[whd23]

Laughter broke out though when Marshall introduced the Geroch/Wald factor, where the two professor at the University of Chicago had told Thorne that his wormhole idea wouldn't work because when the ship was within 10 light years of Earth that electromagnetic radiation traveling through the wormhole could make it collapse.

Marshall pointed out that this would be impossible because the ship is supposed to fly out and back to Earth within a total elapsed time of 10 years, flying at a sub-light speed.

Either the article is written poorly or I just don't get it. Thorne was told that his idea wouldn't work because if the ship was within 10 light years of Earth the wormholes would collapse. So I'm imagining the Earth in the center of a 10 light year diameter sphere; within the sphere no wormholes exist. Marshall's comment about a ten year round trip at sub-light speed simply seems to re-inforce the Geroch/Wald objection to Thorne. Why did that evoke laughter?

[unlearner]

"Why did that evoke laughter?"

Because nobody wants to look like they did not get it (even though they didn't).