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I dunno, after watching thunderf00t's video on hyperloops, I'm pretty convinced that there are fundamental engineering barriers that would have doomed the company anyway.

If not internal squabbles and lawsuits, the practical laws of nature would eventually have to be reckoned with (just like with Solar Freakin Roadways)




Thunderf00t's objections are mostly based on misunderstandings of fluid dynamics and the hyperloop design. It's almost impressive -- he's singlehandedly founded a whole raft of hyperloop engineering myths with one "controversial" video.

There would be no sonic "shock wave" killing everyone in the tube in the event of a breach. Viscous drag on the tube walls would reduce the flow velocity to highway speed in only a couple km. The wave front spreads out, becoming a gradual pressure rise.

The entire tube would be designed for rapid repressurization (under 60 seconds). The cars can easily stop in 15-20 seconds since the passengers are strapped in and possibly in seats facing backward to arrest braking forces.

Expansion joints are easily accommodated at the end stations, and the slight leaks from the sliding interfaces are compensated by mechanical pumps (easy to maintain 1/1000th of an atmosphere, damn near impossible to maintain 1/1000000 of an atmosphere for true vac trains given the linear decrease in vacuum pumping mass flow at low pressures and the need for turbomolucular pumps and/or cryopumps at those pressures).

There's a great need for pumping near the end stations anyway due to residual air entering around the pod in the airlock. They'll pump down the majority of the pressure of course, but due to the exponential drop in pumping speed over time it makes little sense to make passengers wait a long time and pump it down to the exact same pressure when they can cut it off early and just let the tube pumps make it up. Even on the space station (where air is very expensive) they only pump the airlock down part-way and vent the remaining residual atmosphere so the astronauts (whose time is also expensive) don't have to wait.


What convinced that it would not work was reading about the temperature pressure differences the on car motor was supposed to handle. It sounds like there needs to be a giant air compressor strapped to the car. Having been in a garage when an air compressor turns on (unpleasant), I really don't want to be in a tiny metal tube with a giant air compressor on all the time. It sounds several times worse then being in an airplane.


The compressor in your garage is almost certainly a reciprocating compressor (oscillating motion = very loud), while the hyperloop uses an axial compressor (pure rotary motion = much quieter).

The same sound absorbing layers and vibration isolation technology that's used on jet planes could also be used if needed.


Maybe it's just me but I'm more tempted to trust engineers who's day-to-day job is engineering rather then a Youtuber who replaces vowels with letters.

But strawman/direct attacks aside.

In my experience when one engineer is disagreeing with a team of engineers, they're wrong or the team a fundamental misunderstanding of the problem they're working to solve.


Thunderf00t isn't just some average Joe on the street. The guy has a PhD in chemistry and has dedicated a decade to educate the world at large about matters of science and intellectualism. The world would be a better place if we had more Thunderf00ts on YouTube.

His videos on the hyperloop are pretty comprehensive and succinct about their reasoning. Why not watch them instead of mindlessly repeating the same strawman argument that every other Elon Musk fanboy/fangirl left on his videos?

https://www.youtube.com/watch?v=DDwe2M-LDZQ https://www.youtube.com/watch?v=RNFesa01llk


How does a PhD in chemistry make you an expert in mechanical engineering and fluid dynamics?


"Expert" is a vague term, but the parent didn't claim that it did. Do you think that one needs to be an 'expert' (whatever that means) in mechanical engineering and fluid dynamics to make meaningful criticism of a project like this?


Yes. (for technical criticism)


I hope you don't take that to such an extreme as to think that every line item of criticism in which Thunderf00t applied general science principles to the hyperloop paper under discussion is invalid due to a lack of sufficient technical expertise.

Right? Surely Thunderf00t is qualified to make some of the criticism he made?

I would agree that there are likely a few areas in which his criticism exceeded his understanding, though I have yet to read a criticism of his criticism that doesn't mis-represent his claims.

I still don't see the specific relevance of mdorazio's comment to computerex's.


At this depth of the thread we're not discussing whether Thunderf00t is correct in his analysis. Computerex claimed that Thunderf00t wasn't "just some average Joe on the street." His background in chemistry was brought up to show that he has special standing. Mdorazio countered that from the perspective of mechanical engineering and fluid dynamics, he is in fact an average Joe on the street.

Doesn't mean he's wrong, just means he doesn't have special standing.


In my opinion, valarauca's comment is the correct place to start looking at the context, here. V. started the conversation in a way that could easily be construed as an effort to discredit Thunderf00t.

To me, Computerex seems to simply be saying "Thunderf00t has sufficient general knowledge of science to make his debunking videos worthy of watching".

You mention 'special standing', which suggests an 'all or nothing' approach to categorizing people's status and knowledge, rather than a more reality-accommodating recognition that expertise and knowledge are a matters of degree.

Mdorazio did not state what you say they did, they instead asked a leading question in which words were placed in another person's mouth. Further, Mdorazio would be incorrect to state that "from the perspective of mechanical engineering and fluid dynamics, he is in fact an average Joe on the street." because the average Joe on the street, relatively speaking, is not as equipped as Thunderf00t to understand issues of mechanical engineering and fluid dynamics. I'm not saying that Thunderf00t is or is not properly equipped to make each criticism, just pointing out the problem with 'all or nothing' style thinking here.

You would be right to question whether Thunderf00t has sufficiently advanced and detailed knowledge to make each and every one of the criticisms that he makes, but this would depend on the specific criticism and the specifics of Thunderf00ts knowledge.

As it happens, not even having a PhD in fluid mechanics would guarantee that the critic has the relevant knowledge, nor is thinking through the problem correctly.


Read schiffern's comment. I know nothing about engineering so I can't tell if what he's saying is correct or not – but that's the point, isn't it?


> I'm more tempted to trust engineers who's day-to-day job is engineering rather then a Youtuber who ...

Even if those engineers clearly have a financial incentive to make biased claims?


I mean if we toss around incentived claims then you can't trust literally anyone in a capitalist society. Since they can be incentived to lie to you, and you have to do due diligence to prove they aren't before trusting them. This defense is the home of conspiracy theorists and crazy people.

If you are really concerned with this why are you posting on a forum literally owned by a SV Billionaire?

Buts let's pretend you are rational. How does a master in chemistry grant you knowledge of mechanical, structural, and fluid engineering. If you say they're both Math/STEM fields, then why aren't chemistry professors, and comsologist certified electricians? It's related by the same logic.


> I mean if we toss around incentived claims then you can't trust literally anyone in a capitalist society.

Only if you fall prey to logical fallacies. Noting that not all engineers are motivated to be maximally honest doesn't require that you completely mistrust literally everyone. False dilemma.

> If you are really concerned with this

What is it, exactly, that you think I'm concerned about? And how concerned do you think I am?

I can't help you with your chemistry/STEM straw man.


>I can't help you with your chemistry/STEM straw man.

How is this a strawman? Because it is literally the crux of your argument that a masters of chemistry is an expert on structural engineering and fluid dynamics?


I've made no such claim, and have no idea why it is that you think that I did.


What about the guy who warned about the space shuttle's O-rings? And that is an example from a conservative environment.

Now take startups that just want VC money with no intention of producing a product, a team of engineers that likes their salaries and you'll get a fake consensus very easily.


That was one engineer disagreeing with a team of managers.


Thunderf00t's no more credible than your average space-alien-cat in a mask.

Phil Mason, PhD in chemistry, and work in nutrition, physics, and nuclear physics, with 34 published papers to his credit, now he's one sassy frood.

https://en.m.wikipedia.org/wiki/Phil_Mason


Are you trolling?

I guess you don't know how much dedication and effort it takes to earn a good PhD. A PhD in STEM teaches you how to be a good scientist, how to think about problems and how to conduct research. These skills are very useful in pretty much every discipline imaginable.

Not to mention the fact that a PhD in chemistry warrants a very heavy mathematical/physics background. If you honestly think that Thunderf00t has the same credibility as some average Joe on the street about Hyperloop/physics/engineering, you must have a very religious background.


I think he's just having fun being irreverent and silly. Within the larger academic community Thunderf00t isn't some intellectual titan, he's just yet another guy with a PhD. From an academic perspective, I'd think that having a strong youtube following is like being king of the rats.

However, I would absolutely agree with you that Thunderf00t is adequately qualified to make most of the criticism that he has made in a variety of his debunking videos. Thunderf00t is doing our culture a valuable service by debunking that ridiculous re-breather apparatus, 'solar freakin roadways', and the allegedly endless water bottle. Its sad that people are so ignorant of basic science that they are taken in by this snake oil.


Maybe I'm mis-remembering, but I don't recall Thunderf00t's video suggesting that the hyperloop was truly as absurd as, say, the idea of using solar roadways to melt snow off the road.

I thought that his main message was that people are over-selling the feasibility of the hyperloop and playing down the incredible engineering challenges and dangers.


Just out of curiosity, what are the issues it has?


The video he is refering to: https://www.youtube.com/watch?v=RNFesa01llk


[flagged]


What could be more regressive than ignoring one side of an engineering debate because that speaker doesn't agree with your politics?


Snarky reply replaced: I'm sincerely curious if that's really all you're taking away from my comment, including the explicit disclaimer. My advice was to pay closer attention to the material, not to ignore it, so I'm perplexed as to how you managed to get the complete opposite message.

This seems exceptionally straightforward to me, so I'll make it as un-political as I can: There are lifetimes of new content available for your consumption every single day.

Maybe it's not all worthwhile. Maybe not 1% of it is. It doesn't matter-- you'll never get to see an infinitesimal fraction of it, even just the good, true, accurate stuff.

So how do you decide what to pay attention to with your mortal lifespan? Just as a first pass, I like to use filters like "is this notably excellent" or "does this make me want to throw up at all, even just a little".

Then if it's not excellent, or if the speaker doesn't agree with my politics, or especially both, I don't feel any remorse whatsoever about skipping it.

This isn't about shutting myself off. I think it's very important to expose myself to perspectives that differ from my own, to broaden my own frame of reference. I also think that feces play a critically important role in my metabolism, but that doesn't mean I'm excited to open a box of donuts and discover a frosted turd.

And I'll accept exactly 0 concern trolling around my publicly saying, just, hey... look in the box.

If it's a turd in there, you don't still have to eat it.


> if that's really all you're taking away

I'm not commenting on everything, just the things I think are the most important. I can't read your mind, but in your own words you "encourage folks not to watch that video at least without..."

Just my impression, but it appears to me that you aren't even trying to contribute to the actual topics of discussion in any meaningful way.


> but in your own words you "encourage folks not to watch that video at least without..."

Trying really hard not to get back on snark here, but... did you literally just stop reading there? Just finish my sentence: I "encourage folks not to watch that video, at least without [...] making an informed decision."

So, do you think folks shouldn't make an informed decision, or do you think my decision is wrong?

Just my impression, but it appears that you might be arguing one as a proxy for another.


So... watch several of his other videos and then decide whether to watch this one? And that's to save time spent on consuming non-worthwhile content? You could stand to be a lot more specific about what your beef is with this youtuber and how that links back to the arguments given in this video.


> watch several of his other videos and then decide whether to watch this one?

I think that is a generous interpretation. I fear that we are probably being asked to ignore Thunderf00t's criticism of the Hyperloop on the basis of the titles of the other videos - without even looking at the content of those videos!

The titles alone should be sufficient for us to agree that Thunderf000t is so terrible, with his terrible 'regressive' politics, that all of his videos are unworthy of watching.


Do you actually believe that?

I mean, do you actually believe that I think the Hyperloop is extremely important, criticism of it must be quashed at any cost, and this YouTuber will just have to be one of the broken eggs?

I'm serious. Is that... is there a part of your brain that what you just said actually makes sense to?

Is it possible in your universe that I've just expressed my actual feelings? And now we're having a big argument about my actual feelings? Even though at this point I doubt you even know what my actual feelings are?


I mean, do you actually believe that I think the Hyperloop is extremely important, criticism of it must be quashed at any cost, and this YouTuber will just have to be one of the broken eggs?

No, I think GP is suggesting that you have some other sacred cow, and you consider the "quashing" of technical arguments about other topics to be acceptable collateral damage in protecting it.


And yet for some reason, while I've barely so much as mentioned politics, you can't seem to stop talking about it.

If you think I am projecting bias in my comments, you're more than welcome to note it. Unless... is it possible I am not the only one with a sacred cow?


You were the one who brought up politics as a reason one might prefer to avoid watching the video.


Yes, politics is a reason one might prefer to avoid consuming some piece of media, including this one.

In fact I think you have, for the first time, identified the entire content of my original comment :)

So where's the part with the cow, again?


So where's the part with the cow, again?

That was the political objection to a video about the viability of hyperloop that you're so reluctant to explain to us.


No political objection to that video that I am aware of.

Nothing to explain.

Just what I said the first time. Sorry to be such a boring adversary.


No. Just go to the channel, read the titles of some of the other videos, and then either walk away, or not, for your own reasons, or not. Or don't, if that really seems so hard.

Again, weirded out that this is such a burdensome ask for some of you. Like, I'm not even talking about my politics, just pointing out that my politics exist.


You're also refusing to explain what they are or why they're relevant to this video.


So? I'm not asking anyone to adopt my politics.

Don't you want everyone to form their own opinion, without my bias?


That's exactly what they would have done before you decided to poison the well.


:D

So y'all are doubling down on the idea that simply suggesting folks look at the context of the content they consume is some toxic bias?

If I'd suggested actually reading some content, what would that be, the Jedi Mind Trick?

See, this is why I'm not particularly worried about my politics. Even without expressing a viewpoint, your argument is utterly self-immolating.


> did you literally just stop reading there?

Of course not, what a strange question.


Respectfully (because your writing looks fine) but in all honesty, is English your first language?

You ended your quotation on the preposition "without", which alone should tell you that the meaning of the sentence is contingent on what follows. That sentence could end "...without putting on your PPE" or "...without grabbing a popcorn and soda first", completely opposite meanings.

And you called it the "important" part.

I realize it was a strange question. It was a strange quote.


Things have calmed down a bit, so I'll just double down on this before I go:

Do you even hear yourself when you talk? "What could be more regressive?"

Um, how about deporting children? How about mandatory minimums in drug sentencing? How about forced pregnancy to death? How about racial gerrymandering?

How about, jesus, any actually regressive policy? No, when it starts interrupting low-fi YouTube debates about hypothetical public transit infrastructure, that is when the tyranny of the majority has gone too far!

Wow. Honestly, I don't even care if you or anyone wants to use HN to score a few points in Gatorade's famously unpopular ARG. But you know, people do read this stuff, and the public already has a very low opinion of technical folks' political aptitude, so when you say something outright absurd like that it reflects poorly on all of us.

Anyway, there's my "politics", hope you like them <3


If you want to make an argument as to why people shouldn't watch the video, please do so in a more direct manner. You seem to be making an ad hominem argument without even bothering to explain what specific ill the target is guilty of (beyond vague "regressive politics".)


I have made, and am still making, no such argument, at considerable length, in this very thread.

You are more than encouraged to join other commenters in vigorously protesting and debating my non-argument :)


Poisoning the well, are we?

Tunderf00t's youtube channel may seem to be a product of complete lunatic, but is actually an result of years of antagonisation between members of the community that used to be very close but underwent falling out due to internal agendas and opinions on what their community actually should be.


Yes, in my opinion the parent is trying to poison the well while saying "I'm not poisoning the well", then saying "How dare you suggest I'm poisoning the well when I actually said I wasn't poisoning the well".


[flagged]


> If I were discrediting the channel as a means to discredit the video or its content

If that's not your intent, you're just making personal attacks on the creator as a complete non-sequitur to the thread, which is even more of an inappropriate abuse of the HN audience than well-poisoning would be.


> as a complete non-sequitur to the thread,

Yes, exactly. They say themselves: "They could be right, they could be wrong, better engineers than me will tell in the end." They have no interest in the topic at hand, just poisoning the well, then defending their thinly veiled well-poisoning.


Sorry, can you clarify from elsewhere-- am I trying to discredit the topic at hand, or do I have no interest in it?

I know it doesn't really make a big difference to your narrative, but you really need to pick one or the other of "political non-sequitur" and "interested well-poisoning". They just don't go together.


One cannot discredit a 'topic'


am I debating an ELIZA upgrade


You're getting out of bounds. If you think my comments here are irrelevant or abusive, please report them to a moderator and desist replying.

Otherwise, I'm here to talk if you are.


[flagged]


So? I've said a few times I don't care about the claims.

They could be right, they could be wrong, better engineers than me will tell in the end. So what? Saying something true doesn't create an obligation to listen.

In fact, if you say enough true things loudly enough, they'll cart you off to jail. It's really not a great argument.




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