Four Years On, New Experiment Sees No Sign of ‘Cosmic Dawn’ | Quanta Magazine
When astronomers tried to confirm a signal from the birth of the first stars after the Big Bang, they saw nothing.
“The SARAS team took a different approach to antenna design in pursuit of more uniform sensitivity across all wavelengths. “The entire design philosophy is to preserve that spectral smoothness,” said Saurabh Singh, the lead author on the SARAS paper. The antenna — an aluminum cone propped on a Styrofoam raft — was floated in the middle of a placid lake to ensure there would be no reflections for more than 100 meters in any horizontal direction, which Parsons called “a really cool and innovative approach.” Moreover, the slow speed of light in water reduced the effect of reflections from the lake bottom, and the uniform density of the water made the environment much easier to model.”Posted on 2022-03-04T06:00:21+0000