Ask any astronomer what inflation is, and you’ll hear about the moment when the universe’s primordial fireball expanded like a balloon on steroids, smoothing and flattening its initial wrinkles before it grew into the cosmos seen today.
Now, some physicists are trying to let a little air out of that scenario.
Generally regarded as one of the most successful theories about the early universe, inflationary cosmology is not exactly under attack. But a few scientists are questioning whether it deserves its reputation as completely untouchable. Inflation may be the best-developed explanation for many features seen in the modern universe, these researchers say, but it still has problems.