Is there any good writeup on the ‘geophysical ignorance’ anywhere? I checked out some of the comments but they all seemed to be along the lines of ‘hydrogen rules, batteries drool’, and I can’t take hydrogen-car proposals very seriously given Tesla’s demonstrated success.
In any case, I read this a few days ago and found it very interesting. He’s at least up front about the fanboying, and the overoptimism seems to come from Musk directly (before I read this, I assumed that Musk’s talk of going to Mars before 2030 was so much PR intended to keep his mystique alive and stock prices & valuations high and, among other things, deflect attention from the extent to which his companies are still dependent on subsidies; after, I began to take seriously the idea he might actually believe all that), and if nothing else, it seems like this is the closest thing to a comprehensive Musk manifesto—which is interesting all on its own.
I was referring to the grand future presented with Mars terraforming in a ridiculously short time, and talking about terraforming the moons of Jupiter and Saturn.
As for Mars terraforming… we can’t control a 200 parts per million problem in our own atmosphere with a whole civilization’s resources. Mars has at LEAST a 200,000 parts per million problem, and toxic salts in the soil. And it’s covered in crust that has never seen much O2 and will react with and suck it out of the air at a pretty good clip unless compensated for by massive biogenic carbon burial rates.
It is utterly beyond me that anyone could ever consider it possible to terraform Ganymede or Titan. They’re not made of the kind of stuff that is even solid at human temperatures, they’re so cold that according to my calculations boosting the upper ten kilometers of Titan’s crust to human-compatible temperatures would take 50,000 years assuming it was pitch-black and did not radiate any heat to space which is physically impossible (its blackbody temperature would be something like 90 kelvin, you need a hell of a greenhouse...), and the sunlight on Ganymede is 4% that of here and at Titan it’s 1% that of here so I don’t think you could even do that in the first place. These bodies would also have atmosphere lifetimes at human temperatures of single or double digit kiloyears as well as near as I can calculate, especially around Jupiter with the crazy radiation environment.
Isn’t this a bit of a “straw musk”? I haven’t seen it claimed by Musk or anyone competent/high up at Spacex or their fan communities that Mars could be terraformed in a “ridiculously short” time, i.e. < 30 or so years.
Perhaps we should be more precise about what counts as “ridiculously short”, quantify the disagreement, etc.
What’s going on in your first paragraph? How did we get from spaceflight to cars?
Without bothering to read these comments, my understanding is that fuel cells are bad for cars but good for spaceships. Batteries win on energy per volume, but lose on energy per mass. Also, fuel cells can store energy for a longer period of time, but that is relevant to the outer system, not for Mars.
Batteries win on energy per volume, but lose on energy per mass.
No, the issue is power density. Fuel cells win over batteries in terms of energy per mass but lose in terms of power per mass and power per volume. Fuel cells are still an order of magnitude or so behind batteries in terms of deliverable power. This is why they are best suited to applications that require power drain for an extended period of time without the possibility of recharging.
It’s difficult to directly compare batteries and fuel cells, though, because in the fuel cell the actual fuel tank is separate from the electrodes and can be made as large as desired. In the limit of a very large fuel tank, huge energy densities of 20 MJ/kg or 15 MJ/L are possible with methanol. Compare this with about 1 MJ/kg for the best lithium-ion batteries. However, in the same limit, fuel cell power density drops to near zero.
I don’t know much about electric cars, but AFAIK the general consensus was that battery-powered EVs are largely infeasible unless there is some breakthrough in battery technology. Did Tesla achieve that or did they just use bigger and more expensive Li-ion batteries?
If I understand correctly, there isn’t enough easily recoverable lithium in the world to replace but a small fraction of existing vehicles with Li-ion battery-powered EVs. If that’s correct then, barring some breakthrough, Teslas will be forever expensive (and government subsidized) toys for rich people to signal wealth and environmental consciousness.
I don’t know about this specifically, but that sounds surprising: isn’t lithium one of the most common elements in the universe?
This was a minor point in Watchmen, which is where I first heard of it, so this has been the popular perception for why EVs didn’t happen for at least 30 years. It appears to be a somewhat serious concern, but as our experience with oil shows, provable known reserves track price to a degree that pessimistic calculations rarely take into account. (Lithium ion batteries also appear to be easily but expensively recyclable, meaning that once the price gets high enough, the total amount of active lithium is the issue, not the demand for new lithium each year.)
Sure, but if you want hydrogen in order to burn it wit oxygen and make heat and water in large scale then getting hydrogen from water is obviously not an option because of thermodynamics 101.
If you need hydrogen for something else, or if you need it to burn it with oxygen in some special application (e.g. rocket propulsion), then it may an option.
It’s possible that you are not the intended audience for such an article, which is clearly targeted at people like the author: a non-expert who is sometimes interested in technical topics. Simplifications, which were indeed abundant, are not the same thing as errors, which is what it sounds like you were implying with “ignorance”.
If the author was all, “the thrust-to-weight on a Merlin is like, awesome” and you were like, “but that vacuum ISP, yo!” then you should probably be following SpaceX from nasaspaceflight.com rather than from an eclectic blog.
I don’t get why there is so much Elon Musk fanboying in tech/libertarian circles. All the businesses the guy is involved in are heavily subsidized by the US government, and yet he gets heralded as a champion of libertarianism.
We can certainly admire Musk’s talent for finding innovative ways of exploiting the system for personal gain and creating a cult of personality around himself, but a John Galt incarnate he is not.
I don’t get why there is so much Elon Musk fanboying in tech/libertarian circles. All the businesses the guy is involved in are heavily subsidized by the US government, and yet he gets heralded as a champion of libertarianism.
I mostly see the fanboy stuff coming from generic technophiles and millennial liberals/environmentalists.
It wouldn’t surprise me too much if some libertarians are big fans, there is a lot of overlap between technophiles and libertarians for whatever reason. And I suppose moderate libertarians wouldn’t oppose subsidizing corporate R&D if there are plausible positive externalities. Not all libertarians are purists.
Saw this a few weeks ago. The fanboying, overoptimism, and geophysical ignorance causes me great pain.
Is there any good writeup on the ‘geophysical ignorance’ anywhere? I checked out some of the comments but they all seemed to be along the lines of ‘hydrogen rules, batteries drool’, and I can’t take hydrogen-car proposals very seriously given Tesla’s demonstrated success.
In any case, I read this a few days ago and found it very interesting. He’s at least up front about the fanboying, and the overoptimism seems to come from Musk directly (before I read this, I assumed that Musk’s talk of going to Mars before 2030 was so much PR intended to keep his mystique alive and stock prices & valuations high and, among other things, deflect attention from the extent to which his companies are still dependent on subsidies; after, I began to take seriously the idea he might actually believe all that), and if nothing else, it seems like this is the closest thing to a comprehensive Musk manifesto—which is interesting all on its own.
I was referring to the grand future presented with Mars terraforming in a ridiculously short time, and talking about terraforming the moons of Jupiter and Saturn.
As for Mars terraforming… we can’t control a 200 parts per million problem in our own atmosphere with a whole civilization’s resources. Mars has at LEAST a 200,000 parts per million problem, and toxic salts in the soil. And it’s covered in crust that has never seen much O2 and will react with and suck it out of the air at a pretty good clip unless compensated for by massive biogenic carbon burial rates.
It is utterly beyond me that anyone could ever consider it possible to terraform Ganymede or Titan. They’re not made of the kind of stuff that is even solid at human temperatures, they’re so cold that according to my calculations boosting the upper ten kilometers of Titan’s crust to human-compatible temperatures would take 50,000 years assuming it was pitch-black and did not radiate any heat to space which is physically impossible (its blackbody temperature would be something like 90 kelvin, you need a hell of a greenhouse...), and the sunlight on Ganymede is 4% that of here and at Titan it’s 1% that of here so I don’t think you could even do that in the first place. These bodies would also have atmosphere lifetimes at human temperatures of single or double digit kiloyears as well as near as I can calculate, especially around Jupiter with the crazy radiation environment.
Isn’t this a bit of a “straw musk”? I haven’t seen it claimed by Musk or anyone competent/high up at Spacex or their fan communities that Mars could be terraformed in a “ridiculously short” time, i.e. < 30 or so years.
Perhaps we should be more precise about what counts as “ridiculously short”, quantify the disagreement, etc.
What’s going on in your first paragraph? How did we get from spaceflight to cars?
Without bothering to read these comments, my understanding is that fuel cells are bad for cars but good for spaceships. Batteries win on energy per volume, but lose on energy per mass. Also, fuel cells can store energy for a longer period of time, but that is relevant to the outer system, not for Mars.
The linked articles cover pretty much everything, from cars to spaceflight.
No, the issue is power density. Fuel cells win over batteries in terms of energy per mass but lose in terms of power per mass and power per volume. Fuel cells are still an order of magnitude or so behind batteries in terms of deliverable power. This is why they are best suited to applications that require power drain for an extended period of time without the possibility of recharging.
It’s difficult to directly compare batteries and fuel cells, though, because in the fuel cell the actual fuel tank is separate from the electrodes and can be made as large as desired. In the limit of a very large fuel tank, huge energy densities of 20 MJ/kg or 15 MJ/L are possible with methanol. Compare this with about 1 MJ/kg for the best lithium-ion batteries. However, in the same limit, fuel cell power density drops to near zero.
I don’t know much about electric cars, but AFAIK the general consensus was that battery-powered EVs are largely infeasible unless there is some breakthrough in battery technology. Did Tesla achieve that or did they just use bigger and more expensive Li-ion batteries?
If I understand correctly, there isn’t enough easily recoverable lithium in the world to replace but a small fraction of existing vehicles with Li-ion battery-powered EVs. If that’s correct then, barring some breakthrough, Teslas will be forever expensive (and government subsidized) toys for rich people to signal wealth and environmental consciousness.
I do know that battery technology steadily, if unflashily, improves over time; from my evernotes, see for example the Performance Curves Database for some charts or https://www.quora.com/Is-it-true-that-battery-energy-density-improves-5-8-per-year or http://rameznaam.com/2015/04/30/tesla-powerwall-battery-economics-almost-there/
I don’t know about this specifically, but that sounds surprising: isn’t lithium one of the most common elements in the universe?
This was a minor point in Watchmen, which is where I first heard of it, so this has been the popular perception for why EVs didn’t happen for at least 30 years. It appears to be a somewhat serious concern, but as our experience with oil shows, provable known reserves track price to a degree that pessimistic calculations rarely take into account. (Lithium ion batteries also appear to be easily but expensively recyclable, meaning that once the price gets high enough, the total amount of active lithium is the issue, not the demand for new lithium each year.)
Hydrogen is even more common than lithium, but good luck mining it.
It’s just a matter of price. At a sufficiently high price for hydrogen there would be no problems in supplying very large quantities of it.
Not even all that high—water is pretty common...
Basically, the price of energy to split water into oxygen and hydrogen is a hard ceiling for the price of hydrogen.
Sure, but if you want hydrogen in order to burn it wit oxygen and make heat and water in large scale then getting hydrogen from water is obviously not an option because of thermodynamics 101.
If you need hydrogen for something else, or if you need it to burn it with oxygen in some special application (e.g. rocket propulsion), then it may an option.
It is a perfectly good option if you need hydrogen as energy carrier and not as energy source.
It’s possible that you are not the intended audience for such an article, which is clearly targeted at people like the author: a non-expert who is sometimes interested in technical topics. Simplifications, which were indeed abundant, are not the same thing as errors, which is what it sounds like you were implying with “ignorance”.
If the author was all, “the thrust-to-weight on a Merlin is like, awesome” and you were like, “but that vacuum ISP, yo!” then you should probably be following SpaceX from nasaspaceflight.com rather than from an eclectic blog.
Yes.
I don’t get why there is so much Elon Musk fanboying in tech/libertarian circles. All the businesses the guy is involved in are heavily subsidized by the US government, and yet he gets heralded as a champion of libertarianism.
We can certainly admire Musk’s talent for finding innovative ways of exploiting the system for personal gain and creating a cult of personality around himself, but a John Galt incarnate he is not.
I mostly see the fanboy stuff coming from generic technophiles and millennial liberals/environmentalists.
It wouldn’t surprise me too much if some libertarians are big fans, there is a lot of overlap between technophiles and libertarians for whatever reason. And I suppose moderate libertarians wouldn’t oppose subsidizing corporate R&D if there are plausible positive externalities. Not all libertarians are purists.