Frank

Is there a practical application, or is this theoretical? What are the containers made of? How big are they? Are we talking sink and plastic or ocean and tankers? Do we want an exact answer or a general understanding?

Yes, with caveats. Has this setup failed to produce expected results?

Perhaps anhydrous ammonia makes more sense than aqueous. It can be dissociated in the regenerator using a nickel catalyst at a temperature of 920 C : 2 NH3 N2 + 3 H2 then the Nitrogen and Hydrogen can be heated to high ejection speeds. https://www.crystec.com/kllhyame.htm

If water can be used as a propellant, can aqueous ammonia work as well? How would dissociation due to ionization (NH4OH) affect Isp? Would the increase in hydrogen increase exit velocity and Isp? One advantage is a lowered freezing point. Plus many of the advantages of water - smaller tanks, ISRU, non-cryogenic...

I was thinking about the LEO constellation since rocket launch costs are 10x cheaper now and still dropping. Satellites are getting smaller and faster too. Haven't looked into it in depth though, just peripheral info from launch providers (Musk and Beck). (600 kilometers) / the speed of light = 2.00138457 milliseconds (so maybe 5 ms delay?)

I didn't read the article, but POTS can run for 2 weeks off their batteries (need to switch to an old-school line-powered phone) whereas VOIP? That's why I still have a land line, that plus ADSL(internet) comes in on the phone line as well. I think wireless phone towers last a few hours after power goes out (last I heard). It sure will be interesting when satellite phones become cheap - no power outage issues there except your own phone power.

I wonder how that relates to user base, seems like a high percentage of the pop.. Same people may download the app on new phones which are replaced about every 18 months on average and install on their tablet and computer.

All true. The point I was trying to make though is that any IP (like UDP and TCP) packet can be delayed (or even lost/dropped) whereas phone communication uses protocols (and transmission infrastructure) that are timely so that conversations aren't interrupted most of the time. I think in the future as communication becomes cheaper, has abundant bandwidth and is faster, none of this will matter and internet calls will be as smooth as phone calls. VOIP still needs a gateway to POTS/wireless phones though, and that will matter less and less also as more people move to VOIP type of communication.

I think the key is packet delivery in "real time". UDP or TCP IP packets can be delayed finding routes through the internet and delayed by heavy traffic connections or even from local interference of wifi signals. Plus some service providers were caught intentionally delaying packets used for voice presumably to sell their expensive phone communication. Why would anyone use an expensive phone plan when Video/Audio chat is better and data rates are cheaper?

Does Ballistic Capture mean solar engine ships can efficiently bring cargo to Mars? Since Mars gets about half the solar energy the earth does, braking near Mars is that much harder for solar powered spacecraft. Also, Ballistic Capture allows a continuous stream of cargo to be sent, keeping the solar ships continuously operating, no need to wait for that window only open every ~26 month. Return trip doesn't carry as much cargo, so the efficiency lost due to lack of solar energy is reduced. Thoughts?

Radiator inlet/engine temperature is controlled by a thermostat which opens up the flow of coolant to the radiator at a set point, cooling the engine. This regulates the engine temperature.

So each torus will have different levels of artificial gravity. I would think about a tensile structure like a bicycle wheel instead of poles between the tori, less mass or stronger structure for the same mass. It would then be easier to have a large numbers of spokes that could withstand a meteorite (external event) break. Sending such a colony to Mars for example might be another way to colonize. A slow, large ship that can use a low(er) energy Ballistic capture trajectory. Then use small landers that can shuttle people to the surface and back.

I hadn't hear of this experiment, but from what I understand, it's about determining atomic nucleus size and not about blocking cosmic rays. "Most of the -particles were able to pass through the gold foil without encountering anything large enough to significantly deflect their path. A small fraction of the -particles came close to the nucleus of a gold atom as they passed through the foil. When this happened, the force of repulsion between the positively charged -particle and the nucleus deflected the -particle by a small angle. Occasionally, an -particle traveled along a path that would eventually lead to a direct collision with the nucleus of one of the 2000 or so atoms it had to pass through. When this happened, repulsion between the nucleus and the -particle deflected the -particle through an angle of 90o or more. " - http://chemed.chem.purdue.edu/genchem/history/gold.html It's been shown that aluminium typically used in spacecraft scatter high energy particles into many slower particles that cause more damage to human tissue. Despite our orbiting ISS being inside the earth's magnetic field, mostly, astronauts are still affected. Adequate shielding requires heavy material, for example 5 to 10 m of regolith for a moon base to equal earth's protection by it's atmosphere. The latest thing I've read is about hydrogen being the best shield, but still a massive thickness is required. Artificial magnetic shielding so far seems impractical, heavier than the material required to shield, plus needing power and the added risks of large electromagnetic fields.

How are the torus rings arranged? The obvious way would be as a stack which would make me wonder why not a cylinder, then there are no poles to worry about. I haven't found a good way to deal with solar particle events and cosmic rays when considering space colony habitats. It's very important to long term population well being. Have you though of a way around that? As to the pole arrangement, I would think that if the stresses are enough to damage one pole out of seven, six would soon after meet their demise since the same stress would be on the fewer remaining poles.

Interesting. So Qr-codes might mess with the aesthetics? Laser pointer could activate (or even power) a radio transmission (blue-tooth or RFID) as others mentioned. Not so great if many people are using the model simultaneously. Are viewer(s) limited to the perimeter or to an observation area? Or free to roam in the model? Might make some things easier if the vantage point is known. Use the QR-codes at the observation point to load up a map of where things are relative the particular qr-code? RFID could function in a similar way.

True. But qr-codes posters are cheap to print, so can be oriented/positioned. as needed. If line of sight isn't needed, then a simple geolocation map can be used to display targets based on current position in a specialized app. Click on the target (could even be merged with camera view and phone orientation and position to display virtual targets). Update the map as needed. Hard to know without knowing the actual application.

Telephoto lens, smartphone, small qr-code target opens pdf. No batteries in target, cheap, simple, no coding or app needed...

The extra optical zoom lens on a smartphone (plus digital zoom) isn't enough?

Billboard size qr-codes? Does this need to be usable by anyone or someone using special equipment? Smaller qr-codes and magnifying lens? Laser might illuminate the code. RFID are radio frequency waves and lasers are light waves, not really compatible.

If you slide your magnet along aluminium, you will feel slight resistance and lift from the opposing magnetic field induced.

Maybe a cheaper ferrite based on the colour/cost/mass - the darker parts? https://en.wikipedia.org/wiki/Ferrite_core This website forum says aluminium (aluminum) cover. https://hardforum.com/threads/what-metal-is-a-hard-drive-made-of.787462/ Looks like the darker parts are probably plastic, not ferrite.

At concentrations of 10% or less in gasoline, ethanol improves combustion and raises octane, making the up for some of the energy content loss. Ethanol concentrations above 10% don't make much sense to me. Better to harvest electricity for electric vehicles (or hybrids) directly, since, as Ken Fabian wrote, energy conversion is low for crops.

Since the top is being heated, the bottom could house a phase change material like a sodium acetate heating pad which would hold more heat and could also be activated on demand: https://en.wikipedia.org/wiki/Sodium_acetate#Heating_pad

One thought is it could use a radiation heat loss layer on the inside surface - like an aluminium layer or MLI - https://en.wikipedia.org/wiki/Multi-layer_insulation Not sure what the best way to accomplish this is - inner container or maybe painted on. The other thought is to use an insulated bag around multiple units. The bag would have the required insulation thickness and would be used during transport. The last thought is to actively add heat via a battery, like a hunting jacket/socks. One more is to use a material that can retain heat and heat that before putting in the food. Or a phase change material that can be activated closer to readiness time.

It helps to have the right link... I guess I responded too fast and got the wrong link. If figure 1.8 of http://veprints.unica.it/616/1/PhD_Roberto_Pintus.pdf is representative, I think the heat exchangers will make this too bulky and heavy for automotive applications. If someone figures out a way around that, it would be better. The 90% efficiency upper bound is enticing. Vibration in ICE can be cancelled and oil changes are infrequent because there is no side force on the pistons in the free-piston style engines. I'm hoping fossil fuels won't be needed in the future for automotive use because of better battery technology.