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A comment on Where Is the Sun Located in the Milky Way?.

Re:Where Is the Sun Located in the Milky Way? by rb808 on Wednesday October 02, 2019 @04:41PM (#21140531)
Far out in the uncharted backwaters of the unfashionable end of the western spiral arm of the Galaxy lies a small unregarded yellow sun. Orbiting this at a distance of roughly ninety-two million miles is an utterly insignificant little blue green planet whose ape-descended life forms are so amazingly primitive that they still think digital watches are a pretty neat idea.
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Re:Where Is the Sun Located in the Milky Way? by journalctl on Wednesday October 02, 2019 @04:56PM (#21140661)
Wouldn’t it be wondrous if the galaxy had plentiful intragalactic public transit and we don’t have access because we’re the planetary equivalent of the suburbs?
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Re:Where Is the Sun Located in the Milky Way? by antod on Wednesday October 02, 2019 @08:27PM (#21142316)
All the planning charts and demolition orders for it have been on display in the local planning department in Alpha Centauri for fifty Earth years
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Re:Where Is the Sun Located in the Milky Way? by pdonis on Wednesday October 02, 2019 @08:43PM (#21142440)
...in the bottom of a locked filing cabinet stuck in a disused lavatory with a sign on the door...
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Re:Where Is the Sun Located in the Milky Way? by sjwright on Wednesday October 02, 2019 @10:19PM (#21142952)
What do you mean you’ve never been to Alpha Centauri? Oh for heaven sake mankind it’s only four light years away! I’m sorry but if you can’t be bothered to take an interest in local affairs that’s your own regard.
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Re:Where Is the Sun Located in the Milky Way? by journalctl on Wednesday October 02, 2019 @11:08PM (#21143192)
It’s just going to be a bunch of NIMLICs at the meeting anyway (Not In My Local Interstellar Cloud).
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Re:Where Is the Sun Located in the Milky Way? by burpsnard on Thursday October 03, 2019 @05:04AM (#21144992)
'beware of the leopard'.
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Re:Where Is the Sun Located in the Milky Way? by TheRealSteel on Wednesday October 02, 2019 @05:20PM (#21140860)
This is kind of a plot element in Mass Effect, but the humans are lucky enough to have a stop in our system.
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Re:Where Is the Sun Located in the Milky Way? by duncan-donuts on Wednesday October 02, 2019 @09:50PM (#21142799)
What do you mean the humans are lucky enough to have a stop in _our_ system?!
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Re:Where Is the Sun Located in the Milky Way? by paulsen on Thursday October 03, 2019 @12:56AM (#21143860)
I think the Reapers may have arrived 167 years too early.

Come on giant space Cthulhus, we haven't even discovered the Prothean Ruins in Mars yet!

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Re:Where Is the Sun Located in the Milky Way? by antisemiotic on Thursday October 03, 2019 @03:38AM (#21144605)
Did New Horizons categorically rule out that there's something hidded inside Charon?
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Re:Where Is the Sun Located in the Milky Way? by undersuit on Wednesday October 02, 2019 @05:19PM (#21140844)
We just need to build a station in the neighborhood: https://www.technologyreview.com/s/613127/a-halo-drive-could...
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Re:Where Is the Sun Located in the Milky Way? by ars on Thursday October 03, 2019 @04:51AM (#21144928)
It's unlikely. Closer to the core there is too much radiation for life to be possible.

And farther away there are not enough metals.

As best as we can tell we are at the distance where all other life would be.

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Re:Where Is the Sun Located in the Milky Way? by Vesuvium on Wednesday October 02, 2019 @07:42PM (#21141985)
You are not very far from what could be the reality. According to some research the Solar System has 10% less hydrogen than other galaxies, so Bussard ramjets will have an harder time
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Re:Where Is the Sun Located in the Milky Way? by perl4ever on Wednesday October 02, 2019 @08:50PM (#21142483)
What if dark matter turns out the key to a decent space drive? There appear to be galaxies without it (a good reason for believing it exists where there is evidence) and so any aliens there would be SOL.
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Re:Where Is the Sun Located in the Milky Way? by rolleiflex on Thursday October 03, 2019 @12:40AM (#21143781)
Astonishingly enough, you might not be far off. That is the operating principle behind the Alcubierre Drive. https://en.wikipedia.org/wiki/Alcubierre_drive

Edit: Apologies, it seems it does not in fact use dark matter.

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Re:Where Is the Sun Located in the Milky Way? by archgoon on Thursday October 03, 2019 @02:23AM (#21144262)
Unfortunately, Alcubierre doesn't use dark matter. It uses negative mass (or even imaginary mass) matter. Dark Matter is believed to have regular positive mass (if it were negative mass, we'd be wondering why galaxies seemed to have less matter than they should).

The existence of negative mass exotic matter remains an open question.

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Re:Where Is the Sun Located in the Milky Way? by paulrouget on Thursday October 03, 2019 @02:20AM (#21144245)
The Alcubierre drive relies on negative matter, not dark matter.
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Re:Where Is the Sun Located in the Milky Way? by BurningFrog on Wednesday October 02, 2019 @10:19PM (#21142949)
No doubt stolen by the untrustworthy Andromedites!
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Re:Where Is the Sun Located in the Milky Way? by AtlasBarfed on Friday October 04, 2019 @05:12PM (#21161957)
Suburbs intentionally avoid mass transit.

You are thinking of... a ghetto.

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Re:Where Is the Sun Located in the Milky Way? by everdev on Wednesday October 02, 2019 @11:49PM (#21143455)
Or the wilderness
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Re:Where Is the Sun Located in the Milky Way? by trhway on Wednesday October 02, 2019 @06:03PM (#21141244)
my pet theory is that galaxies are more like fireworks wheels, and so we aren't strictly orbiting the galactic center, we're also slowly getting farther and farther from it (that also takes care of the dark matter conundrum in my view), and thus couple billions of years ago we were in the much better and more populated part of the town than the current 'burbs.
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Re:Where Is the Sun Located in the Milky Way? by saghm on Wednesday October 02, 2019 @05:39PM (#21141039)
This is probably a really silly question, but how do astronomers and the like define "west" in this case? I assume it must be useful to have some sort of reference orientation for the galaxy, but how is it defined?
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Re:Where Is the Sun Located in the Milky Way? by ianburrell on Wednesday October 02, 2019 @05:55PM (#21141184)
The directions are defined the same way as directions on the Earth or in the solar system using the right-hand rule to define north and east based on counter-clockwise rotation.
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Re:Where Is the Sun Located in the Milky Way? by spolster on Wednesday October 02, 2019 @06:54PM (#21141644)
West can be defined in terms of spin direction, but western ( as in hemisphere) requires a meridian to define the boundary. I'd have assumed that we'd have put Earth on the galactic meridian, much like the Brits put London on the terrestrial one.
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Re:Where Is the Sun Located in the Milky Way? by BurningFrog on Wednesday October 02, 2019 @10:19PM (#21142954)
I expect it goes through Greenwich, as always!
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Re:Where Is the Sun Located in the Milky Way? by dotancohen on Thursday October 03, 2019 @01:46AM (#21144096)
You are correct, it is determined by spin. However, for some reason that has never been explained to me, we define galaxies to spin in the opposite direction from planets.
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Re:Where Is the Sun Located in the Milky Way? by Keysh on Thursday October 03, 2019 @04:57AM (#21144958)
We don't define galaxies in general to spin in the opposite direction.

Just the Milky Way.

(The reason for this seems to be that Galactic "North" was defined long before we had the data to determine which way the Milky Way rotated -- or even that it rotated. By the time the rotation was definitively determined, it was too late to override convention. This may go back to William Herschel deciding that the "north pole" of the Galaxy should be in the same hemisphere of the sky that the Earth's north pole pointed toward. In retrospect, he had a 50% chance of being right...)

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Re:Where Is the Sun Located in the Milky Way? by RangerScience on Thursday October 03, 2019 @03:14AM (#21144498)
I never thought about this. Will most solar systems form roughly on the same plane as the galactic disk, and will they generally have orbits in the same or the opposite direction as the galactic rotation of their star?
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Re:Where Is the Sun Located in the Milky Way? by Keysh on Thursday October 03, 2019 @05:01AM (#21144980)
It's basically random; the rotation of a solar system depends on the rotation of the gas clump that collapses to form the star and its system, and that depends on local details about the relative orientation of local gas clumps, the possible influence of winds from nearby massive stars and supernova shock waves, and general turbulent motions within molecular clouds.
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Re:Where Is the Sun Located in the Milky Way? by gmiller123456 on Thursday October 03, 2019 @01:16PM (#21149357)
It's not very random. The galaxy also formed from a clump of rotating gas, and this heavily influences the direction all of the sub-bodies will rotate and orbit. Systems influenced by other forces would be the exception to the norm.
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Re:Where Is the Sun Located in the Milky Way? by Keysh on Thursday October 03, 2019 @04:23PM (#21151715)
No, it is pretty random, just as the orbits of binary stars are randomly oriented. The scales of star and solar-system formation are much, much smaller than the scale of the galaxy, so the memory of the latter has been scrambled by all the intermediate and local processes.

From this Cornell "Ask an Astronomer" page (http://curious.astro.cornell.edu/about-us/159-our-solar-syst...)

"The size of a solar system is so much smaller than the size of the Galaxy, that the Galaxy's structure has no impact on the orientation of a solar system. What determines their orientations is the direction of the angular momentum that the system had when it formed, and that's pretty much random."

Or take a look at these ALMA images of protoplanetary disks (solar systems in the making) around pre-main-sequence stars. All are at very similar distances, and most are at very similar positions relative to the Galactic plane, so they should all show very similar projected shapes and orientations if they followed the galaxy's orientation -- but they are all over the place.

https://www.eso.org/public/images/potw1904a/

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Re:Where Is the Sun Located in the Milky Way? by saghm on Wednesday October 02, 2019 @06:26PM (#21141445)
Ah, I forgot that the galaxy rotates as well. That definitely makes things a bit simpler.
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Re:Where Is the Sun Located in the Milky Way? by close04 on Wednesday October 02, 2019 @06:31PM (#21141493)
It's a quote from The Hitchhiker's Guide to the Galaxy. Only hit me at the very end of it... "digital watches are a pretty neat idea".
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Re:Where Is the Sun Located in the Milky Way? by hanniabu on Wednesday October 02, 2019 @09:12PM (#21142604)
Okay, so once you have north, which way is east in a circle?
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Re:Where Is the Sun Located in the Milky Way? by ajuc on Thursday October 03, 2019 @04:11AM (#21144756)
East on Earth is the direction in which we rotate. Should be the same for a galaxy.
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Re:Where Is the Sun Located in the Milky Way? by hanniabu on Thursday October 03, 2019 @10:06AM (#21147075)
That's because earth can be viewed as a plane. The galaxy can't, you need a median.
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Re:Where Is the Sun Located in the Milky Way? by ajuc on Thursday October 03, 2019 @10:12AM (#21147148)
1. Milky Way is much more like a plane than Earth

2. it doesn't matter anyway any object which rotates can have direction named basing on that rotation

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Re:Where Is the Sun Located in the Milky Way? by tiborsaas on Thursday October 03, 2019 @04:28AM (#21144832)
They use giant supercomputers to do simulations which results in these counter intuitive answers. The trick is to ask the right question.
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Re:Where Is the Sun Located in the Milky Way? by taneq on Thursday October 03, 2019 @02:45AM (#21144366)
It's more like spinwards and widdershins, really.
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Re:Where Is the Sun Located in the Milky Way? by Razengan on Thursday October 03, 2019 @03:19AM (#21144516)
Spinwise/turnwise, and rimwards :)
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Re:Where Is the Sun Located in the Milky Way? by leemailll on Wednesday October 02, 2019 @10:32PM (#21143013)
You can try Polaris
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Re:Where Is the Sun Located in the Milky Way? by andrewflnr on Wednesday October 02, 2019 @11:51PM (#21143475)
They don't, AFAIK. You can only get away with it if you're writing exceptionally goofy science fiction.
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Re:Where Is the Sun Located in the Milky Way? by emmelaich on Wednesday October 02, 2019 @09:07PM (#21142583)
Also the Galaxy song is funny and mostly accurate

http://www.montypython.net/scripts/galaxy.php

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Re:Where Is the Sun Located in the Milky Way? by nerfhammer on Wednesday October 02, 2019 @07:21PM (#21141836)
digital watches are a pretty neat idea. they're vastly more accurate than mechanical watches while using incredibly little energy.
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Re:Where Is the Sun Located in the Milky Way? by jgtrosh on Thursday October 03, 2019 @11:00AM (#21147793)
Just bought a Casio digital watch this morning because it has a countdown timer you can adjust up and down. I'm a happy ape right now.
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Re:Where Is the Sun Located in the Milky Way? by SmellyGeekBoy on Thursday October 03, 2019 @05:45AM (#21145200)
It makes me sad how many of the replies here seem to have completely missed the reference. The fact that it's upvoted to the top gives me some hope, at least.
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