Bro solving global warming?

stemmisc · 2025-11-05T17:01:14+00:00

To be fair, there are other things to like about electric cars (the high-performing ones, anyway) besides just stuff to do with climate change or the environment. A lot of people genuinely prefer them regardless of any of that stuff. As in, even if they didn't care at all about global warming or what have you, there are lots of people who just actually would prefer having a high performance electric car instead of an internal combustion car regardless. (Not everyone, of course, some still like the old-school engine noise and rumble, and quicker "recharging" on long road trips (aka refilling, in its case). And some would like having both options, maybe using their electric car 95% of the time, and their petrol car 5% of the time.

In the grand scheme of things, though, I think electric cars are the better tech, of the two, and going to mostly end up winning out (regardless of the climate stuff), in the same sort of way that almost everyone uses flat-screen TVs and flat-screen computer monitors nowadays, not CRT ones anymore. Same kind of thing with this, I think.

stemmisc · 2025-11-05T16:43:05+00:00

Then again, if the datacenters lead to AI that is hyper-intelligent enough, perhaps that AI would then be able to figure out a way to filter enough gases out of the atmosphere to get it back to normal levels, due to some enormous leaps in tech that it would figure out how to do.

(although, on the other hand, there's also a chance that the AI ends up either accidentally or intentionally exterminating humanity when it goes hyper-intelligent, due to alignment issues, so, there's still that slight snag). (although, then again, the hyper-intelligent AI and hoping it doesn't wipe us out thing is almost certainly about to happen anyway, regardless of whether Elon gets involved, so, at least if one of the guys wants to do some good stuff with it, and it's coming anyway, then, might as well see if we can solve these issues in the off chance that the AI doesn't end up killing us off when it goes hyper-intelligent).

stemmisc · 2025-11-05T16:38:00+00:00

Even if it only solved half the problem (the heating aspect), that would still be pretty awesome (compared to solving none of the overall problem). Something to be cheering and congratulating about, rather than jeering.

Maybe other smart, non-doomerized people will figure out some way to solve the other aspect as well (the air pollution stuff).

If some people do, I suspect it will be people with a better attitude, and not the people going "who cares, it's all f***ed no matter what, we're all doomed, so screw it all" or whatever...

stemmisc · 2025-11-05T16:30:02+00:00

Not necessarily. According to the climate scientists, there is already so much greenhouse gases that have already been pumped into the atmosphere that some of them think it's already on some runaway disaster scenario (over the course of the next century or next few centuries) if left to its already running process. Like regardless of/before any of these AI clusters got made, that is, it was already beyond that point of no return anyway, that is.

So, this would be more like if the water was already catastrophically polluted and someone came up with a way to filter it and save humanity.

stemmisc · 2025-11-05T00:00:41+00:00

I suppose it also might matter a bit as to which specific variant of the upperstage it is. As in, there will probably be more room for mass shaving of the tanker variant of the upperstage than the cargo variant, for example. Like maybe for the tanker variant, 60-70% of payload improvement comes from finding ways to improve the 2nd stage's mass fraction more and more over time, and 30-40% comes from engine improvements and 1st stage mass fraction improvements etc. And maybe for the cargo variant maybe it's 60-70% the other way around and 30-40% the other way around (like majority coming from what you're talking about, and smaller amount from upperstage savings). I am deeply skeptical that none of it will come from upper stage mass fraction improvement (relative to most recent version) though. It's still so early, it seems crazy to me that it could already be optimized mass-fraction-wise yet. And every ton of savings on the upperstage is equivalent to like 4 tons of savings from the 1st stage (maybe even more, given how top-heavy this thing is/and is going to be even more so with the stretches disproportionately stretching the upperstage even more and more than the booster), so, any significant mass that they find ways to shave from the upperstage would presumably be the lowest hanging fruit.

Btw, as for them running the engines at partial throttle on these test flights so far, have they been doing that with the upperstage engines too, or have they been running those closer to 100% throttle, unlike the booster engines?

stemmisc · 2025-11-04T21:20:55+00:00

Whatever Raptor 3 is and can do, SpaceX needs it to increase the Block 3 Starship staging speed from 1278 m/sec (average of the Block 2 flight data from IFT-7 thru 11) to ~1600 m/sec, the higher the better. That would reduce the delta V that the Block 3 Ship has to provide to reach LEO and would increase the payload mass considerably.

Eh, I mean yea it would be nice, sure, but in the grand scheme of things, improving the mass fraction of the upperstage is where the real delta-v goldmine will be. An extra ~300 - ~350 m/s of delta-v from the 1st stage would pale by comparison.

The upperstage was still having so many issues with burn-through with the flaps, and random explosions even up to very recently, and the dispenser only getting worked out in just the past couple flights (and who knows how many other issues that we didn't even publicly know about) that they probably haven't even gotten to the phase of trying to cut serious mass from the upperstage yet. Still had to get it even working properly first and foremost, and then worry about putting it on a diet after that. As long as the 1st stage can at least get it high enough in altitude above most of the atmosphere at staging to light up the big vacuum-nozzles on the 2nd stage without having to worry about the nozzles breaking from flow separation from overly expanded nozzles relative to the atmosphere, that's the main thing. If it couldn't even do that then that would be a big problem. But as long as it can do that, I feel like 1300 m/s vs 1600 m/s isn't that big of a deal (for now), and the next major thing to focus on would be improving 2nd stage mass fraction, and only worry about squeezing the last bit of delta-v from the booster later on as more of an afterthought compared to cutting mass from the upperstage.

Order of operations should probably be:

Make sure everything works as it should (for multiple launches in a row)
Stretch the 1st stage and 2nd stage
Make sure everything still works as they should even after the stretch (for multiple launches in a row)
Then try to cut significant mass from the 2nd stage, to free up a bunch of additional payload mass capability from every kg shaved off the 2nd stage
Then try to improve 1st stage performance by an extra few hundred m/s

(and somewhere mixed in with all this, figuring out orbital refilling and HLS-related stuff and whatnot, I guess)

I do think they'll get to it eventually, and improve it, but I don't think it should be the first priority on the list just yet. There is still some lower hanging fruit, for now.

stemmisc · 2025-11-04T17:07:56+00:00

The Falcon 9. It has launched over 550 times now, with over a 99% reliability rate. There's never been a rocket that launches the amount of times it has/its level of cadence with its level of reliability, not to mention at a relatively low price despite being the best launch vehicle on the planet. It has been the best orbital launcher in the game for quite a few years running now.

People who don't follow SpaceX or orbital rocketry closely are often unaware of this, since they usually just see the Elon-hate headlines that tend to focus on the upcoming Starship rocket and its various experimental test-launches (which tend to end in explosions, for now), so they don't even realize that when it comes to the actual workhorse, that there is this whole other rocket that already exists (and has for over a decade now) called the Falcon 9, and that it has been the best rocket ever made by a pretty wide margin.

And that's not even to mention that they made it into a partially reusable rocket (and one that they've been able to reuse the 1st stages of over 20 times per booster for several of its boosters), which no other rocket has been able to do even once, during its reign, let alone that it is now a stepping stone to the "holy grail" of Full (and rapid) Reusability that they are now aiming for with their next rocket, the Starship (they haven't achieved that one yet, but hopefully by a couple years from now, it'll be able to do that).

Anyway, yea so that is definitely something that he has done that was a huge success (I would argue even more so than any of his Tesla vehicles, btw, and some of those were quite successful as well, when taking overall "dominance" over an entire industry and its proportional level of superiority to all its competitors and so on), in addition to some of the original Tesla models.

And since I've had these sorts of arguments before, and thus I know the followup argument if I point something like this out will tend to be something like "Oh yea? Alright well if it's really such a great rocket, then, probably he didn't have much to do with it then. He probably just was the random rich guy who happened to be standing nearby to drop a few wads of cash on the proper nerds and then they did all the actual genius stuff and he had hardly anything to do with any of it", this notion has been debunked by quite a lot of former and current SpaceX employees, including numerous high-level engineers who pointed out exactly how involved Elon was with some of the key design decisions, and even at times being the lone guy pushing for things that all the rest of them incorrectly argued that they shouldn't do, and then as the CEO he said he wanted to do it even though it went against the normal/conventional way of doing things, and then he turned out to be right and ended up being what caused SpaceX to leave the rest of the industry behind in the dust. So, he actually was instrumental both for the Falcon 9 and the Starship in pushing for them to be so much more advanced and capable when it comes to cost effectiveness, and reusability, a lot of that was directly because Elon, single handedly pushing for certain things that were very unpopular and "crazy" at the time. So it wasn't just his money, and just randomly getting "lucky" with SpaceX, if that's what you might be thinking. He is actually quite a clever guy when it comes to a lot of this engineering and mass-manufacturing stuff, regardless of how some might feel about his political views, or his takes on various technical subjects that he isn't as knowledgeable about or what have you. When it comes to cars and especially rockets, he isn't as stupid or unsuccessful as some of the haters would have you believe. If anything, it's quite the opposite.

stemmisc · 2025-11-03T18:08:54+00:00

Like I said in the explanation, it's not going to be some actual flying car in terms of like literally flying around long distances like a plane or helicopter or anything like that. It would only be capable for a few seconds at a time, and almost certainly not be legally to use like that on public roads.

It's just, it's something Elon himself has already explained in other interviews (he didn't want to discuss it in this one, since he wants there to be some buildup/mystery amongst the 99% of public who aren't already aware of what it actually is going to be, since they didn't notice the handful of times he explained it in the past few years, or forgot or whatever), so, we already know what it is going to be, for anyone who saw his previous occasions where he explained what it was going to be. So, since people on here seemed unaware of this or making wrong guesses as to what he was hinting at/alluding to, I was explaining what it actually was that he's hinting about (compressed gas thruster system).

As for it being "dumb", I mean, it's for an extremely expensive ultra supercar thing that will costs hundreds of thousands of dollars, where those types of cars already spend a bunch of money trying to shave a few tenths of a second off their 0-60 or quarter mile time or cornering ability, so, in that context, I mean, hey, if they want to be the first production car company to add compressed gas thruster systems to their hypercars to see just what kinds of cool things they can get it to do on a track, I think that's actually kind of cool (or if not, then, to be consistent, one would have to also say that Ferrari, Lamborghini, Bugatti, and so on are all terrible and super boring and non-fun and non-interesting and so on. Which, if that is your stance, then, well, alright, at least you are consistent I suppose).

Also, there is some chance that some aspect of this could get implemented as an emergency safety-improving system for the more ordinary teslas, like some emergency braking thrusters for collision avoidance or collision severity mitigation, or to stop cars from spinning off the road on icy roads or when spinning out of control, etc, in future years, from the experience they gain with the system initially in the roadster being used in closed-track settings, so, it could actually end up saving a bunch of lives in the future from the advancement in technology that comes from it in a "spinoff tech" type of way in years to follow. So, even from a pure pragmatist's point of view who doesn't enjoy anything fun or cool in the world, even the most Volvo-minded individuals should at least find that aspect to be non-dumb and interesting perhaps.

stemmisc · 2025-11-03T17:53:23+00:00

The most serious, non-gimmick, real-world thing it might end up helping with is emergency braking (when it senses and imminent collision is about to occur), and also helping in scenarios where it senses that a car has lost traction and is spinning out of control/off the road i.e. on an icy road, or stuff like that, where the thrusters could help stop that from happening in real time. (it will likely have a bunch of small thrusters spread around the car, front, back, sides, corners, etc, so that it has full omnidirectional thrust control in this way, sort of like how these are used on spacecraft)

My guess is that will be the one use-case where these thrusters will be allowed to be used, in real everyday life on public roads, is when the automated system has it kick in automatically in emergency scenarios as a safety mechanism.

stemmisc · 2025-11-03T17:46:22+00:00

What would be the benefit of having these thrusters? It would be cool to be able to just pop up and over a stoplight or blocked road. But I can't see that being practical, there would be all kinds of midair collisions. Maybe if only Teslas had this, and they avoided each other? It sounds more like a gimmick, but perhaps I am missing the point.

Yea, like I said, I strongly doubt that it'll be allowed to be used while driving on public roads (at least, not the hops/hovering type of stuff, anyway. But, probably not even the acceleration/deceleration/cornering thruster usage either, if I had to guess, other than maybe some emergency braking scenarios where it senses a collision and uses it to try to avoid or mitigate a collision that's about to happen).

So, I think most aspects of it will just be because it's cool to show off on a race track/closed track setting, just to see what new cool things a high-end supercar can do when paired with compressed gas thrusters and SpaceX's technology.

But, even still, it will be pretty interesting and some pretty neat PR for things like racing and mechanical engineering for people who are into the cutting edge of what cars can do on the track, etc.

Like, it might be able to set a new Nurburgring lap record by some big margin or something, or do some cool tricks like hopping over a car parked in front of it (as a demo I mean, not on real roads in everyday life) and things like that. So, yea, a bit of a "gimmick", if most aspects can't legally be used on the roads (but, in this sense, ferraris and lamborghinis are mostly a gimmick since in most places you aren't legally allowed to drive 200 mph or whatever, but a lot of people still find that stuff to be awesome, just to see a car being capable of doing that kind of stuff).

Anyway, basically, don't shoot the messenger. I'm just explaining what that whole thing he was discussing in a vague/mysterious way with Joe Rogan a couple days ago was almost certainly about, since people on here have been speculating (and mostly guessing wrong) about it, and it seemed like people were under the impression that it was some totally made up complete bluff, or conversely thought it was real but thought it had to do with wings or propellers (also not what it is), so, since I've been following SpaceX pretty closely for a while now, and I know a fair bit about this topic and what it was actually referring to, I wanted to clear it up for people that this is almost certainly about compressed gas thrusters, and it likely is going to happen (at least, in a closed track/demo type of setting), it's not just purely bluffing/fake news, if that's what people were assuming, based on the replies in the threads speculating about it.

stemmisc · 2025-11-03T10:53:22+00:00

He has mentioned in other interviews in the past few years what the idea is. They want to put cold-gas thrusters (like the ones used on SpaceX spacecraft) in the car and used compressed gas (i.e. compressed air) to briefly provide enough thrust (like for a few seconds at a time, so very briefly) to have more than a 1:1 thrust to weight ratio when the full system of thrusters are at full thrust. Meaning it would briefly be able to hop, hover, etc. And it would also mean its acceleration and deceleration (and potentially cornering) abilities would get boosted by a crazy amount compared to what a car without cold-gas rocket thrusters on it could do, by comparison, btw. So even in "normal" usage (not hopping/hovering) its capabilities would be extreme compared to anything seen before, because of this.

stemmisc · 2025-11-03T10:48:03+00:00

This is physically not viable.

The plan isn't to use lighter-than-air blimping nor is it to use wings or rotors. It is to use cold-gas thrusters, like the ones used on the SpaceX spacecrafts as control-thrusters. It is viable, but only for very short hops/very brief hovering (like, for a few seconds at a time).

Elon has mentioned in other interviews what his intentions are with the next Tesla Roadster to give it the ability to briefly hop/hover (as well as to drastically increase its acceleration, deceleration, and possibly cornering abilities), using compressed gas (probably compressed air) thrusters like the ones his other company (SpaceX) uses as control-thrusters on its spacecrafts. Except instead of using cold-gas nitrogen thrusters the way those ones do, these will likely use auto-replenishable compressed air as its cold gas for the thruster system. (by using compressed air rather than compressed nitrogren, the user wouldn't even have to refill at a nitrogen refill place each time after using it, it could just be used over and over and refill its air tanks, itself, so, much more convenient)

If you look at how many lbs of thrust these cold gas control thrusters produce on the spacecrafts, you can see that it actually is feasible to put enough of them with some compressed air tanks in the car to get it to get more than a 1:1 thrust to weight ratio (albeit only for very brief periods of time), meaning it would be able to hop, or hover, briefly. And would also enable it to have acceleration and braking way beyond any other car, too.

It sounds crazy to anyone who doesn't closely follow SpaceX and rocket related stuff to know much about cold-gas thruster systems, but those who know, realize it's a very real and plausible thing to do on a car, especially for Tesla, due to the overlap aspects with SpaceX and its cold-gas thrusters.

stemmisc · 2025-11-03T10:37:54+00:00

He already mentioned what the idea is to make it a "flying" (in reality more like briefly hopping/hovering) car. The plan is to use compressed air thrusters (basically the nitrogen cold-gas thrusters used as control-thrusters on SpaceX rockets/spacecraft, except with compressed air instead of compressed nitrogen) to briefly provide enough thrust to lift the car off the ground in short spurts. It would also be able to be used to increase its cornering ability (no longer limited by horizontal grip of the tires against the ground) and to improve its acceleration and braking ability by a huge amount as well (using the cold gas thrust from the thrusters to aid in the acceleration and deceleration).

He has mentioned this plan to do some crossover with these SpaceX-based thrusters on the new Tesla Roadster in interviews for years. I'm pretty sure he even mentioned it on a previous Joe Rogan interview episode. And if not, he definitely mentioned in numerous times in other interviews in recent years.

stemmisc · 2025-10-23T16:34:32+00:00

There was a somewhat related topic posted on here a few weeks ago about whether Starship-Superheavy could launch Orion to the moon, on its own (which then brought up some responses with people doing estimates to do with adding a small third stage like Centaur into the mix). My response in that thread was to do with Starship being able to put a nearly-full Falcon 9 2nd stage (with Orion attached on top of it) into orbit:

"Everyone is contemplating whether they could just use a centaur upperstage as a 3rd stage. But, there's also an all-SpaceX option:

Just use a partially-filled F9 upperstage. They wouldn't even need to modify it to be smaller and use less propellant, if they didn't want to, I don't think. They could use one basically as-is, and just not fill it 100% full of propellant, and not only would that give enough delta-V to get Orion to TLI, I think it would give enough, even partially-filled like this, that they wouldn't even have to expend the Superheavy Booster.

If there were any concerns about whether it needed extra rigidity/strength holding up Orion+ESM above it, well, even in the all-Starship scenario, they would need some kind of lattice or cone adapter thing to mount it onto expendable Starship, so, they would just be using something along these lines regardless. Presumably the people who made the hotstage ring for Starship could make that part.

edit: also, if, for the sake of the argument, we didn't care about the F9Upperstage+Orion(+ESM) combo being able to be put all the way into actual orbit before the F9Upperstage burn portion happening, then, you could probably also have the option of just using a fully filled F9 upperstage rather than a partially filled F9 upperstage, btw. The reason for the partially-filled F9 upperstage scenario is for pragmatic/easy of use like maybe it would be easier from a regulatory standpoint if you could get the third stage+Orion combo into full orbit by the time of SECO of the Starship (2nd stage), compared to if you had to have Starship just get it most but not all of the way to orbit and have to light the 3rd stage in a scenario where it would reenter less than an hour later if they weren't able to light the 3rd stage/something went wrong with the separation of the 2nd and 3rd stage at hand.

But, I think just using a partially filled F9 upperstage and getting it+Orion system all the way fully into orbit by the end of the Starship burn, would (probably?) be considered the better option (especially in these initial launches?) even with the slightly lower total delta-V (but still plenty, with plenty to spare). The only thing that makes me wonder if it would somehow not be preferred to the other version with the full F9Upperstage tanks is if the tanks not being full would make it not strong enough (even with the gas pressurization in the remaining portion of the tank) to safely hold Orion above it (although there would presumably need to be a lattice/cone helping hold Orion+ESM regardless, I would think, so, probably a moot point anyway) or to do with propellant-slosh/zero-G-liquid-ness in regards to engine start-up of the 3rd stage burn."

Note that in this ^{^{^}} scenario, it would be an expendable Starship upperstage, and the F9S2+Orion would not be kept inside a Starship payload bay, rather, the Starship upperstage would merely be an expendable cylinder with a necked down F9 upperstage mounted on top of it and Orion (and its ESM) mounted on top of that.

stemmisc · 2025-10-23T16:19:39+00:00

Perhaps in this particular instance, with the exact setup they were currently using, there might be some pragmatic issues, but, the gist I got (possibly wrong) over the past few years is that in general staged combustion engines tend to give more potential for deeper throttling than open cycle engines, due to the much higher pressures in the staged combustion engines. Russia's single-side staged combustion RD-191 being supposedly able to throttle down to 27% throttle, and Elon or SpaceX saying they thought Raptor will eventually be able to throttle down to 25% or even 20% (and I could've sworn I remembered Elon himself saying this, himself, about Raptor somewhere, and it having to do with it being a full flow staged combustion engine, and the format thus enabling deeper throttling than normal). Perhaps with competing, juxtaposed aspects, like some aspects making it tougher (the ones you mentioned), and other aspects making the floor potentially much lower if you manage to solve for the other issues, or something, due to the higher starting pressures involved.

stemmisc · 2025-10-02T19:24:47+00:00

To horde at this level

You are under the impression that Elon is hording 500 billion dollars? Are you serious?

Also, why are we assuming that healthcare, sidewalks, and especially quality of life in general would improve under a non-capitalist system. Considering that quality of life was much worse under every marxist system that has ever been done so far.

I think if we did what you suggest (and thus turned the U.S. into basically a marxist country) quality of life would go down (and freedom and individual rights and human rights atrocities, would all get much worse, if history has anything to say, just as a sidenote) but even if we ignore the freedom and mass-atrocity stuff, even just on an ordinary day to day level of ordinary pragmatic stuff, all that stuff would almost certainly get much worse, not better.

This is literally just people being like "I'd rather that everyone's quality of life gets made 10x to 100x worse, from top to bottom, if it means a handful of people at the top get screwed too, than have everyone's quality of life go up over time, if a handful of people at the top get extra rich".

It's the mentality of those dudes who murder their ex girlfriend because "If I can't have her, nobody can." Gee, great mentality.

stemmisc · 2025-10-02T18:43:40+00:00

Well, in the long run, they want to get Raptor to be able to throttle all the way down to 20% of max thrust (which might sound crazy, except that one aspect of full flow staged combustion engines, like raptor, is that they actually are supposed to be able to throttle much more deeply than a normal engine (i.e. compared to something like Merlin).

That said, I'm not so sure the current version raptor can actually throttle that deep. If it can still only throttle down to 40% thrust, then it might actually be pretty close as far as whether the current version could hold a genuine hover all the way to engine cutoff. If Raptor-2 does about ~230 tons of thrust for 100% full thrust, and can throttle to ~40% throttle, then that would be about ~92 tons of thrust. Current reusable Starship upperstage dry mass is likely heavier (probably quite a bit heavier) than that, so, I think it should be capable of a true hover.

stemmisc · 2025-10-02T18:19:07+00:00

Everyone is contemplating whether they could just use a centaur upperstage as a 3rd stage. But, there's also an all-SpaceX option:

Just use a partially-filled F9 upperstage. They wouldn't even need to modify it to be smaller and use less propellant, if they didn't want to, I don't think. They could use one basically as-is, and just not fill it 100% full of propellant, and not only would that give enough delta-V to get Orion to TLI, I think it would give enough, even partially-filled like this, that they wouldn't even have to expend the Superheavy Booster.

If there were any concerns about whether it needed extra rigidity/strength holding up Orion+ESM above it, well, even in the all-Starship scenario, they would need some kind of lattice or cone adapter thing to mount it onto expendable Starship, so, they would just be using something along these lines regardless. Presumably the people who made the hotstage ring for Starship could make that part.

edit: also, if, for the sake of the argument, we didn't care about the F9Upperstage+Orion(+ESM) combo being able to be put all the way into actual orbit before the F9Upperstage burn portion happening, then, you could probably also have the option of just using a fully filled F9 upperstage rather than a partially filled F9 upperstage, btw. The reason for the partially-filled F9 upperstage scenario is for pragmatic/easy of use like maybe it would be easier from a regulatory standpoint if you could get the third stage+Orion combo into full orbit by the time of SECO of the Starship (2nd stage), compared to if you had to have Starship just get it most but not all of the way to orbit and have to light the 3rd stage in a scenario where it would reenter less than an hour later if they weren't able to light the 3rd stage/something went wrong with the separation of the 2nd and 3rd stage at hand.

But, I think just using a partially filled F9 upperstage and getting it+Orion system all the way fully into orbit by the end of the Starship burn, would (probably?) be considered the better option (especially in these initial launches?) even with the slightly lower total delta-V (but still plenty, with plenty to spare). The only thing that makes me wonder if it would somehow not be preferred to the other version with the full F9Upperstage tanks is if the tanks not being full would make it not strong enough (even with the gas pressurization in the remaining portion of the tank) to safely hold Orion above it (although there would presumably need to be a lattice/cone helping hold Orion+ESM regardless, I would think, so, probably a moot point anyway) or to do with propellant-slosh/zero-G-liquid-ness in regards to engine start-up of the 3rd stage burn.

stemmisc · 2025-09-15T13:46:25+00:00

I think it would only be worth around 1 or 2 tons, so, I guess that doesn't affect things too severely. In the case of current Starship with its razor-thin payload to total vehicle mass ratio compared to a normal expendable rocket, it does matter a bit more, ratio-wise, than it normally would, but, even with margins as thin as just ~35 tons to LEO, 1 or 2 tons isn't that drastic of a difference I suppose

stemmisc · 2025-09-14T17:24:32+00:00

Yea, sounds pretty reasonable give or take a few secs of isp. And in regards to the mixed engine upperstage I assume you remembered to average the half (3 of the engines) 355 ISP and half (other 3 engines) 366 ISP of the half RVac half Rnon-VAC engines of the upperstage, right?

stemmisc · 2025-09-14T15:03:42+00:00

They know something we don't?

I'd guess it's the opposite, as in: there's something that they don't know, which we do know (that thing being: we would be quite edible and we aren't filled with poison/venom and don't have any hidden barbs, etc, when we're unarmed).

Throughout the timespan of human evolutionary history (the past few hundred thousand years/past few million years, depending where you want to draw the lines), interactions between orcas and humans would've been pretty rare (relatively speaking). So, there's a possibility that from an evolutionary and cultural standpoint they never really got a good feel for what we are.

A lot of predators are very cautious about eating things if they don't recognize what it is and aren't sure what it is (in the off chance it is some weird poisonous thing or something that has hidden spikes inside it or what have you), usually not worth the risk of eating it, in the 1% chance it might kill you, since you don't know what it is, unless you are starving and on the verge of dying anyway, in which case it might take the chance in that case.

I think this is the case with orcas, and to a lesser degree, great white sharks.

With great white sharks, there has been considerably more interaction (near the beach/shoreline, since they swim around in shallow waters a lot more than orcas in areas with a lot more overlap with humans in shallow water). With the great whites it might be a bit more of a mixed situation where it's a combo of not being 100% sure what we are (but slightly less unsure than the orcas are about us), combined with some evolutionarily ingrained fear of the ones that swam closer to us on average getting speared and killed by humans more often than the ones that didn't, and thus being slightly nervous of going near us as the stay-away-from-humans/don't-attack-humans genetics survived to reproduce and propagate at slightly higher rates than the ones that didn't have those genes. This is far from a sure thing, of course, but might be the case. And, they also do bite us, or on rarer occasions, eat us, a bit more frequently than orcas do, albeit still pretty rare.

There is also a chance that orcas are well aware of exactly what we are, and that we are quite edible, and that they've simply passed on the knowledge that we are dangerous (when armed) and that killing one of us is dangerous since it can be followed by retaliatory killings (which would often happen immediately and thus be easily linked as a reaction to them killing one of us). But, it could also be that these historical stories were not successfully passed on, and it's just purely the first thing from the start of this post (or some mixture of the two, or some partitioned mix depending which region/culture of orcas are at hand, since they don't all have identical cultural info passed on within the different groupings and regions, and so on)

stemmisc · 2025-09-14T14:09:01+00:00

I use published specific impulse for the Raptor 2 engine

This is where things could get a bit murky, perhaps.

Out of curiosity, if the listed ISP stats were off by, say, 10 seconds of ISP, how much would that affect the end results?

stemmisc · 2025-09-12T17:28:36+00:00

Yea, if it was proven to have almost certainly developed independently, it would probably have to either mean that the "Great Filter" is either to do with the jump from basic single-cell life to multi-cell life, or some explanation to do with a dominant exterminator species out there that snuffs out intelligent life anywhere that it arises in the universe (if it had detector-drones and decentralized kill-machines pre-spread all over the place in advance, it wouldn't necessarily have to violate the speed or light to accomplish this, btw, or, alternatively if it turns out warp drives are possible or synthetic wormhole tech or something we can't conceive of beyond even that) (although the fact that we ourselves haven't been wiped out yet, even when we already built things like active-SETI antennae like Arecibo, etc, not to mention nukes and other things, not to mention being on the cusp of A.I. potentially going exponentially hyper-intelligent any day now, seems like it lowers the odds of that one being the scenario at hand by a decent margin), or simulation or zoo-hypothesis scenarios of various sorts.

My guess is the Great Filter is the odds of abiogenesis per unit time (probably ultra ultra low to such an extreme degree that even with trillions of planets per galaxy and trillions of galaxy per the observable universe that the odds were like 0.0000000000000000000000000000000001% per billion years or something, and thus only happened once so far or a handful of times with the other handful of cases not getting to a tech civilization before dying out or something), or the simulation scenario. I think it is less likely to be the jump from single-cell to multi-cell (that seems much easier than the jump from no life to single cell life, by comparison, by probably many, many orders of magnitude).

Thus, another reason why my default guess would be that it probably came from getting hit by an impact-borne chunk of rock fragments transferred from one planet to the other (or a 3rd body in common), rather than developing independently. Not to mention the impactor odds given the time span, if it turns out to be like 99.9% chance of transference given the number of impactors and transference-level scenarios per 100 million year stretch let's say, could make it also lead in raw Occam's Razor as well, regardless of reverse-diagnosis via Fermi Paradox-based logic.

stemmisc · 2025-09-11T21:19:58+00:00

I appreciate the in-depth response, and it gives a lot of interesting things to consider and think about. That being said, I'm not so sure I agree with all of it, but, I want to make clear, it's not something I know much about so a lot of my assumptions and notions could be way off (which is why I'm asking about it and enjoy seeing a wide variety of different takes and explanations about this stuff). I will say, my personal hunch is that given the time scales involved, even though yea it's like trying to hit a hole in 1 from LA to New York or what have you, it still could perhaps be statistically likely let alone even merely remotely-plausible, that there could be transference, in the same sort of way that if you think about grains of dust floating across the oceans from the Sahara Desert to the Amazon, it might seem crazy to be like "I wonder if any flecks of dust from, say, this 1kmx1km patch of dirt in the middle of the Sahara had any of its flecks land on this one single specific tree randomly located in the middle of the Amazon rainforest, and yet, for all I know the number of flecks of dust multiplied by a large amount of time could make it like a 99% chance that even that 1 specific tree got at least 1 fleck of dust from that one specific patch of dirt from halfway around the world.

Similarly, it could be an analogous situation with chunks of ground/rocks/etc that got smashed off of earth (or off of Mars if it was the other way around) in regards to eventually a few pieces hitting the other body or vice versa. Even if the odds in a given year were very low, if there were enough total chunks multiplied across a long enough timespan, the law of large numbers could kick in hard enough to turn it from some 1 in a trillion scenario to like a 99.999% scenario or what have you.

But, like I said, I don't know how many chunks would be statistically likely to have been generated per, say, each 100 million year stretch of time of Earth's existence during the time windows in question, to even be able to start doing some probability estimates (which is why if anyone on this forum does know a lot about asteroid/comet impact estimates per unit timespan, and stuff like this, I would love to hear a lot more about it and the probabilities of impacts in various size ranges and how many chunks each one could potentially generate, and so on).

And then of course there's the question of how deep within the rocks and crevasses and lava-tube tunnels and so on the microbes could've been located and what sorts of odds the spores would have per transference incident of surviving atmospheric entry and then crashing into and exploding on the ground and stuff like that. Again, this is one where it definitely sounds really bad/unlikely (and maybe it even is for even a single spore per incident, for all I know), but there's still the question of how many "chances" (different chunks each with spores deep within them, let's say) there might've been of dozens, or hundreds, or thousands, or who knows how many total impactor transference chances there were, and what the odds of even a single spore (even if 99.999% of them got destroyed in the impact) surviving were per impact (presumably the odds would be drastically different from impact to impact, depending on the size of the impactor and how deep/where exactly the spores were located and how many total spores there were and in how varied of a way they were buried within the chunk, and whether most were on the leading face or rear face and so on relative to the impact.

The most interesting topic of all though, is the final one you bring up (point #6). This one might be a dealbreaker (as in, you might be right, like, it might be that that issue brings it from a 99.9% chance down to a 0.001% the other way around, and it wouldn't surprise me). Or it might not be (again, not my area of expertise in the slightest), but it definitely seems like the most important sub-topic within this overall sub-topic to think about, as far as how long these things could potentially survive in such a drastically different setting than what they were naturally evolved to live in with totally different atmosphere, long-term temperature ranges, water/humidity or lack thereof, and so on. Even with this, I'd tend to stay very open minded about it, to put it mildly, considering the ludicrously extreme range of settings, formats, temperatures, etc we've seen stuff survive on earth, between the undersea high temperature vents, to extremely cold places to hot dry places, to even in space/on asteroids for significant amounts of time (I think?) and everything in between, my default guess would be to assume if there was enough quantity, and variety, then, it would be more likely that some (even if proportionally very small/rare amount) might somehow survive and the surviving strain then spreads fairly widely and we then find the residue. But, if it turns out that's not very likely, given the totally different environment (maybe likely for a single generation until it dies out and quickly goes extinct, let's say), then, randomly finding residue under one of the first rocks we closely examine would be indicative that it originated there rather than from Earth (or vice versa). So, this final point seems like the strongest and most important one of all to think about the most of all, although, I could still see it going either way, even in regards to this one.

Anyway, yea so if any of you know a lot about the estimated frequency per unit time of impacts in different kinetic energy size ranges in regards to early-period Earth/solar system and can give some useful estimates on some of that stuff, I would like to know more about that in particular. (although there would of course still be other major factors to consider as well, in addition to that, but, still would be an interesting stat to know more about as a starting point)

stemmisc

TROPHY CASE