Euler’s Disk
An evening pause: Something for all those new home schoolers, and their parents, to puzzle over and use to learn something worthwhile and real.
Note also how the concave mirror eventually forces the disk into the center of the mirror.
Hat tip Phill Oltmann.
Readers!
My annual February birthday fund-raising drive for Behind the Black is now over. Thank you to everyone who donated or subscribed. While not a record-setter, the donations were more than sufficient and slightly above average.
As I have said many times before, I can’t express what it means to me to get such support, especially as no one is required to pay anything to read my work. Thank you all again!
For those readers who like my work here at Behind the Black and haven't contributed so far, please consider donating or subscribing. My analysis of space, politics, and culture, taken from the perspective of an historian, is almost always on the money and ahead of the game. For example, in 2020 I correctly predicted that the COVID panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Every one of those 2020 conclusions has turned out right.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
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An evening pause: Something for all those new home schoolers, and their parents, to puzzle over and use to learn something worthwhile and real.
Note also how the concave mirror eventually forces the disk into the center of the mirror.
Hat tip Phill Oltmann.
Readers!
My annual February birthday fund-raising drive for Behind the Black is now over. Thank you to everyone who donated or subscribed. While not a record-setter, the donations were more than sufficient and slightly above average.
As I have said many times before, I can’t express what it means to me to get such support, especially as no one is required to pay anything to read my work. Thank you all again!
For those readers who like my work here at Behind the Black and haven't contributed so far, please consider donating or subscribing. My analysis of space, politics, and culture, taken from the perspective of an historian, is almost always on the money and ahead of the game. For example, in 2020 I correctly predicted that the COVID panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Every one of those 2020 conclusions has turned out right.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
Highly suggest any of the physics lectures from Walter Lewin for home-schooling purposes. (High school level.)
–Get yourself a free test-copy (full functionality for 1 month) of Internet Download Manager (or similar downloading Program), download them all off yt, and burn them to DVD. (This by-passes all inserted commercials, and you have a physical copy.)
[If you want ‘mental hygiene films’ from the 1950/1960’s, go to the Archive(dot)org.
Professor Walter Lewin
“I am Still Alive Because of D-Day”
June 6, 2018
https://youtu.be/p5bsw8GNqCM
3:11
a sample….
MIT Physics 8.01x
“Lecture 6 – Newton’s Laws”
Walter Lewin
https://youtu.be/oduZsA0Tk58
49:15
“Watch all my 94 MIT course lectures. Start with 8.01, then 8.02, then 8.03. Do all the homework and take all my exams. Homework and exams are posted below the video thumbnails. I guarantee you, that you will then not fail the Physics portion of any exam.”
Now I wonder if this has a thermodynamic counterpart with “anti-freezing:”
“When vibrations increase on cooling: Anti-freezing observed”
From Aug 4 2021 phys.org at Helmholtz Association… nickel oxide.
The term anti-freezing made me think back to Egon Bach’s ideas of work and “anti-work” when it came to “geometeors” as Olkhovatov thought Tunguska was..