The GP never said nor implied that the cost of LOX is the issue (they argued just the opposite). Their main point was that putting the mass of a O2 liquefaction plant on a rocket, so large that it can liquefy a whole first stage's worth of oxygen in a matter of minutes - and having that be mass that you then have to land if you want the vehicle to be reusable - is not a reasonable approach. They're probably right.
The suborbital travel doesn't even need to be net profitable on its own - it only needs a positive margin. Only "suborbital travel plus Mars tickets" needs to be net profitable. SpaceX added in suborbital travel because they were otherwise going to have these big expensive pieces of hardware just sitting around between launch windows. Might as well use them to bring in additional revenue during that time.
What the heck is wrong with commenters on this Slashdot article? It's like people are just searching for some reason to dig into other commenters.
Tough Love said nothing about "this should have been launched on a Saturn V". They were pointing out that is impressive as this rocket may be, it's nothing compared to what the US was achieving in the 1960s.
Please try to learn not to interpret reflective comments as demands.
Normally I'd write a rebuttal concerning charge times - but in the case of India, honestly, you're spot on. India has been doing this "We want a ton of electric vehicles.... but we're not going to do anything to prepare for them or encourage them" game. I mean, they added a subsidy, but it's very small, and only applies to local manufacturers, which are way behind the game on EV tech investments. The country has put way too little into charging infrastructure, and their anticompetitive trade policies (such as the local sourcing policy) have kept a number of manufacturers out, because EVs tend to have very custom parts lines.
India could be another China when it comes to EVs, but they're going to need to get their act together if they want it to be anything more than talk.
I did a screenshot of him and then punched it into Google reverse image search. Google identified the image as "Bowtie" and suggested the website "How to tie a bow tie".
But yeah... this isn't exactly on par with watching a SpaceX launch. Even if they seemed more excited about their work, the fact that they don't seem to be trying to really achieve anything meaningful, pushing envelopes on what can be done... that sort of guarantees that they're not going to make as interesting of a webcast.
Sad to see those SRBs when they jetison them. After seeing so many SpaceX launches, I automatically expect to see them orient themselves and then do a boostback burn. Then I have to remind myself... no, there's nothing about this craft that's going to be landing, it's all disposable.
What do you do when weapons without AI go south? Same thing. Innocent people die. The point of AI would be to decrease the odds of innocent people dying, not increase it.
First off, all "skynet" stuff aside, we're not talking about "generalized AI". We're talking about stuff like image recognition. Not learning neural nets, just pretrained ones. Secondly, this would be most desirable serving as a backup, not primary, control mechanism. One of the big problems faced by drones is jamming. If a drone gets jammed and you're lucky, it has to return to base autonomously without completing its mission. If you're unlucky, bad things happen. For example, US-made surveilance drones given to Ukraine met with bad reviews because the Russians - oh, I'm sorry, "rebels" - were using advanced electronic warfare systems to down them, and then downloading the images from memory to see where the Ukrainian positions were.
You want a drone that does whatever you want tell it to so long as you can maintain communications with it, but if someone jams your communications, you want it to carry out whatever mission you assigned to it as best as it can.
Beyond drones, AI would be very useful in missiles / guided artillery / etc. You find a target, you lock onto the target, and you want to ensure that the missile hits the target - whether the target is a tank, a plane, a group of soldiers, or whatnot. Your "targets", in turn, deploy a variety of countermeasures to try and make sure that the thing you shot gets confused and can't find it. Simple human-created algorithms describing how to determine what's your target and what isn't can only take you so far; having a neural net which is trained to recognize various types of targets - and various things that aren't targets - can make the weapon much more effective, while reducing the risk of it impacting a non-target object.
Then there's just general surveillance / monitoring. The more visual data you collect, the more manpower it takes to analyze it. But if you train neural nets to recognize weapons systems - from camouflaged tanks to guns in people's hands (trained *against* non-gun items which people might carry) - it can narrow down the imagery that humans need to look at when determining what should be targeted and what shouldn't.
To reiterate: in none of this are we talking about "generalized AI". We're not even talking about "learning AI". We're talking about "AI pre-trained to specific tasks". Which are things we already use in our everyday lives.
Wild blueberries (okay, bilberries) grow abundantly here and when they're in season on my land, there's often purple bird droppings full of seeds scattered all over everything that's left outside.
Nutritious fleshy fruits evolved for a reason...
Some plants even appear to have evolved "cheats" in their fruits. For example, there's a number of fruits that contain non-calorific chemicals that are many times sweeter than sugar; some of them are currently being incorporated into commercial products, while others are still only known in the wild. The theory is that this is part of an arms race with mammals, in that the plants can make the non-nutritious sweetener far cheaper than an equivalent amount of sugar, but eventually mammals evolve a resistance to non-caloric sweeteners in order to ensure that they're actually getting their needed calories in their food. I imagine that you get the same sort of thing with plants evolving gelling agents to make "creamy" flesh in their fruits that tastes fatty without actually being fatty.
Teaspoons are well defined, 4.92892ml. Drop is a unit in pharmacy equivalent to 0,05ml, not a "suggestive single drop" An olympic swimming pool with a nominal depth of 2m is 250000l. Lake Erie is 480 cubic kilometers.
Resiniferatoxin is 1,35g/ml and water is 1g/ml, for where it matters.
* A half teaspoon of resiniferatoxin mixed into a two-litre bottle of water will make it hotter than the same two litre bottle full of pure capsaicin.
* A kilogram of bell peppers, soaked in a solution with a single drop of resiniferatoxin, would be rendered as hot as a kilogram of ghost peppers.
* Six olympic swimming pools of resiniferatoxin could render Lake Erie as hot as a mild pepper, and 30 could make it as hot as a jalapeno. Given that the total synthesis of resiniferatoxin is a solved problem, this actually quite an achievable task.
If you think capsaicin is harsh, try resiniferatoxin. Activates the same receptor as capsaicin, but is 500-1000 times more potent. 16 billion scoville units;) They call it a toxin for a reason. The threshold between pain symptoms and toxic symptoms in chemicals that activate TRPV1 is high, but not unlimited.
There's nothing to contaminate it with, in the end the electromagnetic radiation might break a few chemical bonds, which can be really bad for DNA strands (i.e. cause cancer), but in the case of water it'll just recombine and warm up a bit
Which is why nuclear reactor core coolant doesn't become radioactive, right?;)
3H (effectively) doesn't capture neutrons, but both 1H and 2H do. 1H has a pretty high cross section for them, so readily breeds 2H, although 2H has a rather small cross section, 3 orders of magnitude less than 1H (but you still get some tritium over time). 16O has a rather low cross section (similar to deuterium) and only becomes stable 17O, which can capture to stable 18O, so it's not a major threat concerning low-energy neutron capture. Minor water contaminants can have much larger cross sections (overwhelming their low abundances) and/or create hazardous byproducts. For example, the (n, alpha) cross section of 10B is 4 orders of magnitude higher than 1H (minor boron contamination led the Germans in World War II to incorrectly conclude that graphite had too high of an absorption cross section to be used as a moderator). As a general (but not universal) rule, the heavier the isotope, the more likely that neutron capture will lead to dangerous daughter products.
So don't get me wrong, water is excellent from the perspective of not breeding hazardous isotopes. But it's not immune to it
And the short of it is, no, your water supply is not going to get contaminated. But water alone doesn't really make up an optimal shield; an optimal shield is layered. For example, hydrogen-rich materials, while superb neutron moderators and "decent" neutron absorbers in their own right, tend not to be good shields of EM radiation (high-Z materials work best for that). And there are far better candidates for neutron absorbers than water (for example, heavily borated plastics). But with layering you can create a more effective net whole.
Lastly: the heating of water from GCR or solar radiation is utterly irrelevant.
Indeed. Crocodilians are the closest living relatives to dinosaurs that are not themselves dinosaurs (the closest living relatives are, of course, the avian dinosaurs that are still around - a particularly cute variety of which is is currently trying to preen my fingers while I type;) )
And the driver who destroyed said barrier was not on autopilot. Normal human error.
Check out the intersection on Google Maps and you can see what went wrong, both for the human, and for autopilot. The left line is quite distinct. The right line is rather worn. There is no visible crosshatching at all between them. Once a vehicle crosses the fading line, what looks like a "lane" forms around them, seemingly reinforcing that this is an acceptable place to drive. This happens only seconds before the barrier is hit, so there's not that much time to react to the situation. There are no overhead signs, just the road-level sign. In dense traffic, it's not visible until you're in the invalid "lane".
Any driver, paying attention, will of course not do this. But human drivers' attentions lapse, and that's a mistake that humans can - and recently did - make.
Concerning Autopilot, there's a big question as to what versions people are running. Walter Huang, at the very least, was almost certainly running the old AP. It's not clear what versions the YouTubers were running. There was a massive AP update that just started rolling out recently that makes a huge difference in quality. To the degree that I'm actually rather concerned about it. The more imperfect the system, the more attention you pay to it. I have worries that with the new system, it's gotten good enough that it's going to cause peoples' attention to lapse. Having to touch (with torque) the wheel at regular intervals helps, but I hope Tesla gets eye tracking in place soon.
Don't get your engineering information from a chemist.
PS the infrastructure costs are way more than any highspeed rail
Pulling claims out of a hat is not how you budget; a budget is how you budget.
maintenance of a vacuum
Which is why it is a good thing that Hyperloop does not involve maintaining a vacuum. What people generally refer to as a vacuum - aka, a hard vacuum - is many orders of magnitude more difficult to achieve and maintain than the ~1mbar pressure of Hyperloop. Like on the order of 1e-9 mbar (normal air pressure is close to 1 bar)
Thermal expansion is a huge issue.
Except that it isn't. At all. Engineers deal with thermal expansion every day, and there are numerous ways to handle it, including increasing bend radii (not particularly practical here), expansion joints (Hyperloop Alpha involves one at each endpoint (aka, where the vehicles are moving slowly, on wheels), with the pylons allowing the entire tube to slide freely along its length), or - what HSR generally does - just simply resisting it. Thermal expansion force is just that - a force. It's not some irresistible property of nature; you can resist it with a force running counter to it. HSR generally uses pretensioned rails - that is, they lay them hot, so that when they cool they want to contract - but the contraction is resisted by heavy concrete sleepers anchored well to the ground. That would be a perfectly acceptable approach for Hyperloop as well.
The funny thing is, I was reading a conversation a couple weeks ago, and a person suggested a monorail as an alternative to Loop (not Hyperloop). So I started quoting from the monorail song to him. Except he'd apparently never heard it before and kept making serious replies to each of the "questioner" lines in the song. I couldn't stop laughing. Unfortunately he stopped responding once I asked him if he was sent here by the devil.;)
Why the hell would you label veganism and pollution as taking sides, as if pollution only affects a certain portion of humans? Family values? Censorship? Give me a fucking break.
Yes, all of those right-wing vegans protesting they Keystone pipeline and all of those left-wingers railing about "sexual degeneracy" and shouting drill-baby-drill.
Signs are there that she is a Muslim. But I also see nothing there pointing to her having some sort of "jihadist" ideology. Her rant goes off against everyone who disagrees with her ideology, which appears to be a mix of left and right.
Things she rants about from the left:
* Veganism
* Corporations
* Pollution
Things she rants about from the right:
* Family values
* Sexual degeneracy
Things she rants about that could be from either:
* Materialism (although you probably see complaints more often from the left)
* Censorship (although you probably see complaints more often from the right)
Doesn't fit neatly into any box except "angry and feels the world is against her"
Gross margin = Gross profits / sales = historically around 25%, down a bit recently due to Model 3 production issues Your graph is operating margin, which is EBIT/sales. EBIT = gross profits - operating expenses (SGA, etc) - non-operating income + interest. In 2017, gross profit for TSLA was $2,2B, SGA was $2,5B, and R&D was $1,4B, yielding a net loss of $1,6B (plus everything else = -$2B). But a gross margin around 25% is quite solid for the auto industry. Tesla ran a negative not because of negative automotive margins, but because 1) SGA is scaled up to the size Tesla is actively growing to, not to the company's current sales, and 2) likewise for the R&D budget. Which are both exactly what you want to see in a rapidly growing company. None of Tesla's investors want to see them sit back on their laurels right now and live off of S and X; the point of investing in Tesla is to have a stake in a company that's transforming the automotive market. And that requires rapid scaleup. Gross margins prove the economic case for your products; operating margins remain negative until you've grown large.
Slashdot Mirror
The GP never said nor implied that the cost of LOX is the issue (they argued just the opposite). Their main point was that putting the mass of a O2 liquefaction plant on a rocket, so large that it can liquefy a whole first stage's worth of oxygen in a matter of minutes - and having that be mass that you then have to land if you want the vehicle to be reusable - is not a reasonable approach. They're probably right.
The suborbital travel doesn't even need to be net profitable on its own - it only needs a positive margin. Only "suborbital travel plus Mars tickets" needs to be net profitable. SpaceX added in suborbital travel because they were otherwise going to have these big expensive pieces of hardware just sitting around between launch windows. Might as well use them to bring in additional revenue during that time.
What the heck is wrong with commenters on this Slashdot article? It's like people are just searching for some reason to dig into other commenters.
Tough Love said nothing about "this should have been launched on a Saturn V". They were pointing out that is impressive as this rocket may be, it's nothing compared to what the US was achieving in the 1960s.
Please try to learn not to interpret reflective comments as demands.
"Studio audience"? Cheers "played over and over again"? Are you kidding?
The latest Slashdot conspiracy theory: SpaceX uses prerecorded cheering during launches.
Normally I'd write a rebuttal concerning charge times - but in the case of India, honestly, you're spot on. India has been doing this "We want a ton of electric vehicles.... but we're not going to do anything to prepare for them or encourage them" game. I mean, they added a subsidy, but it's very small, and only applies to local manufacturers, which are way behind the game on EV tech investments. The country has put way too little into charging infrastructure, and their anticompetitive trade policies (such as the local sourcing policy) have kept a number of manufacturers out, because EVs tend to have very custom parts lines.
India could be another China when it comes to EVs, but they're going to need to get their act together if they want it to be anything more than talk.
I did a screenshot of him and then punched it into Google reverse image search. Google identified the image as "Bowtie" and suggested the website "How to tie a bow tie".
Of the people it thought he looked like: link
Meh, they're trying. Belatedly.
But yeah... this isn't exactly on par with watching a SpaceX launch. Even if they seemed more excited about their work, the fact that they don't seem to be trying to really achieve anything meaningful, pushing envelopes on what can be done... that sort of guarantees that they're not going to make as interesting of a webcast.
But again... at least they're trying.
And now it's just narration while we stare at some bored-looking men in suits in mission control.
Sad to see those SRBs when they jetison them. After seeing so many SpaceX launches, I automatically expect to see them orient themselves and then do a boostback burn. Then I have to remind myself... no, there's nothing about this craft that's going to be landing, it's all disposable.
What do you do when weapons without AI go south? Same thing. Innocent people die. The point of AI would be to decrease the odds of innocent people dying, not increase it.
First off, all "skynet" stuff aside, we're not talking about "generalized AI". We're talking about stuff like image recognition. Not learning neural nets, just pretrained ones. Secondly, this would be most desirable serving as a backup, not primary, control mechanism. One of the big problems faced by drones is jamming. If a drone gets jammed and you're lucky, it has to return to base autonomously without completing its mission. If you're unlucky, bad things happen. For example, US-made surveilance drones given to Ukraine met with bad reviews because the Russians - oh, I'm sorry, "rebels" - were using advanced electronic warfare systems to down them, and then downloading the images from memory to see where the Ukrainian positions were.
You want a drone that does whatever you want tell it to so long as you can maintain communications with it, but if someone jams your communications, you want it to carry out whatever mission you assigned to it as best as it can.
Beyond drones, AI would be very useful in missiles / guided artillery / etc. You find a target, you lock onto the target, and you want to ensure that the missile hits the target - whether the target is a tank, a plane, a group of soldiers, or whatnot. Your "targets", in turn, deploy a variety of countermeasures to try and make sure that the thing you shot gets confused and can't find it. Simple human-created algorithms describing how to determine what's your target and what isn't can only take you so far; having a neural net which is trained to recognize various types of targets - and various things that aren't targets - can make the weapon much more effective, while reducing the risk of it impacting a non-target object.
Then there's just general surveillance / monitoring. The more visual data you collect, the more manpower it takes to analyze it. But if you train neural nets to recognize weapons systems - from camouflaged tanks to guns in people's hands (trained *against* non-gun items which people might carry) - it can narrow down the imagery that humans need to look at when determining what should be targeted and what shouldn't.
To reiterate: in none of this are we talking about "generalized AI". We're not even talking about "learning AI". We're talking about "AI pre-trained to specific tasks". Which are things we already use in our everyday lives.
Wild blueberries (okay, bilberries) grow abundantly here and when they're in season on my land, there's often purple bird droppings full of seeds scattered all over everything that's left outside.
Nutritious fleshy fruits evolved for a reason...
Some plants even appear to have evolved "cheats" in their fruits. For example, there's a number of fruits that contain non-calorific chemicals that are many times sweeter than sugar; some of them are currently being incorporated into commercial products, while others are still only known in the wild. The theory is that this is part of an arms race with mammals, in that the plants can make the non-nutritious sweetener far cheaper than an equivalent amount of sugar, but eventually mammals evolve a resistance to non-caloric sweeteners in order to ensure that they're actually getting their needed calories in their food. I imagine that you get the same sort of thing with plants evolving gelling agents to make "creamy" flesh in their fruits that tastes fatty without actually being fatty.
Shouldn't be surprising. Picture eating three orders of magnitude as much pure capsaicin. I don't think you'd survive that either.
Capsaicin is for amateurs. ;)
Teaspoons are well defined, 4.92892ml.
Drop is a unit in pharmacy equivalent to 0,05ml, not a "suggestive single drop"
An olympic swimming pool with a nominal depth of 2m is 250000l. Lake Erie is 480 cubic kilometers.
Resiniferatoxin is 1,35g/ml and water is 1g/ml, for where it matters.
To put that into perspective:
* A half teaspoon of resiniferatoxin mixed into a two-litre bottle of water will make it hotter than the same two litre bottle full of pure capsaicin.
* A kilogram of bell peppers, soaked in a solution with a single drop of resiniferatoxin, would be rendered as hot as a kilogram of ghost peppers.
* Six olympic swimming pools of resiniferatoxin could render Lake Erie as hot as a mild pepper, and 30 could make it as hot as a jalapeno. Given that the total synthesis of resiniferatoxin is a solved problem, this actually quite an achievable task.
If you think capsaicin is harsh, try resiniferatoxin. Activates the same receptor as capsaicin, but is 500-1000 times more potent. 16 billion scoville units ;) They call it a toxin for a reason. The threshold between pain symptoms and toxic symptoms in chemicals that activate TRPV1 is high, but not unlimited.
Burma Shave.
Which is why nuclear reactor core coolant doesn't become radioactive, right? ;)
3H (effectively) doesn't capture neutrons, but both 1H and 2H do. 1H has a pretty high cross section for them, so readily breeds 2H, although 2H has a rather small cross section, 3 orders of magnitude less than 1H (but you still get some tritium over time). 16O has a rather low cross section (similar to deuterium) and only becomes stable 17O, which can capture to stable 18O, so it's not a major threat concerning low-energy neutron capture. Minor water contaminants can have much larger cross sections (overwhelming their low abundances) and/or create hazardous byproducts. For example, the (n, alpha) cross section of 10B is 4 orders of magnitude higher than 1H (minor boron contamination led the Germans in World War II to incorrectly conclude that graphite had too high of an absorption cross section to be used as a moderator). As a general (but not universal) rule, the heavier the isotope, the more likely that neutron capture will lead to dangerous daughter products.
So don't get me wrong, water is excellent from the perspective of not breeding hazardous isotopes. But it's not immune to it
And the short of it is, no, your water supply is not going to get contaminated. But water alone doesn't really make up an optimal shield; an optimal shield is layered. For example, hydrogen-rich materials, while superb neutron moderators and "decent" neutron absorbers in their own right, tend not to be good shields of EM radiation (high-Z materials work best for that). And there are far better candidates for neutron absorbers than water (for example, heavily borated plastics). But with layering you can create a more effective net whole.
Lastly: the heating of water from GCR or solar radiation is utterly irrelevant.
Indeed. Crocodilians are the closest living relatives to dinosaurs that are not themselves dinosaurs (the closest living relatives are, of course, the avian dinosaurs that are still around - a particularly cute variety of which is is currently trying to preen my fingers while I type ;) )
And the driver who destroyed said barrier was not on autopilot. Normal human error.
Check out the intersection on Google Maps and you can see what went wrong, both for the human, and for autopilot. The left line is quite distinct. The right line is rather worn. There is no visible crosshatching at all between them. Once a vehicle crosses the fading line, what looks like a "lane" forms around them, seemingly reinforcing that this is an acceptable place to drive. This happens only seconds before the barrier is hit, so there's not that much time to react to the situation. There are no overhead signs, just the road-level sign. In dense traffic, it's not visible until you're in the invalid "lane".
Any driver, paying attention, will of course not do this. But human drivers' attentions lapse, and that's a mistake that humans can - and recently did - make.
Concerning Autopilot, there's a big question as to what versions people are running. Walter Huang, at the very least, was almost certainly running the old AP. It's not clear what versions the YouTubers were running. There was a massive AP update that just started rolling out recently that makes a huge difference in quality. To the degree that I'm actually rather concerned about it. The more imperfect the system, the more attention you pay to it. I have worries that with the new system, it's gotten good enough that it's going to cause peoples' attention to lapse. Having to touch (with torque) the wheel at regular intervals helps, but I hope Tesla gets eye tracking in place soon.
No, it isn't.
Don't get your engineering information from a chemist.
Pulling claims out of a hat is not how you budget; a budget is how you budget.
Which is why it is a good thing that Hyperloop does not involve maintaining a vacuum. What people generally refer to as a vacuum - aka, a hard vacuum - is many orders of magnitude more difficult to achieve and maintain than the ~1mbar pressure of Hyperloop. Like on the order of 1e-9 mbar (normal air pressure is close to 1 bar)
Except that it isn't. At all. Engineers deal with thermal expansion every day, and there are numerous ways to handle it, including increasing bend radii (not particularly practical here), expansion joints (Hyperloop Alpha involves one at each endpoint (aka, where the vehicles are moving slowly, on wheels), with the pylons allowing the entire tube to slide freely along its length), or - what HSR generally does - just simply resisting it. Thermal expansion force is just that - a force. It's not some irresistible property of nature; you can resist it with a force running counter to it. HSR generally uses pretensioned rails - that is, they lay them hot, so that when they cool they want to contract - but the contraction is resisted by heavy concrete sleepers anchored well to the ground. That would be a perfectly acceptable approach for Hyperloop as well.
The funny thing is, I was reading a conversation a couple weeks ago, and a person suggested a monorail as an alternative to Loop (not Hyperloop). So I started quoting from the monorail song to him. Except he'd apparently never heard it before and kept making serious replies to each of the "questioner" lines in the song. I couldn't stop laughing. Unfortunately he stopped responding once I asked him if he was sent here by the devil. ;)
Yes, all of those right-wing vegans protesting they Keystone pipeline and all of those left-wingers railing about "sexual degeneracy" and shouting drill-baby-drill.
Signs are there that she is a Muslim. But I also see nothing there pointing to her having some sort of "jihadist" ideology. Her rant goes off against everyone who disagrees with her ideology, which appears to be a mix of left and right.
Things she rants about from the left:
* Veganism
* Corporations
* Pollution
Things she rants about from the right:
* Family values
* Sexual degeneracy
Things she rants about that could be from either:
* Materialism (although you probably see complaints more often from the left)
* Censorship (although you probably see complaints more often from the right)
Doesn't fit neatly into any box except "angry and feels the world is against her"
Now up 6,15% pre-market. Aww, whatever happened to Tesla going bankwupt?
Read.
Gross margin = Gross profits / sales = historically around 25%, down a bit recently due to Model 3 production issues Your graph is operating margin, which is EBIT/sales. EBIT = gross profits - operating expenses (SGA, etc) - non-operating income + interest. In 2017, gross profit for TSLA was $2,2B, SGA was $2,5B, and R&D was $1,4B, yielding a net loss of $1,6B (plus everything else = -$2B). But a gross margin around 25% is quite solid for the auto industry. Tesla ran a negative not because of negative automotive margins, but because 1) SGA is scaled up to the size Tesla is actively growing to, not to the company's current sales, and 2) likewise for the R&D budget. Which are both exactly what you want to see in a rapidly growing company. None of Tesla's investors want to see them sit back on their laurels right now and live off of S and X; the point of investing in Tesla is to have a stake in a company that's transforming the automotive market. And that requires rapid scaleup. Gross margins prove the economic case for your products; operating margins remain negative until you've grown large.