For the first time, Earth-based telescopes have cut through ‘cosmic noise’ to reveal how the first stars in the universe affect light emitted from the Big Bang.
The Big Bang occurred about 13.8 billion years ago. It is known as the expansion of the entire observable universe – including space, time, matter and energy – from a hot, dense state.
Roughly 100 million to 400 million years after the Big Bang, the first stars and galaxies formed; this is known as the Cosmic Dawn.
The Cosmic Microwave Background (CMB) is the faint afterglow of radiation from the Big Bang. It is difficult for astronomers to distinguish from other ‘cosmic noise’ coming from space, including radio emissions from the Milky Way, stars and the Sun, as well as interference from the Earth’s atmosphere.
Cosmic microwaves from the CMB are also extremely difficult to measure as they have millimetre-scale wavelengths and are very faint. The polarised portion within CMB radiation, which is the signal from polarised microwave...