Analog SFF, March 2010 Read online

  Kendall's smile turned sad. “Would that it were that simple, Dr. Peale. Truth is, we still need your efforts. There remains much work ahead of us."

  "I understand that, sir. There are a great many involuntary overlays we need to try to reverse. I'm willing to work on that, but it would be a great deal easier if I could do it back at Cal. Berkeley, back home."

  "I'm sorry,” said Kendall. “That won't be possible for a while—and no offense, but Berkeley is the last place I'd choose for any part of this undertaking. Not that reversing the overlays is unimportant. There are easily thousands, even tens of thousands of people Burleigh has scarred, and maybe as many as a hundred honestly had it coming. We have to restore them from their mind wipes as best as possible, but there's also much more we need to do now."

  Lucinda hadn't noticed the perpetual knot in her stomach often the last couple of months. She only noticed it now, when it returned.

  "He diverted masses of resources to his partisan witch hunt, while ignoring and suppressing facts about Black Friday. I doubt you've heard who was really behind the bombing, but—"

  "You mean Iran?” Lucinda said. “And maybe China?” Kendall had briefly gone blank. “I was present for the earliest interrogations."

  "So you were,” Kendall said. “My mistake. So you know the full magnitude of their misprision, their assault against America instead of her true enemies."

  His modulated voice was growing strident. “Burleigh and his crew—his party—have proven themselves an existential threat to America and to our liberties. That cancer cannot be tolerated. We have to eliminate it, with the selfsame method they used in trying to spread it. It's time to change their minds, for the better. And perhaps a great deal more."

  Curt finally spoke. “We're going to be doing more overlays?"

  "After all those gross abuses?” Lucinda added.

  "When neural overlay has been proven so dangerous—"

  "That's just the point, Dr. Garritty,” Kendall said. “You both must understand, the genie is now out of the bottle. Its power is loose upon the earth, available to whoever will use it as a tool, or a weapon. If we forbear to use this tool until the Democrats regain power—and they will: the wheel always turns—they will use it against us again, on all of America and anywhere else they can reach. By the time they're done, they will have abolished even the possibility of dissent against them.

  "With the tool in our hands, we can forestall them. We can fight their absolutism right at the source, keep that nightmare philosophy out of power, perhaps permanently, if we're fortunate. The question now, doctors, is not ‘whether,’ but ‘who.’ Who will benefit from this power, us or them?” He dropped his voice. “It must not be them."

  In the silence that followed, Lucinda yet heard a scream, inside her own mind. This was impossible, unthinkable. But no, nothing had started yet. It wasn't too late. She turned to Curt—

  —who was slowly, and now more rapidly, nodding his head at Rance Kendall.

  "You're right, Mister President. Sad to say."

  "It is sad,” Kendall said, “but the greatest necessities are usually sad ones.” He turned. “Dr. Peale, what say you?"

  His eyes transfixed her, pinning her like a butterfly in a collector's case. She drew two short breaths through the pain in her chest. “Mr. Kendall ... sir ... I'm sorry, but I cannot work for you now."

  Kendall frowned. “Lucinda—” Curt started.

  Lucinda's voice was trembling. “When the agents brought me to Mount Weather, I could see, from the helicopter, Washington still burning a hundred miles away. That's how long Burleigh had me working, without any let up—until four days ago, when it was almost my turn to be ‘fixed,’ to have my mind wiped. I am ... oh, God, I am so tired. I can't ... I can't..."

  Lucinda was sobbing. Curt reached for her, enfolding her stiff body with his arm.

  "...can't start this all over again. No..."

  Curt patted her shoulder with his free hand. “Gov—Mr. Pre—sir, for what it's worth, I will vouch for the terrible pressures Lucinda has endured over the last eight months. Much of that time she was completely alone, everyone around her enemies, no one she could trust. And all that time, she was compelled to perform acts that violated her ethics and conscience.” He looked pityingly on her. “Everyone has limits."

  "Of course, of course. Dr. Peale?” He waited until Lucinda lifted her eyes. “Doctor, I won't rush your decision. You take whatever time you need. For now, though, you do have those base scans of the overlay victims. I will see that they, and others, are used promptly to restore as many people as possible."

  Lucinda nodded jerkily, as she began to recover from her outburst. Kendall reached to shake her hand. Her grip was still weak.

  "Thank you again, Dr. Peale, for what you've done and what you've borne.” He took Curt's hand. “And you, too, Dr. Garritty. I'll have people in contact with you soon.” He got up, and by the time the others could stand, he was already leaving, without a trace of ceremony.

  Lucinda snuffled and rubbed her face. “I'm sorry I made that scene, Curt."

  "It's okay, it's okay.” He embraced her again, and still she didn't yield. “A delayed reaction. I don't blame you at all. But please, let me know how to help."

  She pulled herself away gently. “I just need some time alone to pull myself together.” She forced a smile. “I'll be better tomorrow, honest."

  She headed toward the door, but Curt trailed her. “If what the president said disturbed you, Lucinda, gave you doubts, we really—"

  "No, Curt. No doubts. Like I said, I'm terribly tired."

  He smiled and nodded. Lucinda kept her own pleasure inside. He believed her, because he wanted to believe her—even though she had told him several times, the best way to hide lies was within truths.

  She squeezed his hand at the door and girded herself to tell him that one unequivocal lie. To her relief, it was easy.

  "I'll see you tomorrow, Curt.” And she walked away, not looking back.

  * * * *

  She rolled into the tall grass, then got onto all fours and started to crawl away. A cry of “Dr. Peale!” stopped her for a second. He seemed familiar....

  "Luci!"

  That voice she knew. She scrambled back toward the road, as the passenger door swung open. She dove inside, and had her arms around Josh Muntz in an instant. “Oh God, Josh. So good to see you."

  "Oh, Luci, thank God you're safe."

  "Not yet, we aren't.” She pulled back and only then noticed Josh's other passenger. “Sam!"

  Sam Jeong was half reclining in the back seat, to accommodate his braced leg. She reached over the seat back to surprise him with his own hug. “I thought you'd been killed,” she said.

  "Almost was,” said Sam. “And we feared the worst about you, that you'd been—"

  "Almost was,” she said. Josh was pulling back into traffic. “No, Josh, not west. Turn us around and go north for a couple miles."

  As they made their turn in the diner's parking lot, Lucinda saw fresh headlights coming from the direction of the base. She hid herself under the dashboard. “What are you doing here? Why didn't you tell me?"

  "We decided to drive cross-country to get you home after your last e-mail,” Josh said. “We thought Burleigh's bullies might still be tapping things, so we didn't say anything and made sure your parents didn't either."

  So that's why she had gotten no replies. “And Sam, where have you been?"

  "Hiding out, here and there. I hunkered down with Josh's dad for a few months. We thought the authorities might check your parents’ place, and they did."

  Lucinda hadn't the luxury to feel outraged that moment. “Where were you thinking of taking me?"

  "Ummm ... we hadn't really decided,” Josh said. “We meant to collect you and head back to California. Good an idea as any."

  "So what's the crisis?” Sam asked. “Are the Democrats getting back in control?"

  They were northbound, and Lucinda sat back
up. “Worse, Sam. Kendall, the Republicans, they're intent on doing the same things Burleigh did. Overlaying ideological enemies, eliminating dissent. ‘Us or them,’ he said right to me, six hours ago. That's when I decided to escape."

  Both men said “Oh God,” as one. Sam went on. “I can see where Kendall's coming from, but—"

  "But nothing!” Josh shouted. “If Lucinda says we're fighting them, we are. So are we?"

  Lucinda could not bring herself to look Josh in the eyes. He was so ready to support her, and she had betrayed him. And the man she had betrayed him with—how fast one's feelings could change. How fast a crisis could reveal true character.

  How much would Josh's feelings change when she finally confessed her true character to him? She would do it—once they were off the road, resting for a while—but this moment, she had to lead.

  "We're fighting them. I'm not sure how yet. Maybe we should stop somewhere with Internet access and get my story out. Or maybe I should get my story composed now, so I'm not trying to hurry and stumbling over words."

  "I know who you can contact,” Sam said. “Frances Roselli at UCLA. I've gotten secret messages to her a few times. She'll be on your side."

  Lucinda chuckled bleakly. Frances had left the Berkeley team early on, because she didn't like the turn toward politics overlay research had taken—a turn facilitated by Lucinda. A whole lot had happened since then.

  "I'll write to her,” she said. “I'll write to plenty of people. That'll ensure word gets around."

  "And if that isn't enough?” Josh asked.

  Lucinda thought, then laughed again. “Kendall seemed to use the word ‘now’ very often when he spoke to us. Sauce for the goose."

  Sam chuckled in quick, staccato bursts. Josh grinned at the show of confidence. Lucinda smiled for their benefit, even as she considered the odds.

  Maybe President Kendall was right. Neural impression might be beyond control, and the only choice left was who would employ it to their ends.

  But she wouldn't concede that without a fight.

  They drove on, the car turning west toward the last glow of sunset light on the horizon.

  Copyright © 2010 Shane Tourtellotte

  (EDITOR'S NOTE: Earlier “First Impression” stories include “Trial by Fire” [April 2007], “Acts of Conscience” [March 2005], and “A New Man” [October 2003].)

  [Back to Table of Contents]

  Science Fact: ISOTOPY by Stephen L. Gillett, Ph.D.

  Isotopes may be an old concept, but it's still important on the frontiers.

  It sounds like something that's illegal in various backward places, huh? But it actually does mean the study of isotopes. The applications of measuring isotopic variations are now legion in the natural sciences, and they run from prosaic to very glamorous indeed.

  Of course, we all now learn about isotopes in beginning science classes: they're different versions of the same chemical element. An element's properties are determined by the number of protons in the nucleus, the so-called atomic number, because that determines how many electrons orbit1 the nucleus, and that, in turn, determines the element's chemical properties. The number of neutrons in the nucleus, however, doesn't affect the chemical properties2, because, after all, they're electrically neutral. So different numbers of neutrons with the same number of protons lead to isotopes.

  The sum of the number of protons and neutrons is the mass number, and so each isotope has a different mass number. Furthermore, for a given mass number it turns out that only certain combinations of protons and neutrons are stable—i.e., have the lowest energy or (alternatively phrased) the lightest mass. In fact, at most two3 combinations, separated by two atomic numbers, are stable. Other combinations will change, at a particular rate, to reach that stable mixture. That is, they're radioactive. For example, calcium-40 (40Ca, 20 protons, 20 neutrons) and argon-40 (40Ar, 18 protons, 22 neutrons) are both stable, but potassium-40 (40K, 19 protons, 21 neutrons) is not. It decays to one or the other, with an overall half-life of some 1.3 billion years—half-life, of course, being the time it takes for half the original amount of radioactive substance to decay.

  All this is taught in high-school chem classes now. But isotopes’ discovery was fraught with more than the usual controversy and blind alleys. It all began around the turn of the last century, by two different paths that only converged by the 1920s or so.

  And that fitful journey may hold a moral or two for the present, as well.

  * * * *

  Radioactivity and Isotopy

  The first path was radioactivity. The demonstration that elements could spontaneously change was bad enough for the staid structure of nineteenth-century science. What was worse was the demonstration that some species with very different radioactive properties proved to be chemically indistinguishable. A mixture of ionium and radiothorium with thorium could not be separated by any chemical means, despite the fact that these three species have quite different radioactive properties. In modern terminology, ordinary thorium is thorium-232, with a half-life of some 14 billion years. Ionium is 230Th, with a half-life of only 7,700 years. It occurs in the decay chain for uranium-238. Finally, radiothorium is 228Th, with a half-life of less than two years. It occurs in the decay chain of 232Th itself.

  All these nuclei, of course, contain the 90 protons that define thorium's chemical properties. In 1913, Frederic Soddy proposed “isotope” (from the Greek for “same place") to cover such situations: two radioactive substances that are chemically “indistinguishable” but have very different decays.

  In the light of modern understanding, this all seems utterly reasonable. But imagine how preposterous it sounded to your well-trained nineteenth-century chemist!

  And things just got worse. It was realized that radioactive decays must involve systematic changes of both atomic number and mass number. A beta decay (the expulsion of an electron) raises the nuclear charge by one; an alpha decay (expulsion of a helium-4 nucleus, with two neutrons and two protons) decreases the nuclear charge by two and the mass number by four. But you could compare the difference between the atomic numbers of uranium (92) and thorium with that of lead (82), and see immediately that there wasn't room for all the in-between decay products to be different elements! So some of them must be isotopes.

  * * * *

  The Mass Spectrograph

  Also around 1900, the study of electrical discharges into gases was a big deal. Such studies, of course, led to such practical devices as neon signs and fluorescent tubes—not to mention the discovery of the electron by J.J. Thomson in 1897.

  And such studies provided the other path to the discovery of isotopes. In modern terminology, the high-energy electrons in the discharge knock electrons off the gas atoms (or molecules), leaving the atom with a positive charge—i.e., a positive ion.

  Obviously such ions will be attracted to a negative electrode. Thomson initially studied these “positive rays” just before WW I. It was difficult initially to distinguish their masses, because the rays came in all different energies, and of course the total energy depends on both mass and velocity. Finally, with a clever arrangement of magnetic and electric fields, he was able to focus ions with different masses at different places, independently of their velocities. (Note that all electrons are the same, so the question of distinguishing the masses of negative rays never arose.)

  Thomson had invented the first crude “mass spectrograph"—or “mass spectrometer,” as they're called now. And using it, he showed that ordinary neon was made up of two masses of atoms, what we now call 20Ne and 22Ne, in the ratio of roughly 10:1. (Actually, there's a third stable isotope, 21Ne, but with an abundance of only 0.27%, its detection was far below the precision of Thomson's primitive device.) This provided evidence that “isotopes” not only were not confined to the heavy elements, but also weren't necessarily connected with radioactivity.

  * * * *

  Atomic Weights

  Here's where the threads came back together. The nuclear
decay chains of uranium and thorium both end at lead, and must involve a progressive loss of mass. Moreover, the lead derived from the decay chains must consist of different isotopes. Hence, the atomic weight of lead should depend on the source of the lead.

  In a groundbreaking paper, Richards and Lembert (1914) found measurable differences in the atomic weight of lead from uranium decay, using only the classic chemical methods for the determination of atomic weight4. It's hard to imagine how astonishing this was at the time. Atomic weight was thought to be one of those Constants of the Universe. It's as though pi had turned out to be a variable. In fact, there's a whole forgotten literature on speculations for why atomic weights should have the values they do.

  Richards had contributed to that literature; but more importantly, he was an extraordinarily careful experimentalist who'd specialized in determining atomic weights and had demonstrated their constancy within experimental error—till the work with radiogenic lead. (Of course, his reputation made that work all the more credible among chemists!) He received the Nobel Prize in 1914, becoming the first American chemist to do so. Even though it became obvious, with the discovery of isotopes, that atomic weights were not fundamental constants, he remained enthusiastic about the new studies. Indeed, in a major review written not long before his death (Richards, 1924) he presented the modern understanding of atomic weights as simply the weighted average of the isotopes making up that element. That's, of course, how scientists should behave, and it happens more often than is sometimes suspected.

  Anyway, it turns out, too, that lead is the only element for which the so-called “radiogenic” components—those resulting from radioactive decay—can lead to a measurable difference in macroscopic atomic weight as found by traditional techniques. For example, as we'll see below, the proportion of strontium-87 (87Sr) in terrestrial strontium is slowly increasing over geologic time, because it's continually being added by the decay of rubidium-87 (87Rb). However, the overall change in strontium's atomic weight is utterly undetectable by classic wet-chemical methods. (It makes you wonder what else we're missing because we can't measure precisely enough, but I'm getting ahead of myself....)