Correction: presumably if the air and the vehicle were both moving at 600+ MPH, the air *would* be somewhat compressible, but that's a far cry from saying everything would be hunky dory in the vehicle. The fact that the air has nowhere else to go (assuming no fancy safeguards) is the overriding issue here.
That's unconfined air; air that can freely bounce off and choose a new direction. There's a reason why I've been saying "wall of air". This is air uniformly moving in one direction, with no other place to travel and literally miles and miles (i.e. tons of tons) of more air behind it also moving in the same direction.
And after I did a tiny bit of research last night, it appears that air is really not all that compressible even at those speeds. I fail to see how that wouldn't result in, at the very least, a too-rapid deceleration of the relatively light vehicle. The only hiccup I could see is an apparent tradeoff between pressure and flow. Thunderf00t specifically said it would be a 1 atmosphere pressure wave traveling at the speed of sound, whereas a quick and naive glance at Bernoulli's equation seems to imply the pressure should drop as the speed increases.
Stay tuned; I think the good folks at/r/AskPhysics might have something to say about all of this.
pressure differential propagates backward once air is in the pipe
Makes no sense. The air is already moving at a good clip this way =====> in an effective vacuum. There's nothing I can see to slow it down quickly enough to do that. The air pressure resistance just inside the breach should be negligible until the entire tube is filled.
you could add air between a breech and the train to provide a barrier
I didn't say it was impossible to do. I said it was going to be expensive, on top of an already very expensive project.
The other important thing is that air, unlike a solid can flow around things.
If it's moving at near the speed of sound as Thunderf00t claims (and in the absence of a good explanation--WHAT IS THE CONSTANT SPEED IT SETTLES AT? Is it a function of pipe diameter?--I see no reason to doubt it), doubtless the deceleration alone will kill the occupants even if the vehicle remains intact. If you disagree--what do YOU think happens when a relatively lightweight vehicle traveling at 600 MPH down a tube slams into a mass of air also traveling at 600 MPH... in the other direction?
And if the air is not moving at 600 MPH, how fast is it moving? There should be a very simple answer to this question if indeed it is a constant speed, but Google isn't shedding any light on the issue. Guess I need to head over Stack Exchange to settle this. Maybe Reddit.
Constant at what speed and why? I'm not chastened yet. You didn't show your work.
The "vacuum is not a vacuum" thing has been played to death and is bullshit. 1/1000 atmosphere is close enough to ignore whatever is in there. This is akin to taking off your sunglasses before stepping on the scale.
friction between the air and the interior surface of the tube
Pretty darn sure this is irrelevant as well. If you cannot ignore these minor details...
So, as more air enters the tube, the total mass in the tube goes up, reducing the overall acceleration.
Bah. Show your work. The mass in the tube is already moving quickly in one direction and losing negligible speed. That mass is in fact connected to the mass outside (all the way up to the upper reaches of the atmosphere, presumably), and it probably needs to be modeled as one continuous entity.
The only reason I'm doubting my interpretation of it is my lack of experience in fluid dynamics.
Turbulence - which is probably the biggest factor
Nonsense. There is effectively zero turbulence (at least in any traditional sense of the word) inside the pipe. With a full diameter breach, the molecules are all moving in one direction pretty damn uniformly. They don't have a choice in the matter. There will be turbulence near the breach, sure, but I'm not seeing it being some big unpredictable disruptive thing. Vacuum cleaner hoses don't randomly have surges or dips in power due to turbulence.
Can we please get some scientifically literate moderators in here? This is getting absurd. He thinks that the closer you are to the site of the breech the worse off you'll be. This is a blatant violation of conservation of momentum. What the hell is acting on the in-rushing air to slow it down to protect something that is "about ten feet away"? The 1/1000th of an atmosphere that's supposed to be in there?
If there's something wrong with the assertion that the air will accelerate up the tube (not travel constantly), I will be suitably chastened but still curious to hear the explanation of where and how that gravitational kinetic energy is being transfered. (Air pressure is created by gravity.) Post AC if you've already modded.
His "shot from a gun" explanation in that first short vid isn't the whole story, by the way. 15 min into the this vid is where he talks about a head-on collision. No, I'm not saying Thunderf00t is an absolute authority on anything. I'm saying his explanation more or less made sense to me right away, whereas yours makes no sense at all.
They Hyperloop uses a near vacuum so... yeah. And even if it didn't about ten feet away it would be perfectly safe in a rupture. It's crazy to think this is any danger except for the moron that tries to pierce the tube.
If what you were afraid of was an issue every person with an air compressor would be in mortal danger.
Air is pushed (accelerated) into the tube by the weight of the air around it (air pressure.) That weight (yes, literal weight, caused by gravity) keeps "falling" down the tube, picking up speed as it goes, and since it's a near-vacuum there is very little to slow it down. Acceleration over many seconds gives you a significant speed. I'm unfamiliar with the behavior of compressible fluids to know whether or not this would actually reach the speed of sound, but given what I do know it sounds plausible enough, and at the very least I would expect the wall of air to be moving at hundreds of MPH.
Conservation of momentum inside that tube must hold. And energy (more acceleration) is constantly being added. Where do YOU think that energy is going to go?
Thunderf00t provided a minor demonstration of this whereby a very heavy steel ball was fairly rapidly accelerated over a short distance and easily broke through the glass tube it was in. He didn't use an "air compressor" to push the ball. He used ordinary air pressure, i.e. he used gravity. Which is a force that accelerates you. (He has fuller explanations of the forces and issues involved in othervideos.)
No, I'm not a massive Thunderf00t fanboy. I strongly suspected this thing was bullshit long ago.
Nope, it would simply come to a stop.
Physics 101 dude. This is air being ACCELERATED down the tube, not air moving at a constant speed. Air will only compress up to a point.
15 >= 120... Nope, does not compute.
I clearly said the trip time was on the order of half an hour. If you have a link to a seriously proposed hyperloop path that is a 2 hour journey, please provide it.
I'm going to let you have the last word on this since you seem to be way more unreasonably fanatically against anything Musk might have thought up
Paypal was a good (if evil) idea. He's done some decent stuff on SpaceX, though the Mars colony stuff is fairly dumb and pretending that he's going to dramatically reduce the cost of spacetravel is foolish since they aren't using radically new tech (spacegun, space elevator, whatever.) Tesla is a force for good in the world, although I wish Musk would talk about batteries a lot more. Next gen battery improvement is much more important than everything else combined.
And the hyperloop is a silly pipe dream.
I calls them like I sees them. If my understanding of physics is wrong... please, enlighten me.
That's SpaceX's *other* big myth, though: there's a pretty hard floor on how low the price can go on these things. Being good at shaving off some nickels and dimes here and there simply means you're competitive; it doesn't at all mean you're revolutionary. They're not (to my knowledge) building a space elevator or railgun launch system or something.
A 2x speed improvement is a huge deal for any traveller.
To be partially belied by the increased security concerns. A tube rupture isn't like a break in the track. The wall of air that goes rushing on both directions at hundreds of miles per hour poses a huge hazard, and the proximity to the interstate makes this worse in several ways. There *will* be security to get onto this thing.
Just the fact you don't have to go through security means an automatic two-hour total reduction in travel time before you factor in actual trip duration
The duration of the proposed route was only what, something like 30 minutes? (I'm not looking it up right now, but I know it wasn't long.) It doesn't take much of a security delay for people to start wondering "why am I paying so much for this ticket again?"
It may not be cheap but it uses a lot less energy per trip
Unlikely to matter. And the increased costs of the hyperloop could, in a fair comparison, be spent on a solar panel farm to compensate for the decreased efficiency of other rail solutions. (But first you have to admit that *of course* the hyperloop would be much more expensive.)
and requires less maintenance
Delusional nonsense, particularly if you're comparing this vs. non-elevated track, but even vs. other elevated solutions the airtight tube is a hell of a lot more fragile and expensive. You realize the joints between the tubes probably can't be a plain seal made of the same material as the rest of the pipe, right? There needs to be an airtight seal that can accommodate for thermal expansion/contraction.
Also, the high RPM jet engine on the nose of the thing will require considerably more maintenance than a linear motor alone. In particular, Maglev will certainly have lower wear and tear.
Traditional rail is as you said at least 2x slower
Discounting the increased security required for what is going to be a hugely attractive target for terrorists.
But even if someone managed it would just stop the trip, it wouldn't kill anyone.
I don't pretend to know for certain that Thunderf00t's calculations are accurate (as I recall, he says that after some seconds there will be dozens of tons of air rushing down the tube at close to the speed of sound), but even before his video I knew the forces involved here would be non-trivial. When a wall of air going at least a hundred miles per hour hits a little lightweight car going 600+ MPH I am fairly sure of this: everyone on that car is going to die. And the safeguards required to prevent this are absurdly expensive.
it makes way more sense than a train because of the huge speed improvement
Again, a mere 15 minute delay due to security removes most of that advantage. Passenger capacity, ticket cheapness, durability and robustness vs. accidents and attacks are more important. Vacuum tube trains are really only interesting at very long distances (so that they can reach thousands of miles per hour), but unfortunately the issues of tube cost and vulnerability to terrorism only become more pronounced as the length increases.
But the Hyperloop is an idea that makes a ton of sense because of the large spread of benefits it offers.
The hyperloop is a watering-down of a very old idea that was impractical ~100 years ago and is impractical today. People seem to like it and defend it primarily because it's cool.
Yes, SpaceX is doing alright. But he's still talking nonsense about establishing a colony on Mars as well, isn't he?
There are fantastic-seeming things that are plausible in our lifetimes. Like, say, general AI or the scaling up of countless nanotech technologies that are still in their infancy. It's a waste of street cred for him to talk about this stuff. It's not that I fear his failure; it's that I fear young geeks becoming disillusioned when they realize his failures were mostly due to him being full of crap. Why can't we give young people at least semi-realistic dreams?
If we wanted a Mars colony then it's all about biotech or maybe (if someone can invent some nanites) nanotech. The rocket to get us there should be at the bottom of our priority list.
Elon Musk tweeted a news article about the incident, adding more credibility to the matter.
How the hell does this add credibility? Discounting entirely the nutjob stuff the guy has promoted[1], when CEO of Foo, Inc. tweets a news article about Foo's product, that does not in my mind increase the credibility of that news article.
1. I'm sorry to all the starry-eyed engineer geeks out there, but the hyperloop in its proposed forms is a fantasy that really isn't all that fast (only 2x Maglev), won't be cheap (a jet engine, linear motor AND an airtight tube instead of a track? And how many ticket-paying people can cram into these cars vs. traditional rail?) and cannot possibly be safer than or more convenient than air travel given the vulnerability of the tube to terrorist attacks. This requires some basic independent critical thinking rather than accepting the figures estimated by self-interested individuals. The unquestioning worship of Musk is one of the most depressing social phenomena (in geek circles specifically) that I've ever seen.
Did Tesla also report any/all instances where the forward collision warning sounded, regardless of whether or not a crash subsequently occurred? Otherwise this is just PR.
First off, an erratic driver is obviously worth paying attention to, so it's worth having the beep for near-crashes as well.
Also, in terms of the warning system's efficacy effects this probably isn't relevant unless it beeps so much as to cause drivers to ignore it. The false positive rate could be 75% and it still probably wouldn't beep more than once a week at the most (depending on where you live / Boston joke goes here.)
To acknowledge my own limited research in this area, there are probably other Xen-based projects I'm not aware of that do security by isolation, but if they do exist I'm not sure why their codebase couldn't / wouldn't overlap a lot with Qubes'. The stuff Qubes does with templates, driver isolation and network isolation are useful just about anywhere.
A security tool is never ignored for being not bulletproof.
That's why I said "they're worth pursuing to an extent". ASLR is obviously useful even in the context of an isolated VM setup, but there have been multiple attacks against multiple implementations of it. I even recall reading once where one of the PaX/grsec guys was basically saying "yeah, you realize this is just a stopgap right? It's not a magical like a lot of people are pretending", but I can't find the link at the moment.
You would only choose not to use it if the protection it adds is disproportionate to its cost. These days ASLR is inexpensive relative to the protection it adds so you'd be silly not to include it.
If a given implementation is pretty much 'done' and robust then sure. If it's nowhere near bulletproof and this is an ongoing arms race, and/or if it's going to require a lot of code refactoring to enable it for something specific, I would question whether it's worth making the top priority. The Qubes team isn't huge, but they have already produced a surprisingly user friendly general purpose GUI desktop distro. I believe that security-by-isolation principles, using full OS (para)virtualization, are ideal for many other contexts, but this isn't widely talked about. (Partially because they've been overshadowed a bit by Docker/LXC, which is great for userspace but can't protect you from kernel or driver exploits.)
But if using ASLR is a simple matter of setting a flag by all means, do that. I just think the conversation and manpower are better focused elsewhere. I think the conversation clearly needs to be shifted. There are no forks / "based on" / companion distros of Qubes that I'm aware of, and a sad lack of third party produced templates (though I did stumble on a MirageOS based replacement for the firewall VM the other day that sounded pretty neat.)
It's semi-walled, with obvious kill switches[1] in case any third party project gets too popular. OP might have overstated the current status, but the concerns are valid. Particularly in light of Pixel.
1. A focus on permissive licenses instead of GPL, plus the OEMs and phone carriers being generally hostile to user modding.
A noble effort, but tools like ASLR have in practice shown themselves to be less than bulletproof. They're worth pursuing to an extent, but they aren't enough for a truly robust preemptive security strategy and shouldn't be our primary focus.
The future of secure computing is obviously a ground-up microkernel affair that allows strong sandboxing. But that's going to take... a while to mature, in terms of native application support. In the meantime, a stopgap using paravirtualization and hardware assisted virtualization is the best that can be done. It's not as efficient, but it's a lot snappier than you'd expect and silicon is cheaper than programmers' time.
The basic security idea of Qubes (putting aside its UI innovations, which obviously aren't important on embedded devices) is that Dom0[1] entirely lacks networking, including the networking driver. The networking driver is isolated in its own VM with its own separate kernel, and on a vt-d capable machine that VM's access to shared resources is controlled (meaning you can't use a DMA attack to access another VM's data from RAM.) After the networking VM comes a separate firewall VM, and other VMs can have connectivity through the firewall VM.
This is pretty damn robust, but in this scenario you could and should do even better by modifying Dom0[2] to verify commands and/or update signatures for your mission-critical VM. Dom0 itself should never be accessed or updated over the network (and it doesn't need to be, since it isn't vulnerable to remote exploits and isn't directly involved in whatever the main functionality of the medical device is.)
Assuming we can't rewrite everything from scratch to function in a pure microkernel universe (with no VMs), the best we can do right now is to have completely separate OSes with separate kernels, connected and coordinated by a hypervisor. There's still the very real possibility of a Xen exploit (which would need to be stacked with other severe Linux exploits to be useful), but Xen is less than 150,000 lines of code and should be easier for security folks to reason about than the Linux kernel.
This all may not be viable for implanted devices due to the added power requirements but for external devices... why the hell not? The extra hardware required would surely be less than $100 wholesale, on a device that probably costs thousands.
1. With Xen, this is roughly comparable to the "host OS" used with type II hypervisors like Virtualbox, VMware, KVM / QEMU, but there are important differences. Namely, it's possible for device drivers to be located in unprivileged domains instead of Dom0.
2. Or perhaps another VM without network connectivity at all, using a more limited mechanism of data passing along the lines of Qubes' VM-to-VM copy mechanism.
ROFL...yeah, you had that if you were willing to pay a shitload of money for it.
As I recall, T-Mobile had a perfectly usable option that was a $6 add-on. YEAH ROFL SO EXPENSIVE!!!! Granted, one generally didn't use it to stream video (I don't think the iPhone 1 had a Youtube app at launch, either... and Youtube was only like a year old at that point), but it was snappy enough.
Keep in mind AT&T had to do massive system upgrades to support the iPhone.
Not for bandwidth they didn't. Their routing may have sucked, I don't know. As far as I can recall, the real problems didn't pop up until the iPhone 3G finally came out.
Because the internet on the cellphone up till that point was a fucking joke.
As I just pointed out, streaming video was still a fairly new thing when the iPhone 1 came out. The internet went through a pretty massive change in the late 00s, but I hate to break it to you... it turns out Apple didn't actually invent Netflix or Youtube or Hulu.
Also, the iPhone had Wifi. Suck on that.
And you think this is even remotely revolutionary because?
You should really take a step back and listen to yourself; just imagine a BMW fan talked the way you did about Apple. I don't have a problem complementing Apple when they do good. OS X was a decent OS. Objective-C is a good language (if a little immature in the early years). Capacitive screens would be superior to resistive if only they would work on higher quality plastic ones. Magnetic cables are amazing.
But Apple didn't develop any of those things in-house. They (wisely) purchased them. Apple is not an innovator to any remarkable degree; they are primarily a marketing powerhouse. Why is that so hard for you to admit?
Uh, what? I had internet in 2006 and it was EDGE speed, just like the iPhone 1. I don't know what you mean by always-on. You could leave apps running and they would stay connected and the 'EDGE' logo would stay on screen as long as you were within range of a tower. Not sure what you call it, but I call that always-on.
Way to completely ignore my entire post. His base didn't elect him.
Independents favoring him (who were mostly saying that he was full of shit, but the lesser evil) combined with Democrats who didn't bother showing up were the most decisive factors.
and his supporters are now saying stuff like
Who cares? Go look up the numbers if you don't believe me. Pay attention not just to 2012 but also 2008 to see what the left is capable of with a strong candidate bringing a message (however misleading it may be) of change. Trump won only by tens of thousands of votes in several key states. Millions of registered Democrats stayed home, and independents sided against Hillary. But legions of people like you *still* want to talk about the basket of deplorables?
Wake the fuck up. Your thesis that the base was responsible is clearly contradicted by the facts: Rs did not turn out in significantly greater numbers at the polls this year. But millions fewer Ds (and particularly the young left-leaning voters) bothered to vote.
It's dangerously irresponsible to ignore this reality... unless you'd rather we were stuck with Trump for eight years instead of four.
They "changed" it because they had an ultra-loyal fanbase that would scream endlessly about their products (primarily iPods in those days) to non-techies to the point where they could simply charge 2x for a middling product. Android was right around the corner, Apple or no Apple, and Nokia was obviously going to put Maemo on a phone (it was out on PDA devices prior to the iPhone 1) just as soon as they figured the battery life out (little did they realize that people would simply adjust to the reality of charging their phones nightly, or even multiple times per day if under heavy use. In those days, reviewers would complain if you could "only" get a few days' worth of standby time.) But Apple preempted them both with a shittier and more expensive product and thereby convinced people like you they invented it.
The N900 was superior to the iPhone 1 in pretty much every way. (As was the G1.) It's a huge pity Nokia played such a conservative game with Maemo, but then again they never had the power to leverage the Apple Tax or command such over the top hype so they might not have been able to pull it off regardless.
If you aren't wiling to discuss specific technologies, be they capacitive screens or MMS or 3G, then I'm pretty sure you're the one there is no hope for. Keep swallowing that blue pill. After all, if it's popular it must be innovative.
Slashdot Mirror
Correction: presumably if the air and the vehicle were both moving at 600+ MPH, the air *would* be somewhat compressible, but that's a far cry from saying everything would be hunky dory in the vehicle. The fact that the air has nowhere else to go (assuming no fancy safeguards) is the overriding issue here.
That's unconfined air; air that can freely bounce off and choose a new direction. There's a reason why I've been saying "wall of air". This is air uniformly moving in one direction, with no other place to travel and literally miles and miles (i.e. tons of tons) of more air behind it also moving in the same direction.
/r/AskPhysics might have something to say about all of this.
And after I did a tiny bit of research last night, it appears that air is really not all that compressible even at those speeds. I fail to see how that wouldn't result in, at the very least, a too-rapid deceleration of the relatively light vehicle. The only hiccup I could see is an apparent tradeoff between pressure and flow. Thunderf00t specifically said it would be a 1 atmosphere pressure wave traveling at the speed of sound, whereas a quick and naive glance at Bernoulli's equation seems to imply the pressure should drop as the speed increases.
Stay tuned; I think the good folks at
pressure differential propagates backward once air is in the pipe
Makes no sense. The air is already moving at a good clip this way =====> in an effective vacuum. There's nothing I can see to slow it down quickly enough to do that. The air pressure resistance just inside the breach should be negligible until the entire tube is filled.
you could add air between a breech and the train to provide a barrier
I didn't say it was impossible to do. I said it was going to be expensive, on top of an already very expensive project.
The other important thing is that air, unlike a solid can flow around things.
If it's moving at near the speed of sound as Thunderf00t claims (and in the absence of a good explanation--WHAT IS THE CONSTANT SPEED IT SETTLES AT? Is it a function of pipe diameter?--I see no reason to doubt it), doubtless the deceleration alone will kill the occupants even if the vehicle remains intact. If you disagree--what do YOU think happens when a relatively lightweight vehicle traveling at 600 MPH down a tube slams into a mass of air also traveling at 600 MPH... in the other direction?
And if the air is not moving at 600 MPH, how fast is it moving? There should be a very simple answer to this question if indeed it is a constant speed, but Google isn't shedding any light on the issue. Guess I need to head over Stack Exchange to settle this. Maybe Reddit.
The "vacuum is not a vacuum" thing has been played to death and is bullshit. 1/1000 atmosphere is close enough to ignore whatever is in there. This is akin to taking off your sunglasses before stepping on the scale.
friction between the air and the interior surface of the tube
Pretty darn sure this is irrelevant as well. If you cannot ignore these minor details...
So, as more air enters the tube, the total mass in the tube goes up, reducing the overall acceleration.
Bah. Show your work. The mass in the tube is already moving quickly in one direction and losing negligible speed. That mass is in fact connected to the mass outside (all the way up to the upper reaches of the atmosphere, presumably), and it probably needs to be modeled as one continuous entity.
The only reason I'm doubting my interpretation of it is my lack of experience in fluid dynamics.
Turbulence - which is probably the biggest factor
Nonsense. There is effectively zero turbulence (at least in any traditional sense of the word) inside the pipe. With a full diameter breach, the molecules are all moving in one direction pretty damn uniformly. They don't have a choice in the matter. There will be turbulence near the breach, sure, but I'm not seeing it being some big unpredictable disruptive thing. Vacuum cleaner hoses don't randomly have surges or dips in power due to turbulence.
(This is a full-diameter breach we're considering here, obviously.)
Can we please get some scientifically literate moderators in here? This is getting absurd. He thinks that the closer you are to the site of the breech the worse off you'll be. This is a blatant violation of conservation of momentum. What the hell is acting on the in-rushing air to slow it down to protect something that is "about ten feet away"? The 1/1000th of an atmosphere that's supposed to be in there?
If there's something wrong with the assertion that the air will accelerate up the tube (not travel constantly), I will be suitably chastened but still curious to hear the explanation of where and how that gravitational kinetic energy is being transfered. (Air pressure is created by gravity.) Post AC if you've already modded.
Why am I not surprised you're a dogmatic Apple apologist as well? You don't even understand that air pressure is powered by gravitational acceleration.
His "shot from a gun" explanation in that first short vid isn't the whole story, by the way. 15 min into the this vid is where he talks about a head-on collision. No, I'm not saying Thunderf00t is an absolute authority on anything. I'm saying his explanation more or less made sense to me right away, whereas yours makes no sense at all.
They Hyperloop uses a near vacuum so... yeah. And even if it didn't about ten feet away it would be perfectly safe in a rupture. It's crazy to think this is any danger except for the moron that tries to pierce the tube. If what you were afraid of was an issue every person with an air compressor would be in mortal danger.
Air is pushed (accelerated) into the tube by the weight of the air around it (air pressure.) That weight (yes, literal weight, caused by gravity) keeps "falling" down the tube, picking up speed as it goes, and since it's a near-vacuum there is very little to slow it down. Acceleration over many seconds gives you a significant speed. I'm unfamiliar with the behavior of compressible fluids to know whether or not this would actually reach the speed of sound, but given what I do know it sounds plausible enough, and at the very least I would expect the wall of air to be moving at hundreds of MPH.
Conservation of momentum inside that tube must hold. And energy (more acceleration) is constantly being added. Where do YOU think that energy is going to go?
Thunderf00t provided a minor demonstration of this whereby a very heavy steel ball was fairly rapidly accelerated over a short distance and easily broke through the glass tube it was in. He didn't use an "air compressor" to push the ball. He used ordinary air pressure, i.e. he used gravity. Which is a force that accelerates you. (He has fuller explanations of the forces and issues involved in other videos.)
No, I'm not a massive Thunderf00t fanboy. I strongly suspected this thing was bullshit long ago.
Nope, it would simply come to a stop.
Physics 101 dude. This is air being ACCELERATED down the tube, not air moving at a constant speed. Air will only compress up to a point.
15 >= 120... Nope, does not compute.
I clearly said the trip time was on the order of half an hour. If you have a link to a seriously proposed hyperloop path that is a 2 hour journey, please provide it.
I'm going to let you have the last word on this since you seem to be way more unreasonably fanatically against anything Musk might have thought up
Paypal was a good (if evil) idea. He's done some decent stuff on SpaceX, though the Mars colony stuff is fairly dumb and pretending that he's going to dramatically reduce the cost of spacetravel is foolish since they aren't using radically new tech (spacegun, space elevator, whatever.) Tesla is a force for good in the world, although I wish Musk would talk about batteries a lot more. Next gen battery improvement is much more important than everything else combined.
And the hyperloop is a silly pipe dream.
I calls them like I sees them. If my understanding of physics is wrong... please, enlighten me.
That's SpaceX's *other* big myth, though: there's a pretty hard floor on how low the price can go on these things. Being good at shaving off some nickels and dimes here and there simply means you're competitive; it doesn't at all mean you're revolutionary. They're not (to my knowledge) building a space elevator or railgun launch system or something.
And here come the Musk fanboys to mod me down.
A 2x speed improvement is a huge deal for any traveller.
To be partially belied by the increased security concerns. A tube rupture isn't like a break in the track. The wall of air that goes rushing on both directions at hundreds of miles per hour poses a huge hazard, and the proximity to the interstate makes this worse in several ways. There *will* be security to get onto this thing.
Just the fact you don't have to go through security means an automatic two-hour total reduction in travel time before you factor in actual trip duration
The duration of the proposed route was only what, something like 30 minutes? (I'm not looking it up right now, but I know it wasn't long.) It doesn't take much of a security delay for people to start wondering "why am I paying so much for this ticket again?"
It may not be cheap but it uses a lot less energy per trip
Unlikely to matter. And the increased costs of the hyperloop could, in a fair comparison, be spent on a solar panel farm to compensate for the decreased efficiency of other rail solutions. (But first you have to admit that *of course* the hyperloop would be much more expensive.)
and requires less maintenance
Delusional nonsense, particularly if you're comparing this vs. non-elevated track, but even vs. other elevated solutions the airtight tube is a hell of a lot more fragile and expensive. You realize the joints between the tubes probably can't be a plain seal made of the same material as the rest of the pipe, right? There needs to be an airtight seal that can accommodate for thermal expansion/contraction.
Also, the high RPM jet engine on the nose of the thing will require considerably more maintenance than a linear motor alone. In particular, Maglev will certainly have lower wear and tear.
Traditional rail is as you said at least 2x slower
Discounting the increased security required for what is going to be a hugely attractive target for terrorists.
But even if someone managed it would just stop the trip, it wouldn't kill anyone.
I don't pretend to know for certain that Thunderf00t's calculations are accurate (as I recall, he says that after some seconds there will be dozens of tons of air rushing down the tube at close to the speed of sound), but even before his video I knew the forces involved here would be non-trivial. When a wall of air going at least a hundred miles per hour hits a little lightweight car going 600+ MPH I am fairly sure of this: everyone on that car is going to die. And the safeguards required to prevent this are absurdly expensive.
it makes way more sense than a train because of the huge speed improvement
Again, a mere 15 minute delay due to security removes most of that advantage. Passenger capacity, ticket cheapness, durability and robustness vs. accidents and attacks are more important. Vacuum tube trains are really only interesting at very long distances (so that they can reach thousands of miles per hour), but unfortunately the issues of tube cost and vulnerability to terrorism only become more pronounced as the length increases.
But the Hyperloop is an idea that makes a ton of sense because of the large spread of benefits it offers.
The hyperloop is a watering-down of a very old idea that was impractical ~100 years ago and is impractical today. People seem to like it and defend it primarily because it's cool.
Yes, SpaceX is doing alright. But he's still talking nonsense about establishing a colony on Mars as well, isn't he?
There are fantastic-seeming things that are plausible in our lifetimes. Like, say, general AI or the scaling up of countless nanotech technologies that are still in their infancy. It's a waste of street cred for him to talk about this stuff. It's not that I fear his failure; it's that I fear young geeks becoming disillusioned when they realize his failures were mostly due to him being full of crap. Why can't we give young people at least semi-realistic dreams?
If we wanted a Mars colony then it's all about biotech or maybe (if someone can invent some nanites) nanotech. The rocket to get us there should be at the bottom of our priority list.
Hah, beat me to it. And you did it more amusingly; well done.
Elon Musk tweeted a news article about the incident, adding more credibility to the matter.
How the hell does this add credibility? Discounting entirely the nutjob stuff the guy has promoted[1], when CEO of Foo, Inc. tweets a news article about Foo's product, that does not in my mind increase the credibility of that news article.
1. I'm sorry to all the starry-eyed engineer geeks out there, but the hyperloop in its proposed forms is a fantasy that really isn't all that fast (only 2x Maglev), won't be cheap (a jet engine, linear motor AND an airtight tube instead of a track? And how many ticket-paying people can cram into these cars vs. traditional rail?) and cannot possibly be safer than or more convenient than air travel given the vulnerability of the tube to terrorist attacks. This requires some basic independent critical thinking rather than accepting the figures estimated by self-interested individuals. The unquestioning worship of Musk is one of the most depressing social phenomena (in geek circles specifically) that I've ever seen.
Did Tesla also report any/all instances where the forward collision warning sounded, regardless of whether or not a crash subsequently occurred? Otherwise this is just PR.
First off, an erratic driver is obviously worth paying attention to, so it's worth having the beep for near-crashes as well.
Also, in terms of the warning system's efficacy effects this probably isn't relevant unless it beeps so much as to cause drivers to ignore it. The false positive rate could be 75% and it still probably wouldn't beep more than once a week at the most (depending on where you live / Boston joke goes here.)
To acknowledge my own limited research in this area, there are probably other Xen-based projects I'm not aware of that do security by isolation, but if they do exist I'm not sure why their codebase couldn't / wouldn't overlap a lot with Qubes'. The stuff Qubes does with templates, driver isolation and network isolation are useful just about anywhere.
A security tool is never ignored for being not bulletproof.
That's why I said "they're worth pursuing to an extent". ASLR is obviously useful even in the context of an isolated VM setup, but there have been multiple attacks against multiple implementations of it. I even recall reading once where one of the PaX/grsec guys was basically saying "yeah, you realize this is just a stopgap right? It's not a magical like a lot of people are pretending", but I can't find the link at the moment.
You would only choose not to use it if the protection it adds is disproportionate to its cost. These days ASLR is inexpensive relative to the protection it adds so you'd be silly not to include it.
If a given implementation is pretty much 'done' and robust then sure. If it's nowhere near bulletproof and this is an ongoing arms race, and/or if it's going to require a lot of code refactoring to enable it for something specific, I would question whether it's worth making the top priority. The Qubes team isn't huge, but they have already produced a surprisingly user friendly general purpose GUI desktop distro. I believe that security-by-isolation principles, using full OS (para)virtualization, are ideal for many other contexts, but this isn't widely talked about. (Partially because they've been overshadowed a bit by Docker/LXC, which is great for userspace but can't protect you from kernel or driver exploits.)
But if using ASLR is a simple matter of setting a flag by all means, do that. I just think the conversation and manpower are better focused elsewhere. I think the conversation clearly needs to be shifted. There are no forks / "based on" / companion distros of Qubes that I'm aware of, and a sad lack of third party produced templates (though I did stumble on a MirageOS based replacement for the firewall VM the other day that sounded pretty neat.)
It's semi-walled, with obvious kill switches[1] in case any third party project gets too popular. OP might have overstated the current status, but the concerns are valid. Particularly in light of Pixel.
1. A focus on permissive licenses instead of GPL, plus the OEMs and phone carriers being generally hostile to user modding.
Bubububu... they told me that permissive licenses are the only way we can have real freedom!
Meanwhile, consumers everywhere are still feeling the painful loss of freedom after Linksys/Cisco was forced to release their modifications to GPLed source code 14 years ago.
A noble effort, but tools like ASLR have in practice shown themselves to be less than bulletproof. They're worth pursuing to an extent, but they aren't enough for a truly robust preemptive security strategy and shouldn't be our primary focus.
The future of secure computing is obviously a ground-up microkernel affair that allows strong sandboxing. But that's going to take... a while to mature, in terms of native application support. In the meantime, a stopgap using paravirtualization and hardware assisted virtualization is the best that can be done. It's not as efficient, but it's a lot snappier than you'd expect and silicon is cheaper than programmers' time.
The basic security idea of Qubes (putting aside its UI innovations, which obviously aren't important on embedded devices) is that Dom0[1] entirely lacks networking, including the networking driver. The networking driver is isolated in its own VM with its own separate kernel, and on a vt-d capable machine that VM's access to shared resources is controlled (meaning you can't use a DMA attack to access another VM's data from RAM.) After the networking VM comes a separate firewall VM, and other VMs can have connectivity through the firewall VM.
This is pretty damn robust, but in this scenario you could and should do even better by modifying Dom0[2] to verify commands and/or update signatures for your mission-critical VM. Dom0 itself should never be accessed or updated over the network (and it doesn't need to be, since it isn't vulnerable to remote exploits and isn't directly involved in whatever the main functionality of the medical device is.)
Assuming we can't rewrite everything from scratch to function in a pure microkernel universe (with no VMs), the best we can do right now is to have completely separate OSes with separate kernels, connected and coordinated by a hypervisor. There's still the very real possibility of a Xen exploit (which would need to be stacked with other severe Linux exploits to be useful), but Xen is less than 150,000 lines of code and should be easier for security folks to reason about than the Linux kernel.
This all may not be viable for implanted devices due to the added power requirements but for external devices... why the hell not? The extra hardware required would surely be less than $100 wholesale, on a device that probably costs thousands.
1. With Xen, this is roughly comparable to the "host OS" used with type II hypervisors like Virtualbox, VMware, KVM / QEMU, but there are important differences. Namely, it's possible for device drivers to be located in unprivileged domains instead of Dom0.
2. Or perhaps another VM without network connectivity at all, using a more limited mechanism of data passing along the lines of Qubes' VM-to-VM copy mechanism.
ROFL...yeah, you had that if you were willing to pay a shitload of money for it.
As I recall, T-Mobile had a perfectly usable option that was a $6 add-on. YEAH ROFL SO EXPENSIVE!!!! Granted, one generally didn't use it to stream video (I don't think the iPhone 1 had a Youtube app at launch, either... and Youtube was only like a year old at that point), but it was snappy enough.
Keep in mind AT&T had to do massive system upgrades to support the iPhone.
Not for bandwidth they didn't. Their routing may have sucked, I don't know. As far as I can recall, the real problems didn't pop up until the iPhone 3G finally came out.
Because the internet on the cellphone up till that point was a fucking joke.
As I just pointed out, streaming video was still a fairly new thing when the iPhone 1 came out. The internet went through a pretty massive change in the late 00s, but I hate to break it to you... it turns out Apple didn't actually invent Netflix or Youtube or Hulu.
Also, the iPhone had Wifi. Suck on that.
And you think this is even remotely revolutionary because?
You should really take a step back and listen to yourself; just imagine a BMW fan talked the way you did about Apple. I don't have a problem complementing Apple when they do good. OS X was a decent OS. Objective-C is a good language (if a little immature in the early years). Capacitive screens would be superior to resistive if only they would work on higher quality plastic ones. Magnetic cables are amazing.
But Apple didn't develop any of those things in-house. They (wisely) purchased them. Apple is not an innovator to any remarkable degree; they are primarily a marketing powerhouse. Why is that so hard for you to admit?
Uh, what? I had internet in 2006 and it was EDGE speed, just like the iPhone 1. I don't know what you mean by always-on. You could leave apps running and they would stay connected and the 'EDGE' logo would stay on screen as long as you were within range of a tower. Not sure what you call it, but I call that always-on.
his base simply does not care /.
Way to completely ignore my entire post. His base didn't elect him.
Independents favoring him (who were mostly saying that he was full of shit, but the lesser evil) combined with Democrats who didn't bother showing up were the most decisive factors.
and his supporters are now saying stuff like
Who cares? Go look up the numbers if you don't believe me. Pay attention not just to 2012 but also 2008 to see what the left is capable of with a strong candidate bringing a message (however misleading it may be) of change. Trump won only by tens of thousands of votes in several key states. Millions of registered Democrats stayed home, and independents sided against Hillary. But legions of people like you *still* want to talk about the basket of deplorables?
Wake the fuck up. Your thesis that the base was responsible is clearly contradicted by the facts: Rs did not turn out in significantly greater numbers at the polls this year. But millions fewer Ds (and particularly the young left-leaning voters) bothered to vote.
It's dangerously irresponsible to ignore this reality... unless you'd rather we were stuck with Trump for eight years instead of four.
They "changed" it because they had an ultra-loyal fanbase that would scream endlessly about their products (primarily iPods in those days) to non-techies to the point where they could simply charge 2x for a middling product. Android was right around the corner, Apple or no Apple, and Nokia was obviously going to put Maemo on a phone (it was out on PDA devices prior to the iPhone 1) just as soon as they figured the battery life out (little did they realize that people would simply adjust to the reality of charging their phones nightly, or even multiple times per day if under heavy use. In those days, reviewers would complain if you could "only" get a few days' worth of standby time.) But Apple preempted them both with a shittier and more expensive product and thereby convinced people like you they invented it.
The N900 was superior to the iPhone 1 in pretty much every way. (As was the G1.) It's a huge pity Nokia played such a conservative game with Maemo, but then again they never had the power to leverage the Apple Tax or command such over the top hype so they might not have been able to pull it off regardless.
If you aren't wiling to discuss specific technologies, be they capacitive screens or MMS or 3G, then I'm pretty sure you're the one there is no hope for. Keep swallowing that blue pill. After all, if it's popular it must be innovative.