An overlooked era of cosmology is stealing the show in the quest to understand the cosmos

Could you imagine if pagers made a comeback? Sure, your smartphone would still be your notepad-flashlight-camera-personal assistant-MP3 player-wallet-social media browser. But imagine if pagers made it so easy to do that one important thing—pinging your friends and associates—that we all brought them back into our lives, or adopted them for the first time.