The letter also hints at Einstein's meeting with fellow Nobel laureate Karl von Frisch, who was a leading bee and animal sensory researcher of the time. In the April of 1949, Professor von Frisch presented his research exploring how honeybees are able to navigate by using the polarisation patterns of light scattered from the sky — a lecture which Einstein is known to have attended. The day after, it is understood that the two scientists shared a private meeting, in which they may have discussed the intricacies of Professor von Frisch's work. In his letter, Einstein wrote: 'Dear Sir: I am well acquainted with Mr. v. Frisch's admirable investigations. But I cannot see a possibility to utilize those results in the investigation concerning the basis of physics. 'Such could only be the case if a new kind of sensory perception, resp. of their stimuli, would be revealed through the behaviour of the bees.' However, he concluded: 'It is thinkable that the investigation of the behaviour of migratory birds and carrier pigeons may some day lead to the understanding of some physical process which is not yet known.'