mark-r (u/mark-r) - Readit News

mark-r commented on LED lighting undermines visual performance unless supplemented by wider spectra nature.com/articles/s4159... · Posted by u/bookofjoe

palmotea · 15 days ago

> The push toward LED seems to be primarily for emission target related reasons. It is very hard to buy incandescent bulbs in the UK; even for those of us that accept the cost implications.

Can you even buy them without buying new old stock? In the US they're banned and there's zero production.

I recall there was a guy in the EU who tried to get around the regulations by selling "heat bulbs" that were exactly the same as traditional incandescent bulbs but marketed as a heat source, but I think he was slapped down.

mark-r · 14 days ago

In the US they've even banned selling new old stock. I believe that was a recent change within the last few years.

mark-r commented on The super-slow conversion of the U.S. to metric (2025) thefabricator.com/thefabr... · Posted by u/itvision

pandaman · 19 days ago

>Lots of useless names and numbers to memorize

Do you have problems with time too? I mean, 1 minute = 60 seconds, 1 hour = 60 minutes, but one day = 24 hours? Wtf??! And one week = 7 days! And one month is 30 unless you mean an actual month which is anywhere from 28 to 31. And the year is 365 days, unless it's a leap year with 366. How do you cope with that?

mark-r · 19 days ago

Back in the 1970's I tried to come up with a metric time system by breaking a day into powers of 10. A centiDay was 14.4 minutes.

I realized it would never catch on, because a 30 minute TV show would have to fit into 28.8 minutes, and the only way to do that was to lose a couple of commercials. Never gonna happen.

mark-r commented on The super-slow conversion of the U.S. to metric (2025) thefabricator.com/thefabr... · Posted by u/itvision

MarkusWandel · 19 days ago

Handily enough the speed of light is about a foot per nanosecond, give or take. A nanosecond doesn't sound like much, unless you start to work out, for example, how many bits are inside your 40Gbps USB-C cable at the moment (they do travel at less than the speed of light).

mark-r · 19 days ago

Grace Hopper used to hand out pieces of wire to represent nanoseconds. She used pepper to represent picoseconds.

mark-r commented on The super-slow conversion of the U.S. to metric (2025) thefabricator.com/thefabr... · Posted by u/itvision

MarkusWandel · 19 days ago

Here in Canada, my family ran a fishing camp with a lot of US customers. I was talking with one of them about metric vs. US units and to demonstrate I said how about this: How many gallons in a cubic mile? And he was able to work it out in his head, and pretty quickly too. Whoa. The point I was trying to make that is than in metric (say, liters per cubic kilometer) you just need to get the number of zeroes right, but you can't argue with results.

mark-r · 19 days ago

I was able to do something similar by using gross approximations and conversions to/from metric. My coworker had just bought a surplus stainless steel water tank for solar heating, and was wondering how much it would weigh when full. It was cylindrical, so I asked him for the diameter and the height. In my head I converted those measurements to inches, then to centimeters by multiplying by 2.5. I divided the diameter by 2, squared it, and multiplied by 3 (close enough to pi) to get the area. Then I converted the area and the height to their nearest power of 2 so I could take advantage of logarithms. Multiplying the area and height was as easy as adding the exponents, which gave me cubic centimeters. The weight of water is almost by definition 1 gram per 1 cc. Divide by 1000 to get kg by subtracting 10 from the exponent, then multiply by 2 to get approximate pounds by adding 1 to the exponent. By the time he was done telling me the dimensions, I had an answer for him. It definitely wasn't correct, but all he needed was a ballpark anyway.

mark-r commented on The super-slow conversion of the U.S. to metric (2025) thefabricator.com/thefabr... · Posted by u/itvision

maxerickson · 19 days ago

The pre decimal systems were built with lots of prime factors. The divisions were less obvious but arguably more convenient (it's often simpler to separate something into 8ths than 10ths, and so on).

mark-r · 19 days ago

I love the way 360 (degrees) divides evenly by so many small integers: 2, 3, 4, 5, 6, 8, 9, 10, 12, 15.

mark-r commented on The super-slow conversion of the U.S. to metric (2025) thefabricator.com/thefabr... · Posted by u/itvision

mark-r · 19 days ago

We may get there eventually just as a consequence of being part of the world economy.

I noticed a couple of years back that my "U.S. Customary" wrenches weren't fitting my new plumbing fittings which were definitely not metric, but metric wrenches did. Probably made in China.

Then last summer I noticed something similar with lag bolts. The U.S. Customary socket fit the head, but it was nearly identical to a metric one that fit just a little better. The threads are designed to go into wood, not a nut, so if they were metric you'd never even know.

mark-r commented on Amazon is ending all inventory commingling as of March 31, 2026 twitter.com/ghhughes/stat... · Posted by u/MrBuddyCasino

themaninthedark · 22 days ago

But it sounds like their superior delivery service is a lie too. Promise next day or 2 day service but delivery in 3-4 days.

mark-r · 21 days ago

It wasn't even next day, it was same day! But yes, it was a complete lie.

mark-r commented on Amazon is ending all inventory commingling as of March 31, 2026 twitter.com/ghhughes/stat... · Posted by u/MrBuddyCasino

groundzeros2015 · 22 days ago

You’re saying that you still use Amazon because it offers a superior delivery service?

Then aren’t you glad that option exists when you need it?

mark-r · 21 days ago

I didn't need it that same day - if I had, I would have driven 5 miles to the nearest retailer that carried it and Amazon wouldn't have even been considered.

I was seriously impressed that they made that promise, thought I had nothing to lose. And I re-learned a lesson, if something's too good to be true then it probably isn't. I certainly won't be putting any faith in same-day service in the future. They proved their "superior delivery service" is just an illusion.

mark-r commented on Amazon is ending all inventory commingling as of March 31, 2026 twitter.com/ghhughes/stat... · Posted by u/MrBuddyCasino

petcat · 22 days ago

Nobody stops you from buying products directly from the company's website. You don't have to buy everything from Amazon.

I browse on Amazon, and then go to the company's website directly for the purchase. USPS, UPS, and FedEx will still deliver it just the same.

mark-r · 22 days ago

But not same-day. But even that's a bit iffy - I made a purchase from Amazon recently where they promised same-day delivery, on a Sunday no less! But it didn't actually arrive until Wednesday.

mark-r commented on Amazon is ending all inventory commingling as of March 31, 2026 twitter.com/ghhughes/stat... · Posted by u/MrBuddyCasino

happymellon · 22 days ago

I wonder how they are planning on de-mingling existing products that don't have the required Amazon barcodes that should or vice versa.

mark-r · 22 days ago

Maybe that's why it will take 2 months, they need to clear out the old inventory so they don't have a de-mingling problem.