MAA Found Math: Benyavut Jirasutayasuntorn snapped this photo at Temple Israel in Stockton, California. He wrote, "Infinity and beyond. This temple wall depicts the Hebrew letter, 'Aleph'. Mathematically they are a sequence of numbers which are used to represent the cardinality or size of infinite sets."
In set theory, the Hebrew aleph glyph is used as the symbol to denote the aleph numbers, which represent the cardinality of infinite sets. This notation was introduced by mathematician Georg Cantor (Source).