"You must have all gone mad over there if you think that for a sack of gold you can invite anyone," Andre Geim replied.

I buckled myself to the knees into my sack and made a hearty meal; and as soon as the sun went down, I pulled my cap over my eyes and fell asleep.

But when he saw that Sagan couldn't keep up, "he literally picked me up like a sack of potatoes over his shoulder and carried me around," Sagan said.