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jerzmacow commented on Optical Fresnel zone plate flat lens: colored photoresist through I-line stepper   nature.com/articles/s4137... · Posted by u/bookofjoe
rocqua · a year ago
A diffractive lens works by having small holes in a plate, at least as I understand it. The diffractive pattern then interferes constructively at the focal point. So the transparent material is just 'air' or more likely, vacuum. It doesn't need to be solid.

The problem I forsee is that it doesn't let much light through. Because most of the lens isn't holes, but instead solid non transparent material.

jerzmacow · a year ago
Do we possess the technology to place atoms sufficiently close enough to direct euv? Considering the fact euv is already close to the limit of our abilities
jerzmacow commented on Speed, scale and reliability: 25 years of Google datacenter networking evolution   cloud.google.com/blog/pro... · Posted by u/sandwichsphinx
jerzmacow · a year ago
Wow and it doesn't open with a picture of their lego server? Wasn't that their first one, 25 years ago?
jerzmacow commented on One dead as London-Singapore flight hit by turbulence   bbc.com/news/articles/c88... · Posted by u/yowmamasita
Andrews54757 · 2 years ago
You won't gain additional momentum from a loose belt. But a loose belt may give your body the chance to slip out. The impulse you feel from a tight belt will be no less than the impulse you feel from a loose one.
jerzmacow · 2 years ago
I disagree, a tight belt will cause the least amount of injury. Look at fall arrest systems.

If you're harness is loose, or your line is slack without an energy absorber, it'll break your back when you fall!

jerzmacow commented on Doomscroller.xyz   doomscroller.xyz/... · Posted by u/arfrank
jerzmacow · 2 years ago
This is really neat, I wonder how hard it would be to retool for Android camera controls. There's an accessory for the iPhone to get physical camera controls, but it's thicc
jerzmacow commented on Tesla FSD v12.3.3 still runs down child mannequins. Unfixed for 1.5 years [video]   vimeo.com/932562717/5fb31... · Posted by u/Veserv
jerzmacow · 2 years ago
I would sooner rally against SUV / Truck grills what hide 12 children under their exaggerated height.
jerzmacow commented on Low Cost Robot Arm   github.com/AlexanderKoch-... · Posted by u/pbrowne011
jerzmacow · 2 years ago
Wow, I was building a Thor 3D printed arm, and this project looks way better! I think I'm going to Pivot.

Side bar: these servos are a game changer.

jerzmacow commented on What happens to Google Maps when tectonic plates move? (2020)   nautil.us/what-happens-to... · Posted by u/dmitrysergeyev
dhosek · 2 years ago
I remember having a hand-held Garmin GPS unit back in the '00s that I used on a trip to Berkeley from Los Angeles (one bonus was that the speedometer in my car didn’t work¹ so I was able to use it as a speedometer for the trip). The location that it showed on the map was consistently off by about 50 feet. I wonder now if this was a tectonic drift or just an inherent inaccuracy of the unit.

1. When I think back to that car, it’s amazing what a piece of junk it was. On the other hand, it was a convertible, so a lot of fun although my wife considered it a deathtrap.

jerzmacow · 2 years ago
Back in the day GPS was intentionally offset so countries couldn't use it for weapons.. well except it's owner of course!
jerzmacow commented on Lenovo announced ThinkPads for 'better sustainability and extended repairabilty'   news.lenovo.com/pressroom... · Posted by u/opengears
bzzzt · 2 years ago
> Soldered NAND is a wear item and a WAY bigger deal.

"Citation needed". For anything resembling normal usage an SSD will last well beyond the economic lifetime of the rest of the components surrounding it. So why is it that big a deal to replace it?

jerzmacow · 2 years ago
I'm sure my usage would be excessive compared to a normal user, but I find SSDs last 2-3 years on average. I buy Samsung, perhaps that's the real issue
jerzmacow commented on Biggest airport to open by 2030 with 6 runways and 120M passenger a year   thesun.co.uk/travel/26285... · Posted by u/teleforce
wkat4242 · 2 years ago
Well they do have the money. I'm sure they can build it.

They won't get the tourists (except for the yearly mekka pilgrimage) but perhaps they're going for a hub thing like Dubai.

jerzmacow · 2 years ago
I always wonder if having unlimited money is all it takes. There's only so many excavators in the world, and hiring every single one would probably tank someone's economy
jerzmacow commented on Rise of fast-fashion Shein, Temu roils global air cargo industry   japantimes.co.jp/business... · Posted by u/PaulHoule
tyrfing · 2 years ago
Shipping/fulfillment costs are simply far more expensive than most people assume. If you buy a $15 item on Amazon, Amazon keeps about half of that. The seller still has to pay for the entire process of getting it to an Amazon warehouse.

Air freight China to US is very roughly $3/KG. Assume T-shirts (as a light weight good that is going to trend lower price), at an ASP of $5 and weight of 150g. A $30 order (Shein minimum for free shipping) is going to be 6 shirts at 900g for a cost of $2.70. Surepost/Smartpost tier delivery is $5 or lower; even retail-available services would be $7. In comparison, Amazon FBA for 2 shirts at $15 each would charge $7.16 for fulfillment. At December rates, they would also have charged $5.1 in platform fees, which was reduced to as low as $1.5 now due to this competition. That's $12.26 in fulfillment cost for the Amazon order of 2 T-shirts, compared to 6 T-shirts shipped China to US door for $8.70 est.

The above is generous to Amazon. 6 shirts for $5 each on Amazon would cost $22.98-26.58 to sell, and they have an array of additional fees.

It also ignores FBA freight costs - sea freight and duties/tariffs that D2C air avoids due to de minimis. On the other side, I'm ignoring fixed/semi-fixed platform costs and pick/pack costs; I have no idea what that costs in China, but it has to be a tiny fraction of the cost in the US.

jerzmacow · 2 years ago
Do you work in this industry?

u/jerzmacow

KarmaCake day61August 24, 2020View Original