Kimble, who had been listening silently to the arguments. "These damned threads... If we hit them, what will happen?"
"At the point of contact, material is probably converted into hard radiation..." surmised Clive in a melancholy tone.
"What??? Why didn't you warn me earlier?"
Steve and Clive looked at each other.
"Well, we've only just thought it out ourselves," said Steve, embarrassed.
"With what precision have you determined the location of these threads?"
"Probably to within three to five thousand kilometres. Could be ten."
Kimble shot up from his seat.
"Could be ten? What about 20?"
"That's possible."
"Oh, that's great! We're already closer than twenty thousand!" Kimble was beside himself with rage at these damned scientists. He gestured to the computer:
"All engines stop. Reverse along same trajectory. Immediately!"
The ship shook and began to decelerate sharply. Some things lying on the table began sliding in the direction of flight.
"Sir, the field intensity gradients are falling in all directions. We are in the epicentre or very close to it," the computer unexpectedly reported a few minutes later.
"Yes, the error must be just on twenty thousand," muttered Clive, earning an angry glare from Steve.
"Oh, hell! This thing, is it like a mesh, or what?" Kimble was boiling with indignation.
"I don't think so. The aliens must have to fly through the gate somehow. More likely the threads simply encircle the radiating shape. That's if they exist at all, these threads," said Steve, trying to pacify Kimble, though he was feeling uneasy himself.
A few hours later, when the ship had withdrawn to a respectable distance, the tension on the bridge had eased off.
"Let's not have anything like that again! Get your little grey cells working quicker!" said the captain sternly, after sitting in silence.
Clive did not admit his guilt.
"I was only proposing a theory, what's wrong with that?"
Kimble just gave him a discontented look, finished his drink and went out. He could be heard swearing as he went away along the corridor.
Steve and Clive were left on their own, and Steve breathed a sigh of relief.
"OK, we'd better report the latest results to Shelby," he said.
Clive signalled to the computer to record a message.
"Message for Shelby. We have reached the point of maximum intensity of the signal. Judging from the scan results of the vicinity of the epicentre, the source is not a point, but takes the form of a cuboid, with a radiation area of 40 square kilometres.
"Apart from that, the source is non-material. We did not succeed in detecting any rotating or oscillating mass. I have... We have a version according to which the waves may be created by the oscillations of fine baryonic threads restrained by a magnetic field. Please propose a descriptive mathematical model.
"From a close distance, we can distinguish a whole harmonic range, consisting of the basic tone and numerous harmonic overtones. The latter are of lower intensity, close to or even below the sensitivity threshold of our apparatus.
"The hypothesis of non-natural origin is being considered as a priority. I am sending the scanning data. We are continuing our research. Message ends."
7
Shelby, the elderly dean of the astrophysics faculty, and also concurrently head of the expedition's scientific group, had last been on the Space Force's military base some days after the 'Dawn' project had been put on hold. Then, although mobilisation had been cancelled, the base had still been a hive of activity. The corridors were full of armed guards who were constantly checking personal data, creating long queues. To enter the building and reach the required sector, it was necessary to pass through several checkpoints, all irritatingly taking DNA scans.
Outside, it was no better. Ships were constantly arriving at the base and leaving it. The launch facilities could barely cope with so much traffic. Military and transport spacecraft were landing one after the other, filling the surroundings with an incessant roar. Patterns of vapour trails were visible in the sky, coming from spacecraft which were descending from and climbing into orbit at higher speeds than usual to increase the throughput capacity of the spaceport.
But today everything was different. A calm had again descended on the base, similar to that which had greeted the professor when he first visited it. The people on duty there looked fresher; they even had time for a joke during their document checks and DNA scan taking. Everything about the base indicated that life had returned to normal.
Shelby was escorted to one of the conference halls and left to wait for General MacQueen, Commander of the Space Fleet. He was not long in coming. The professor had barely had time to pour himself some sparkling water from one of the bottles thoughtfully left on the table when the door opened and the general entered the hall. Smiling as if to an old friend, he was clearly glad to see Shelby again.
In spite of their different ages and occupations, good relations had been established between Shelby and MacQueen during their joint work on 'Dawn'. They understood each other very easily. Probably each of them subconsciously felt that in spite of their different approaches, they were the right people for their respective jobs, and knew what they were doing.
"Glad to see you, Professor," said MacQueen. Today his smile was particularly broad and sincere. He took the last few steps with his hand extended in greeting.
Shelby shook his hand in response.
"The feeling is completely mutual. I see your department is gradually getting back to normal."
"Yes, it is, I'm glad to say." He gestured to Shelby to turn towards the window, which gave a view towards the launch pads.
"The intruder certainly stirred things up here. It was the first time in the history of the space fleet that we had conducted such a wide mobilisation. Doing so revealed that we were not at all prepared for such a turn of events."
"It seemed to me that it all went like clockwork," remarked Shelby in some surprise.
"From the civilian point of view, yes. But war is a serious matter, it does not forgive mistakes. The enemy usually attacks not head-on, but at the weakest point, and during mobilisation we discovered a whole lot of them. So that means a lot of work. We are now completely reviewing the entire structure of the space fleet."
There was a short silence.
"Well then," said MacQueen eventually. "Shall we get down to business?" He pointed to the nearest chair in front of the table, and sat in the chair next to it without waiting for his guest to take his seat.
"Our expedition has achieved the aims of its journey and is continuing its research," Shelby began. "The scientific team periodically sends the results of its work. On the basis of the latest data, we are inclining towards the theory that the anomaly is of artificial origin."
"But you already knew that before the expedition, didn't you?" asked MacQueen.
"It was the working hypothesis. But now we have experimental arguments in its favour."
"What exactly?"
"My people succeeded in determining its location. The point is that it begins not from a point source, as we assumed initially, but is spread out in space, as it were. That is, it has a certain shape. Such geometrical shapes are not characteristics of nature in the raw."
"Interesting..."
"It is a rough approximation of a cuboid, or hexahedron..."
"Excuse me, what's that?"
"The three-dimensional equivalent of a rectangle. Like a tabletop, for example," explained Shelby, drumming his fingers on the table.
MacQueen nodded in satisfaction.
"Taking recent events into account, we think that this phenomenon is connected with the visit of our mysterious guest. My team collected more precise information about the radiation, and this made it possible to improve our methods of detection. Working from here, from Earth, we have scanned our galaxy and have discovered dozens of similar phenomena."
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"Excuse me for interrupting you, but if these things are scattered all over the Milky Way, why haven't we noticed them before?"
"The problem has many aspects. It is difficult to detect gravity waves due to their low intensity, particularly when they are of natural origin. As I said before, the generation of such waves requires the oscillation of massive heavenly bodies, such as a binary neutron star system. These stars rotate at high speed around their own centre of mass, and moving with acceleration - and movement in a circle is always movement with acceleration - they create a ripple in space-time.
"The cosmos we are studying is extremely noisy. Everything that exists in it, the planets, gas clouds, stars, black holes, all this fills it with noise in some waveband or other, littered with elementary particles. Or rather each of these objects emits noise in all wavebands, but more in one and less in another, depending on the nature of the heavenly body. For example, our Sun is extremely noisy in the infrared and visible spectra of electromagnetic radiation, because they are the ones in which it radiates most of its energy. And let us not forget solar wind. It is like a bombardment with an ocean of elementary particles.
"Apart from this, our Universe is filled with residual radiation coming in from all directions. If man had organs capable of registering all this radiation of energy, it would seem to him that the world was filled with loud noise, the song of Nature. It is very difficult to identify and separate out any unknown signal from it. But the problem is made easier if we know exactly what we have to look for.
"My lads on the ship who are