But Joggy was still hypnotized by the Time Bubble.
"Then how is it, Hal," he asked, "that light comes out of the bubble,
if the people don't? What I mean is, if one of the people walks toward
us, he shrinks to a red blot and disappears. Why doesn't the light
coming our way disappear, too?"
"Well--you see, Joggy, it isn't real light. It's--"
Once more the interpreter helped him out.
"The light that comes from the bubble is an isotope. Like atoms of
one element, photons of a single frequency also have isotopes. It's
more than a matter of polarization. One of these isotopes of light
tends to leak futureward through holes in space-time. Most of the
light goes down the vistas visible to the other side of the audience.
But one isotope is diverted through the walls of the bubble into the
Time Theater. Perhaps, because of the intense darkness of the theater,
you haven't realized how dimly lit the scene is. That's because we're
getting only a single isotope of the original light. Incidentally, no
isotopes have been discovered that leak pastward, though attempts are
being made to synthesize them."
"Oh, explanations!" murmured one of the newly arrived girls. "The cubs
are always angling for them. Apple-polishers!"
"_I_ like this show," a familiar voice announced serenely. "They cut
anybody yet with those choppers?"