Feynman: FUN TO IMAGINE

This is an old video, but this is a new HD rip from the 16mm film.  I really recommend watching it if you haven't ever.

https://www.youtube.com/watch?v=nYg6jzotiAc

Radio Transmissions From Police Helicopter's Chase Of Bizarre Craft Over Tucson Add To Mystery

https://www.thedrive.com/the-war-zone/42021/radio-transmissions-from-police-helicopters-chase-of-bizarre-craft-over-tucson-add-to-mystery

On February 9, 2021, a U.S. Customs and Border Protection (CBP) helicopter encountered what was described as a “highly modified drone” hovering in controlled airspace above Tucson, Arizona. A Tucson Police Department (TPD) helicopter was called in to aid the CBP aircraft in its pursuit of the small aircraft, but the drone, or whatever it was, was able to outrun both of them as it flew through military airspace, deftly maneuvered around both helicopters with bizarre agility, and ultimately disappeared into cloud cover above the altitude the helicopters could safely fly. A police report previously obtained by The War Zone showed that the TPD crew described the drone as “very sophisticated / specialized” and “able to perform like no other UAS” they had previously encountered. Now we have the actual audio from the CBP helicopter’s interactions with air traffic controllers in Tucson during the incident, as well as audio from an after-action call between the TPD crew and the air traffic control tower.

How many Perseids will I see in 2021?

 https://blogs.nasa.gov/Watch_the_Skies/2021/08/09/how-many-perseids-will-i-see-in-2021/?linkId=127090324

 

Where Are The Robotic Bricklayers?

https://constructionphysics.substack.com/p/where-are-the-robotic-bricklayers

There seems to be a few factors at work. One is the fact that a brick or block isn’t simply set down on a solid surface, but is set on top of a thin layer of mortar, which is a mixture of water, sand, and cementitious material. Mortar has sort of complex physical properties - it’s a non-newtonian fluid, and it’s viscosity increases when it’s moved or shaken. This makes it difficult to apply in a purely mechanical, deterministic way (and also probably makes it difficult for masons to explain what they’re doing - watching them place it you can see lots of complex little motions, and the mortar behaving in sort of strange not-quite-liquid but not-quite-solid ways). And since mortar is a jobsite-mixed material, there will be variation in it’s properties from batch to batch.