理论物理学家与实验物理学家的工作不是完全同步、密切对接的.20 世纪20 年代在德布罗意提出物质波假设之前， 戴维孙等人已经做了慢速电子的衍射实验.弗兰克是最早认识到戴维孙实验意义的人之一.他的弟子艾尔萨色也独立认识到了这一点，并尝试做进一步的实验验证.但是未能如愿.寻求弗兰克的帮助，也未如愿.艾尔萨色发表了一篇理论分析小文章，明确提出让电子通过晶体可以观察衍射图案，从而验证德布罗意的物质波假设.该文发表两年左右后，玻恩在牛津的一次学术会议上重提艾尔萨色的文章，才真正引起戴维孙和汤姆逊的注意，很快他们得到了很好的实验结果，获得了1937 年诺贝尔物理奖.弗兰克的忽视使艾尔萨色的一个很重要的想法丧失了先机.

The research works of the theoretical physicists and experimental physicists are not synchronous and not seamless. In 1920s，before the hypothesis of de Broglie wave，Davisson and Kunsman had done the diffraction experiment of electron. Franck was one of the people who first knew the meaning of the experiment. Elsasser，one of Franck’s students，grasped it himself，and he wanted to do further experiment research，but did not get any result. He seeked help from Franck，but also failed. Elsasser published a note paper，presented that we could got the pictures of electrons diffraction when electrons go through crystals. Two years later，Born in a report in Oxford mentioned the paper of Elsasser again. Born’s words attracted the attention of Davisson and G.Thomson. Quickly they got good result and won the Nobel Price in 1937. Franck did not value the idea of Elsasser and made him lost a good chance to be one of the Nobel Price winners.