Wednesday, September 26, 2018

history - What is the source of Yartzeit tablet?


Who invented the Yahrtzeit tablet (panel)?


Standard synagogue


At first glance, this could not have been common before 150 years ago, as there is no room to place candles where the electric lights go.



Who invented it, and is it mentioned anywhere in seforim?




No comments:

Post a Comment

periodic trends - Comparing radii in lithium, beryllium, magnesium, aluminium and sodium ions

Apparently the of last four, $\ce{Mg^2+}$ is closest in radius to $\ce{Li+}$. Is this true, and if so, why would a whole larger shell ($\ce{...