A Sleek New Jet Just Cracked the Sound Barrier — With a Whisper

Professor Pip stood on a sunny hilltop, the long grass tickling his bushy tail. He patted his bulging green coat pockets, fished out a small white paper airplane, and grinned. "Aha! Just what we need."

Mia and Leo sat cross-legged in the grass beside him, looking up. "What's that for, Professor?" Mia asked, brown braids bouncing.

"Today," Pip announced, adjusting his crooked spectacles, "we are going to learn how a brand-new airplane can fly faster than sound itself — without making a giant boom!"

"Faster than sound?!" Leo gasped. "Sound goes fast!"

"Very fast indeed!" said Pip, his tail swishing. "Sound zooms through the air at about seven hundred and sixty miles every hour. But here is the question — what happens when an airplane goes even faster than that?"

He held up the paper airplane. "Watch closely." He gave it a gentle toss. It glided in a soft, silent loop.

"Now," he said, "imagine I'm zooming a plane so fast that the air can't get out of the way in time. The air piles up in front, like a snowplow pushing snow." He swooped his paws through the air. "That pile makes a giant pressure wave — a shock wave. And when that wave reaches your ears…" He clapped his paws together. CRACK!

Both kids jumped, then giggled. "That's the boom!" said Mia.

"Exactly right!" Pip beamed. "We call it a sonic boom. But the X-59 has a clever trick. Its nose is super long and pointy, and its body is sculpted just so. Instead of letting all the shock waves slam into one giant CRACK, it spreads them out…" He fluttered his paws apart slowly. "…so they reach the ground one at a time. A gentle thump-thump-thump."

"Oh!" said Leo, eyes lighting up. "Like raindrops on a roof instead of a thunderstorm!"

"Precisely!" Pip clapped his paws. "Scientists hope that one day, planes like this could fly across the whole country in half the time, without rattling anyone's windows."

Pip looked up at the blue sky, his crooked spectacles catching the sun. "Imagine that. We taught the air to whisper."

He handed each of them a paper airplane. "Now you try. See how the air pushes back as it flies. That same air — just zoomier — is what the X-59 was talking to today."