Christian Andreas Doppler ( ; 29 November 1803 – 17 March 1853) was an Austrian mathematician and physicist. He formulated the principle – now known as the Doppler effect – that the observed frequency of a wave depends on the relative speed of the source and the observer.
Countess Marie Louise Larisch von Moennich (also known as Countess Marie Louise Larisch-Wallersee and Countess Marie Larisch) (24 February 1858 – 4 July 1940) was
a niece and lady-in-waiting of Empress Elisabeth of Austria. She was implicated in the Mayerling Incident which resulted in the death of her married cousin Crown Prince Rudolf and his mistress Baroness Mary Vetsera, who was also her friend. She published several books with a ghostwriter about the Imperial household.