Like a car, the Universe has a speedometer: early readings say 67 km/h, later ones 73. An invisible cosmic 'nitro booster' that recently kicked in could have skewed the numbers. Physicists came up with a model where a hidden chameleon field creates such an effect.
🎯 If the Universe had expanded slower in the past, gravity would have squashed everything back; if faster, galaxies could never have formed. We exist on a knife's edge.