Terwin

Are you suggesting that zero-boiloff technology has advanced to the point that we can store an unpowered, liquid hydrogen fueled vehicle in an unair-conditioned garage in a southern state for days without a need to vent? That should make storing cryogenic hydrogen all the way to Mars pretty simple in comparison.

Nuclear plants Are cost-prohibitive in the US because the department of energy is both authorized and encouraged to tighten safety requirements any time nuclear becomes cost-competitive with any other power generation system in common use(like when fuel prices spike for existing plants of other types) And they cling to their no-threshold metrics in spite of the substantial and confirmed evidence against them. If the department regulating nuclear power were not incentivized to block future development, it would be much more affordable (but that could undermine the stock value of important donors) CO2 and nitrogen are frozen at MRI temperatures. You need something that can get much colder than those can. You suggest that a hydrogen fueled motorway is not full of ignition sources? How about the enclosed garage where the car is stored over night or while the family is away on holiday? Does hydrogen have a strong scent like spilled petrol does to warn away from turning on the lights?

A few points: Renewables are not 'free once set up' and you would need grid-scale storage of hydrogen. Hydrogen storage is notoriously difficult even for short-term usage(like single-use rockets) Hydrogen quickly destroys any container that holds it through embrittlelment, and is hard to store long-term because it can slip between the atoms of the storage container. Hydrogen is highly flammable and can explode when mixed with air. In short, even using 'cheap' petroleum sourced hydrogen is completely untenable for consumer use. Hydrogen is a (very bad) storage medium, not an energy source. Even in rocketry, hydrogen is only used by the government and only because it is easier to throw money at the problem instead of finding other solutions. Evidence: MRI machines could be cooled by hydrogen just as well as very expensive helium, but hydrogen just causes too many problems to be cost-effective.

That is only if you go slow.(like 0.1c or less) Sort of like going over a speed bump at 2mph vs 60mph. The first you might barely notice, and the second could break your axle or your spine. Every body is at the bottom of a well, and if you have no inertial dampeners, then zipping past ceres at near-light speeds might break bones and break off pieces of your ship just due to the rapidly shifting gravity. Fly past a real planet and you can get everyone smeared against the starboard wall of their current room as the ship gets jerks to port because of the the 'gravity pot-hole' created by the planet. And if any other ship uses the same sort of drive, then they might well fling your ship into a star anyway, just because you are unanchored to local space while they are moving in a different direction..

Except the corporations with the most money to spend on AI will not want any of those pesky ethics or morals you mentioned.

The resources themselves never run out, but you can only harvest it so quickly based on how rich it is. Think of it as having a limited number of useful mining sites in the biome for that resource. The mines never run dry, but you can only build so many of them before you run out of veins.

Don't forget Sturgeon's law. Only the best of the best survives the dust-bin of history.

Without magical inertial dampening(probably an instant reverse gravity effect to counter any impacts, or just a low-level warp effect that dampens inertia directly), you risk having your entire crew being turned to goo any time you pass too close to a nebula at warp speed(or pass through any other significant change in the density of the interstellar medium). This sort of effect would be needed for any sort of super-luminal travel that passes through real space.

99.86% of the mass of our solar system is in the sun. The remaining 0.14% is orbiting the sun using the net orbital momentum of the starting material. When you only need to orbit 0.14% and you are pulling in particles from thousands of au away, a tiny amount of initial momentum is all you really need. Light pressure from distant stars may well be all it takes. Anything not in the orbital disk will collide with something in the disk and either move closer to the disk, or closer to the sun/escape velocity. Only things with very few chances to interact with the orbital disk will be notably eccentric (like long period commets), as many interactions (collisions or gravitational interactions) will get them lined up with the disk.

When a photon hits a particle, the particle can absorb the photon, thus increasing the energy level of the particle(such as an electron). If a particle is in an excited state(such has having recently absorbed a photon), then it can emit a new photon as it returns to a lower energy state. (this new photon will often be at a different frequency depending on the particle that emitted it) If you are talking about a photon 'disappearing' during something like the double-slit experiment, then it does not disappear, it was never there, that location was just inside the probability area where the photon might have been.

True, any sorts of details that might help non-US interests in developing similar rocket capabilities might be illegal for SpaceX to share. Might be why there are lots of FOA requests and it has not been released: the US gov says 'No'

Kind of makes you wonder if 'dark energy' is just the consequence of a plank-length type limitation on gravitational waves, limiting the effect of gravity at longer ranges much like the plank length prevents the 'ultraviolet catastrophe' with very short EM waves. Then that might suggest that 'dark matter' is a consequence of something akin to emission spectra, but with a spectra specific to our galaxy/universal constants/etc. Then again, that may not provide any testable predictions, making it a rather useless interpretation.

light waves also get stretched in the same manner(called red-shift), but as the amount of space between here and there grows faster than what could be covered when traveling at the speed of light, it can never get here. Those stars are not moving compared to the local space, it is just that there is more space being created between here and there than could be covered if you were moving at the speed of light. If there is more space-time, then both gravity and light must travel the same distance and would get 'stretched' the same amount. Unless gravity waves can travel faster then the local speed of light, they can never 'pass' light that is traveling through a vacuum, and have the same range limit due to the expansion of space-time. Just because the speed of sound may be higher in a stretched rubber sheet than in a relaxed rubber sheet, does not mean that gravity waves can travel faster than a photon in a vacuum, regardless of how that space is stretched or warped.

I see no reason that gravity waves would not have the same limitation. Gravity waves do not get to exceed C just because the points they are traveling between are further apart than they were at some point in the past. They may get to stay at C instead of occasionally getting absorbed and re-emitted like EM waves, but that is the only difference I see between their travel speeds. Perhaps you can explain how a gravity wave travelling in a straight line can get ahead of a laser traveling parallel to that wave through a perfect vacuum without breaking relativity? Without this, gravity waves are stuck in the same light cone as EM radiation, and only have greater coverage within that cone because it is much easier to shield a region from light than it is to shield it from gravity. A light-wave and a gravity wave traveling through 'stretched' space would travel at the same speed unless blocked by other obstacles, and both would get frequency-shifted by the same amount by the expansion of the universe. Perhaps you could argue that gravity waves of a high enough frequency and amplitude could be detected more easily at a certain distance than light of the same frequency and amplitude, but the light would still be there, just less of it because light is easier to block or re-direct.

That does not seem particularly mentally healthy, are you confident that spending time with those people is not having a deleterious effect on your own mental health?

Sounds like good practice for remote operation of robots for construction in hostile environments such as orbit, Luna, or Mars.

Cold water tends to work so long as the cold is being applied, but for longer lasting relief, take water just below the temp where it is painful on healthy skin, and apply it to the irritated skin. If it is not painful on healthy skin, it should not cause any damage, but on the irritated skin it will be painful, then after you remove the heat it will not itch for a while. I suspect it is related to either desensitization or using up neurotransmitters for your pain receptors, so that it takes a while before the itch can return. (often long enough to fall asleep if you hold it under the hot water until it is no longer painful) This is the most effective method I have found for dealing with the itch of poison ivy without damaging the skin by popping all of those fluid filled blisters with scratching.

Musk wants to 'go fast and break things' so making mistakes and learning from them is part of the game plan. 'If you do not need to put it back at least 10% of the time, you are not removing enough parts' sounds like another 'make mistakes and learn from it' Verifying safety for human passengers by successfully launching unmanned lots of times with plenty of safety margin seems more reliable than proving that the vehicle is theoretically safe on paper like they did for the shuttle(before they realized it was a lot less safe then they thought).

Maximum dV is usually achieved with a TWR close to 1. There may be a desire to 'get them out' quickly, and thus have a higher TWR at launch. a TWR of 1.1 is fairly high, Super heavy with Starship has a TWR of 1.4, which is rather high (according to this 6 year old reddit thread: https://www.reddit.com/r/SpaceXLounge/comments/ae79vi/any_idea_about_the_thrustweight_ratio_of_super/ ) Anything over 1.5 is often considered wasteful for a rocket. Your missile would need a TWR of 1.64 to get off the ground. Missiles will often have a higher TWR for the sake of speed(and not getting shot down) Wiki (https://en.wikipedia.org/wiki/Intercontinental_ballistic_missile ) says that ICBMs burn for 3-5 minutes to a velocity of 4km/s with solid fuel burning out faster. If we take 4000m/s over 180 seconds we get an average thrust of 22.2 m/s/s The best possible scenario for your heavy rocket would be a thrust of ~32m/s/s which would result in a total thrust of 19.5m/s/s or a twr of just under 2 for your version compared to a little over 3 for the original. But that would be a very poorly designed rocket because it would almost always be throttled lower than it could be. Usually you get much more thrust towards the end of your burn than towards the beginning, so you would probably spend a significant percentage of your fuel before lifting off, just because the engine is too weak to lift the much higher mass.

It already got TOTM for Nov 2023, is it even eligible for more than one?

Makes me think back to family road-trips where the back of the van was packed with coolers, bedding, etc. until it was roughly even with the back seat. If that room has a 40' celling, they will probably have so much stuff packed into that room that they do not see the beds until they get back to earth orbit.(not even then if it is half-filled with surface samples)

I think step size is related to average leg or stride length. Then again, kids with more energy can jump up multiple steps with shorter legs, while older people with less energy can struggle for the one step at a time, so perhaps not?

How much money have they saved on being able to use this booster 23 times? Even if the engines are only $1M each, that is 198M in engines alone.

To be fair, if you discover proof that the universe is not compatible with the rational mind, then the only rational thing to do is to disconnect from the universe...

'Nearby thunder usually has a sound pressure of 165-180db and sometimes more than 200db' 'A sonic boom is typically around 110db'. 'Sonic booms can be particularly loud and startling from large supersonic aircraft' 'Technically thunder is a sonic boom' Boca chica, TX averages 78 days of rainfall per year. Sounds like regulatory paperwork requirements more than a specific identified need to me.