This is slightly misleading advice. The ideal place for the display has the top of the display at roughly eye level, or for a very large display maybe slightly above, which puts most of the display below eye level. Humans actually have great ability to look slightly downward for long periods of time while doing stuff with their hands, even while keeping their head held up straight, and indeed our eyes can more comfortably focus on close objects in the lower part of our field of view than straight ahead. What you don't want to do is slouch or bend your neck too much.
A laptop display attached to the keyboard usually isn't an ideal placement, but it's generally not too bad.
Welcome to "tech neck" - upper crossed syndrome, from looking slightly down.
You're inviting some surprising symptoms, not just neck and back pain, but things like numbness, tingling, or pain shooting down your arms. Really not fun.
Key posture correction seems to be pulling head back. Some physical therapy exercises can help as well.
Having the desk low, the chair high, or putting a laptop on your lap is okay. Having the desk or table "high" (i.e. at normal height for writing with a pen or eating a meal) is generally worse but not an insurmountable problem.
In either case, the most important thing is to keep your wrists in as straight and neutral position as possible, with your palms and wrists "floating" rather than resting on anything while actively typing. Having the wrists either flexed downward or extended upward is a really bad idea. Having the wrists turned out to the side isn't great either, but not as bad.
The keyboard should be positioned close enough to your body so that your shoulders can be relaxed with your upper arms hanging loosely. The laptop surface should be roughly parallel to your forearms, so if you have a high desk or table relative to your torso you will need to prop up the far side to tilt it up a bit.
If your wrist is in contact with the edge of the laptop while you are actively typing, then your typing style has a good chance of giving you RSI. You'd be better off trying to fix that than trying to make the fast path to RSI more convenient.
How the f are you supposed to type? Ideally I'd like full support for my arms from the elbow to the wrist.
In my first job - i think it was in 1997, I had my own small room with an L-shaped desk with a rounded corner. That gave a few inches of space for resting my arms - both when typing on a quite reasonable Pentium laptop, and especially when using the mouse.
Since then, the desks and the chairs has become shittier and shittier. Except perhaps when a was a consultant for an HR-department.
The U-shaped desk was probably the best ergonomically designed workplace I've had. Maybe a wheat-filled pad along the desk would have made it better.
If your arms are resting, then your fingers and wrists are doing the maximum amount of reaching as you type. If you use a wrist rest you are encouraging your fingers/wrist to reach up (bend in your wrist) instead of neutral or reaching down (more natural position).
Constant change in position, dynamic motion, strong & brief muscular exertion of whole hand and arm, even including the shoulder vs constant static position w/ small repetitive motions, where the fingers really are doing almost all the work.
You should try to avoid continuous static load on your muscles, especially the smaller ones. So you should find a typing position where that doesn't happen. You also want to use your muscles in the strong and comfortable part of their range of motion, which depends on the entire chain of joints, because tendons have to stretch past several joints to get to whatever bone they attach to – so for fluent finger motions, you want to keep wrists and hands in as neutral a position as you can.
If your wrists are not straight while typing a lot, that's really bad. I constantly see people typing with their wrists either significantly flexed or significantly extended; doing that a lot is a fast road to RSI, and even doing it a little is pretty unpleasant and inadvisable.
If you are going to type a whole lot at a stretch (say, as a programmer or writer), you want your arms to be mostly passively supported from the shoulder. Having your arm bent at the elbow doesn't cause much strain, as long as the upper arm is hanging loosely down with your shoulder relaxed – so bring the keyboard relatively close to your torso. Resting your wrists, palms, or forearms on some surface and then typing generally causes more strain than having your wrists and palms "floating" above the keyboard while actively typing. You can rest the fingertips lightly on the key tops if you want. You can rest your palms on a palmrest or arms on an armrest (or table, or lap, or whatever) while you are taking a break from typing. It's generally a good idea to take regular breaks.
There doesn't appear to be good evidence that this is better for RSI. I found one study that shows greater shoulder and back strain when doing the hover hands approach. It might make more sense for piano since you need more mobility up and down the keyboard, but for typing your hands don't need to move nearly as much, so resting should be just fine. The do suggest some sort of support under your wrists, though.
Huh, seriously? Have you ever worked in an office? Perhaps your mental picture of what op is describing might be misaligned? I just always assumed it was a rarer/ more disciplined style some people had
On a modern laptop, the keyboard is on the top half of the lower case these days, not the bottom.
My palms are hovering over or resting on the chassis, and I sit high enough that my wrists do not come in contact with the edge of the case or desk. The majority of the weight of my arms is supported by my shoulders. For me, the ideal height happens to be pretty close to a neutral wrist position.
A more concrete way of putting it is if you are putting so much weight on your wrists that the edge of the MacBook is making you uncomfortable, you're probably doing it wrong.
I've heard this but I've personally been typing this way for 25+ years (wrists on the rest, including on laptops exclusively for the last 15) and my wrists are fine. Meanwhile people I know with ergonomic keyboards and everything that's supposed to save your wrists are the ones with bad wrists.
The reasonable takeaway from that correlation is that people with preexisting issues turn to ergonomic keyboards to avoid worsening those issues, not the other way round.
While this is true, if standard keyboards were bad then everyone who uses them would have issues, yet many (most?) don't.
Sometimes I think it comes down to actual typing technique. For example. I've heard of "Emacs pinky" which is easily avoided by simply using the Ctrl key opposite the key being pressed (use right Ctrl for C-c for example). I religiously never use Ctrl, Shift or Alt + another key with the same hand and I feel that's been huge. Also my elbow, wrist and hand always form a straight line to the keyboard with a standard laptop keyboard and the right body position/desk and chair adjustment.
After RSI years ago, I switched to an X220 and had 100% the opposite experience. The curve at the front of the case was a perfect resting point for the heel of my (average size) hand to allow easy reach of the keys. I replicated this geometry by sanding a pine 1x4 and wrapping that in soft leather for a wrist rest with a procession of mechanical keyboards (currently a Lenco Majestouch 2). Literally decades later, all is well.
Magnus "drives meaningful outcomes" because he's really good at chess and members of the public enjoy watching him play, so various chess-related businesses will pay him money for sponsorship. How do you propose to "not allow him" that influence? Ban all use of people's names in marketing and products?
My commentary goes above and beyond just Magnus. Re: Magnus. Sponsorships are fine. Him making money is fine. He shouldn't be able to dictate the rules of the game or the platforms by which it is played. IMO.
He's not the first person to be "really good at chess".
It's a broad statement meant to mean "celebrities have too big of a platform and too much influence over the average joe".
Magnus doesn't "dictate the rules of the game or the platforms by which it is played", so I'm not sure what your point is.
You think Magnus should be forced to participate in chess events he doesn't enjoy / doesn't like the format of? Or you think organizations like FIDE or chess.com should be blocked from trying to entice Magnus to participate in their events?
Thanks, that's great to know! However, I also had to remove the high-CRI lights from some lamps because I found that they disturb my sleep if I have them on in the hours before bedtime.
I live in a 240-volt country, though, and I've never seen a dimmer switch here.
The sodium lamps are in fact safer for driving, because they preserve drivers' night vision, which improves visibility into the shadows, and because they cause less glare.
What they aren't good for is LED manufacturers' bottom line, and the lighting industry spent a lot of lobbying money to entice friendly politicians to heavily subsidize them with public infrastructure budgets, with those subsidies then misleadingly sold to the public as "efficient" and "environmentally friendly".
They're also not very good for reading the newspaper or doing critical color analysis. Thankfully such tasks do not need to be done at night in the middle of the street.
That would make sense. Otherwise I have no idea how people wouldn't have noticed how much more difficult it makes seeing anything outside of the sharp cutoff of the light cone (or, of course, for the person being dazzled on the other side).
It's not especially close to the peak sensitivity of the human eye (in either bright or dim conditions), but that's entirely okay. The goal should be to not affect people's level of dark adaptation.
If you use shorter ("bluer") wavelengths, as happens with white LEDs which consist of a blue LED + phosphor, it causes people's eyes to become bright adapted and effective night vision is ruined, causing people to have much worse vision in the shadows.
Also, if you use bluer light, the lights themselves cause dramatically more glare in peripheral vision, because the shorter-wavelength-sensitive "S" cone cells and rod cells are mostly absent from the fovea (center of the retina), and prevalent in the outer areas of the retina. This is why LED headlamps on cars are so obnoxious for drivers going the opposite direction.
Also, the LEDs clobber people's circadian rhythms and are extremely disruptive to wildlife.
Finally, the light pollution caused by the LEDs is much worse for seeing the stars, which is maybe not as important as the other harms, but still kind of sad.
> It's not especially close to the peak sensitivity
The sensitivity at sodium light is above 75% of the peak human vision (photopic) sensitivity.
This is a very small difference in light sensitivity. For example in the case of many sources of red light or blue light the sensitivity can be 5 to 10 times lower than the peak sensitivity.
Moreover, a perfect source of white light cannot achieve a better sensitivity than around 37%, i.e. less than half of the efficiency of an ideal source of monochromatic light at the sodium emission line.
Therefore the fact that currently LED lamps and low-pressure sodium lamps have about the same energy efficiency is caused by the LED lamps having a higher photonic efficiency and a lower threshold voltage (caused by a P-N junction voltage instead of the ionization potential of sodium), which compensate the disadvantage of using white light. A monochromatic LED lamp with the same color as the sodium lamps could have an energy efficiency at least double over the white LED lamps.
Red light would be even better for affecting the dark adaptation, but it has other disadvantages, like much worse energetic efficiency and lower visual resolution.
Yellow light a.k.a. amber light around the sodium emission line is a good compromise between energy efficiency, visual resolution and dark adaptation.
That's not necessarily a downside for traffic safety, though. Though I imagine someone must have studied the effects of various wavelengths on drivers...
My understanding is that cellophane generally does biodegrade in most settings. Polylactic acid (those cornstarch-derived bags) mostly biodegrades in hot enough compost or (after several years) in ambient-temperature soil, but not very well in cooler water (One study: "The half-life period of degradation [of polylactic acid in artificial seawater] is 12 [days at 90° C] or 468 days [at 60° C]").
Those temperatures are certainly hard to find in nature, outside of hot springs! Even if this is an error and we are talking about 90°F/60°F, the higher temperature is pretty much constrained to the tropics, so we're talking a year+ to degrade in real conditions. It is better than centuries, but not exactly rapid?
Yeah, I imagine it's considerably slower at ambient ocean temperature. Don't throw your PLA bags in the ocean or a river. Here's a different paper:
> For example, PLA is not biodegradable in freshwater and seawater at low temperatures [32,36–39]. There are two primary reasons for this: (i) The hydrophobic nature of PLA, which does not easily absorb water [40–42]. In aqueous environments, the lack of hydrophilicity diminishes the hydrolysis process, which is crucial for the initial breakdown of PLA into smaller, more degradable fragments. (ii) Resistance to enzymatic attack; the enzymes that degrade PLA are not prevalent or active under typical freshwater and seawater conditions [39,43,44]. The microbial communities in these environments may not produce the necessary enzymes in sufficient quantities or at the required activity levels to effectively breakdown PLA. Additionally, the relatively stable and crystalline domains of PLA can further resist enzymatic degradation.
Also:
> It should be emphasized that neat PLA cannot be classified as a completely biodegradable polymer, as it generates microplastics (MPs) during biodegradation.
BART is full of white-collar people who use it to commute and to travel around the area (alongside all sorts of other kinds of people, as you would expect for a broadly used service).
Ridership collapsed in 2020 because of the pandemic, for obvious reasons, but it's hard to really blame that on the service itself, or the riders.
Ridership has been gradually recovering since then. Total trips are now up to something like 70% of 2019 levels, and continuing to rise. Number of unique riders is actually above the 2019 level now.
Maybe you haven't tried riding BART again within the past several years?
I left SF ~2021, but even in 2019 it was kind of in a death spiral. Hopefully it's better now, loved it back when I lived there. But still hear mixed reports from friends.
This is slightly misleading advice. The ideal place for the display has the top of the display at roughly eye level, or for a very large display maybe slightly above, which puts most of the display below eye level. Humans actually have great ability to look slightly downward for long periods of time while doing stuff with their hands, even while keeping their head held up straight, and indeed our eyes can more comfortably focus on close objects in the lower part of our field of view than straight ahead. What you don't want to do is slouch or bend your neck too much.
A laptop display attached to the keyboard usually isn't an ideal placement, but it's generally not too bad.