By the end of the year Lena and Karl were a couple. She spent more time at his apartment, a shabby room in the southern part of Hyde Park, than Ursula’s, but Ursula didn’t seem to mind. It was as if her aunt knew what was happening and tacitly approved. Karl was invited to Shabbos dinner every Friday; it became the only big meal they ate, except when they went out.
The night she and Karl made love for the first time, she had the feeling she was his first. Afterwards she knew she had to write Josef. At first she had been wracked with guilt, and tried to keep Karl at a distance. But he was so unassuming, gentle, and smart she soon developed feelings for him. There had been no letter from Josef in months, anyway. Memories of him were fading like dried flowers inside a book, a book that had been written centuries earlier.
Meanwhile the Physics Department was suffused with an enthusiasm that hadn’t been present before. Compton, the head of the department, was known for studying cosmic rays, but the experiments that intrigued the students were those Enrico Fermi started in 1934 in Europe.
One night, after they made love, Karl tried to explain Fermi’s work in a way Lena could understand. “It has to do with bombarding elements with neutrons instead of protons. One of the elements Fermi uses is uranium, which is one of the heaviest of the known elements.”
“Why is that important?” Lena asked.
“Because the result turned out to be lighter than the elements he’d started with.”
She frowned. “What do you mean?”
“Fermi himself didn’t really understand why, but others were quick to link it to Einstein’s theory of E=mc2.”
“Why?”
Karl grinned. “Because a great deal of energy was released during the bombardment.” He paused. “When we figure out exactly how it happened and what exactly was released, a new world of possibilities will emerge.”
Lena loved to listen to Karl. She barely understood what he was talking about, but his eagerness and love of learning kindled a desire in her to go back to school. To finish what they called, in the States, high school. Maybe, afterwards, she would even enroll at the university.