would give anyone a clue to the fact that there is a method of acceleration aboard.Understood?"

  "Ye-es, Mah-ike."

  "O.K."

  Mike switched off the vocoder, flipped his intercom to the temporarygalley in the morgue, and ordered two breakfasts readied. Then he setoff for the morgue.

  Mike Blackhawk located Dr. Y. Chi Tung's hammock, and nudged thescientist unceremoniously. The small physicist awoke and attempted tosit up in one gesture; bumped his head on the hammock above, and laidback down just as suddenly.

  "Come on down to engineering will you Ishie?" The request was spokensoftly.

  "Hokey, dokey," said Ishie and crawled out of the narrow aperture withthe agility of a monkey.

  Gesturing to the other to follow him, Mike led the way to the galleyfirst, where the two picked up the readied breakfast and took them toMike's quarters.

  The "cups" of coffee were squeeze bottles; the trays were softplastic packages, similar to the boil-in-the-bag containers of frozenfood that had been common on Earth for some time.

  Mike hesitated at the entrance to his engineering quarters,considering whether to shut the bulkhead, but discarded the idea asbeing more of an attention-getter than a seal for secrecy. He gesturedIshie to the bunk, and parked himself at his console.

  "We're in trouble," he said. "You and I together are responsible forthe first space attack on Earth."

  He stopped and waited, owl-eyed, but the small physicist simplytackled his breakfast with no further comment than a raised eyebrow.

  "We," said Mike solemnly, "wiped out Thule Base last night."

  "As Confusion would say, there's no Thule like a dead Thule. What areyou getting at Mike? You sound serious."

  "You mean you slept through ... you didn't know we ... you didn't hearthe ... yes, I guess you slept! Well...."

  Rapidly Mike sketched the events of the past nine hours, bringing hisstory completely up to date, including the information he'd gleanedfrom the Cow, but making no reference to his access to the computer'sknowledge. Instead, he attributed the conclusions to himself.

  The physicist sat so still when he had finished that Mike becameseriously concerned. "Thule...." he began, but Ishie started to speak.

  "Mike, it did? It couldn't ... but ... of course, it must have ... thefields ... six hundred forty pounds of thrust! Only six hundred forty,yet ... yes, it could, if the thrust were exactly aligned ... thrust ...Mike, thrust! _Mike, thrust!_ Real thrust! Mike do you know what thismeans?" His eyes were alight. His voice was reverent. He sprang fromthe bunk and knelt before the rack that held the churkling Confusor.

  "My pretty," he said. "My delicate pretty. What you have done! Mike,we've got a space drive!"

  "Ishie. Don't you realize? We wiped out Thule!"

  "Thule, schmule--Mike, we've got a space drive!"

  Mike grinned to himself. He needn't have worried. Not about Ishie, anyhow.

  But now Ishie was gesturing him over.

  "Mike," he said, "you must show me in detail. In exact detail. Whatdid you do? What was your procedure?"

  Mike came over and casually reached towards the churkling device,saying "Why, I--" but Ishie reacted with catlike swiftness, blockingthe man before he could even touch the rack.

  "No, don't touch it! Just _tell_ me what you did!"

  Carefully now, Mike began outlining in detail his inspection of thedevice and each step he had taken as he added to its complexities.

  When he had finished, the two sat back on their heels thinking.Finally, Mike spoke.

  "Ishie, will you please tell me just how does this thing ... thisConfusor ... _get_ that thrust? Just exactly what is involved here?"

  Ishie took his time answering, and when he did his words come slowly."Ah, yes. Confusor it is. I was attempting to confound Heisenberg'sstatement; but instead I think between us we have confused the issue.

  "Heisenberg said that there was no certainty in our measurement of theexact orbit of an electron. That the instrument used to measure theposition of the electron must inevitably move the electron; andthe greater the attempt at precise measurements, the greater the errorproduced by the measurements.

  "It was my hope," he went on, "to provide greater accuracy ofmeasurement, by use of statistics over the vast number of electrons inorbit around the hydrogen atoms within the test mass. But this,apparently, will not be.

  "Now to see what it is we have done.

  "First, let us make a re-expression of the laws of math-physics. Youunderstand that I am feeling my way here, for what we have done andwhat I thought I was doing are quite different, and I am looking withhindsight now at math-physics from the point of reality of thisthrust.

  "As I understand it, there's a mutual exclusiveness of particles,generally expressed by the statement that two particles may not occupythe same space at the same time.

  "But as I would put it, this means each particle owns its own place.Now, inertia says that each particle not only owns its own place, butowns its own temporal memory of where it's going to be unlesssomething interferes with it.

  "Now let me not confuse you with semantics. When I say 'memory' and'knowing' I am not implying a sentient condition. I am speaking of thetype of memory and knowing that is a strain in the structure of theproton or atom. This is ... well, anyhow, not sentient. You will haveto translate for yourself.

  "So to continue, inertia, the way I would put it, says that eachparticle not only owns its own place, but owns its own temporal memoryof where it is going unless it is interfered with.

  "In other words, the particle arriving here, now, got here byremembering in this other sense that it was going from there to thereto there with some inherent sort of memory. This memory can't beclassified as being in relation to anything but the particle itself.No matter how you move the things around it, as long as the thingsaround it don't exert an influence on the particle, the particle'smemory of where it's been and where it's going form a continuousstraight line through space and must, therefore, have spatialco-ordinates against which to form a 'memory' pattern of former andfuture action.

  "Now as I understand gravity, it's simply the statement that allparticles in space are covetous, in this same non-sentient sense, ofthe position in space of all their neighboring particles. In otherwords, it's a contravention or the attempted contravention of thestatement that two particles may not be in the same place at the sametime. It seems that all particles have an urge to try to be in eachother's space. And this desire is modified by the distance thatseparates them.

  "This adds up to three rules:

  "1. No two particles may occupy the same space at the same time.

  "2. Even though they can't, they try.

  "3. They all know where they're going, and where they've been withoutrelation to anything but the spatial co-ordinates around them.

  "That third statement seems to me to knock something of a hole inEinstein's relativity theory. Unless you wish to grant all theseparticles some method of determining their relationship to particlesthat are not near them.

  "Communication between particles by any means is apparently limited bythe speed of light, which is a relationship between space and time,but apparently, from what we know of inertia, if the universecontained only a single particle, and that particle was in motion, itwould continue to move regardless of the fact that its motion couldnot be checked upon in relation to other particles.

  "This indicates to me that the particle has an existence in spacebecause it is created out of space, and that space must, therefore,have some very real properties of its own regardless of what is or isnot in it. The very fact that there is a limiting speed to light andparticle motion introduces the concept that space has physicalproperties.

  "In order to have an electromagnetic wave, one must have a medium inwhich an electric field or a magnetic field may exist. In order tohave matter, which I believe to be a form of electromagnetic field instasis, one must have special properties which make the existence ofmatter possible. In order to have
inertia, one must also have spatialproperties which make the existence of inertia possible.

  "People are fond of pointing out that there's nothing to get hold ofin free space in order to climb the ladder of gravity, or in order tomove between the planets, and that the only possibility of motion of avehicle in space is to throw something away, or, in other words, losemass in order to gain speed by reaction. Which is simply a statementthat as far as we can tell a force can only be exerted relative to twopoints--or between two points or masses.

  "But this does not account for the continuance of motion once started.

  "Inertia says a body will move once started, but it doesn't say
Leigh Richmond and Walt Richmond's Novels