ncmncm

85 ms·

961.
by ncmncm 4y ago
You can stand up a thermoelectric panel exactly at the terminator, and collect energy by transferring heat from its day to its night side. The night side would be radiating to -270 degrees Celsius, warmed only by whatever convective air is
962.
by ncmncm 4y ago
"electrolysis". Hydrolysis is a wholly different activity. The intent of the method presented is to make electrolysis energetically cheaper. It might end up financially cheaper, depending on what the apparatus costs, which will o
963.
by ncmncm 4y ago
Centrifugal force is v^2/r, so smaller r increases it. And we have higher v, besides.
964.
by ncmncm 4y ago
Wheat is hard to grow in permanent twilight. And, with no water, because it is all frozen onto the night side. This is no more earthlike than Mars.
965.
by ncmncm 4y ago
Needs heat. But that is all found thousands of km away.
966.
by ncmncm 4y ago
With exactly zero liquid water available? Not likely.
967.
by ncmncm 4y ago
Most likely none.
968.
by ncmncm 4y ago
In any case all its water would be locked up in ice on the night side.
969.
by ncmncm 4y ago
Probably. And certainly tidally locked, so 1 year = 1 day, with a permanently boiling day side, a hard-frozen night side, and a temperate, twilit ring straddling them. All moisture would naturally migrate to the dark side and freeze there,
970.
by ncmncm 4y ago
The authors' speculations on how hydrogen may be used are irrelevant to the substantive content of the article. There is no shadow of doubt about whether hydrogen production will be massively important in the immediate future, so bette
971.
by ncmncm 4y ago
Done.
972.
by ncmncm 4y ago
It had air, water, game, forest, and immediately arable land (cleared by people who had died in imported pandemics). It even had gravity. What does Mars have besides caustic dirt? We have no valid reason to assume a pregnancy could be carri
973.
by ncmncm 4y ago
Last year the world used seven hundred million tons of hydrogen, almost all produced from natural gas. In the future the world will use many, many times more, on top of all current uses producing steel, ammonia, and even methane, liquifying
974.
by ncmncm 4y ago
"Life in excrements" is supposed to evoke an image of maggots poking up out of horseshit. At the time, maggots were thought to form spontaneously. Fly eggs were discovered sometime later.
975.
by ncmncm 4y ago
Obviously all conversions involve losses. If you have electric power but need hydrogen, you have to make the hydrogen, whatever the loss. This method has lower loss than others. Probably ammonia will be a better transport medium than hydrog
976.
by ncmncm 4y ago
The need for higher mass density exhaust to provide enough absolute thrust to get off the ground overwhelms H2's energetic efficiency. Thus, SLS, like STS before it, depends on solid-fuel rockets until well clear of the pad, and then j
977.
by ncmncm 4y ago
Electricity supply cost is plummeting. Water is plentiful, but pure enough water not to foul electrolysers has not been, and efficiency has been low. Avoiding liquid phase bypasses all the difficulties of existing electrolysis.
978.
by ncmncm 4y ago
The article is specifically about an efficient process to produce it at point of use, so it need not be stored.
979.
by ncmncm 4y ago
Efficient photochemical lysis is *possible", but not the way to bet. If it happens, it will enter the mix. There is no reason to think it would involve less use of metals than photovoltaics. Until hydrocarbon burning is a negligible pa
980.
by ncmncm 4y ago
LH2's extreme mass-energy density will make other aircraft unable to compete, because the weight savings may be sold as additional paying cargo capacity. That presumes a joule of LH2 is the same price as of kerosene. But LH2 may end up
981.
by ncmncm 4y ago
If you are not talking about solar panels, you are not in the conversation. Photovoltaic solar is vastly cheaper than any known photochemical process. It is strongly carbon-negative. The metals involved do not make it a polluter. It is poss
982.
by ncmncm 4y ago
You miss the meat of the article. Highly efficient production not subject to fouling makes hydrogen generated at point of use practical. H2 has myriad uses, and is gaining more at breakneck pace.
983.
by ncmncm 4y ago
You seem to have read only the introductory paragraphs. There is little need to store or transport hydrogen that may be produced right where and when it is needed.
984.
by ncmncm 4y ago
It is vastly more cost effective to build electric transmission lines instead of gas pipelines, and crack hydrogen at the point of use. Furthermore, the desert is a lousy place to put solar panels. They get hot and dusty, making them ineffi
985.
by ncmncm 4y ago
Only if he misses the point.
986.
by ncmncm 4y ago
Yes. The tech seems very interesting. The key observation seems to be that atmospheric water vapor is massively purer than any terrestrial water source. And, production directly from vapor avoids efficiency and fouling problems seen when wo
987.
by ncmncm 4y ago
That wholly misses the point. We need hydrogen production in unlimited amounts for myriad processes. Want synthetic ammonia? Need hydrogen. Methane? Hydrogen. Kerosene? Hydrogen. Green steel production? Hydrogen. Furthermore, liquified hydr
988.
by ncmncm 4y ago
The point is, it doesn't, mostly. It mostly just churns.
989.
by ncmncm 4y ago
Compilers have had many years of work put into generating optimal instruction sequences for POWER. That is all flushed away moving to RISC-V. Momentary "vitality of the ecosystem" just seems like a poor basis to choose the underpi
990.
by ncmncm 4y ago
Exactly the point: not technical merit.

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