funny thing though, the ghosts on the moon can't tolerate it; see, they are immune to the normal gravity here, but if they get near the gravity well, they get sucked in and they can't escape. they just don't have any way of getting loose, they are not strong enough to do whatever it is that ghosts have to do to move around...the difference in the gravity is just enough to catch them. so they just bobble there like blow-up knock-me-down popeye dolls moaning and rattling their chains against the sides of the crater. it's kind of weird, in a way.

the doctor told me i really had to get more exercise, lose some weight, and i figured what the hell. i packed up my scale and headed out there. Sam Whitebread came with me for company, he's as thin as a rail, so he just goes to enjoy the feeling of the extra weight.

the ghosts make such a ruckus that it's easy to find the spot. we went over to a corner that didn't seem too crowded and put i put my scale down. Sam was silly-walking, picking up and putting his feet down in big clumping steps, laughing. as i was about to get on the scale, there was a loud wail behind me that shivered my spine, i really wasn't expecting it from the shrimpy ghost that was standing there, footrooted. Sam jumped, or he tried to, but his feet kinda stuck to the ground.

"pleeeeeeaassse help me." the voice said.

Sam turned to him, "you know that's against the law."

"pleeeeeeeeeeeeeeaaaaassssse." the ghost said, and in a way that made me really want to help him, if only to make him go away.

"who are you -- or rather, who were you?" Sam asked him.

"Albert Einstein." he said, holding out his chains.

"Albert Einstein," Sam said, "the ghost of Albert Einstein. i always wanted to talk to you. i've studied your work and i think there's a pretty big problem with it."

"if i can clear it up will you help me?" he asked Sam, his face wrinkled up like a prune, his eyebrows reaching towards us.

"deal." Sam said. i looked at Sam, surprised at the quickness of his answer. if we got caught, there'd be the devil to pay, Sparky comes around once a month to collect the ghosts, he sells them by the gallon on the black market.

"so what's the problem?" Albert Einstein's ghost asked Sam.

"not a problem," Sam said, "it's just that you got it wrong, you missed something major."

Albert seemed surprised, his eyebrows rose up in the air about two feet above his head. "nonsense," he said. "i taught at princeton for many years; how can you say such a thing?"

"look," Sam said, "the problem is with the whole time thing."

"the time thing?"

"yeah, the time thing. you forgot that there is no such thing as time."

the eyebrows came down into a tight V, and he coughed a laugh at Sam, "of course there is such a thing as time."

"dude. i really expected better from you. you're supposed to have been a smart guy." Sam would have been strutting, except for the heavy gravity, instead his feet were plopping down into the dust with thick dull thuds.

"prove that there's no such thing as time," the ghost said.

Sam stopped and held up three fingers "ok, let's say there are three kinds of events. events that have already happened," he folded down one finger, "events that haven't happened yet," he folded down another, "and all the other events." and he held up his last finger, victorious.

"so?" Albert was getting annoyed. "you're telling me the obvious."

Sam smiled an evil smile. "see, there are no members in the third set. either something already has happened or it hasn't happened. it's a total illusion that there is something between the past and the future. they touch."

"in the now," Albert the ghost said, crossly.

Sam shook his head "where the past and the future touch there is nothing between them. events in the future change to being events in the past. instantaneously."

"they have to pass through now to do it," Alfred said. I could see the stars through his face.

"OK, how long is now?" Sam asked him, "is it an hour? a minute? i don't think so. a second? nope. a millisecond? -- no matter how you try to slice it there is always another slice that is thinner. it is tangential to zero, equal to a duration of exactly zero. there is no such thing as now."

"is not." Sam said.

"is too." the ghost of Albert Einstein said.

"not"

"is"

"NOT!" Sam was getting mad.

"you can't prooove that you said that," said the ghost, "when did you say it?"

"in the past. proves my point." Sam's eyes were hard.

"does not."

"does TOO!!!"

"guys! guys! take it easy," i said, "look, fact is, you are both right."

they looked at me, quiet for a minute. Sam opened his mouth, then closed it. the ghost of Albert Einstein worked his eyebrows up and down.