This came to the forefront of my brain as I embark on a new sci-fi novel and start thinking about time, space, and how all of that crap would actually work in a "real life" space-faring society. Kepler's supernova is a perfect example. For reference, this was the last supernova to be unmistakably observed by the naked eye (you could see it during the day!) here on Earth in 1604 , roughly 400 years ago, to make a nice round number out of it. Given that light travels at the speed of light, an observer on a planet 400 lightyears from Earth would not have seen this happen yet. It would still appear to be a plain ol' star in the sky from where they are today. So say you live in a commonplace, space-faring society like Star Wars or Star Trek where crossing vast stellar distances doesn't take much longer than a trans-Atlantic flight or whatever. 400 lightyears is nothing in stellar distances. Maybe an hour car-ride in our world for the sake of discussion. So in theory, an observer could watch Kepler's supernova explode, be like, whoa, far out man, hop in their ship, travel a few light minutes away, watch it again, back up some more, watch it again, etc. Taking it a step further, supernova remnants often create planetary nebulae after they blow, like the Crab Nebula and many others that are easily observable with a basic telescope or even the naked eye from clear areas of the world (definitely not from the urban American Northeast where I live). Those nebulae grow and evolve over thousands of years. So hopping around in our spaceship, it would be one size and shape on one planet but appear vastly different from other planets. It grows larger as you move toward it and shrinks as you move away from it. Back up far enough, and the supernova hasn't "happened" yet, the nebula has yet to form/grow, and all you see is a boring ass star. (we're assuming here that space travel happens quickly. I don't know (or care) what the internal rules of Star Trek or Star Wars are, but for narrative purposes, it doesn't seem like it takes that long to get where you want to go) I'm thinking about this now because in my current WIP I have a character marooned on a deserted planet, looking into the night sky and wondering where she is (don't ask how somehow can crash a spaceship and not know where they are... as soon as I figure that out, it will be narratively airtight). Part of the gag is that she's looking for famous nebulae and supernova remnants, which in their world, have become common place landmarks. Like if this nebula is shaped liked A, you're probably somewhere in section Y. Or if it looks like B, you're probably in sector Z. Constellations would work the same way in that the stars that make a shape are nowhere near each other distance-wise but just happen to line up from our vantage on Earth. Travel a few light years in a different direction, though, and Orion is no longer Orion, and Cassiopeia is no longer Cassiopeia (though the Pleiades is star cluster IIRC and would appear so from different planets, but in a different configuration). But the big ass bright stars like Rigel, Arcturus, and Betelgeuse would still visible from many, many planets even if the constellations we use on Earth to locate them are not. So it's not much of a leap for a character in a space-faring society to be able to look at the sky, recognize a famous star, and be able to narrow their general location by whatever "new" constellation is formed around it. I don't really have a direct question here... just wondering if any sci-fi authors out there have messed with things like this. Or looked at things in the same way. I'm not an astronomy expert but I've studied it on and off for decades with the eye of a sci-fi writer, trying to extrapolate how the basic physics might play in a fictional sense. Kind of like the technobabble thread, specifically how to avoid it, I try to avoid that by incorporating how a layperson (such as myself) would use this stuff to their advantage. Any thoughts or comments are welcome. Like I said, no direct questions... just wondering if anybody but myself thinks about crap like this.
I haven't actually seen a lot of this kind of thing discussed in hard sci-fi books or in the Star Trek universe. For Trek, they get away with FTL observations and communications by saying it's done through "subspace." The ole technobabble. So they're not too worried about the visuals outside of a window and are instead focused on the sensor readings instead (which one would presume are then interpreted by the main computer and then projected to the main viewer). I think you should run with the concept; I mean, undoubtedly it's been explored in the past, but it's probably seldom used. I'm a big sci-fi consumer and can't think of an example off the top of my head. The first thought that entered my mind after reading your post was that perhaps navigation based on purely observations in a hard sci-fi setting would have to rely on landmarks. Maybe some well-known, highly visible, and unique star systems that could only be the same one that someone has observed from some other place. Something unusual like a trinary star system. It'd be too complicated for a human brain to do the calculations, but if someone could ask a computer like, "hey if this trinary system is X, what are the probabilities that this other system is Y, and this other one Z, etc." And kinda go from there trying to solve the mystery of where they actually are.
Oh, I've thought about it. I'm no expert either. In my book I have something called "The Eye" which is a sort of satellite "superscope" that travels at the speed of light, away from that which it observes. So if you know the time and place of an event, you can set up The Eye to travel in the distance at which its feint light can still be seen and the eye will be able to observe the moment in real-time. So if you have a bad guy that did something horrible at five o clock in a certain position on a planet, you can send The Eye to be in a position that views the event. Through some tehcno-magic it is also able to see events beneath the surface of planets or behind walls. It is able to reconstruct sound as well. Quite the powerful observation device. Only downside is, you need to know the time and place. I also have rich people in that universe who wanted a more beautiful night sky. They blew up a nearby star, and used some local spacetime accelerators to have the created nebulae appear rather quickly as viewable in their sky. But do mind, this is more of a science fantasy than a hard science story. In that universe, civilisations are able to manipulate the universe in many different ways.
Star Trek's subspace is a universal frame of reference. In practical terms, what that means is that whatever you see now is happening at the same time in its local space. So if you see a supernova happening *now* from Earth, it's happening now whereever it happens to be, whether that's 400 light years away, or several million. I refer you to Rodenberry(?)'s answer on how the Heisenberg compensators work - "Very well, thank you.". But as far as identifying different star systems is concerned, it's certainly possible if you know certain characteristics. For example, if you see a GINORMOUS star, and you can measure its apparent diameter, then no matter where you are, it's likely to be Stephenson 2-18, especially if it is in close proximity (in interstellar terms) to other humongous red stars. Or Eta Carinae, which has quite a distinctive shape, and you'd probably need to directly facing pole-on to mistake it for something else. You could probably narrow down the probability of a match to a known star by matching its other physical characteristics (mass, diameter, luminosity, pulse frequency, if it's a supernova remnant, rotation rate, planetary system etc.) rather than just visible observation.
I've recently been on a project involving astronomy and the public, as someone who knew almost nothing at all before hand and still knows almost nothing now. That in mind my inane contribution to this thread is that to gain the absolute trust of the average layman in your total command of the subject all you have to do is throw in one or two mentions of 'right ascension' and/or 'declination'. As in, "Mary sat down heavily on an obsidian outcrop, looked up at the alien sky with an expression that would murder the universe, if it cared to look back, and began the long task that was in front of her. "For the next four hours any casual passer-by --- on the barren and uninhabitable rock that was Mary's new and hopefully temporary home --- would have heard her muttering to herself. "Phrases such as, "Invert the declination and--- no, it still doesn't fit," and, "That could be Kefflinger 434, but the right ascension is all wrong for the forth quandrant, so it must be..."" They'll swallow anything you write after a good declinated, right ascended seeing to. I love the idea, which @Homer Potvin has just introduced me to, that with FTL if you travel far enough away you will see the beginning of the universe. Assuming, of course, that your FTL drive is fast enough that you don't have to travel so far that the photons are too dissipated to see anything at all. I was never very good at physics. Well that's all right then!
I'd say the short answer is; whatever is essential to the plot. I wouldn't get too hung up on how anything works. The skill set of the MC will likely not match the skills of her people as a whole. If your MC is not an accomplished astronomer or navigator, she could look at the night sky and not recognise anything. Maybe she doesn't have a telescope or it's always overcast. Long explanations of stellar navigation would likely be as dull as ditch water anyway. Just get on with the story.
For things like this, I've used spectroscopy in almost all of my sci-fi writing. Every star has a unique fingerprint in its emission/absorption lines, so it wouldn't be difficult to identify a random patch of stars from any vantage. Then it's just a matter of discerning distance, using apparent luminosity vs absolute luminosity. A little triangulation and some basic math, and boom! You can locate your ass. We can do this now on Earth, but there's a lot of estimation needed in luminosities and stellar distances, using parallax, spectroscopic parallax, black body curves, Hubble's Constant, etc. The margin for error is huge... like 25-40% with only Earth based observations at our disposal, I think. A futuristic society would obviously be able to travel to the stars directly and catalogue their luminosities, thus eliminating most of the needed estimation. Here's wiki for the Cosmic Distance Ladder (or Standard Candles): https://en.wikipedia.org/wiki/Cosmic_distance_ladder As far as fiction goes, it's not a leap to imagine that technology could place a spectroscope in a smartphone equivalent that every 12 year old would know how to use. But the character in my story only has her eyes at her disposal for first. Oh, snap. That's butter! If you're referring to the Big Bang, technically there was no space to travel into to watch it happen, but I'm smelling what you're stepping in.
You wouldn't be able to view it anyway. For a few seconds after the Big Bang, there were no photons, and then, until around 370,000 years later, the universe was too dense for you to see through it and see what was going on.
Sort of on topic, but did anyone at the more southern latitudes get the Northern Lights a few weeks ago? I never see it here at 42 North, especially living in the city, but that Coronal Mass Ejection was the largest in decades and flambeed the sky a brilliant purple here. Very cool. Then it knocked the WiFi out at three of my restaurants and a bunch of others in town, which wasn't so cool. I guess it's been known to knock out anything with a radio signal, but sporadically, unlike an EMP or whatever. They were freaking out in Florida because the hurricanes were in full force and they were worried about the losing the rest of the power grid. I was unaware that that could happen, but will definitely use that in the writing.
Here in Sweden, the MSB, authority for society protection and readiness sort of, has informed us about the dangers of sunstorms. They could, if powerful enough, wipe out our electricity. As far as I understand, they could severely affect our modern society. The locations closer to the poles are more vulnerable to these, but if a big and powerful one enough happens, every country on the planet might need spare electronic parts. And since society is becoming more and more dependent on electronics, we are, in my opinion, setting our bed up for a hassle. Because as far as I understand, everything hit by a massive solar storm, will need new electronic parts, that includes the machines that makes electronics... in other words, we are effed... I think we should maintain a sort of dependency system that does not rely on electronics to work. This includes, hard cold cash/metal money, biking/horse powered nation-wide messenger service (so that the authorities can still communicate should the worst occur), and perhaps more local food production.
A CME, coronal mass ejection, will make an EMP, Electro-magnetic pulse, when it hits the atmosphere. The report is here. The problem is the expense of protecting electronics, the power grid, etc.
Fortunately, only a few restaurants lost WiFi. It was kind of funny because I was sitting on my patio at home just about half and hour after sunset with my phone blowing up. I was muttering aloud about how the hell three stores could be losing WiFi at once when I looked up, saw the sky, and was like, whoa, far out, bruh! It really does knock out radio signals. I then texted all 15 of my managers to tell any complaining guests to take it up with the sun!
