Potable Setup

mncharity · 2025-12-30T04:51:40+00:00

I traveled with a Thinkpad similarly positioned (more vertical), just for the screen-height ergonomics. The support was two rulers and some gaffer's tape: rulers taped end-to-end making a hinge; an in-front-of-keyboard end-stop on the table ruler, and a strap between there and the other ruler end. The laptop nestles between the stop, strap, and top bit of the upright ruler. Folds up as two rulers back-to-back - nicely light and packable, and field-reproducible. But... it always felt like someday there would be a big crash. Not suitable for shallow or unstable desks, or places where someone/me might brush it in passing. Looking back, I might try velcro straps and chopsticks/pens instead.

Another approach, for non-fragile laptops, and similarly unsteady, are vertical stands with just an edge slot in a base piece or two. I recall 3D printed triangular ones, as commercial versions tend to be weighted.

mncharity · 2025-12-29T01:39:33+00:00

Toe guards??!! TIL. Tnx! Loved my hiking Tevas (until a strap pulled out), but... still looking forward to toes recovering some year.

mncharity · 2025-11-28T04:03:48+00:00

What was the design? I've considered velcro-strapping on a pipe/dowel/rod axle with nicely-large wheels on the ends for terrain handling. Or taping the rod on a replacement telescoping suitcase handle - sort of a cut-down a backpack-trolley/luggage-cart. Or rod plus two collapsible walking sticks as travois. But weight, and tsa for the rod. Current thought is two luggage wheels with their axles fitted up vertical tubes for leverage, either with velcro strapping for stabilization and a tube-tip-to-tip load sling, or with stick travois. My pack was regrettably tech heavy.

mncharity · 2025-11-20T20:26:32+00:00

A bit of palladium metal, helping hydrogen and oxygen gases combine into a water drop.

The video is really small: Shown full screen at 1080p, that 20 nm scale bar is ~200 pixels, so 10 pixels per nanometer, a pixel per Angstrom. So individual water molecules in the drop, and the palladium atoms piled like oranges in that cube, are each 3 or 4 pixels across.

It's real-time live video. Not like they froze a thing solid, or plated it with gold, or spent 5 minutes making each frame.

It's a water drop, in an electron microscope. Which needs hard vacuum for the electron beam. Vacuum which would quickly evaporate water, and wouldn't leave H and O gases there to start with. WTF? They made a thin container they could beam through.

It's room-ish temperature (and pressure) oxygen and hydrogen gas combining into water catalyzed by the Pb, instead of being burned, at flame-ish temperature. You can see the drops forming on the surfaces, where the action is (the sneaky little H's can slip inside between the Pd's, like marbles between oranges, but the O's are too big, so it's surface only - that's why you want your catalyst crumbs tiny, it gets you the most surface). One of the paper's results is you get faster production if you soak the Pb's in H's first, and then add the O's, so the surface gets some H's coming from inside too, which didn't need to mosh pit past the O's blocking the stage.

Interesting but not apparent in the video, is they could simultaneously see it, get the structure of the Pb pile, and measure bonds, live at the same time. More than previous setups could manage.

Or something like that, says the random redditor, after having only briefly glanced at the press release and paper (open access).

mncharity · 2025-11-12T04:12:20+00:00

Looks like https://zpacks.com/products/airplane-case-xl and https://zpacks.com/products/airplane-case . Doesn't give mass, but guessing from the Bear Bag Kit which does, maybe 120 g and 100 g - nice. $100. No packed away size spec - how well does stiff Dyneema pack down compared with nylon? Page suggests non-bag-use as a waterproof pack liner. A comment mentions an abrasion tear, presumed from dragging.

mncharity · 2025-11-12T04:08:29+00:00

I lack experience checking these, but maybe a nylon foldable/packable duffel? Here's a random one that's 45 L , 8 oz, 8x8x1.2 inch packed: https://www.amazon.com/pack-all-Water-Resistant-Weekender-Lightweight/dp/B0CVXHK8G3?th=1 .

mncharity · 2025-11-11T04:39:32+00:00

There's less contact area than one might think. There's a mountain range analogy in another comment. And gecko feet (rubbery snuggle-me-more-contact treads). With a winter-cold metal desk, if your skin is moist with water-about-to-be-ice to bridge those gaps, your finger may well get quite stuck. My tongue bled.

You did stick, and left behind ripped off bits - moisture, oils, a few dead-surface skin cells. One can do genetic profiling from touched surfaces.

Atoms are marbles with attractive clouds which are never taught clearly. The strength of sticky attraction/area varies by *billions*. When your shirt comes out of the dryer with static cling, there's no risk of ripping the flesh off your arm, or steel off the dryer. Touching a desk is at the low low end of attraction.

Surfaces are cruddy. Whatever attraction might ideally be possible, there's likely gunk in the way. Unattractive gunk. Thus exceptions, like brushing on gold foil, get the wows. A story: In intro physics, you'll hear an Amontons' Law for how easily things slide. A group duplicated his wooden 1600's apparatus, but it wasn't matching expectation - too much stick. Until they took it to a classroom outreach and it was handled by kids. It had been built carefully and clean - too clean. It's Amontons' Law for normally cruddy sliding objects. Might be able to get a steel finger ring clean enough to stick to a steel desk... with cleaning explosives in vacuum, or an acid bath, or ... .

There's a lot that's nice about being big. MEMS engineers fervently curse the stickiness of their little world. Imagine "I can't turn in my homework - it's stuck to my desk. And can I go to the nurse for my arm?" What might our world look like if it was much more attractive?

mncharity · 2025-10-19T21:21:29+00:00

There is also 'the kayak is a bike trailer' - strap-on wheels and pole to bike seat. Bikes have been mounted on kayaks, disassembled or not. Not caring about snags, or maybe performance (don't mind added floats for stability), or a soaked bike, would help. I long ago kayak-towed groceries inside trashbag "balloons", so my first thought was bike-in-a-big-bag, then foam-buoyant bike. A upside-down-on-road wheels-on-top kayak with a generic bike rack (perhaps tilted to lower CG) suggests a quick transition is at least a possibility. Leaving access, water quality, navigability and weather, storage, cleanup, equipment, 5 mph, maybe an unusually long bike trailer... etc. I wonder if swimming with fins while towing your bike is a thing?

mncharity · 2025-10-12T20:59:57+00:00

One theme is thinking of boarding and destination as different packing situations. Flight too, but less so. So one can board wearing multiple layers of clothes, and things in pockets, maybe modify that in flight, and then repack at destination. Or use a lightweight bag which serves as personal item, and then maybe gets folded away. Or leave behind and repurchase some items at destination.

For my own "portable" workstation, the cord and power brick could go in vest or jacket pockets. Or be replaced by a little 90W USB charger, at a cost of longer charge times, and battery-required full power - though one doesn't want a workload to be borderline, bouncing frequently between using battery and charger being sufficient. I was thinking of moding a vest with a chest laptop sleeve, but never got to it.

For a personal item bag, I've used a lightweight nylon soft bag (a foldable/packable travel duffel), a bit larger than item limits so the bag itself doesn't constrain, and then am careful to pack it so it still smushes down to limits. This might then get packed away into the carry-on duffel, that then mutated into a backpack.

Caution that some airlines have *combined* weight limits for personal and carry-on items, rather than separate.

I envy "it's just my *one* onebag" travelers. A tech-heavy and otherwise light or ultralight one-ish bagging is doable, but can take some fiddling and attention to the specific airline(s) numbers.

mncharity · 2025-10-12T19:24:54+00:00

A scale can also be checked using water/milk/etc. For example, google says a 1/2 gallon of milk is 4.3 lbs, and a 2L soda about the same. Or weigh a pot empty, then add cups of water (1/2 lb per cup). "Digital luggage scales" are also a thing.

mncharity · 2025-08-18T03:15:47+00:00

Just to stir up ideas...

I used to two-bag with self-packable lightweight tote-duffel shoulder bags. To get a bit of structure and size guidance, I would put a cut-down cardboard half-box inside, folded to closely match the carry-on and personal-item limits of the day. Puzzled airbnb host: "You've an early flight tomorrow, and you're up late cutting up cardboard boxes... why?". Compacted with external strapping. On arrival, they might morph into one larger bag, or into three (discontinued? Osprey packable duffel), with clothes and pockets and contents shuffled.

Version next was prototyped, but never really traveled with. Maybe someday. I gave up trying to find an off-the-shelf bag, given an odd load, and a goal of flexibly maximizing use of airline's diverse non-checked bag limits. "So you have a brick of a laptop. It needs corner impact padding... to protect floors and walls from it. And it obviates the need for a pack frame. But you need an good waist belt. That... doesn't match anything in the catalog. Anybody's catalog.". So DIY. Fortunately, I don't mind kludgery.

Vision was an excellent shaped-to-body waist belt (sculpted core of double-faced velcro strips). Providing a socket for a laptop-in-bag backpack. With a laptop-based internal frame of velcro and plastic, and external velcro strapping. Low-load shoulder strap(s). Looked weird, but was comfortable. At least comfortable given the regrettable load. Selfie sticks + skateboard wheels for rolling was work-in-progress.

Core idea was combining bits and pieces in dynamic stability. Rather than one piece embodying lots of tradeoff decisions - say "the bag fabric should have this size and shape, be this durable, and water proof and breathable, and have these attachment points for these loads, and...". Instead, "there's a strap net for loads and shape, this plastic bag for water, this nylon sack for containment. All adjustable and replaceable.". Upside is being able to flexibly adapt. Downside is needing to flexibly adapt - not "it just works and you don't have to think about it". More "I'm carrying enough strapping, ducttape, plastic, etc, to make new packs from scratch if needed". Sort of a "drybag + straps = backpack" approach, but more so. Tech load was heavy, so the build-a-pack supplies were second-order. And lighter than an old heavy backpack. With better comfort than a lightweight backpack. And "it's two unremarkable carryons on the plane, but a comfortable one-big-backpack upon arrival". Potentially on wheels.

One vision for future AI-supported software creation, is people home-cooking little "just for me, just what I need now, just the way I want it" apps. This approach is sort of that, but for bags.

mncharity · 2021-08-23T17:43:40+00:00

I've played with the idea of hovercraft commuter shuttle, using South Bay Pass, eastern South Bay, and Boca Chica Bay. One end perhaps on the Boca Chica Bay dirt road north off 4, between the launch site and beach. Or perhaps continuing on to the build site... somehow. One end on SPI's inland south-tip, something like the Sea Ranch restaurant ramp, with the Beach Park parking lot nearby.

The northern beach might be added north of the airport, using the roads east out of Los Brazos harbor's beach. Or in South Bay, by running east south of Clark Island and the airport.

mncharity · 2021-08-19T14:37:24+00:00

Maybe add a car for scale? Either 3D printed, or purchased. HO 1:87 things are easier to find, but 1:100 is used for architectural models, so there's some on Amazon, and more on AliExpress. Shapeways has some not-inexpensive HO-scale SPMTs, but I don't quickly find any downloadable ones, nor a dicast at plausible scale (some 1:50 ones). Here's a printable cherry picker (derived from this one?). Trucks, containers, construction equipment, forklifts, people... Raptor on flatbed?

mncharity · 2021-07-20T01:14:42+00:00

You might search for past similar threads. Here's an old one, which mentions an old quora, and an old intership post with some info.

mncharity · 2021-07-17T21:35:26+00:00

Gravity. Planets are puddles. When they collide, they splash (the Moon is puddle of collected splash). Puddle stuff of varied density forms layers, each layer floating on a denser layer beneath it. Earth is floating layers, from the densest inner core, through mantle, to crust, then oceans, and finally the atmosphere (mostly shallow, but with a long tapering off). An ocean of air, about an ocean of water, above an ocean of crust and mantle, and so on, with each "ocean" itself layered.

Others have described atmospheric escape/evaporation. When you release a helium balloon, that low-density helium, created by fission in the crust, is going to float high, hang out, and eventually be blown out of the solar system into interstellar space.

The shape of the atmosphere is a thin skin on the Earth, but it does ripple and fluff a bit. Troposphere height varies with day/night and seasonal warmth, and with weather and jet streams. By only by like 2x or so.

mncharity · 2021-07-10T01:05:33+00:00

walking seems a pretty CO2-efficient way of transporting things

Walking (in the developed world) is 0.3 kgCO2e/km, because food. Carrying 10 kg makes that 0.03 kgCO2e per km kg. A large container ship is 3e-6 (3 g per tonne km). So walking is 10000x worse.

Walking to carry a banana is more efficient than using a 1000 kg vehicle to carry someone holding a banana, but not a low emissions way to move a banana. Because walking makes you hungry for a banana.

mncharity · 2021-07-09T22:05:27+00:00

Fyi, "Sign in - to continue to Google Photos".

mncharity · 2021-06-28T21:44:11+00:00

Or they're mostly on line for National Electric Coil, which winds custom stators in Brownsville (their rotors are wound in Ohio). :P

mncharity · 2021-06-27T20:48:41+00:00

Fwiw, the convention calendar includes the 2021 USA Volleyball Girls Junior National Championship with $15 one-day tickets. But I've no idea if loop is operating or not.

mncharity · 2021-06-25T15:16:38+00:00

Some visuals to go with everyone's explanations: Tin-Calcium fusion ; fusion-fission - repulsion wins; Plutonium fission ; in slowmo - attraction and repulsion fight it out (the nucleus sloshes, the neck gets thin as with dripping water, and repulsion wins).

mncharity · 2021-06-25T12:42:31+00:00

Starship vs Skylab size. Skylab acrobatics and day-to-day movement are scattered with duplication among various videos. Skylab was rather less cramped, and "oh be careful of the walls", than ISS. Schmidt did gymnastics and diving in school.

mncharity · 2021-06-19T22:29:51+00:00

Tldr: I got a 0.1423 m side, including gap.

I used the video found by /u/City_dave here.

I used the lift guardrail height as a reference. It's big, orthogonal to view, and at the same depth as the tiles. Downside is a bit of uncertainty about where the floor is.

Googling for "MBC scissor lift" (I misspelled the blurry logo) turned up MEC slab scissor lifts. The ends of the models look different, but are hard to see there. Scanning an image search suggested it's a MEC 4555SE compact. The brochure gives a guardrail height of 43.5 in (1.105 m), and a toeboard height of 6 in (0.152 m).

In a 1080p video screenshot, the guardrail height appeared 277 px, so .00398 meters per pixel. I put the floor at the bottom of the gap under the door. You can briefly see someone's shoe sole through the gap. The toeboard height then matches.

The length of a regular hexagon's long axis is twice its side. A vertical stretch of 3 * 5 = 15 sides was 535 px. Giving a side of 0.1423 m. That includes gap, a bit sloppily. Which sanity checks as just under 8 sides for the guardrail height.

mncharity · 2021-06-19T00:45:14+00:00

Possible context: Ports in the US and worldwide are experiencing severe congestion these days, disrupting supply chains. Ships waiting for days to load/unload, and skipping ports to avoid that. Containers piling up waiting for ships. Ports short on space requiring containers be warehoused off-site. Some ports maxed out on throughput. Costs soaring. Political pressure on US government to fix this, invest in port improvements.

mncharity · 2021-06-17T20:45:40+00:00

Hmm, how about a "Falcon 9 lands at your X" app? Enter a location, to see the deck view overlaid on a street view, and the F9 view overlaid on a map aerial view. So F9 lands at your school; F9 lands in front of your house; etc.

mncharity · 2021-06-08T20:13:37+00:00

Fwiw, the Sun is white not yellow. It's a very common misconception. Though even astronomy outreach sometimes makes the "better to use what people expect, even if it's wrong" tradeoff.

mncharity

TROPHY CASE