nixiebunny
nixiebunny t1_ja848x7 wrote
Reply to comment by rosen380 in ELI5: why do grocery stores in the US keep such a large inventory? Aside from being prepared for episodic panic buying like toilet paper or bottled water, is there an economic reason to do this? How much of the food ends up going bad? by DrEverythingBAlright
Yes, but that's a forgotten story. UPC is still with us.
nixiebunny t1_ja7wqlq wrote
Reply to comment by phiwong in ELI5: why do grocery stores in the US keep such a large inventory? Aside from being prepared for episodic panic buying like toilet paper or bottled water, is there an economic reason to do this? How much of the food ends up going bad? by DrEverythingBAlright
The bar code was invented for grocery stores.
nixiebunny t1_j9rx4wi wrote
Reply to Challenge: Building a Box WITHOUT WOOD by KompassTheBand
Aluminum square tubing and sheet metal. Rivets or screws.
nixiebunny t1_j9hgfrx wrote
Reply to P-trap replacement by Chak-Ek
Rubber gaskets in plumbing joints don't need or want anything else. Only use plumber's putty when setting a drain in a sink etc., only use pipe thread tape on tapered pipe joints. Compression fittings are assembled dry. Plumbers guffaw when they see sealant used where it shouldn't be.
nixiebunny t1_j8bnd54 wrote
Reply to Cried tonight. by [deleted]
Neil deGrasse Tyson said that a similar experience led him to pursue astronomy as a career.
nixiebunny t1_j4x0leo wrote
If you think that's strange, you should visit the South Pole. The sun travels in a circle, at an angle of elevation that slowly changes over the weeks and months. And the architects of the base have imposed a NSEW Cartesian grid over the area to make navigation and planning easier.
nixiebunny t1_j2pjrn6 wrote
Reply to Proper use of ball bearing for a vertical rotation (azimuth rotation for a ground station) by Fun-Palpitation81
I work on radio telescopes. They typically have a large diameter roller bearing to support the yoke. The azimuth drive is completely independent of this bearing. Some use a friction roller, others a ring gear with two motors with pinions, one has a direct drive motor built into the housing (not recommended).
nixiebunny t1_j2e4r1p wrote
Reply to Hanging 15 lbs child from a 1x6 over head. Which supports more downward force - screwing horizontally into the 1” edge, or vertically straight up into the 6” face? by Jolly-Performer
Screws are much stronger in shear than tension. Use a bracket from the sides rather than trusting the life of your kid to a wood screw in tension.
nixiebunny t1_j29sz5c wrote
Reply to comment by Zocalo_Photo in My wife’s clock uses LEDs to illuminate individual pieces of glass with numbers to display the time. by Zocalo_Photo
It was tiny light bulbs at the bottom, controlled by stepping relays.
nixiebunny t1_j29audv wrote
Reply to My wife’s clock uses LEDs to illuminate individual pieces of glass with numbers to display the time. by Zocalo_Photo
It's an edge-lit display. This was used in the early 60s in some voltmeters made by Non-Linear Systems and others. https://www.sr-ix.com/Archive/instruments/Cubic-V45/
nixiebunny t1_ixzn6mz wrote
Reply to comment by ProFromFlogressive in Need help with vintage electric motor restoration by ProFromFlogressive
In that case, you probably want to get some oil in the bearings so they will last longer. 50 year old oil isn't trustworthy.
nixiebunny t1_ixxysva wrote
Don't be surprised if the sleeve bearings are worn out on a motor that old that's never been lubricated after installation. You can try spinning the shaft to see if it makes a rumbling noise, which means they're worn out. Replacing them is tricky at best.
nixiebunny t1_ixv6ca1 wrote
Reply to comment by Pure-Negotiation-900 in Frank Zappa - gender-bender style pioneer (1967) by MonotonousSolid
Yeah, more poodle than anything else.
nixiebunny t1_ixtex13 wrote
Reply to Can a single stud hold a 13kg TV by YoMADAv2
Many drywall anchors can hold that easily.
nixiebunny t1_iqtnebo wrote
Reply to comment by Old_comfy_shoes in If objects in space are far away, does light get scattered enough that it would look “low resolution” by the time it reaches us? by hau2mk7pkmxmh3u
There's not much of a theoretical limit to the resolution. If you can make a telescope the size of the galaxy, it would have quite high resolution. But where would you put it?
nixiebunny t1_iqtmx52 wrote
Reply to comment by Adrewmc in If objects in space are far away, does light get scattered enough that it would look “low resolution” by the time it reaches us? by hau2mk7pkmxmh3u
Yes, the interstellar medium (ISM) is rather opaque to visible light, but more transparent to infrared. My day job is in millimeter wave radio astronomy, which studies the makeup and behavior of the ISM.
nixiebunny t1_iqrjv82 wrote
Reply to If objects in space are far away, does light get scattered enough that it would look “low resolution” by the time it reaches us? by hau2mk7pkmxmh3u
There's a lot of nothing in space, so not much scattering happens until the light reaches the Earth's atmosphere. The images we get from such telescopes as JWST are "diffraction limited", which means that the resolution is a function of the size of the telescope's mirror, in the case of JWST it's the mirror segments that cause the starburst pattern. A huge single-mirror telescope in space could make much higher resolution images.
nixiebunny t1_jadf7dw wrote
Reply to comment by sailingtroy in This new Stanley tape measures is missing a few marks between 24 and 25... by Jay_Ray
Yup. Imagine being the scale inspector at the Stanley factory, and your supervisor starts asking you uncomfortable questions about how this one got out the door...