How do you know what you’re not allowed to see?Olivier Bonin / SLAC National Accelerator LaboratoryDecember 2, 2024, 7:30 AM ET In the early months of 2023, the astronomer Željko Ivezić found himself taking part in a highly unusual negotiation. Ivezić is the 59-year-old director of the Vera Rubin Observatory, a $1 billion telescope that the United States has been developing in the Chilean high desert for more than 20 years. He was trying to reach an agreement that would keep his telescope from c...