> The woodpecker’s head strikes with at least 1,000 times the force of gravity (1,000 g), yet the bird suffers no apparent harm. By contrast, any human who experienced a 100 g impact would surely die.

Nope, not true. 100 g accelerations of the human head (not just the helmet) happen routinely in football.

> VT researchers gather data with the Head Impact Telemetry System, which employs sensors and wireless transmitters in helmets. "We see 100-g impacts all the time," says Stefan Duma, director of the university's Center for Injury Biomechanics, "and several over 150 g's."

https://www.popularmechanics.com/adventure/sports/a2954/4212...

In generally, using g's (acceleration) to measure impact severity is fraught because the damage is also highly dependent on the during of the impact. Just a few g's is enough to kill if sustained for long enough. Fighter pilots can handle 8-9 gees for a second or two, but will pass out after longer. But a human can handle way more from brief (sub second) impacts.