'They've got atomic power. Gravity - even Jupiter's - means nothing once you've put unstable atomic nuclei to work for you.'
Orloff crushed his cigarette to extinction with a nervous gesture. 'But their atmosphere -'
'Yes, that's what's stopping them. They're living at the bottom of a three-thousand-mile-deep ocean of it, where the hydrogen of which it is composed is collapsed by sheer pressure to something approaching the density of solid hydrogen. It stays a gas because the temperature of Jupiter is above the critical point of hydrogen, but you just try to figure put the pressure that can make hydrogen gas half as heavy as water. You'll be surprised at the number of zeros you'll have to put down.
'No spaceship of metal or of any kind of matter can stand that pressure. No Terrestrial spaceship can land on Jupiter without smashing like an eggshell, and no Jovian spaceship can leave Jupiter without exploding like a soap bubble. That problem has not yet been solved, but it will be some day. Maybe tomorrow, maybe not for a hundred years, or a thousand. We don't know, but when it is solved, the Jovians will be on top of us. And it can be solved in a specific way.'
'I don't see how -'
'Force fields! We've got them now, you know.'
'Force fields!' Orloff seemed genuinely astonished, and he chewed the word over and over to himself for a few moments. 'They're used as meteor shields for ships in the asteroid zone -but I don't see the application to the Jovian problem.'
'The ordinary force field,' explained Birnam, 'is a feeble rarefied zone of energy extending over a hundred miles or more outside the ship. It'll stop meteors but it's just so much empty ether to an object like a gas molecule. But what if you took that same zone of energy and compressed it to a thickness of a tenth of an inch. Molecules would bounce off it like this - ping-g-g-g! And if you used stronger generators, and compressed the field to a hundredth of an inch, molecules would bounce off even when driven by the unthinkable pressure of Jupiter's atmosphere - and then if you build a ship inside-' He left the sentence dangling.
Orloff was pale. 'You're not saying it can be done?'
'I'll bet you anything you like that the Jovians are trying to do it. And we're trying to do it right here at Ether Station.'
The colonial commissioner jerked his chair closer to Birnam and grabbed the Ganymedan's wrist. 'Why can't we bombard Jupiter with atomic bombs. Give it a thorough going-over, I mean! With her gravity, and her surface area, we can't miss.'
Birnam smiled faintly, 'We've thought of that. But atomic bombs would merely tear holes in the atmosphere. And even if you could penetrate, just divide the surface of Jupiter by the area of damage of a single bomb and find how many years we must bombard Jupiter at the rate of a bomb a minute before we begin to do significant damage. Jupiter's big! Don't ever forget that!'
His cigar had gone out, but he did not pause to relight. He continued in a low, tense voice. 'No, we can't attack the Jovians as long as they're on Jupiter. We must wait for them to come out - and once they do, they're going to have the edge on us in numbers. A terrific, heart-breaking edge - so we'll just have to have the edge on them in science.'
'But,' Orloff broke in, and there was a note of fascinated horror in his voice, 'how can we tell in advance what they'll have?'
'We can't. We've got to scrape up everything we can lay our hands on and hope for the best. But there's one thing we do know they'll have and that's force fields. They can't get out without them. And if they have them, we must, too, and that's the problem we're trying to solve here. They will not insure us victory, but without them, we will suffer certain defeat. And now you know why we need money - and more than that. We want Earth itself to get to work. It's got to start a drive for scientific armaments and subordinate everything to that. You see?'
Orloff was on his feet. 'Birnam, I'm with you - a hundred percent with you. You can count on me back in Washington.'
There was no mistaking his sincerity. Birnam gripped the hand outstretched toward him and wrung it - and at the moment, the door flew open and a little pixie of a man hurtled in.
The newcomer spoke in rapid jerks, and exclusively to Birnam. 'Where'd you come from? Been trying to get in touch with you. Secretary said you weren't in. Then five minutes later you show up on your own. Can't understand it.' He busied himself furiously at his desk.
Birnam grinned. 'If you'll take time out, doc, you might say hello to Colonial Commissioner Orloff.'
Dr. Edward Prosser turned on his toe like a ballet dancer and" looked the Earthman up and down twice. The new un, hey? We getting any money? We ought to. Been working on a shoestring ever since. At that, we might not be needing any. It depends.' He was back at the desk.
Orloff seemed a trifle disconcerted, but Birnam winked impressively, and he contented himself with a glassy stare through the monocle.
Prosser pounced upon a black leather booklet in the recesses of a pigeonhole, threw himself into his swivel chair and wheeled about.
'Glad you came, Birnam,' he said, leafing through the booklet. 'Got something to show you. Commissioner Orloff, too.'
'What were you keeping us waiting for?' demanded Birnam. 'Where were you?'
'Busy! Busy as a pig! No sleep for three nights.' He looked up, and his small puckered face fairly flushed with delight. 'Everything fell into place of a sudden. Like a jig-saw puzzle. Never saw anything like it. Kept us hopping, I tell you.'
'You've gotten the dense force fields you're after?' asked Orloff in sudden excitement.
Prosser seemed annoyed. 'No, not that. Something else. Come on.' He glared at his watch and jumped out of his seat. 'We've got half an hour. Let's go.'
An electric-motored flivver waited outside and Prosser spoke excitedly as he sped the purring vehicle down the ramps into the depths of the Station.
'Theory!' he said. 'Theory! Damned important, that. You set a technician on a problem. He'll fool around. Waste lifetimes. Get nowhere. Just putter about at random. A true scientist works with theory. Lets math solve his problems.' He overflowed with self-satisf action.
The flivver stopped on a dime before a huge double door and Prosser tumbled out, followed by the other two at a more leisurely pace.
'Through here! Through here!' he said. He shoved the door open and led them down the corridor and up a narrow flight of stairs onto a wall-hugging passageway that circled a huge three-level room. Orloff recognized the gleaming quartz-and-steel pipe-sprouting ellipsoid two levels below as an atomic generator.
He adjusted his monocle and watched the scurrying activity below. An earphoned man on a high stool before a control board studded with dials looked up and waved. Prosser waved back and grinned.
Orloff said, 'You create your force fields here?'
'That's right! Ever see one?'
'No.' The commissioner smiled, ruefully. 'I don't even know what one is, except that it can be used as a meteor shield.'
Prosser said, 'It's very simple. Elementary matter. All matter is composed of atoms. Atoms are held together by interatomic forces. Take away atoms. Leave interatomic forces behind. That's a force field.'
Orloff looked blank, and Birnam chuckled deep in his throat and scratched the back of his ear.
'That explanation reminds me of our Ganymedan method of suspending an egg a mile high in the air. It goes like this. You find a mountain just a mile high and put the egg on top. Then, keeping the egg where it is, you take the mountain way. That's all.'
The colonial commissioner threw his head back to laugh, and the irascible Dr. Prosser puckered his lips in a pursed symbol of disapproval.
'Come, come. No joke, you know. Force fields most important. Got to be ready for the Jovians when they come.'