I do not have the proper database in my scanner, but it is a common plant grown for living fencing on colony worlds. Desperate for a distraction, Kirk said, "I've been trying to learn Vulcan. Do you have the patience to teach me a little? The local star had inexorably traversed the sky and hung fifteen degrees above the other horizon when Spock stopped and said, "It has been thirty one hours since a rest period.
You are quite fatigued and require sleep. This felt like a command and Kirk realized from the oddness of it that he'd been ordering Spock around all day. He was clumsy by the time they made it to the ravine shelter. Kirk fell directly on the dirt and fell directly into sleep. Kirk awoke to his stomach clawing at him. Spock was sitting on the far side of the shelter, watching him. Kirk rolled onto his back. The sky was orange. A long, long day had passed and still no ship.
Kirk pulled his kit over, pulled out the second to last energy snack, broke it in half and held half out.
He might have slapped the Vulcan. His eyes went wide, then sharp for an instant, then he returned to unemotional. Kirk combed his hair back with his fingers. I'm treating you like you are crew assigned to me. Hidden emotions and motivations are deadly to a mission. I prod at them without thinking about it. But not at all the way I'd expect from most aliens.
And I notice you are pretty familiar with humans at a casual level. You accommodate me in lots of small ways I don't think you are aware of. That and your eyes leaves me to guess that you are not one hundred percent Vulcan. I'm not saying it's a fault of yours, just reality. Kirk's stomach ached, his limbs were shaky. He stood and looked around at the undulating landscape, half hidden in shadows. Kirk dug it out of the medkit and handed it over.
Stay in range of hearing at all times. Spock stepped back, used the scanner, stepped back farther. Then returned and handed it to Kirk, who powered it down and put it away. Spock remained standing just before him. It sounded parental. You are simply able to ignore the discomfort. Both of us are drastically shorted on nutrients.
Your nature doesn't allow for you to go completely without, indefinitely. Physics would argue otherwise. Kirk sat back, made himself comfortable, looked up at Spock. You are arguing some kind of reality of the mind.
Spock returned to his corner, wrapped up in his blanket, and sat cross-legged on the ground. You are familiar with death and fighting with the potential to die and that is fascinating.
My rank was higher before I got demoted. Commander was a little atypical at my age. Here on this planet, after surviving, Kirk could feel none of the sting to his pride. He even laughed lightly at how free he felt. But I lost my team to the bots because my team did exactly that to me. So not a good thing. That was a mistake. At that time I resisted doing the exercises I was given.
I wanted to write a program that overcame all other programs. A program that did its own programming by exploiting code it found. We are set to compete against each other in our lessons and I was determined to prove something.
He paused. I wanted to work on something with the elegance of biology. The mindless reordering of genetics. That was not the difficult part. The difficult part was representing any target system in the same terms so that the virus can utilize the program machinery it finds for its own purposes, just like a virus forces host cell rna to do its work. That is my program's weak spot, if it has one, that it had to have at least a few cases hard coded into it.
It was not possible to create a fully generic representation of any adaptable computer system so that the code could mutate as I wanted it to. Sharing parameter data would not suffice.
I have a theory that the colonists didn't know how to avoid building in this manner, that in fact, the default systems they designed from are responsible for their success, not the colonists' intentional programmatic design. There is no AI present. It is simply biological style optimization run over enough generations of programmatic change. Every time one bot has a better outcome that learning is transferred to the others.
And not just at the individual level, also at the network level, in the very way they organize themselves. Witness the two scouts who sprinted toward us.
They were gathering data, trying a new program out. The network assigned them that task, therefore their learning, or in this case, my virus, was easily transferred back to the swarm from one of those units. Kirk said, "No wonder we've been having such a miserable time of it. The Federation should have every advantage of resources and technology, but we are slowly falling behind.
Daybreak came on in earnest. Kirk stood before the high shelter, looking out. Spock was studying samples of dirt he'd collected on their surveys. Kirk was feeling less hungry, as if he'd passed through the pain of it as through a curtain and now glided over it, untouched. Spock had found a salt deposit so Kirk no longer felt dizzy when he drank enough water to make his stomach feel full for a few minutes.
Kirk said, "Can you make the escape pod orbit once with the scanner? There was another landing party, four thousand clicks to the east. But I don't want to put the equipment at undue risk either. Spock did basic maintenance on the engines of the pod and rigged the medical sensor into it. Kirk helped as much as he could, determined to stay out of the way. Spock was clearly accustomed to working alone. A few hours later, Kirk watched the pod as it faded to a speck on the horizon.
He wasn't feeling hopeful about much. Learning that Red and his team were okay would help Kirk's outlook a lot.
Spock moved his fingers over the controls of the medical scanner. Minutes passed. Kirk moved over beside him to look too, but the screen was updating too rapidly for Kirk to interpret it. Kirk thought back to their briefing before the landing. Ninety mark three.
Spock raised a brow, then returned to the sensor. After a few minutes, he shook his head. This device is not sensitive at range, however. And it would be easy to block. Under current atmospheric conditions your communicator should be in range at least one quarter of the time. But you have received no response on it. Kirk climbed away over the uneven rocks, partly because he needed to move but partly to keep his emotions to himself.
He felt bleak. He stood where the rise formed a ridge that fell away into a valley off to the south. He was becoming familiar with the barren alien landscape and that did not improve his mood. I give it less than two percent chance. And that is with some assumptions applied. One: that they encountered the robot pickup ship leaving orbit and engaged with it. Two: that they either communicated with it over an insecure connection capable of not just data, but code.
This would be a gross security risk and I think it doubtful. Or that they brought aboard equipment from that ship. But I suppose it's possible. At the same time I want to gut punch you for making it the reason. Kirk laughed without feeling it. I won't hit you. Realize that normally, if lunch is an hour late I get moody. His mood slipped farther. If you feel confident to stand against me, then I won't feel guilty for letting that slip.
I see. Yes, I am quite confident. My family traditions keep alive several martial arts that would otherwise have been lost. Kirk looked out again, memorizing the view for lack of anything else to do. Starfleet will send another ship, but it may be weeks. Or months. This is how the rebel colonists get us. They make us make bad decisions, like assuming this was an easy mission for a single small ship. They always seem to have more resources to throw at us than we expect.
And are picking us off one at a time, which stretches the fleet even thinner. Kirk rubbed his face, his eyes. Somewhere deep inside himself was that optimism that usually never failed him. Spock said, "I have an experiment, but it needs to be conducted in the ravine where there is more moisture. Spock collected things on the way, branches, dirt from crevices in the rocks.
Kirk started collecting similar things, hooking the thumb of his useless hand in the edge of his shirt to carry them. It felt good to have something to do. It kept his brain from feeling like it was vibrating in his skull. Spock pounded the twigs into a mulch, mixed it with different soils. He could have been in a lab for all the precision he was using. He gave Kirk the task of hollowing stones into shallow vessels with the phaser. Kirk longed to sleep, but there was a lot of daylight left.
He was having flashbacks to his academy survival trip. He'd been insanely hungry then too, but he'd known it had an end, a return to a real bed. Lots to eat. He had stopped fantasizing about a shower to cut down on the number of things he longed for. He wondered if he could roll in the dust and feel cleaner, and the itching would stop. Dust had gotten under his padding, was abrading his neck. He wore it loosely, but that made it worse since it collected more dust.
He'd have to try beating it on a rock. They went deeper into the ravine, carrying a vessel under each arm. Kirk hadn't even asked what they were doing. He amused himself by not asking until they stopped. Likely imports from other colony worlds. Spock finished and stood before saying.
Spock flailed his arm wide, freeing himself. His posture remained alarmed, only calming by degrees. They were in a narrow warm spot of the ravine, out of the wind.
The heat made Kirk want to lay there and soak it up like a nutrient. I wasn't sarcastic or flattering. Just impressed by how much you know. That's all. I'm sorry I touched you. I'm an idiot. I do know better. Kirk kept talking, seeking the magical combination of words to get back to where they had been. I didn't mean to. I like you. Spock studied him. He nodded. That was a concession.
Kirk shut up then. They walked in silence back to the shelter. In the warm shade, Kirk curled up with his shoulder pads as a pillow and tried to sleep. He swam in utter exhaustion but didn't drop off into blissful unawareness. He watched the light shadows moving across the ravine floor, closed his eyes, watched the shadows.
Despite the daytime heat, Spock sat with his blanket over his shoulders as he scanned samples of dirt. Kirk groaned and sat up.
His head lolled. He had some salt and water and felt a bit better. His body ached when he sat up; it ached when he lay down. He rested on his back, fixating on the arch of carved rock.
The sweeps from the phaser had left little grooves that seemed to be trying to impress some abstract meaning on his brain. Kirk put his hand behind his head to prop it up. His arms felt half numb but ached despite this. He could have been drugged, or ill with something nasty. The idea that mere food would cancel out his physical problems irked him.
Kirk smiled. But even so. I'd chose you over most of my shipmates if I was faced with an actual choice. Spock actually rolled his eyes, mostly sideways, but it made Kirk smile more. He fetched out the open snack bar and handed half over.
Kirk nibbled on his, one tiny morsel at a time. Saliva poured into his mouth, flooding out of his lips, made each morsel float on an ocean. He might have spent half an hour eating two and a half bites. Kirk propped himself up on his pads, legs stretched out crossed before him.
This laziness was like shore leave only with much less food and booze. I shouldn't use human terms. He wanted to say 'kind' but couldn't reframe it in safe terms. You are easy to work with, and that's considering we've never worked together before. You are-". Where does that come from? He felt drunk the way sitting straight was so difficult. I just don't understand that misunderstanding.
It worries me. Kirk eventually said, "So. I understand you don't want to be flattered. That's perfectly acceptable. I'm not doing that. I'm telling you how I perceive you.
Some people like receiving positive reinforcement. Kirk watched him. He looked vulnerable. Kirk could think of only one explanation. Kirk stared. He died when I was young. I didn't see him much. He was like me now. A Lieutenant in Starfleet. Kirk shrugged. We get a lot of kids come through. That's part of my job. I sort out who is really capable of what.
Half the time, people are struggling to separate out what they want from their parents' expectations when suddenly that oppressive control is half a galaxy away. It's refreshing and surprising when it's not the case. Kirk spoke into the ensuing silence. She sure as hell didn't want me in Starfleet.
Kirk waved his arms. Kirk leaned his head back and talked to the rocky ceiling above. Let's just leave it at that. Kirk closed his eyes. He swam again in fatigue, but didn't sleep. A long time passed. An hour maybe. Kirk curled up on his side this time. He felt he weighed twice normal the way his bones ached where they pressed into the ground.
Kirk must have slept. Next thing he knew the sun was gone from the ravine floor and the wind had risen. Sleep didn't make him feel any better. Spock was scanning the rock wall of the ravine, looking up and down at it. He turned as if sensing Kirk's attention.
Kirk forced himself to sit up and drink water. This made him need to find a private spot. He returned and stretched despite his body insisting he lay down again and contemplate never suffering through getting up again.
Walking helped. Kirk stretched again when they arrived. He felt compulsive about it, as if he could ease the ache in his limbs if he tried just once more. The sky grew orange. Kirk flipped open his communicator. He experienced a forgotten memory of being a child with a toy one of these. It also had dead air since Sam had broken it the day Kirk had received it as a present.
That hadn't stopped Kirk from having imaginary conversations with his father over it. If he died here, he wouldn't even have managed to outlive his father. Against myself, really. That was at least the second time Kirk had seen that. If he sunk low enough, Spock felt compelled to reach out a bit in a non-Vulcan way.
Something we have in common. It grew dark. Kirk had never before felt so much numbness and so much aching, so much fatigue and so very wired and awake. Gravitational waves, analogous to waves upon an ocean, are ripples in four-dimensional spacetime.
These exotic waves, predicted by Einstein's theory of relativity, are produced by massive objects in motion and have not yet been directly detected. Created in a star explosion, a pulsar is born spinning, perhaps 30 times per second, and slows down over millions of years. Yet if the dense pulsar, with its strong gravitational potential, is in a binary system, it can pull in material from its companion star.
This influx can spin up the pulsar to the millisecond range, rotating hundreds of times per second. In some pulsars, the accumulating material on the surface occasionally is consumed in a massive thermonuclear explosion, emitting a burst of X-ray light lasting only a few seconds.
In this fury lies a brief opportunity to measure the spin of otherwise faint pulsars. Seeker's Bad Science podcast explores the science behind the reboot of the venerable sci-fi series.
It's hard to believe that nearly a decade has passed since director J. Abrams delivered his hugely anticipated reboot of the Star Trek movie series. The film, titled simply Star Trek, was a massive commercial success and it introduced a new generation to the crew of the Starship Enterprise.
But how does the real science behind the movie hold up? These are computed from the raw timing data by Tempo , a computer program specialized for this task. After these factors have been taken into account, deviations between the observed arrival times and predictions made using these parameters can be found and attributed to one of three possibilities: intrinsic variations in the spin period of the pulsar, errors in the realization of Terrestrial Time against which arrival times were measured, or the presence of background gravitational waves.
Scientists are currently attempting to resolve these possibilities by comparing the deviations seen between several different pulsars, forming what is known as a pulsar timing array. The goal of these efforts is to develop a pulsar-based time standard precise enough to make the first ever direct detection of gravitational waves. They used observations of the pulsar PSR J This discovery presented important evidence concerning the widespread existence of planets outside the Solar System , although it is very unlikely that any life form could survive in the environment of intense radiation near a pulsar.
In , AR Scorpii was identified as the first pulsar in which the compact object is a white dwarf instead of a neutron star. Initially pulsars were named with letters of the discovering observatory followed by their right ascension e. CP As more pulsars were discovered, the letter code became unwieldy, and so the convention then arose of using the letters PSR Pulsating Source of Radio followed by the pulsar's right ascension and degrees of declination e.
Pulsars appearing very close together sometimes have letters appended e. The modern convention prefixes the older numbers with a B e. All new pulsars have a J indicating Pulsars that were discovered before tend to retain their B names rather than use their J names e. Recently discovered pulsars only have a J name e. All pulsars have a J name that provides more precise coordinates of its location in the sky. The events leading to the formation of a pulsar begin when the core of a massive star is compressed during a supernova , which collapses into a neutron star.
The neutron star retains most of its angular momentum , and since it has only a tiny fraction of its progenitor's radius and therefore its moment of inertia is sharply reduced , it is formed with very high rotation speed. A beam of radiation is emitted along the magnetic axis of the pulsar, which spins along with the rotation of the neutron star.
The magnetic axis of the pulsar determines the direction of the electromagnetic beam, with the magnetic axis not necessarily being the same as its rotational axis. This misalignment causes the beam to be seen once for every rotation of the neutron star, which leads to the "pulsed" nature of its appearance.
In rotation-powered pulsars, the beam originates from the rotational energy of the neutron star, which generates an electrical field from the movement of the very strong magnetic field, resulting in the acceleration of protons and electrons on the star surface and the creation of an electromagnetic beam emanating from the poles of the magnetic field. When a pulsar's spin period slows down sufficiently, the radio pulsar mechanism is believed to turn off the so-called "death line".
Though the general picture of pulsars as rapidly rotating neutron stars is widely accepted, Werner Becker of the Max Planck Institute for Extraterrestrial Physics said in , "The theory of how pulsars emit their radiation is still in its infancy, even after nearly forty years of work.
Three distinct classes of pulsars are currently known to astronomers , according to the source of the power of the electromagnetic radiation:. Although all three classes of objects are neutron stars, their observable behavior and the underlying physics are quite different. There are, however, connections.
For example, X-ray pulsars are probably old rotationally-powered pulsars that have already lost most of their power, and have only become visible again after their binary companions had expanded and began transferring matter on to the neutron star. The process of accretion can in turn transfer enough angular momentum to the neutron star to "recycle" it as a rotation-powered millisecond pulsar.
As this matter lands on the neutron star, it is thought to "bury" the magnetic field of the neutron star although the details are unclear , leaving millisecond pulsars with magnetic fields , times weaker than average pulsars. This low magnetic field is less effective at slowing the pulsar's rotation, so millisecond pulsars live for billions of years, making them the oldest known pulsars. Millisecond pulsars are seen in globular clusters, which stopped forming neutron stars billions of years ago.
Of interest to the study of the state of the matter in a neutron star are the glitches observed in the rotation velocity of the neutron star.
This velocity is decreasing slowly but steadily, except by sudden variations. One model put forward to explain these glitches is that they are the result of "starquakes" that adjust the crust of the neutron star.
Models where the glitch is due to a decoupling of the possibly superconducting interior of the star have also been advanced. In both cases, the star's moment of inertia changes, but its angular momentum does not, resulting in a change in rotation rate. When two massive stars are born close together from the same cloud of gas, they can form a binary system and orbit each other from birth.
If those two stars are at least a few times as massive as our sun, their lives will both end in supernova explosions. The more massive star explodes first, leaving behind a neutron star. If the explosion does not kick the second star away, the binary system survives.
The neutron star can now be visible as a radio pulsar, and it slowly loses energy and spins down. Later, the second star can swell up, allowing the neutron star to suck up its matter.
The matter falling onto the neutron star spins it up and reduces its magnetic field. This is called "recycling" because it returns the neutron star to a quickly-spinning state. Finally, the second star also explodes in a supernova, producing another neutron star. If this second explosion also fails to disrupt the binary, a double neutron star binary is formed.Future spacecraft can use pulsars to navigate completely autonomously "As the first to demonstrate X-ray navigation fully autonomously and in real-time in space, we are now leading the way.