I always wonder how Wesley Crusher can set coordinates in space when there's no fixed reference point. When the Enterprise is out in the middle of the universe, how can they set coordinates to a specific planet? I'm no scientist obviously, but somehow it just doesn't seem possible. Any thoughts??? Or actual scientific answer?
Setting coordinates in space
- Thread starter caroln
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if you're dealing with the universe, true. However on more localized bodies there are often central points. There is a central point to this galaxy, and of course singular star systems are easy enough to sort out. In any case it looks like the federation grids out its territories heliocentrically, which must be a bit annoying for non humans
He used a computer.
Oh....If I understand the info from wikipedia ("The origin is the zero distance point") the star ship itself is the reference point and they plot the course from that. I get it. I think. Did I get it?
I always thought of the center of the galaxy as a point of reference, with a circular system.. and the up and down based off the ship..
so a course of 180, would be a direction of "Galactic South" and the second number of like Mark 40 is like a 40 degree up angle of the glactic plane..
but a course of Latitude and Longetude for the location of a planet would be the galaxy in a grid and the planets location in that grid.
so a course of 180, would be a direction of "Galactic South" and the second number of like Mark 40 is like a 40 degree up angle of the glactic plane..
but a course of Latitude and Longetude for the location of a planet would be the galaxy in a grid and the planets location in that grid.
Correct.
They know where they are to a high degree of accuracy, so setting course is just pointing the ship in the direction they want to go relative to it's current heading. So with "xxx mark yyy", xxx is the x-axis direction specified in number of degress with 000 being straight ahead and 180 directly behind and yyy is the y-axis direction.
If one knows where one is and it's charted, they can look up a destination and have the computer do the calculations. Yes, a captain can tell a computer and computer could do it all automatically but there are plenty of reasons for the crew to be on the ship and not just a tangible sense of community. If they go on a rescue mission, there's another set of hands to assist in x amount of capacity/ies.
At some point the general direction has to be superseded by more precise coordinates. Space is a big place and depending on orbit of the planet around its star, it's position is going to be slightly different. And after a few centuries or millennia, it'll have to be remapped. If our moon shifts orbit an inch per year... I mean, I thought 8 inches was big, but 100? Given the scale of an annual orbit and all, those older star charts will still need some tweaking and tickling...
Our Galaxy is definitely not a static place and no celestial body stays in the same place forever. Starfleet and other starfaring organizations are probably always updating their star charts, but I would wager that current galaxy map is only precise to a certain point (where particular star systems are) with more accurate navigation handled when a ship is actually approaching a planet or space platform. Eventually even those star systems won't be in the exact same place after centuries of interstellar drift, but by then the charts will likely have been updated to reflect that, IMO.
Or not.
The general course gets the ship in the "ballpark," then the ship's sensors locates the star while still a dozen lightyears out and the course is altered.
Then while in the outer system (still at warp) the intented planet is spotted in the anticipated orbit, the course is altered again to have the ship exit warp a convenient distance away.
If a planet is a technological one, locate traffic control would be contacted at some point. Requesting a approach and orbit assignment.
So , knowing the exact co-ordinates at any time while convenient likely would not be necessary. Drive down 2nd street until you see the blue house.
This also explains how the Reliant would end up at a desert planet when her crew is looking for a desert planet, and never bother to establish that they are on the wrong desert planet. Mindlessly following a set of coordinates just isn't practical.
FWIW, it's extremely rarely that coordinates are actually mentioned in Star Trek. Headings and bearings, yes - two-dimensional things that lack information on distance. But coordinates, 3D spots in space, only ever appear, like, half a dozen times, and almost invariably in shady situations where the thing at X is supposed to be hidden from public view (I think TNG "We'll Always Have Paris" is the first-ever Star Trek episode to feature navigation coordinates in dialogue).
There are two or three instances of transporter coordinates being mentioned, and the format from TOS "Mark of Gideon" is cutely adhered to in modern DSC. When a starship is to travel to places, though, formats are all over the place, and sometimes don't seem to come in groups of three, either. Then again, all militaries are notorious for using coded/obscured coordinates that cannot easily be associated with any map... Starfleet just might go one step further and use different coding a different times. Indeed, perhaps the "coordinates" we hear are merely the code key for deciphering the true navigational data?
Timo Saloniemi
FWIW, it's extremely rarely that coordinates are actually mentioned in Star Trek. Headings and bearings, yes - two-dimensional things that lack information on distance. But coordinates, 3D spots in space, only ever appear, like, half a dozen times, and almost invariably in shady situations where the thing at X is supposed to be hidden from public view (I think TNG "We'll Always Have Paris" is the first-ever Star Trek episode to feature navigation coordinates in dialogue).
There are two or three instances of transporter coordinates being mentioned, and the format from TOS "Mark of Gideon" is cutely adhered to in modern DSC. When a starship is to travel to places, though, formats are all over the place, and sometimes don't seem to come in groups of three, either. Then again, all militaries are notorious for using coded/obscured coordinates that cannot easily be associated with any map... Starfleet just might go one step further and use different coding a different times. Indeed, perhaps the "coordinates" we hear are merely the code key for deciphering the true navigational data?
Timo Saloniemi
Or that their sensors didn't immediately alert them to the fact that the Ceti Alpha star system was missing a planet. Starfleet sensors seem to be incredibly reliable when needed and incredibly unreliable when the plot demands it (it's almost like it's a work of fiction and operating by those rules...).
Generations does lampshade this with the Stellar Cartography scene, but that was something that happened very recently, not 17 1/2 years earlier.
Picard said:
It does seem like, at least by the 24th century, it was assumed the computer would account for gravitational forces in a sector. Maybe the 23rd century sensors/computers were not this advanced, but still...
Back to the explicit topic, I can accept the coordinates/bearing issue on a regular basis, but I'm always amazed at how often ships are thrown to uncharted regions and immediately be able to plot a course back home (with an estimate of how long it will take).
How could they?
I mean, what sort of sensor could even theoretically alert the sidekicks to something not being there? Most of the universe lacks the presence of a planet. No particular spot in the Ceti Alpha system should be special in that respect.
No maybe about it. There's no way folks in the 23rd could tell what was happening in distant star systems unless a starship was sent there to have a look (see all episodes of TOS for starters). So the Reliant takes a look, and sees what she sees. There's no point of comparison that would make her crew think there's something wrong with what is seen.
Generally, the estimate is on how long it won't take: "at maximum speed, it would be years, but we can't do maximum speed and we can't do years so that's that". So this estimate need not be anywhere near correct and precise, and might be 50% off without altering anything.
Otherwise, navigation would be an iterative process where the position fix improves with every passing second even if starting out real coarse.
Timo Saloniemi
If you detect the mass of the star in the system, and the mass of the planet, and the distance between them, and the speed of the planet and the direction it is travelling you can calculate its future orbital path and track it past orbital path. If there are other planets in the star system their orbits need to be studied and then how the planets perturb each others' orbits can be calculated.
You only need a few observations of the planets to imput the data into a computer program to calculate the future positions of the planets for centuries or millennia to come.
So you use your computer to use the orbital elements of the planet compute where it will be when you enter the system, and when you get there you point a telescope at it and maybe ping it with radar to confirm that it is exactly where it is supposed to be.
And of course you can calculate where the planet is while you are still halfway to the star system and use your telescope to check that it is there, and do that periodically as you approach the star system.
So the Reliant should have noticed that Ceti Alpha VI was not where it was supposed to be
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Not a great example. One, it is using half of a coordinate system and navigation aids to put the driver into a small enough area that the visual identification would be efficient. Two, the house is not in motion like a planet, where the goal would be arriving at the point where it would be at a specific time.
But having a starship makes all that unnecessary. Worrying about where a planet "should" be is stupid when it being on this side of the star rather than that will only ever involve a minute course correction and possibly two and a half seconds of a difference in flight time.
Conversely, the great powers of a starship mean that a ship entering a star system would not limit herself by aiming her sensors at a preselected spot. She has enough capacity to do a situational awareness scan, which will reveal the presence of things both expected and unexpected, and then quickly and increasingly focus on the interesting at the expense of the uninteresting. It won't reveal the absence of things, though, unless there's some solid reason to expect presence instead - and this doesn't apply to the CA V/VI case at all, because there's no absence of an expected desert planet there.
We never get any suggestion that Starfleet would keep track on where planets "should" be; it's like making cloud maps, in a universe as active as Trek's. If a planet changes orbit, a starship need not worry: mobile planets never posed that much of a threat, despite being encountered with some frequency. Sure, some egghead down on Deck 15 might write a paper on the orbit shift one day, perhaps on the topic of the low levels of reliability in probe-made maps. But the folks up on Deck 1 would be within their rights to shrug.
Timo Saloniemi
Conversely, the great powers of a starship mean that a ship entering a star system would not limit herself by aiming her sensors at a preselected spot. She has enough capacity to do a situational awareness scan, which will reveal the presence of things both expected and unexpected, and then quickly and increasingly focus on the interesting at the expense of the uninteresting. It won't reveal the absence of things, though, unless there's some solid reason to expect presence instead - and this doesn't apply to the CA V/VI case at all, because there's no absence of an expected desert planet there.
We never get any suggestion that Starfleet would keep track on where planets "should" be; it's like making cloud maps, in a universe as active as Trek's. If a planet changes orbit, a starship need not worry: mobile planets never posed that much of a threat, despite being encountered with some frequency. Sure, some egghead down on Deck 15 might write a paper on the orbit shift one day, perhaps on the topic of the low levels of reliability in probe-made maps. But the folks up on Deck 1 would be within their rights to shrug.
Timo Saloniemi
This argument is based on the idea that Reliant went to Ceti Alpha to find a planet in an exact spot. It didn't. It went to Ceti Alpha to find a specific planet, within tolerances, which it did. Was that planet in the exact orbit the computer said it would be? No, but that can be explained by orbital drift over the years since the last scan was made. Anything, and I mean ANYTHING, can change the orbit of a planet. It may get hit by an asteroid. A nearby pulsar may have intermittent gravitational effects. Is scanning for these things part of Reliant's mission? No. So they don't do them. They just find the type of planet they're looking for, and go there, even if the orbit is off.
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