"The failure of the bomb was temporary. A later model worked. But in our world science is completely free and untrammeled. Unlike your world, Virginia Carlson, where science is deeply regulated and directed at one and only one idea, our science knows neither bonds nor interference.
"If you ever get outside in our world you will see atomic power in its fullest use. You will see advances made that are and will always be impossible in any system where a man or a group of men can direct in any way the course of science."
Virginia nodded glumly. "I know," she said. "I've always known of the openings into fields of science that might lead to great things but they were closed because of the necessity of pursuing the one idea toward our future."
Kingston nodded. He admitted the unhappy fact but his own position was none too certain—or had not been until recently.
"If your world is so excellent," asked Virginia bitterly, "why...?"
"The time is approaching when only one future can remain," said Kingston. "No one but an utter egomaniac would consider that the entire universe is regulated for the benefit of mankind. We have yet to make a real attempt to reach the other planets. Have you ever considered the rather impossible proportions of this temporal fission? I doubt it.
"Is, for instance, there a complete universe for each of the time-trails? Or if Earth One and Earth Three both sent rockets to Venus would they meet because Venus was common to both time streams? Think of the energy required to separate a complete universe and ask yourself whether you think it possible."
"Energy has little to do with it," replied Virginia. "Who knows the functioning of the thing we call time—possibly for the want of a better word. Who knows why we have trepidation? Certainly the energy required to cause a planet to falter in its orbit is not truly expended but trepidation is caused by something that seems to require little or no energy."
"We're far from the original premise," said Kingston. "We may never know whether or not the temporal paths are merely local or widespread. It is not a matter of organic versus inorganic matter, for neither is controlled nor directed from any of the other streams of time.
"Were this not so, every time a workman lays a brick on Earth One the same brick would move and be cemented in situ on the other two worlds. And a car on the street might have an accident with a car common to all three worlds but driven only by a driver on Earth One.