How many people still hold the memory of snow in Vienna on Kristallnacht? Not the ordinary kind of white, wet snow that falls from the sky, but something different; something soft and fluffy and ethereal that came floating down from the upstairs windows of Jewish homes all over the city on that night of destruction, exactly 80 years ago today, a night that plunged the world into chaos. The breaking glass of storefronts made sharp, crashing noises as howling mobs of Nazis made them shatter and fall, but the feathers that sailed gently, softly, silently to earth and blanketed the streets below held a seething violence of their own. My newly married parents huddled in a dark corner of their second-floor bedroom as two SS men booted open the door to their home, grabbing my father by the back of his collar and pulling him out of my mother’s arms.“You will come now with me,” one said, his voice quiet, almost silky, in the darkness.My father turned to put up his hands, willing them not to tremble. “And why?” he said.“You are a Jew, no?”My mother reached for him but the second officer pulled out a knife and ran toward her, pushing her down to the floor and leaping not onto her, as she’d feared, but onto the featherbed, slashing and tearing into the plump quilts and pillows and throwing them out the window. My father was led away and out the door and down the stairs and into the writhing mob and the street littered with an unholy mix of feathers and glass, leaving my mother to sob alone in her torn and broken home, a home in which all solace and comfort and safety had been destroyed. How do I know this? My father told it all to me over and again, sometimes even with a touch of glee.“I am here,” he said. “You are here. See? I outwitted Hitler.”I didn’t learn until many years later how that happened, or that 30,000 other Jewish men throughout Germany and Austria were also arrested that night.Weeks after Kristallnacht, my father said, as my mother ran from police station to police station, she finally learned he had been sent to Dachau, a concentration camp near Munich, almost 300 miles away. Like all the wives and mothers, she was desperate to get him out. Few men had come home, and some who did so arrived in a box. A pile of ashes. A severed hand, still wearing a wedding ring.She never told us what she traded to get him back, but she traveled to Munich and returned to Vienna with what she wanted and in less than a month she and my father had escaped, leaving all their possessions, their livelihood, their language, their families and their belief in goodness behind.By the time I was born, nearly a decade later and safe in New York, my mother had already been informed through the Red Cross that both her parents had been murdered in Auschwitz. But for many years she could still not see a feather float by without pulling me close. It wasn’t until I had been an adult for a decade or more that I understood how odd it was that even though I had never been to Vienna, had never even seen a Nazi, I felt as if it had all happened to me, that I’d been in the apartment that night and through the weeks and months of hatred and violence.Psychologists have long known, of course, that severe and prolonged trauma can live on in its victims long after the actual events end, but what I and other members of the so-called Second Generation – the children of Holocaust survivors – continue to experience has only very recently been explained. Epigenetic scientists like Siddhartha Mukherjee and Rachel Yehuda call this inter-generational transmission of trauma.They say we were born with physical scars from traumatic events that our parents endured before we were even conceived. Their experiments demonstrate how epigenetic changes in our parents’ genes, such as stress characteristics that cannot be turned off, came to us through biological information passed down genetically and that we have literally inherited the Holocaust.We know now that many more people are likely to fully recall the snow in Vienna on Kristallnacht than were physically present for the event. The effects of that night – and of all the traumatic Holocaust experiences our parents lived through – are more than just a legacy, they are a physical presence in our bodies, living on through us and through the genetic inheritance we pass on to our own children and to theirs.The writer is the scholar-in-residence at the Holocaust Memorial & Tolerance Center of Nassau County, N.Y.