The Truth About Albert Einstein's Mysterious First Daughter

"I love her so much and I don't even know her yet!" Those were the words a 22-year-old Albert Einstein penned in a 1902 letter about a baby girl that most of the world still doesn't know, per the Guardian. Einstein sent that letter roughly three years before he would officially father the theory of relativity, but he had already fathered a relative through a process best captured in the following equation:

E = jaculation multiplied by a woman plus Einstein times the speed of his lovemaking

To be clear, no one is claiming that Einstein made love at the speed of light, just implying it for the purposes of kidding, which is fitting, since Einstein produced a kid that way — speed notwithstanding. The woman in the equation was Einstein's former classmate and not-yet-wife, Mileva Marić, who gave birth to their daughter, Lieserl, while staying at her family home in Serbia. At the time Einstein was working as a patent office clerk in Bern, Switzerland, and burning with excitement over the prospect of fatherhood. He wanted to know what Liesel's "little eyes" looked like, which parent she resembled more, whose boobs were nurturing the girl. Sadly, it doesn't appear that he really got to know to know the daughter he loved before ever laying eyes on her.

The Guardian writes that when Mileva Marić joined Albert Einstein in Bern, third person was missing from the equation: their little Lieserl. Her fate remains an unknown variable. At some point the child came down with scarlet fever, but it seems that the bouncing baby Einstein bounced back from her illness. Some scholars have argued that she was given up for adoption. There is no record of Einstein ever visiting her, and her very existence didn't become public knowledge until decades after the scientist died.

Why would the genius scientist say goodbye to the daughter he so dotingly wrote about without ever saying hello? Why was she kept a secret? It turns out that Lieserl was born into controversy. As Time describes, Einstein's mother disapproved of his union with Marić, who was an older woman that adhered to a different religion. Momma Einstein even cautioned, "If she gets a child, you'll be in a pretty mess." Einstein and his wife remained tight-lipped about Lieserl's birth, not even telling close friends. As for the possible adoption, there may be a very sad, but certainly unconfirmed reason for that.

According to Michele Zackheim, who spent five years researching Lieserl, the girl had trisomy 21, the medical condition more commonly named Down syndrome. Contrary to what others have claimed, Zackheim argued that Lieserl was left to live with her Serbian grandparents. Furthermore, alleged Zackheim, Lieserle succumbed to scarlet fever at 21 months old. To this day, no one truly knows what became of her.