Heinlein, Robert A – Expanded Universe

that?” His voice sounded muffled from behind the dust mask.

“The last stage has to be exposed to air,” explained Karst. “The hood gets

most of it. We could control it, but it would mean a quite expensive new

installation.”

“No trouble about that. We’re not on a budget, you know, It must be very

annoying to have to work in a mask like this.”

“It is,” acknowledged Karst. “The kind of gear it would take would enable us

to work without body armor, too. That would be a comfort.”

I suddenly had a picture of the kind of thing these researchers put up with.

I am a fair-sized man, yet I found that armor heavy to carry around. Estelle Karst

was a small woman, yet she was willing to work maybe fourteen hours, day after day,

in an outfit which was about as comfortable as a diving suit. But she had not

complained.

Not all the heroes are in the headlines. These radiation experts not only

ran the chance of cancer and nasty radioaction burns, but the men stood a chance of

damaging their germ plasm and then having their wives present them with something

horrid in the way of offspring-no chin, for example, and long hairy ears.

Nevertheless, they went right ahead and never seemed to get irritated unless

something held up their work.

Dr. Karst was past the age when she would be likely to be concerned

personally about progeny, but the principle applies.

I wandered around, looking at the unlikely apparatus she used to get her

results, fascinated as always by my failure to recognize much that reminded me of

the physics laboratory I had known when I was an undergraduate, and being careful

not to touch anything. Karst started explaining to Manning what she was doing and

why, but I knew that it was useless for me to try to follow that technical stuff. If

Manning wanted notes, he would dictate them. My attention was caught by a big

boxlike contraption in one corner of the room. It had a hopperlike gadget on one

side and I could hear a sound from it like the whirring of a fan with a background

Page 45

of running water. It intrigued me. I moved back to the neighborhood of Dr. Karst and

the Colonel and heard her saying, “The problem amounts to this, Colonel: I am

getting a much more highly radioactive end product than I want, but there is

considerable variation in the half-life of otherwise equivalent samples. That

suggests to me that I am using a mixture of isotopes, but I haven’t been able to

prove it. And frankly, I do not know enough about that end of the field to be sure

of sufficient refinement in my methods. I need Dr. Obre’s help on that.”

I think those were her words, but I may not be doing her justice, not being

a physicist. I understood the part

about “half-life.” All radioactive materials keep right on radiating until they turn

into something else, which takes theoretically forever. As a matter of practice

their periods, or “lives,” are described in terms of how long it takes the original

radiation to drop to onehalf strength. That time is called a “half-life” and each

radioactive isotope of an element has its own specific characteristic half-lifetime.

One of the staff-I forget which one-told me once that any form of matter can

be considered as radioactive in some degree; it’s a question of intensity and

period, or half-life.

“I’ll talk to Dr. Ridpath,” Manning answered her, “and see what can be

arranged. In the meantime you might draw up plans for what you want to reequip your

laboratory.”

“Thank you, Colonel.”

I could see that Manning was about ready to leave, having pacified her; I

was still curious about the big box that gave out the odd noises.

“May I ask what that is, Doctor?”

“Oh, that? That’s an air conditioner.”

“Odd-looking one. I’ve never seen one like it.”

“It’s not to condition the air of this room. It’s to remove the radioactive

dust before the exhaust air goes outdoors. We wash the dust out of the foul air.”

“Where does the water go?”