Why is nobody talking about 'inter-Galactic'?

[Draco T stand-up guy]

On 7/7/2020 at 3:18 AM, Kaerbanogue said:

People have different fields of expertise, they are not "ignorant" because they don't know what you concider the basises.

I consider knowing the difference between a solar system and a galaxy to be fairly basic for any journalist as it comes down to knowing the meaning of the words that they use for their job.

[Kaerbanogue]

41 minutes ago, Draco T stand-up guy said:

I consider knowing the difference between a solar system and a galaxy to be fairly basic for any journalist as it comes down to knowing the meaning of the words that they use for their job.

I think he confused the prefixes intra and inter which both share the same etymology apparently. And most people don't even know how many planets there are in the SS nor their names. Most of people just don't care about astronomy. See how NASA desperately tries to appeal to new audiences by promoting movies like the martian for exemple or how Nasa news are becoming sciencepost level of clickbait...

We know astronomy stuff because we like it but maybe the guy who wrote the article is fan of cooking and would think you're a retard if you can't make an omelet !

[jimmymcgoochie]

Just making a small star cluster will give more than enough planets, moons etc. to explore. There are more than twenty stars within 12 light years of our own solar system and many more not much further away so a few light years across is all you’d need in Kerbal scale. Torchships and Daedalus drives would then be enough to go between them in years or decades rather than centuries or millennia and no need to add physics-melting warp drives either. Intergalactic travel is pointless when you have billions of stars in one galaxy to explore and colonise.

 

[Superfluous J]

21 hours ago, Draco T stand-up guy said:

I consider knowing the difference between a solar system and a galaxy to be fairly basic for any journalist as it comes down to knowing the meaning of the words that they use for their job.

You seem to have high expectations for others and unless you want to spend your life sad and angry, you may want to temper them a bit.

[Draco T stand-up guy]

1 hour ago, Superfluous J said:

You seem to have high expectations for others and unless you want to spend your life sad and angry, you may want to temper them a bit.

Misuse of words results in miscommunication - so, yeah, I expect people to use the right words especially when its central to their job.

[Overfloater]

23 hours ago, Kaerbanogue said:

maybe the guy who wrote the article is fan of cooking and would think you're a retard if you can't make an omelet !

But you don't have to be a cooking enthusiast to make that distinction.

[Superfluous J]

6 hours ago, Draco T stand-up guy said:

Misuse of words results in miscommunication - so, yeah, I expect people to use the right words especially when its central to their job.

I'm not saying it's an unreasonable expectation. I'm just saying it's going to make you sad and angry.

[sturmhauke]

On 7/6/2020 at 7:45 AM, problemecium said:

Indeed, 100% of humankind thought the galaxy and the universe were the same thing until the 1920s when Hubble (I think... names and dates aren't my forte) measured the distance to the famous Andromeda nebula and discovered that it was outside the universe and also twice the size of the universe - thus the known universe at the time was re-dubbed "island universe" and eventually "galaxy," a word derived from a Latin term for milk in honor of the Milky Way.

That's mostly correct, but astronomers were already using both terms since the 18th century, somewhat interchangeably. It wasn't until the 20s that telescopes were good enough to distinguish nebulae from galaxies; before then, they both appeared to be groups of stars, but astronomers couldn't see enough detail to make reliable measurements.

[problemecium]

Oh, interesting. I'm just parroting what I remember hearing in TV specials or reading in books years ago so as long as the general gist was right I didn't worry about splitting hairs. I hadn't heard about the term galaxy being used earlier. Do you really mean the 18th century (1700s) or actually mean the 1800s (19th century)? Cuz the former would be way earlier than I thought o_o

[Kaerbanogue]

4 hours ago, problemecium said:

Oh, interesting. I'm just parroting what I remember hearing in TV specials or reading in books years ago so as long as the general gist was right I didn't worry about splitting hairs. I hadn't heard about the term galaxy being used earlier. Do you really mean the 18th century (1700s) or actually mean the 1800s (19th century)? Cuz the former would be way earlier than I thought o_o

See yonder, lo, the Galaxyë
Which men clepeth the Milky Wey,
For hit is whyt.

— Geoffrey Chaucer The House of Fame, c. 1380.

[sturmhauke]

4 hours ago, problemecium said:

I hadn't heard about the term galaxy being used earlier. Do you really mean the 18th century (1700s) or actually mean the 1800s (19th century)? Cuz the former would be way earlier than I thought o_o

There seems to be some disagreement on the topic.

https://www.etymonline.com/word/galaxy

Quote

galaxy (n.)

late 14c., from French galaxie or directly from Late Latin galaxias "the Milky Way" as a feature in the night sky (in classical Latin via lactea or circulus lacteus), from Greek galaxias (adj.), in galaxias kyklos, literally "milky circle," from gala (genitive galaktos) "milk" (from PIE root *g(a)lag- "milk").

The technical astronomical sense in reference to the discrete stellar aggregate including the sun and all visible stars emerged by 1848. Figurative sense of "brilliant assembly of persons" is from 1580s. Milky Way is a translation of Latin via lactea.

https://ned.ipac.caltech.edu/level5/March02/Gordon/Gordon2.html

Quote

The idea that our Sun is just one of myriads of stars in a huge stellar system, the Milky Way, and that there may be many other stellar systems of equal rank outside the Milky Way can be traced back to the early eighteenth century (1). These early speculations (1) by the Swedish philosopher, Emanuel Swedenborg (2) had no basis in actual observations. Yet they are remarkably close to the present-day views of the cosmos. Thomas Wright of Durham in England, writing at the middle of the same century (3), conceived the idea apparently independently and was the first to appeal to observational evidence in support of it (2). The best-known of the early exponents of the 'island universe' theory are the German philosopher Immanuel Kant (4), who acknowledged his indebtedness to the ideas of Wright, and the English astronomer, Sir William Herschel, who was the first to bring observational techniques to bear specifically on the study of nebulae and clusters of stars. In contrast, Messier compiled his catalogue of nebulae and clusters, which predates Herschel's work, primarily as a list of 'nuisances' to be avoided in his search for new comets (5).

...Swedenborg wrote in the first chapter of the third part of his Principia:

'The common axis of the sphere or starry heaven seems to be the galaxy, where we perceive the greatest number of stars....'

Note that Swedenborg died in 1772.

[Bej Kerman]

On 7/13/2020 at 3:42 AM, SJC_Hacker said:

Interestingly, the leap from interstellar travel to intergalactic travel  is not as big as one would expect.  

Distance from Earth to Pluto ~0.0004 light years

Distance to nearest star (proxima centaru) ~4 light years.  This is also roughly the average distance between stars in the Milky Way.   Increase by factor of 10,000 vs. Pluto trip.

Milky Way diameter  ~100,000 light years   Increase by factor 25,000 vs trip to nearest star or average trip between stars..  

Distance to Andromeda  (nearest galaxy)   ~2.5 million light years.    Increase by factor of only 25 vs. traversing the Milky Way

Average distance between galaxies ~10 million light years.  Still only a 100x increase. 

Light takes 4 years to reach Proxima, 50,000 years to reach Sagittarius A* and 2.5 million years to reach Andromeda. Do you really think that's not a big leap?

[HansAcker]

What's this "interstellar" I keep hearing about? Just go from Intergalactic to Planetary, Planetary -> Intergalactic. scnr, really.

Spoiler

 

 

[jimmymcgoochie]

6 minutes ago, Bej Kerman said:

Light takes 4 years to reach Proxima, 50,000 years to reach Sagittarius A* and 2.5 million years to reach Andromeda. Do you really think that's not a big leap?

4 miles, the length of the Grand National and easily walkable.

50,000 miles, around the world twice.

2.5 million miles, to the Moon and back five times and then back to the moon a sixth time.

Barring some kind of magic faster than light drive or the discovery/creation of wormholes, travelling from one galaxy to another is utterly infeasible and dismissing it as ‘only’ a couple of orders of magnitude further than before missed the (quite literally) astronomical distances involved and the impossibly durable spaceships that would be needed in order to make the journey. Pinging from star to star a few light years at a time is much more practical and there are more than enough in the Milky Way alone to make going anywhere else not worth the effort.

[Bej Kerman]

9 minutes ago, jimmymcgoochie said:

26 minutes ago, Bej Kerman said:

Light takes 4 years to reach Proxima, 50,000 years to reach Sagittarius A* and 2.5 million years to reach Andromeda. Do you really think that's not a big leap?

4 miles, the length of the Grand National and easily walkable.

50,000 miles, around the world twice.

2.5 million miles, to the Moon and back five times and then back to the moon a sixth time.

Barring some kind of magic faster than light drive or the discovery/creation of wormholes, travelling from one galaxy to another is utterly infeasible and dismissing it as ‘only’ a couple of orders of magnitude further than before missed the (quite literally) astronomical distances involved and the impossibly durable spaceships that would be needed in order to make the journey. Pinging from star to star a few light years at a time is much more practical and there are more than enough in the Milky Way alone to make going anywhere else not worth the effort.

With a theoretical top speed of 1< mile a year, such a Kerbal feat would be impossible.

[SJC_Hacker]

1 hour ago, Bej Kerman said:

Light takes 4 years to reach Proxima, 50,000 years to reach Sagittarius A* and 2.5 million years to reach Andromeda. Do you really think that's not a big leap?

My point was the *ratio* of the distances between Earth and Andromeda and Earth to Sagitarrius A  is not as big as the ratio of the distances between Earth and Proxima Centauri and Earth to Pluto.  

If you can get to Sagitarrius A in a month from Earth, that means you can get to Andromeda is about 25 months from Earth.   

Whereas if takes you month to get to Pluto, its going to take you 10,000 months to get to Proxima Centauri.

Now its true, if it takes you a month to get to Proxima Centauri, it would take you over 10,000 months (833 years) to get to Sagittarius A.  So galactic distances, are of comparable magnitude to average interstellar distances within the galaxy.

But the interesting aspect of travelling across the galaxy, there is alot in between.   So it takes you a month to get to Proxima Centauri.  Then its roughly another month to get to next star over.  So you could keep making small hops and eventually get to Sagitarrius A, though true, it would take you a very long time even if you can do Proxima Centauri relatively quickly

This is a little bit different than the leap from interplanetary to interstellar.  There isn't much of anything in between the Solar System and Proxima Centauri.  so we would have to do it all in one go.   If it there were thousands of stars in between, however, then eventually getting to Proxima Centauri would be much easier.

I think its inevitable that a civilization which could make those small interstellar hops, would eventually fill the whole galaxy.  In a similar fashion, humans (and some other animals) eventually spread out over much of the surface of the Earth through thousands of years, by just walking, even though the distance from one end of the Earth to the other, is pretty vast in terms of walking speed.  And no one could really do it (reasonably), in one human lifetime. But they could stop and settle along the way, then their descendants would make the next trip.

 

[Bej Kerman]

3 minutes ago, SJC_Hacker said:

If you can get to Sagitarrius A in a month from Earth, that means you can get to Andromeda is about 25 months from Earth.

Best you can do with KSP 2 tech is 150,000 years to SagA*.

3 minutes ago, SJC_Hacker said:

My point was the *ratio* of the distances between Earth and Andromeda and Earth to Sagitarrius A  is not as big as the ratio of the distances between Earth and Proxima Centauri and Earth to Pluto.  

Don't be silly. Look...

1 hour ago, jimmymcgoochie said:

4 miles, the length of the Grand National and easily walkable.

50,000 miles, around the world twice.

2.5 million miles, to the Moon and back five times and then back to the moon a sixth time.

"Going around the world at 0.3 miles a year was easy, going to the Moon 5^1/2 times should be a piece of cake because the ratios are slightly less astronomical!"

Edited July 15, 2020 by Bej Kerman

[SJC_Hacker]

3 minutes ago, Bej Kerman said:

Best you can do with KSP 2 tech is 150,000 years to SagA*.

Don't be silly. Look...

"Going around the world at 0.3 miles a year was easy, going to the Moon 5^1/2 times should be a piece of cake because the ratios are slightly less astronomical!"

I wasn't specifically talking about KSP 2 tech.  I was imaging a hypothetical civilziation in which travelling was across the diameter of their home galaxy if it was roughly the size of the Milky way was relatively easy.  Comparable to us travelling across the solar system.    But since we can travel across the solar system, does not mean we can reach the next star.  That leap is alot greater.  But a civilization that could travel across the galaxy, would have a much easier time getting to the next one.   Maybe not trivial (like if they could do it in a year, then next galaxy would be 100 years, which may be a tough barrier to overcome on a human time scale), but a much less of a leap, than the initial problem of getting across the galaxy or getting to the next star.

Travelling between ends of one galaxy and the other, and travelling to the other galaxies is not fundamentally different except for the time it takes, as far as we know.

If we could walk to the Moon, there was breathable air and resources along the way,  then yes, getting to the Moon would be a piece of cake  on a long enough time scale.  If the Earth was only two islands separated by a vast ocean, it would be much harder for the two inhabitants on the island to ever meet.

 

[SJC_Hacker]

1 hour ago, jimmymcgoochie said:

4 miles, the length of the Grand National and easily walkable.

50,000 miles, around the world twice.

2.5 million miles, to the Moon and back five times and then back to the moon a sixth time.

Barring some kind of magic faster than light drive or the discovery/creation of wormholes, travelling from one galaxy to another is utterly infeasible and dismissing it as ‘only’ a couple of orders of magnitude further than before missed the (quite literally) astronomical distances involved and the impossibly durable spaceships that would be needed in order to make the journey. Pinging from star to star a few light years at a time is much more practical and there are more than enough in the Milky Way alone to make going anywhere else not worth the effort.

Distance Earth to Moon 384,000 km

Distance Earth to Neptune 4.3 billion km.   

Ratio ~10,000.   Yet a civilization that sent probes to the Moon, was able to send probes to Neptune relatively quickly.   Maybe not astronauts, but thats another matter - we don't send astronauts to Neptune (not yet at least) because its inhospitable to human life, and we can do the science we need with probes much easier and cheaper.

Edited July 15, 2020 by SJC_Hacker

[Bej Kerman]

1 hour ago, SJC_Hacker said:

1 hour ago, Bej Kerman said:

Best you can do with KSP 2 tech is 150,000 years to SagA*.

Don't be silly. Look...

"Going around the world at 0.3 miles a year was easy, going to the Moon 5^1/2 times should be a piece of cake because the ratios are slightly less astronomical!"

I wasn't specifically talking about KSP 2 tech.  I was imaging a hypothetical civilziation in which travelling was across the diameter of their home galaxy if it was roughly the size of the Milky way was relatively easy.  Comparable to us travelling across the solar system.    But since we can travel across the solar system, does not mean we can reach the next star.  That leap is alot greater.  But a civilization that could travel across the galaxy, would have a much easier time getting to the next one.   Maybe not trivial (like if they could do it in a year, then next galaxy would be 100 years, which may be a tough barrier to overcome on a human time scale), but a much less of a leap, than the initial problem of getting across the galaxy or getting to the next star.

Travelling between ends of one galaxy and the other, and travelling to the other galaxies is not fundamentally different except for the time it takes, as far as we know.

If we could walk to the Moon, there was breathable air and resources along the way,  then yes, getting to the Moon would be a piece of cake  on a long enough time scale.  If the Earth was only two islands separated by a vast ocean, it would be much harder for the two inhabitants on the island to ever meet.

Assuming magic exists, it's a piece of cake to survive re-entry naked. But if we stop being silly, then it becomes quite clear you're kidding yourself to think naked re-entry is survivable. I am, of course, making fun of "If we could walk to the Moon, there was breathable air and resources along the way,  then yes, getting to the Moon would be a piece of cake  on a long enough time scale". But of course, magic doesn't exist, Humans nor Kerbals have FTL and you're being really silly. Again, 5 and a half trips to the Mun is a massive step from circumnavigating the Earth.

Edited July 15, 2020 by Bej Kerman

[jimmymcgoochie]

2 hours ago, SJC_Hacker said:

Distance Earth to Moon 384,000 km

Distance Earth to Neptune 4.3 billion km.   

Ratio ~10,000. 

Distance is one thing. Actually getting there is another thing entirely- it took a very convenient planetary alignment and some massive gravity assists to get to Neptune, once, and that probe was just coasting at that point with no real control of where it was going, never mind trying to slow down and orbit.

Now consider this: Neptune orbits at 30AUs from the Sun (Earth is 1AU); the closest star to us is Proxima Centauri, and that's about 270,000AUs away. Neptune is 3.5 light hours away, the closest star is over 4 light years away. Assuming you could build a spaceship capable of reaching 1/4 of light speed, it would take about seventeen years to get to the closest star (and would pass Neptune's orbit in about 14 hours). Andromeda is the closest large galaxy to our own, and it's 2.5 million light years away.

There are estimated to be between one and four hundred billion stars in our own galaxy. Why exactly would anyone ever bother going to another one with so many stars (and inevitably planets) within easy reach?

I don't expect more than five solar systems in KSP2 and none beyond a couple of light years away (or possibly a lot less, given how small KSP's planets are) from the Kerbol system. A small star cluster would provide more than enough places to explore and colonise, anything beyond that would require too much development for relatively little reward.

[SJC_Hacker]

17 minutes ago, jimmymcgoochie said:

Distance is one thing. Actually getting there is another thing entirely- it took a very convenient planetary alignment and some massive gravity assists to get to Neptune, once, and that probe was just coasting at that point with no real control of where it was going, never mind trying to slow down and orbit.

Now consider this: Neptune orbits at 30AUs from the Sun (Earth is 1AU); the closest star to us is Proxima Centauri, and that's about 270,000AUs away. Neptune is 3.5 light hours away, the closest star is over 4 light years away. Assuming you could build a spaceship capable of reaching 1/4 of light speed, it would take about seventeen years to get to the closest star (and would pass Neptune's orbit in about 14 hours). Andromeda is the closest large galaxy to our own, and it's 2.5 million light years away.

There are estimated to be between one and four hundred billion stars in our own galaxy. Why exactly would anyone ever bother going to another one with so many stars (and inevitably planets) within easy reach?

I don't expect more than five solar systems in KSP2 and none beyond a couple of light years away (or possibly a lot less, given how small KSP's planets are) from the Kerbol system. A small star cluster would provide more than enough places to explore and colonise, anything beyond that would require too much development for relatively little reward.

Yes, you are to wait for a launch window.  But they occur roughly every 13 years, and that is with waiting for Jupiter assist (which gives you a Jupiter flyby, as well)

https://space.stackexchange.com/questions/22825/when-are-there-launch-windows-to-neptune-via-jupiter

Its true, the special alignment that the Voyager 2 was able to take advantage of was incredibly fortuitous as it only occured once every few centuries, and were able to do a flyby of all four of the outer gas giants in one trip.    However a craft dedicated to getting to just one of them, even if you wait for a Jupiter assist, is not all that infrequent.   This is what Cassini-Huygens did. 

I agree that having thousands of habitable systems and visiting the entire galaxy No Man's Sky style, shouldn't be part of the game.  I would much rather have a half dozen interesting systems to explore than thousands of dull probably procedurally generated planets.  At the level of detail that KSP has, that would be incredibly slow.. 

[Bej Kerman]

4 hours ago, SJC_Hacker said:

Distance Earth to Moon 384,000 km

Distance Earth to Neptune 4.3 billion km.   

Ratio ~10,000.   Yet a civilization that sent probes to the Moon, was able to send probes to Neptune relatively quickly.

Well it's a good thing there's not a 1 mile a year speed limit in space!

[sturmhauke]

5 hours ago, SJC_Hacker said:

If you can get to Sagitarrius A in a month from Earth, that means you can get to Andromeda is about 25 months from Earth.

...I think its inevitable that a civilization which could make those small interstellar hops, would eventually fill the whole galaxy.  In a similar fashion, humans (and some other animals) eventually spread out over much of the surface of the Earth through thousands of years, by just walking, even though the distance from one end of the Earth to the other, is pretty vast in terms of walking speed.  And no one could really do it (reasonably), in one human lifetime. But they could stop and settle along the way, then their descendants would make the next trip.

I agree that if a civilization has colonized the entire galaxy it will eventually move to other galaxies. But that's a cosmically large if, and would take place over the course of eons - far too large a scale for a realistic(ish) game.

[problemecium]

On 7/15/2020 at 4:53 AM, sturmhauke said:

stuff

Neat! I learned something today.