,700/year [0] (nominal conversion). Your link claims it's $12,000/year for an individual, but if you investigate further, that's the mean of the high-income expats who visited that English-language website about international costs of living and filled out a survey. The very existence of this large expat population skews the mean; I'd guess "typical", median wages are a lot lower than $4,700. [0] "Average annual income for a family in 2012 was 13,000 renminbi, or about $2,100. When broken down by geography, the survey results showed that the average amount in Shanghai, a huge coastal city, was just over 29,000 renminbi, or $4,700, while the average in Gansu Province, far from the coast in northwest China, was 11,400 renminbi, or just under $2,000. Average family income in urban areas was about $2,600, while it was $1,600 in rural areas." http://www.nytimes.com/2013/07/20/world/asia/survey-in-china-shows-wide-income-gap.html http://www.nytimes.com/2013/07/20/world/asia/survey-in-china...
- mrfusion 13y agoPersonally I'm still worried about the claustrophobia issues. And I'm not even really claustrophobic. There's just something about being in a small seat in a concrete tube with no exit for 100's of miles that really freaks me out.
- FatalLogic 13y agoPerhaps good design can help deal with some of that fear? Most people can handle being in elevators OK, despite being in claustrophobic box full of people, hanging on a cable, inside a vertical tunnel. They just don't think about where they are.
- aestra 13y agoI'm claustrophobic. Elevators are fine, they are plenty big enough. MRIs are not. There are different levels of claustrophobia though, some people need to sit next to an exit in a room, for example, and not in the back for easy escape.
- athanasius 13y agoI didn't realize I might be more than very slightly claustrophobic until I had an MRI recently. I wonder if there might be a greater incidence than most people consider.
- aestra 13y agoAnywhere between 4–20% of patients refuse to go through with the MRI due to claustrophobia. Sources in http://en.wikipedia.org/wiki/Claustrophobia http://en.wikipedia.org/wiki/Claustrophobia
- derekp7 13y agoWhen you are entering it in the station, you have a lot of open space until the hatch closes. So what about instead of having windows, make them 3D holographic displays that look like you are peering out an airplane window? There is still the mental knowledge that your are in a tube (like a subway tube) but it might be enough to fool your subconscious.
- jcchin41 13y agoNASA engineers have also released an optimization framework for the Hyperloop concept as well. It's completely open-source and written in Python. Docs here: http://openmdao-plugins.github.io/Hyperloop/ http://openmdao-plugins.github.io/Hyperloop/ Their baseline optimization focuses on 5 subsystems: Compressor Cycle Analysis, Pod Geometry, Tube Flow Limitations, Tube Wall Temperature, and Mission Analysis Initial results indicate that the concept is still very viable. However, due to very tight coupling between the tube and vehicle size, the tube size will need to be around twice as large as originally proposed by the Tesla/SpaceX team to reach the proposed speeds. Feel free to download the entire analysis and play with it yourself, without purchasing several expensive toolboxes from MATLAB!
- justingray 13y agoAs one of the authors of this work, I would like to add that our goal was to provide an open source foundation for modeling the hyperloop system. Our initial work focused on the pod itself, but we want to expand it to include trajectory analysis as well as cost modeling.
- codereflection 13y agoThank you for making your work open source too.
- omegant 13y agoHi Justin, do you have an email to reach you or some body else at the team?
- justingray 13y agoyou can reach me at justin.s.gray@nasa.gov
- acadien 13y agoComparing redundant independent simulations is the next best thing to actual experiments regardless of your politics on the Matlab business. Thanks for the link, its new to me.
- bane 13y agoI remember hearing an interview with a civil engineer about why highways have all these "unnecessary" curves in them. Why can't engineers build highways that are more direct and straight? After going on a bit about requirements for different kinds of terrain, the kind of strata the road needs to go on etc. and how those were difficult and expensive to surmount (so curves were often chosen to deal with it instead of a more expensive solution). He lamented that the most difficult and expensive aspect of new road construction was right of way through existing developments and other properties. Most of the curves we experience on highways are apparently the result of somebody, or a block of people, simply not wanting to give up their land.
- stephencanon 13y agoHmmm; maybe in some parts of the world. Around here (NH/VT) the curves are pretty obviously imposed by geology (if they didn’t follow narrow valleys, they would constantly be going up and down 1-2k ft ridges, and river valleys are not straight).
- maaku 13y agoThere is the concept of eminent domain which lets the government force-purchase land for this purpose. However it's typically only done in cities or where the geography / geology requires it. Out in California's central valley where it is flat as far as the eye can see, it's sometimes better politically to do a curve to follow edges of property lines than to piss off some big wig ranchers.
- bane 13y agoWell, that's what he was talking about, terrain isn't a problem if you don't mind blasting and clearing things or building lots of tunnels. It's expensive, but it's technologically possible.
- kalleboo 13y agoAnd this is what Japan does to build high speed rail in a mountainous country where all the land that's possible to grow or build on is already owned. On some Shinkansen routes you spend half your time going in an out of tunnels
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- pbreit 13y agoA fun article and exercise but a bit suspect since the only image of a difficult turn is not one the hyperloop is actually scheduled to take (the design document linked shows the route continuing straight along HWY 238 at that point). But the next turn north along 880 looks tricky (it looks like there might be some room at the school, cemetery and empty lots to smooth it out a bit).
- penrod 13y agoMy only objection to Hyperloop is that it's so damned ugly. What ought to be an inspirational feat of engineering looks, under the proposed pillar design, like an elevated oil pipeline. I can't imagine anyone wanting to look at it, let alone having it blight their property. It's a shame they haven't proposed a graceful cable-stayed structure.
- NAFV_P 13y agoThis reminds me of the Red Bull X1 out of GT5. I remember going round a hairpin at 250km/h, that's bound to snap your neck.