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OneDonOne

27 karma · joined August 14, 2022

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OneDonOne··on India's first privately-developed rocket reaches orbit on debut launch
Again,

Smaller radiator = bigger heat pump + more batteries and solar panels

Satellites have a mass and power budgets. Your scheme only looks at temperature. If you want to build infinitely large AI Data satellites, go ahead.

OneDonOne··on India's first privately-developed rocket reaches orbit on debut launch
See:

SNAP-10A

BES-5 (oops, sorry 'bout that Canada!)

TOPAZ-I

Kiwi, Phoebus, and NRX (Mars here we come!)

RD-0410 (Dossvidanya Solar System!)

SP-100

TOPAZ-II

Kilopower

OneDonOne··on India's first privately-developed rocket reaches orbit on debut launch
The Caltech Concept is just that — a concept. No prototype, no tests, no manufacturing, no results. When they achieve this order of magnitude improvement on a prototype scale, that's when we should take them seriously.
OneDonOne··on India's first privately-developed rocket reaches orbit on debut launch
It just goes to show magical thinking isn't just an American thing.
OneDonOne··on India's first privately-developed rocket reaches orbit on debut launch
Ah yes. The heat pump.

My response:

Carnot's theorem and refridgeration cycles rear their head. Your heat pump still needs power to pump heat uphill., negating any savings from a smaller radiator. And what happens when you shrink a radiator? It becomes a high temperature radiator, meaning the GPU must operate outside its operational tmperature of about 70 degrees C. So small radiator = big pump + extra solar panels and batteries + dead GPU

Also, how do you deal with the added cost and complexity for the solar tracking mechanisms for the "edge-on-to-the-Sun" radiator?

OneDonOne··on India's first privately-developed rocket reaches orbit on debut launch
> Ok, there are at least two bad assumptions there.

> First, it assumes the radiator is at the same temperature as the GPU. But radiators become dramatically more effective as temperature increases, with radiated power increasing as the fourth power of absolute temperature. So a heat pump that drives the radiator at higher temperature could make the radiator far smaller.

Carnot's theorem and refridgeration cycles rear their head. Your heat pump still needs power to pump heat uphill., negating any savings from a smaller radiator. And what happens when you shrink a radiator? It becomes a high temperature radiator, meaning the GPU must operate outside its operational tmperature of about 70 degrees C. So small radiator = big pump + extra solar panels and batteries + dead GPU

Also, how do you deal with the added cost and complexity for the solar tracking mechanisms for the "edge-on-to-the-Sun" radiator?

OneDonOne··on India's first privately-developed rocket reaches orbit on debut launch
This reminds me of the railgun. Basic math and physics tells us that not only would the (very expensive) barrels wear out very quickly, but that it would have had to be fitted on on a nuclear-powered pocket battlecruiser.

Worse, the technology for firing any meaningful payloads from an electric gun (8" Small Diameter Bomb equivalents, guided, airburst, incendiary) simply does not exist.

Same as with Musk's California Vacuum Tunnel (which diverted attention from passenger rail). And his Neuralink. In the 1980s, it was nuclear pumped space-based lasers and Soviet particle beam weapons.

All of the above can be debunked with 2 years undergrad physics and a Casio calculator. Yet they were still taken seriously by high-level politicians and business, some of whom were deeply connected with the military-industrial complex.

People have shrugging of questions like 1 and 2, only for 3 to hit them very hard. But we will see if they can launch 600 of these satellites as they claim.

OneDonOne··on India's first privately-developed rocket reaches orbit on debut launch
If the "physics" tells you that your satellite cannot radiate heat away from your nVidia GPU cluster because each H100 needs 1.1 meter square of radiator, then opinions do not matter. The same applies to power supply and bandwidth.
OneDonOne··on India's first privately-developed rocket reaches orbit on debut launch
This borders on science fiction. 88,000-and 1-million satellite clusters (as claimed in your link) are hard to take seriously, especially with the possibility of Kessler Syndrome. Also:

1. How do you cool your chips? Vacuum is a thermal insulator, so radiators are required to remove heat. nVidia (or even ASICs) require much and specialised cooling.

2. How does one radiation harden a H100?

3. I'm also seeing where TCO for these are 78x their terrestrial equivalents [0]. Is that financial sustainable?

And there still remain issues with power supply, regulations, and bandwidth. This feels more like a thought experiment rather than an actual serious engineering or business case.

[0] https://www.abiresearch.com/blog/data-centers-in-space

OneDonOne··on Why jet engines aren't made in China
Yes indeed, you are correct. My mistake.
OneDonOne··on Why jet engines aren't made in China
The ball is not microscopic, but the tolerances required to make the ball spherical and fit into the socket are.
OneDonOne··on Why jet engines aren't made in China
They do. The micro-precision subculture required to (in order):

1. Powder prep your tungsten carbide

2. Form said powder

3. Thermally prepare the resulting slurry using a vacuum forming furnace

4. Finish it with diamond lap grinders, lapping machines and polishing machines

5. Clean it ultrasonically, with solvent, rinse, then dry them.

6. Have the metrology required to test thousands of micron-scale balls a day (a world-beating skill in itself)

7. Build a QA lab that can assure the quality of said balls statistically (you can test them all).

8. And then integrate them via socket assembly

are not just hereditary, but proprietary. And assuming a competitor does manage to achieve the basic ISO 3290 and ASTM F2094 standards, you still need tacit knowledge. Stuff like sintering temperature curves, proper powder grain distribution, polishing chemistry, proper statistical rejection thresholds and a whole lot more.

And that is just the ball. Not the socket, or the ink channels. Making a perfectly spherical 0.5 mm ± 0.0001 mm tungsten carbide ball requires the same techniques used in building micromotors, medical devices, and semiconductor subcomponent manufacturing. Techniques such as high-volume sorting, advanced powder metallurgy, controlled sintering, and precision machines that operate 24-hour shifts without drifting. All operated by modern process engineers who are the spiritual (or actual?) descendants of Swiss watchmakers or the glassmakers of Murano.

OneDonOne··on Why jet engines aren't made in China
It is not the pen, it is the pen tip. Ballpoint pen tips are microscopic tungsten carbide ball held inside ultra-thin steel sockets. So you need cutting tolerances precise to 0.001 millimeters. If the socket is a fraction of a micron too loose, the ink leaks. Too tight, and the pen won't write.

Source from al-Arabiya: https://english.alarabiya.net/variety/2017/01/14/At-last-Chi...

The point (no pun intended) is that China was beginning to crack the processes for making the precision machine tools that make machine tools.

OneDonOne··on For the first time in the U.S., renewables generate more power than natural gas
How does that change the fact that solar panels cannot be manufactured without high quality coal? (0) And doesn't that undermine the "cement for nuclear power" argument?

(0) https://www.researchgate.net/publication/335083312_Why_do_we...

OneDonOne··on For the first time in the U.S., renewables generate more power than natural gas
By that logic solar power should also be banned, due to the amount of coal required per panel (0) both for reduction and Czochralski process. And remember, solar panel factories don't run on solar power.

(0) https://co2coalition.org/2024/05/21/coals-importance-for-sol...

OneDonOne··on Record wind and solar saved UK from gas imports worth £1B in March 2026
The LCOE may be triple, but the LFSCOE [0] (full system cost, not just cost of generation) however of solar, is triple that of nuclear in Texas, and 15x that in Germany. Notice that 1. Solar Irradiance per location is actually taken into consideration and 2. Renewables have not stopped the ongoing deindustrialization of Germany due to high energy costs.

[0] (PDF) https://iaee2021online.org/download/contribution/fullpaper/1...

OneDonOne··on Jack Dorsey says Block employees now bring prototypes, not slides, to meetings
Stupid question from a foreign newbie.

What separates a code monkey from a domain expert? Can you use infosec and embedded systems as two examples please?

OneDonOne··on Europe asks if reviving nuclear is the answer to energy shocks
I see Germany now has the third highest price for industrial electricity in Europe. Why is that then?
OneDonOne··on Europe asks if reviving nuclear is the answer to energy shocks
Has Germant's Energewiende helped with solving this energy issue?
OneDonOne··on OpenBSD on Motorola 88000 Processors
An excellent source for this architecture is Mitch Alsup and his Usenet posts going back to the late 1980s (he still posted regularly in the 2020s.)
OneDonOne··on Iran war energy crisis is a renewable energy wake-up call
Not only are electric trucks are unprofitable, it means you switch your dependency from Middle-Eastern fossil fuels to Chinese rare earths. At least we can make biofuels from sugarcane
OneDonOne··on Iran war energy crisis is a renewable energy wake-up call
The overbuilding that is required for stable electricity from the sun or wind makes that a non-starter. It is no wonder that when Germany tried this, they deindustrializrd, with some of the world's highest electricity prices. That should be a lesson to anyone who believes in renewables. Never mind the various issues that would occur with charging EVs during the night/overcast/non-breezy cconditions
OneDonOne··on Iran war energy crisis is a renewable energy wake-up call
Solar power is not infinite. Abd as long as you are using the same amount of energy/power to obtain the energy you wsnt to use, the pyshical limits of the size of the solar plant, time it takes to produce said energy, and other factors, makes said meyjod economically unviable.

Which is why we aren't doing already.

OneDonOne··on Iran war energy crisis is a renewable energy wake-up call
> Even during WWII Germany had to synthesize much of its hydrocarbon fuel.

Germany [0], as well as Apartheid South Africa (SASOL), and now China, synthesized that fuel from coal. Which is itself a fossil fuel.

[0] https://warhistory.org/@msw/article/synthetic-production-of-...

> Obviously, this will not be done as long as cheaper fossil hydrocarbons are offered. However the use of fossil hydrocarbons for plastic, asphalt or other applications that do not release CO2 is not harmful.

The issue with any fuel/feedstock production is not just the financial cost but the amount of energy returned on the energy invested. A modern civilization (like Japan) requires 10:1. Synfuels made using the method you described are 1:1 - they provide as much energy as it takes to make them.

OneDonOne··on Iran war energy crisis is a renewable energy wake-up call
Good for the Chinese. The rest of us do not have the upfront capital to purchase these trucks. And there is still the matter of fertilizer, concrete, bulk chemicals etc. And solar panels. There is a very good reason why solar psnel factories (like JinkoSolar run off coal or hydro and not solar power.
OneDonOne··on Iran war energy crisis is a renewable energy wake-up call
One of those dependencies w.r.t large solar panel buildouts, will be charcoal. [0] And lots of it.

[0] https://www.researchgate.net/publication/335083312_Why_do_we...

OneDonOne··on Iran war energy crisis is a renewable energy wake-up call
By feedstock, I mean the hydrocarbons that are required for the bulk chemicals, fertilizers, plastics, rubbers, detergents, pharmaceuticals etc. that we take for granted.

And you still need trucks for last mile haulage.

OneDonOne··on Iran war energy crisis is a renewable energy wake-up call
Modern civilization requires semiconductors, concrete, asphalt, fertilizer, and plastics to function. Never mind aviation and marine fuel to function. All of these require hydrocarbons. As long as that is the case, renewable power will continue to be a niche.
OneDonOne··on Iran war energy crisis is a renewable energy wake-up call
And how will renewables like solar and wind wirk with Class 8 trucks, shipping, aviation or process heat or as feedstock? How have they worked in Germany, which has shut down her nuclear plants and Russian hydrocarbons?

Please - tell us.

OneDonOne··on Iran war energy crisis is a renewable energy wake-up call
In the West you mean? The Asians seemto have this particular industrial aspect somewhat under control.
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