Does anyone recognize the equation carved on this object?

The only hint I have is that the back side has the word "orbit" carved into it.

It may be incomplete or incorrectly copied.

enter image description here

My best interpretation in MathJax:


My grandmother carved the object. She had a hobby of carving small figures and objects out of blackboard chalk. She made (among other things) chess figures and a scene with her brother posing with his new car.

This figure was presumably carved during the space race in the 1960s.

Grandmother was a grade school teacher, so I'm pretty sure she didn't understand it and just copied it from a magazine or newspaper article.

  • 3
    $\begingroup$ @Ludo: It looks more like Rôh to me. $\endgroup$
    – JRE
    Oct 22, 2022 at 22:12
  • 5
    $\begingroup$ I'm getting a whiff of escape velocity $v_e = \sqrt{2\mu/r}$ but that's obviously not all of it $\endgroup$
    – Erin Anne
    Oct 22, 2022 at 23:16
  • 1
    $\begingroup$ I'm seeing that "g" as more of a greek small case rho ($\rho$ or ϱ from here). Looks a bit like this stuff which of course is related to escape velocity as well. We should use dimensional analysis here. Also, this depends on $R^{3/2}$ so look for things that have a 3/2 power law dependence. Sorry not much help. $\endgroup$
    – uhoh
    Oct 23, 2022 at 3:30
  • 1
    $\begingroup$ Note that it may be that the part starting with $R_0\sqrt{}\dots$ may actually be an exponent of $e$... all kinds of rocket related equations have exponential relations, that may give someone a clue. Why the $U$ that precedes that looks to be above the $e$ may just be another indication that it was copied without being fully understood... $\endgroup$
    – Amit
    Jun 11, 2023 at 23:25
  • 2
    $\begingroup$ Btw, this also makes it more likely a $\rho$ rather than a $g$, that is, charge density perhaps. $\endgroup$
    – Amit
    Jun 12, 2023 at 21:17


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