主题：被原子弹之父羞辱的一位来自亚洲的诺贝尔物理奖得主 -- 黄河故人

From wiki,

It is estimated that in the 11th century Ashkenazi Jews composed only three percent of the world's Jewish population, while at their peak in 1931 they accounted for 92 percent of the world's Jews.

Ashkenazi Jews used to live in central and eastern Europe. Many of them lived together with Germans and started to pick up German/Dutch last names when they moved around in Europe and finally settled in the US (or Australia or Russia or Canada).

So it is normal to see German Americans and their Jewish neighbors in States share the same last name, but they might not like each other at all.