JoeSchmuckatelli

I like the description in your post - a question: I was surprised to see a recommendation of running the calculations in terms of frames. Would this be possible to do as part of the 'exiting the VAB' process, and then only recalculate whenever there is a change to the craft (such as triggering decoupler / opening a payload / extending a part?)? If it were done prior to launch, could it remain persistent through the entire flight (planes) or is there something that needs fairly frequent calculation?

LOL In that theme, Mrs. JoeSchmuckatelli says this: It's a transmissible disease - I catch my kids yelling "Deploy, Deploy, Deploy!" whenever we need to rush out the door.

The whole perspective plus movement of Jupiter is playing havoc with my brain. Ostensibly the orbiter (Juno?) is moving right to left, which would explain the apparent faster speed of the outer moon - but Jupiter also seems to be rotating in the same direction as well?

The video suggested that as a possibility - the very end, where he's selling wallets - they shot the aluminum wallet and it looks like they got a weld. Entirely possible that the penetration / tunneling evacuated the target material (aluminum in the video, wood, possibly, back in the day) leaving fresh clean lead to weld / cold weld as they met.

Apparently, I am now a quantum physicist. Hopefully youtube sends my diploma soon

Grin - it's not a you problem, it's a me problem. I only got through calculus in college by taking a winter semester-break course on 'business calculus' - and about the only thing I remember from it was something about making the route walked by a postman more efficient.

When people who can do the numbers in physics write stuff like this... I get flummoxed.

Law of large numbers - or some other way of saying monkeys and typewriters.

If / when we decide to send something interstellar (as it's purpose, as opposed to the Voyagers and New Horizons) - would we originate from Earth's orbit? Or - Would we start at a place like Mercury which has ~ half again the orbital velocity of the Earth... Or just drop in for a flyby of the Sun? What's the plan for interstellar levels of delta v? (current tech, not sci fi)

Repeating rifles and revolvers really first started making their appearance during the time of the American Civil War. After it, no respecting gun slinger would be caught dead (well, maybe caught dead) with a muzzle loader. The thing with militaries is that procurement is extremely expensive, and often cool tech lags deployment by a few years. So what you should look at is when the Springfield rifled muskets were acquired, and especially in what numbers to see why the armies were equipped with what they had. The other piece of the equation that no one ever looks at is logistics. Far easier to keep people in the fight if they're all using the same kit. If you suddenly need to provide supply in a variety of calibers to different people - it gets complicated quickly. Spencer repeating rifles did show up on the Union side - especially for use by cavalry regiments - but did not replace the muskets issued to line troops. Rifled muskets were still standard issue until the Model 1873 - which was a breach loader. AFAIK it was chosen for reliability and because someone high ranking did not trust the new fangled repeaters. We did not start fielding bolt action guns until the 1890s. Pretty sure we were still using bolt action in the First World War - 1903s and Enfields, which if I recall correctly fired a thirty-aught-six cartridge (which is a big damn round that will punch holes at a thousand yards, and bruise your shoulder if you don't know what you're doing). Semi-autos were already invented by then and still were not common, and certainly not standard issue. This. Actual laughter!

Taking a break from trying to find the end of the internet (it's out there, somewhere!)... I found myself doing what I often do to let my subconscious churn on something. Sudoku. It's a habit I picked up in the early days of Covid. Days before our local lockdown, I picked up a book of puzzles intending to play them with my kids. Wasn't in anticipation of the lockdown... just something I thought would be fun. Then it happened. They had school via zoom... and in between everything else, I had Sudoku. It's literally the only thing that has remained with me from that time. (FWIW - I'm still not great at them. Can crack an 'expert level' in about 10 minutes... which makes it perfect for listening to podcasts or other news things where I don't have to fully pay attention to what's going on.) So - to the extent that anyone is interested in sharing... what kinds of 'innocuous habits' have you picked up, and what's the provenance?

Body armor proliferation, yes... it's a factor. Urban fighting becoming commonplace features in the discussion as well. But before you think about tank level fire control in battle rifles - understand that 'down the line' is quite a number of years away. Far better to have rugged and reliable than high speed and finicky. Mind you, there's this story floating around about an investigation after Fallujah (when the ACOG was first fleeted) of too many head shots... the story is basically you take guys who are perfectly capable of 500m shots on a point target with the Mark 1 eyeball and iron sights and give them a 3x magnification? Things are gonna happen. That's after just 2 weeks of training. The computer used was wetware. No need for fancy systems for anything under a kilometer away, tbh.

Different ammo, caliber and barrel length combos determine the chamber pressure and muzzle velocity. Adding a suppressor tends to increase chamber pressure and can have an effect on the round - so if you are firing suppressed and want to keep the round from cracking through the air, you get a round that won't go supersonic just because you increase the chamber pressure. I.e. Two subsonic rounds 290m/s and 270m/s. The 290 is more accurate with better terminal ballistics. Fire both from the same suppressed gun, and the 290 is noticeably loud b/c increased pressure means it's now over 300m/s. But if you take the same rounds and fire the quiet without the suppressor, you get pretty bad (inconsistent} performance. But with the suppressor? They're magically better. If you want a real rabbit hole, try to figure out why the M-4 is hot garbage (despite all the fan Bois saying it looks so kewl and the *gasp* Rangers carry them). All the post-2003 reports are why militaries are searching for 5.56 alternatives... Which, despite the fact that the full length rifle performance was perfectly fine, it just isn't kewl

Consistency of results. If the powder effectively fills the cavity you get a consistent burn pretty much every time which equates to predictable performance.

That was cool. @magnemoe - good point about the rifling, they were clearly counterspinning and this could certainly be a factor... Except for one thing. I went back to the video and it's a Minnie ball from 1862. Meaning it was fired from a muzzle loading rifle. During the Civil War (1861-65), the basic firearm carried by both Union and Confederate troops was the rifle-musket and the Minié ball. The federal armory in Springfield, Massachusetts, produced a particularly effective rifle-musket that had a range of around 250 yards; some 2 million Springfield rifles were produced during the war So the Smithsonian rounds would have been fired by rifled barrels, spin stabilized and thus something else has to be the key. I suspect they may be correct about the metal composition and velocity. They're trying to adjust for speed with powder (the part about the long vs short cartridge) and I'm surprised they did not consider wadding in the longer cartridge to maintain a good seat (the inconsistent performance with the short cartridge is actually a sign of them creating a dangerous condition using an incorrect sized cartridge for the gun). As to the metal composition? I don't know. They used to use scrap metal back in the day, and varying degrees of alloy resulted. Tin and antimony are mentioned in the literature - but finding anything about the ductility / cold welding property of 1860s lead is beyond my Google - fu

Can you (or someone) point me to a decent resource on what aerospikes are good for? I thought it was a clever design that increases efficiency, but the only drawback was current materials science... Sounds like there is more to it than I suspected.

The moon was a sideshow. If the wind had been stronger we could have seen past the edge and finally discovered the sex of Great A'Tuin.

Judging from the time stamps from OP to the various posts above yours... you had your work cut out for you. How many trucks to haul away all that phlegm?

One of the things I've seen from them is that they appear to be keen students of SX. Inspired by certain SX choices, cautioned, informed and imitative while still innovating in their own right. It's one sign of SX's success, and I hope a harbinger of good things to come. --- the thing I've liked about SX is they're taking Rocket Science from being something wholly in the realm of the wizards of government/academia/contractors and making it look a lot more blue collar / shade-tree-mechanic. The 'common as commercial air' idea is actually a good one. Stoke seems to be a beneficiary of the changing attitudes.

They're certainly doing interesting stuff, have a cool name and fun vids

Subtitle: That's playing fast and loose with the term, 'expert'. I suggest 'idiot' completes the sentence better and describe the content better. It's like the advice I got in college from a certain expert at a Frat party: "When the alcohol and narcotics start making you feel too sleepy, the solution is more cocaine!"

I've seen similar - and it kind of boggles the mind how something like that could happen. Apparently, moving continents and massive terranes is both hot and heavy enough to treat rock like putty (given enough time). The other boggling thing that got me recently (staying on the Pacific NW theme) was just how aggressive erosion is. Apparently, much of the Sierra Nevadas once looked like the Cascades with hundreds of volcanoes like Ranier. But those typically don't last more than 2 million years, before eroding away and leaving terrain like Yosemite (exposed batholith granites). There are evidence of scores of 'ghost volcanoes' (batholith remnants) all over the Cascades, some of which were bigger than Ranier. Most of which have eroded so much that you would never know a 15,000 foot mountain once stood where ridges of lavas and sedimentary layers fan out from the batholith granites. When you try to imagine the surface elevations of scores of statovolcanoes being gone, and how erosion would have had to transport millions of cubic acres of rock to explain the sedimentary layers? Water, wind, temperature and sun are AGGRESSIVE.

I used to live up that way (Seattle) and also in Northern California. Was a regular at Lassen and Mount Shasta, and have climbed around Ranier and other Cascades for fun. Thought I knew the 'story' of the topography. Seems like the last 20 years or so have been transformative - there's a lot of really interesting paleo-mag data showing significant movement of the landforms we take for granted. If interested, I also recommend the rabbit hole he opens up for how the Rockies were formed by processes other than a 'shallow Farallon plate' as was the traditional view. The big part I did not know about was the implication that much of the Northern California to Alaska terranes were presumed to be off-shore island chains (think Philippines/Indonesia) that accreted to the continent as it overran Farallon and the Pacific Plate.

That is a nice gif of how mid ocean rifts work - but they should have added additional volcanoes at the subduction zones. The problem is that they also show a major volcano atop the plume, which makes it look more like a hotspot volcano, like Hawaii or Yellowstone... But for that to be accurate, the oceanic / continental plate would have to be transiting over the hotspot. Iceland is a possible example of what the gif depicts, but generally spreading ridges don't build big cones like that. Correction - as I look at it again, it's not a major cone... It's likely a conical subsurface section depicting how the spread zone is thin and thickens as the magma cools. So - yeah - cool animation! This guy does some really cool lectures on geology (pacific northwest focus)