"Let's wait," cautioned Morey. "We can't make a very careful choice at this distance, anyway; we're beyond the enlarging power range of the telectroscope here. In another half million light years, we'll have a much better view, and that comparatively short distance won't take us much out of our way."
"Wait a minute," said Fuller. "You say we're beyond the magnification range of the telectroscope. Then why would half a million light years out of ten million make that much difference?"
"Because of the limit of amplification in the tubes," Arcot replied. "You can only have so many stages of amplification; after that, you're amplifying noise. The whole principle of the vacuum tube depends on electronic emission; if you get too much amplification, you can hear every single electron striking the plate of the first tube by the time the thing reaches the last amplifying stage! In other words, if your incoming signal is weaker than the minimum noise level on the first amplifying stage, no amount of amplification will give you anything but more noise.
"The same is true of the telectroscope image. At this distance, the light signal from those galaxies is weaker than the noise level. We'd only get a flickering, blurred image. But if we go on another half million light years, the light signal from the nearer nebulae will be stronger than the base noise level, and full amplification will give us a good image on the screen."
Fuller nodded. "Okay, then let's go that additional half million light years. I want to take a look at another galaxy."
"Right." Arcot turned to the intercom. "Ready, Morey?"
"Anytime you are."
"Here goes!" said Arcot. He pushed over the little red control.
At full power, the air filled with the strain of flowing energy and actually broke down in spots with the terrific electrical energy of the charge. There were little snapping sparks in the air, which, though harmless electrically, were hot enough to give slight burns, as Wade found to his sorrow.
"Yike! Say, why didn't you tell us to bring lightning rods?" he asked indignantly as a small spark snapped its way over his hand.