THE birth of the first stars may have been triggered by cosmic strings – giant threads of energy that lashed about chaotically in the early universe.
This peculiar idea, put forward by two physicists in the US, is an attempt to solve the cosmological puzzle posed by the widespread existence of ionised hydrogen – in the form of protons and electrons – in today’s universe. The ions that filled the universe immediately after the big bang cooled enough to form neutral hydrogen atoms about 300,000 years later, but the hydrogen has again been largely reionised.
Theorists have suggested that the reionisation was…
