Free Tom Swift and His Cosmotron Express by Victor Appleton II Page B

way we use a system of extremely fine laser beams to detect and measure any twists or bends in the structure that signify a passing G-wave."
    "Lasers are used in all of them, aren’t they?" objected Emda mildly.
    "This approach is new. We don’t measure simple bounceback or beam interruption, but use a phenomenon called photon convection to get three-dimensional information from all along the surfaces of the rods at one time, analyzing the resulting inputs with phase interferometry." Tom explained how fringe photons were serially refracted at the sapphire surfaces, following the curves like a thin coating of oil. "The goal isn’t just to detect the gravity waves, but to determine a precise propagation vector. With that sort of data, even as small a baseline as our Earth-Moon trip should be enough to determine the location of Emma—within a few hundred million miles, at least; which would be a very big improvement on what StarWhisper has come up with so far."
    "As I said, Swift ingenuity, famed the world over," pronounced Andor Emda. "When do you begin taking readings?"
    Tom chuckled. "When? Three weeks ago! The detector has been running continuously, digitally recording the raw data for computer enhancement and analysis."
    Bud’s intercommed voice interrupted the scientific conclave. " Skipper, we’re starting farside traverse ."
    "Come on," said Tom to his companion. "Let’s go solve our number one space mystery!
     

CHAPTER 9
DEAD-ENDED
    THE Challenger , now in lunar orbit, had commenced its passage over the side of the moon never seen directly from the surface of the earth. In the control compartment the team of astronauts watched their blue planet sink below the lunar horizon.
    "Useta think the other side o’ the moon was dark all the time," remarked Chow. "But there’s the ol’ sun right up in the sky—if y’ wanna call it sky —and as much sunshine as Texas."
    "The farside’s only dark to Earth -shine, pardner," Bud noted.
    At the secondary science station, separated from the main control board, Tom began to extend and adjust the various instrumental antennas, including the telespectrometers built into the repelatron dishes. "We’ve used this sort of space-tracking method before," commented the young inventor quietly. "But by now the solar wind has thoroughly dispersed any loose atoms from the Dyaune or its propulsion tail."
    After scanning local space for a half-hour, Tom concluded that his pessimism was justified. "Nothing definite," he reported. "Let’s switch to the duo-phased X-raser sweep you came up with, Andy."
    Emda nodded tensely. "You should be able to pick up chains of entrained exhaust ions if the ship left orbit for deep space."
    "Wouldn’t X-rays just go right through them?" objected Sue.
    "Not in this case, my dear," was Emda’s reply. "The particles will become energized and ‘phone home’."
    But after several minutes Bud said, "Great in theory, Andy, but our phone isn’t ringing."
    The Brungarian-American’s brow creased. "And so the mystery deepens. Did they get gobbled by space termites?"
    "Mebbe they wudden out there in the first place," said Chow suspiciously. "I mean—we’re just up here b’cause of what somebody said , am I right?"
    "Sounds like you don’t much trust my ancestral homeland," said Emda smoothly. "Of course, they do talk a little funny, Chow. Do I? But hey, I’m from Texas."
    "Sure," conceded the cook. "We’re s’posed to talk a little funny."
    "Let’s remember that this has all been confirmed by our own government as well," Tom said firmly. "The Dyaune —or something that looked a lot like her—was in orbit about the moon. Something happened, and it wasn’t termites."
    "Well," Bud put in humorously, "let’s not jump to conclusions."
    Tom smiled. "Let’s start surveying the surface. I’m afraid the most likely scenario is that the Dyaune has crashed."
    "They might have landed intentionally and established a base," said Andy.
    "If they did," Tom