mrfox

The counter-argument to this is that having a clear delineation around the freezing point of water plays a much more important role in identifying hazardous weather conditions in our day to day lives. 32f is rather arbitrary given the major effects freezing water has on our eco-system.

What is even more suspicious is how close 1 imperial foot is to 1 light nanosecond. It does make it really easy to guesstimate astronomical distances in conversation.

A day cycle is important because day/night. Year because of seasons. 4 weeks roughly follows the lunar cycle and hence - tides. But why should the 12 month cycle be kept besides convention?

Could you elaborate on this? Is this a scenario where there is an established infrastructure of nuclear space tugs? or is the mass trade off for shielding so great that it is better to have a (baseball analogy) pitcher/catcher setup on either end even for a single use mission?

In a later post you referred to the “BSHP island” for reciprocating piston engines. In a gas turbine (or any turbine really) this island is absolutely minuscule in comparison - basically, anything other than near max rated power at close to max rated RPM - efficiency falls off a cliff. This is because while the compression ratio and efficiency is mechanically fixed (and independent of RPM) in Otto/diesel cycle engines, it is highly variable with RPM in a gas turbine/brayton cycle engine - the spinning compressor absolutely depends on being at high RPM to achieve anything near design compression. Just look at an idling gas turbine’s fuel consumption - it is horrendous in comparison to a piston engine. And turbines also take forever to spin up - so its not like you can just shut the turbine off Willy nilly like a piston engine to avoid idling either.

Not saying it proves anything for what happened in the movie, but I do wonder how the spitfire compares with the shrike in terms of L/D ratio? A quick google shows the spit’s L/D max out around 13 at best glide... nothing found for the shrike.

Here’s the US FAA guidelines. Your regulatory standards may vary. https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/aam/ame/guide/app_process/exam_tech/item49/et/

They must’ve sent up the wrong core

Play around with this https://observablehq.com/@jake-low/satellite-ground-track-visualizer Placing the launch site anywhere else within the USSR would have require orbits of even higher inclinations if the constraint of no overflight over china in the initial orbit is observed.

But those same panels would be better utilised installed on your roof. The car can charge from them when needed. Same reason nature don’t put leaves on animals.

The USAF has airstream trailers that can be bolted in for use as VIP transport.

Here’s the FAA’s take on seizures and epilepsy. https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/aam/ame/guide/app_process/exam_tech/item46/amd/nc/ I was not aware of such a thing as Rolandic epilepsy. I, like many others, had always assumed epilepsy is automatically disqualifying. Interesting. I would suggest a “off the record” consultation with someone familiar with aviation medicals in your country.

plus pretty much all coffee grounds are full of roach parts. same reason no one bats an eyelid at hot dogs either.... its all about the packaging (and lots of seasoning).

Interesting point - I am surprised at how much nitrogen the cycle can lose due to off-gassing. https://nutrientstewardship.org/implementation/nitrogen-loss-pathways-which-is-yours/ If rainfall, irrigation (>1/2 in. within a few days after application), or tillage do not soil incorporate surface-applied urea or urea-containing N fertilizers within a few days after application, ammonia volatilization (gaseous loss as ammonia) may range from 20 to 40% of the N applied, and rival N losses from leaching and drainage. Gaseous loss of N from soils as nitrous oxide (a potent greenhouse gas affecting climate change), through nitrification and denitrification processes, is often <2 to 8 lbs of N/A in humid regions and may be <1 to 2 lbs/A in less humid regions (e.g. west of the Mississippi River).

Terrestrial insects might potentially be easier to farm for protein - just grind it up as protein powder if palatability is an issue. Realistically it’ll probably be cheaper to import the essential nutritional requirements, and mix with locally grown bulk for calories.

Ironically written by someone called “tater” Like it or not, potatoes (and sweet potatoes) are the best bang for the buck - literally, when resource constrained. TABLE 4.1 - Comparison average energy and protein production of selected food crops In developing countries (per hectare and per day) Crop Growth duration (days) Dry matter (kg/ha/day) Edible energy ('000 kcal/ha/day) Edible protein (kg/ha/day) Production value (US$/ ha/day Potato 130 18 54 1.5 12.60 Yam 180 14 47 1.0 8.80 Sweet potato 180 22 70 1.0 6.70 Rice, paddy 145 18 49 0.9 3.40 Groundnut in shell 115 8 36 1.7 2.60 Wheat 115 14 40 1.6 2.30 Lentil 105 6 23 1.6 2.30 Cassava 272 13 27 0.1 2.20 Source http://www.fao.org/3/t0207e/T0207E04.htm

I see a design tradeoff between a massive, 2-dimensional pressurized farming area constructed with fragile transparent material, vs a larger, but unpressurized outdoor solar array that pipes electricity into a smaller, more structurally efficient opaque pressure vessel. With artificial lighting, the grow beds can be oriented 3 dimensionally around the light source to optimize the use of interior space, not to mention increased biomass productivity from the availability of higher intensity, around -the-clock lighting if energy storage or a secondary power source is available. Please note this farming stuff is beyond subject areas with which I am familiar, so any corrections or links to further info/research/sources/numbers would be appreciated.

An interesting example is the cupola module in the ISS. It took over 2 decades of inter-departmental and international squabbling to eventually get something built and sent up that was half its original design size. And this is after 40 years of space station design iterations and experience - from the Salyuts, Almaz, and Skylabs, to Mir. 40 years - and 10 stations - with nothing but portholes. IMHO the cupola was lucky to have been built when it was, any further delays would’ve put it squarely against the remote video monitoring tech of today, and made its primary observational role superfluous and its risk even harder to justify. Still looks cool though. A CAD monkey does as he/she is told. A “good” designer must ask and evaluate what the the risk-reward balance is worth. Otherwise, you risk being remembered in posterity in engineering ethics textbooks as an example of what not to do.

Forgot the last and most important line - “Finally, the CEO will ask - can we afford to do it?” (Or not do it, in this case) Because we will likely have limited resources. And there will be so many priorities ahead of “a pretty but expensive view”. Igloos don’t have windows. And this is the level of austerity I imagine a Mars colony will be operating under using current tech. Now if we can hand-wave in some magical future tech which drastically lowers the cost of building, transporting, and erecting Mars infrastructure - in that case this is more of a sci-if then a science-tech discussion, and I defer the podium to Elon’s, yours and everyone else fancy renderings. There are way cheaper and easier ways to provide psychological relief from enclosed spaces. The cost-benefit ratio of windows makes no sense at our current tech level.

It certainly is “possible”. I mean there are airplanes and submarines out there with bubble canopies. The question is, whats the tradeoff, and is it worth it? Its like the old engineering proverb - A scientist will ask whether it is possible. Marketing will ask what it can be used for. Accounting will ask how much it will cost. and engineering will ask whether its worth the effort to build. Your underwater restaurant is the perfect example - how many have been built? And how much does it cost to dine there?

Its not simply material strength. You have to consider the load paths of whats holding the rest of the structure together. A large window is a large structural void, with its associated stress concentrations. More importantly there are also failure mode considerations. Part of aircraft window sizing specifications involves consideration in the case of a window blowout. On aircraft, it is related to how quickly it can descent to a safe altitude. On a Mars hab - it would be how quickly a compartment can be evacuated or emergency equipment be activated vs how long the space can be kept partially pressurised. You can’t design a safety critical structure based on the premises that “nothing will break them”.

Its fun and exciting to imagine what these fancy futuristic habs migh look like - but what would be the tech readiness level of these designs? Realistically, and for the forseeable future - the overriding structural consideration for these habs will be the pressure vessel. So the design of these habs will be similar to an underwater hab. Like this https://en.wikipedia.org/wiki/Helgoland_Habitat https://en.wikipedia.org/wiki/Tektite_habitat Skylights and panoramic windows makes as much sense here as they do on an airplane or submarine. Think portholes.

With regards to any sort of exodus earth scenario- short of a disaster involving the earth’s crust melting away or its atmosphere stripped, it will always be less resource intensive to maintain a civilisation of some form here on earth, vs starting one elsewhere in the solar system. Even if we end up living deep underground, sucking on recycled filtered air while seeking refuge from a nuclear winter apocalypse... still easier here. This says more about the potential resource requirements and hardships of future inter-planetary settlements than anything else. This balance will likely not change with technological advancement either - as any given tech advantage developed for colonisation will prove equally useful for improving the habitability and carrying capacity of earth. What this means, however, is that for most of us, we are most likely not going anywhere. For better or worse this is going to be home for the foreseeable future and there will be no easy do-overs elsewhere. So we better start looking after the place.

This above is a actually a great reason for establishing a research colony on mars - biological/zoological research on the effects of long term martian living. Before sticking humans permanently there, it might be wise to stick a few colonies of primates and see how they do, and more importantly - whether procreation and gestation under martian environment is possible. Question is could this be done with an unmanned station? It’ll get done a lot quicker if its a one way trip for our monkey “friends”. Should it be done?