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General FreeSpace => FreeSpace Discussion => Topic started by: Retsof on February 03, 2008, 03:01:07 pm

Title: Speed in Nebulas
Post by: Retsof on February 03, 2008, 03:01:07 pm
Now, before we start, no "its a game" replies.
Shouldn't the fighters, which tend to be more aerodynamic, move faster in the nebula, as the engines have something to push on, not just newtons law?  Also, the capships should be slowed down from the drag, as they are anything but aerodynamic.
Title: Re: Speed in Nebulas
Post by: Herra Tohtori on February 03, 2008, 03:15:12 pm
Now, before we start, no "its a game" replies.
Shouldn't the fighters, which tend to be more aerodynamic, move faster in the nebula, as the engines have something to push on, not just newtons law?  Also, the capships should be slowed down from the drag, as they are anything but aerodynamic.


All engines that work on reaction principle have ideal efficiency in vacuum.

That is because external pressure slows down and prevents the exhaust gases from reaching as high velocity as they would in vacuum. Thus, the gases get less momentum, and the rocket gains equally less opposite momentum. Pushing against something doesn't have any effect whatsoever, since the exhaust plume doesn't act like a hovercraft's air cushion against ground.

Regarding the existence of the nebulas in the first place - that's in the "it's a game" department. That kind of nebulas don't exist in space. The thickest gas clouds (apart from gas giants' atmospheres, or stars' thinnest outer layers), there simply isn't that dense gas concentrations in space that they would block the view after less than a kilometre. The gas clouds in space usually are really big and really thin when you get on-location. You would see objects "close" to you about as good as you can see, say, Jupiter, Saturn, Venus and Mars from Earth. You wouldn't feel like sailing in strawberry jam.

The question about thrust and speed is valid to think about considering possible atmospheric flight support in some distant future, though.
Title: Re: Speed in Nebulas
Post by: Mobius on February 03, 2008, 03:20:14 pm
1) The plural form of "nabula" is "nebulae";

2) Herra, I think that in dense fields visibility can be poor. Many stars originate from the nebula left from a supernova, the gas concentrates and nuclear reactions start when the temperature has reached a certain value(i.e. density is incredibly high);
Title: Re: Speed in Nebulas
Post by: Polpolion on February 03, 2008, 03:22:17 pm
No, because the nebulas are still very much like a vacuum. A better question would be: "How can gas miners suck in gas from the nebula if the nebula's pressure is so low?"
Title: Re: Speed in Nebulas
Post by: Jeff Vader on February 03, 2008, 03:24:21 pm
1) The plural form of "nabula" is "nebulae";
Actually, both forms are acceptable.
Title: Re: Speed in Nebulas
Post by: Mobius on February 03, 2008, 03:26:20 pm
No, because the nebulas are still very much like a vacuum. A better question would be: "How can gas miners suck in gas from the nebula if the nebula's pressure is so low?"

How can a nebula dense enough to allow the birth of several stars be "very much like a vacuum"?

1) The plural form of "nabula" is "nebulae";
Actually, both forms are acceptable.

[size=8]No![/size][/i]
Title: Re: Speed in Nebulas
Post by: castor on February 03, 2008, 03:34:24 pm
Most nebulae are dense only in the relative way, i.e. compared to the nothingness (whatever that is) of empty space. (something/almost nothing == a lot)  :p
Title: Re: Speed in Nebulas
Post by: Jeff Vader on February 03, 2008, 03:40:53 pm
No!
Quote from: Cambridge Dictionaries Online
noun [C] plural nebulae or nebulas

Quote from: Dictionary.com
–noun, plural -lae,  -las.

Quote from: Wiktionary
nebula (plural nebulae or nebulas)
In your face.
Title: Re: Speed in Nebulas
Post by: Herra Tohtori on February 03, 2008, 03:46:22 pm
Plural of nebula can be either nebulae, nebulæ or nebulas, depending of preference.

In English, that is. Dunno about Latin or Italy. :p


Also, most nebulas are locally pretty much see-through. The exceptions would be planetary nebulae or supernova remnants immediately after the incident - but you wouldn't enjoy flying around those hot zones of gas for a very long time. As demonstrated in FS2 campaign ending. In these cases, it would take months or years for the gas to spread and cool down to the point where it wouldn't emit light itself, at which point it would become pretty much clear locally.

Protostars forming in emission nebulae belong to same category, but the other way round... you wouldn't like the radiation and heat conditions, and you can't really call it a nebula either.

Emissive nebulae might be bright, even locally, but in between the protostars, the matter itself would still not be as thick as the "fog" in FS2 seems to be. Not by a long shot.
Title: Re: Speed in Nebulas
Post by: Mobius on February 03, 2008, 03:55:55 pm
I criticize the English way to bastardize words and create multiple "acceptable forms".

Saying that both "nebulae" and "nebulas" are acceptable forms means that "nebulae" is the most correct and "nebulas" is acceptable only because its use is wide.

Saying "nebulas" is a logic consequence of ignorance. The use of that form became wide="acceptable".

What about the word "Wikipedia"? Most English speaking people misspell the "W" and I don't think there are going to be "two acceptable forms" because "wiki" is an hawaiian word with a certain pronunciation no one is able to change.

Back to the main subject of the discussion...after many years the gas should start comprising thanks to gravity.
Title: Re: Speed in Nebulas
Post by: Retsof on February 03, 2008, 04:02:05 pm
Explanation and more deplorable grammar  :P :
It was a brain fart, okay?  I knew that the proper plural is "Nebulae" but it's not really something I think about every day.  Also, say, for discussion purposes, that the nebula you fly into in Freespace is unusually dense or something.
Title: Re: Speed in Nebulas
Post by: Mobius on February 03, 2008, 04:03:20 pm
...and I said why it's "unusually dense".
Title: Re: Speed in Nebulas
Post by: Flipside on February 03, 2008, 04:07:11 pm
Remember that when you look at a Nebula, you are seeing something hundreds to thousands of light years in size, from hundreds of thousands of light years away, if nebulas were as dense as, say, water vapour, it would be gravitic and thermal chaos in there, you wouldn't get a few stars like the Pliades, you'd get the stars almost reforming into the proto-giant stars that are believed to be the source of some of the larger ones. The whole entropy thing prevents that from happening.

The Earth is travelling in a massive cloud of interstellar gas, which could, for all we know, look like a nebula from someone in, say, the Crab Nebula, but it's far too thin to show up as anything other than a few measurement errors here on Earth.
Title: Re: Speed in Nebulas
Post by: Herra Tohtori on February 03, 2008, 04:13:07 pm
You can criticize all you want, but the fact of the matter is that you don't really have any authority to define correct spelling of English language. If a form of a word is regularly used and comprehended, it has become part of the language due to cultural and lingual evolution. Languages evolve. It is the way of the Force world. If you want to act the grammar inquisitor, target all the ridiculous forms like "your" instead of "you're" and "cannon" instead of "canon" (the horror!), where the misspellings actually change the meaning of the words... :blah:

Back to the main subject of the discussion...after many years the gas should start comprising thanks to gravity.

Not if it gains escape velocity from it's own mass in the explosion. If, for example, you were to shoot a bullet straight up at velocity 11.2 km/s (ignoring the atmospheric friction), it would keep ascending forever, but it's velocity would get closer and closer to zero.

Mathematically, it's velocity would react zero after infinite time, at infinite distance from Earth, but that's neither here nor there (literally as well as metaphorically).

Which, unsurprizingly, it most often does in both nova and supernova types of explosions.

Of course, if there are structures formed into the expanding gas cloud, those can after time form local centers of gravity and compress into new stars.
Title: Re: Speed in Nebulas
Post by: Flipside on February 03, 2008, 04:17:28 pm
Look at it this way, why do you think all the inner planet are rock and metal, and all the outer planets are gas and water? It's to do with mass, everything is spinning, and the lighter materials end up on the outside. When a nebula, particuarly a Supernova-generated one is formed, much of that lighter material can actually be travelling too fast to be pulled back :)
Title: Re: Speed in Nebulas
Post by: Mobius on February 03, 2008, 04:40:14 pm
You can criticize all you want, but the fact of the matter is that you don't really have any authority to define correct spelling of English language. If a form of a word is regularly used and comprehended, it has become part of the language due to cultural and lingual evolution. Languages evolve. It is the way of the Force world. If you want to act the grammar inquisitor, target all the ridiculous forms like "your" instead of "you're" and "cannon" instead of "canon" (the horror!), where the misspellings actually change the meaning of the words... :blah:

That's pretty much what I was about to say. Soon "its" and "your" will become acceptable variants of "it's" and "you're".

Languages evolve but "evolution" doesn't necessarily mean "becoming better".


Quote from: Herra Tohtori
Not if it gains escape velocity from it's own mass in the explosion. If, for example, you were to shoot a bullet straight up at velocity 11.2 km/s (ignoring the atmospheric friction), it would keep ascending forever, but it's velocity would get closer and closer to zero.

Mathematically, it's velocity would react zero after infinite time, at infinite distance from Earth, but that's neither here nor there (literally as well as metaphorically).

Which, unsurprizingly, it most often does in both nova and supernova types of explosions.

Of course, if there are structures formed into the expanding gas cloud, those can after time form local centers of gravity and compress into new stars.

Yes but we're talking the nebula we see in FS2....wait...is there a sun in that nebula? I think I remember one!
Title: Re: Speed in Nebulas
Post by: Retsof on February 03, 2008, 05:15:47 pm
Quote
Look at it this way, why do you think all the inner planet are rock and metal, and all the outer planets are gas and water? It's to do with mass, everything is spinning, and the lighter materials end up on the outside. When a nebula, particuarly a Supernova-generated one is formed, much of that lighter material can actually be travelling too fast to be pulled back


Actually, the solar wind from the young sun blew all the lighter elements away.  The gas giants are too far away to be affected like that.
Title: Re: Speed in Nebulas
Post by: jdjtcagle on February 03, 2008, 05:21:36 pm
Nebula...

Nebulae...

Life goes on, is it really worth the big capital NO! :p

Spoiler:
please don't pull the big capital yes
Title: Re: Speed in Nebulas
Post by: Mobius on February 03, 2008, 05:39:50 pm
You mean:

Nebulae or Nebulas...this is the problem!
Title: Re: Speed in Nebulas
Post by: Unknown Target on February 03, 2008, 06:21:46 pm
On topic, please?
Title: Re: Speed in Nebulas
Post by: IceFire on February 03, 2008, 07:06:24 pm
Now, before we start, no "its a game" replies.
Shouldn't the fighters, which tend to be more aerodynamic, move faster in the nebula, as the engines have something to push on, not just newtons law?  Also, the capships should be slowed down from the drag, as they are anything but aerodynamic.
A nebula shouldn't be dense enough to cause a significant increase in friction/drag.  The nebula we have in the game isn't really representative of a real nebula either.  But really...the answer you don't want to hear is the right one.  It IS a game and the fact that the ships stop when you cut the throttle and the fact that the nebula conditions are not realistic makes further discussion sort of moot in my view.  If we examine this as a gameplay mechanic...sure I guess we could do it so that speeds are reduced for everything across the board...but I don't see this as making a huge difference.  Capital ships are already slow as can be and fighters zip around at speeds that are relatively close.  There are better gameplay mechanics for the nebula and Volition already included most of them...the reduced visibility/sensor range and EMP lightning are good examples.
Title: Re: Speed in Nebulas
Post by: Woolie Wool on February 03, 2008, 08:54:28 pm
Now, before we start, no "its a game" replies.
Shouldn't the fighters, which tend to be more aerodynamic, move faster in the nebula, as the engines have something to push on, not just newtons law?  Also, the capships should be slowed down from the drag, as they are anything but aerodynamic.

Realistically, if the nebula were as dense as shown in FS2, it would collapse into a star. The FS2 nebulae are many, many orders of magnitude denser than real nebulae. The extreme density of the nebulae and the lightning are more characteristic of a gas giant atmosphere, and you'd have to go down quite a ways for it to be like that. Hope your fighter has air conditioning, because it's hot down there.
Title: Re: Speed in Nebulas
Post by: Kazan on February 03, 2008, 09:27:44 pm
the nebulae in the game are 10-20 orders of magnitude more dense than real nebulae (except in small specific regions where a star is soon [in galatic time] to form)
Title: Re: Speed in Nebulas
Post by: jdjtcagle on February 03, 2008, 11:55:34 pm
There is a star in the Fs2 nebula could definitely be a (unintentional) connection?
Title: Re: Speed in Nebulas
Post by: Kosh on February 04, 2008, 06:13:02 am
Speaking of nebula's, how accurate are the Freelancer nebula's?
Title: Re: Speed in Nebulas
Post by: Jeff Vader on February 04, 2008, 07:57:51 am
Speaking of nebula's, how accurate are the Freelancer nebula's?
I think pretty much as accurate as my knowledge on quantum mechanics. If you google any of the names of the nebulas (like Edge Nebula, Crow Nebula and Walker Nebula), you only find Freelancer related sites. Wikipedia doesn't give anything on those exact names.
Title: Re: Speed in Nebulas
Post by: Flipside on February 04, 2008, 08:21:52 am
Freelancers nebulas are excellent as an in-game feature, but to be honest, they are less real than FS2 nebula, you 'might' get little localised pockets of gas like that, but 'little' in astronomical terms is several AU's in size, not about 20km :)
Title: Re: Speed in Nebulas
Post by: Flipside on February 04, 2008, 08:23:42 am
Quote
Look at it this way, why do you think all the inner planet are rock and metal, and all the outer planets are gas and water? It's to do with mass, everything is spinning, and the lighter materials end up on the outside. When a nebula, particuarly a Supernova-generated one is formed, much of that lighter material can actually be travelling too fast to be pulled back


Actually, the solar wind from the young sun blew all the lighter elements away.  The gas giants are too far away to be affected like that.

Nope, it's to do with the spin of the young proto-star, coupled with the rotation of the Galaxy that threw the material around, not the Solar Wind, since the Solar System was starting to form before the Sun had become properly active, so there was no Solar Wind to move it. Trust me, Gravity had far far more impact on the formation of the Solar System than a stream of ionised gases from a newly fused star.
Title: Re: Speed in Nebulas
Post by: Retsof on February 04, 2008, 03:24:40 pm
Quote
Quote
Quote
Look at it this way, why do you think all the inner planet are rock and metal, and all the outer planets are gas and water? It's to do with mass, everything is spinning, and the lighter materials end up on the outside. When a nebula, particuarly a Supernova-generated one is formed, much of that lighter material can actually be travelling too fast to be pulled back

Actually, the solar wind from the young sun blew all the lighter elements away.  The gas giants are too far away to be affected like that.
Nope, it's to do with the spin of the young proto-star, coupled with the rotation of the Galaxy that threw the material around, not the Solar Wind, since the Solar System was starting to form before the Sun had become properly active, so there was no Solar Wind to move it. Trust me, Gravity had far far more impact on the formation of the Solar System than a stream of ionised gases from a newly fused star.
But think, centrifugal force and acceleration affect things as though there is gravity puling them out.  Think of that carnaval ride where you can sit on the walls.  The air doesn't get sucked to the edges before you do.  Similarly, the heavy elements would end up on the outside if spin was the only factor.
Title: Re: Speed in Nebulas
Post by: Flipside on February 04, 2008, 03:42:50 pm
Gravity doesn't work like that, however, remember, we all think about the Earth pulling us 'down' as being Gravity, and forget that we are, in fact, also pulling the Earth a tiny fraction 'up'. It's the same with particulate matter, it's not just a question of force pushing them outwards, it's also the force pulling them back in, and larger, higher mass material is easier for gravity to attract than light molecules such as Hydrogen will tend to sit out in the further edges of the Solar System because the Suns gravity isn't strong enough to pull them back in, and because their own minute gravity is not sufficient to prevent them from reaching an 'escape velocity' for want to a better word. So Hydrogen atoms are more prevalent in the outer half of the Solar System, not all of it escapes, but Jupiter contains massive amount of light materials such as Hydrogen, Nitrogen and Carbon, whereas the heavier compounds such a Silicon and Metallic compounds are far more prevalent in the inner system, after all, if it worked like centrifugal force, then Jupiter would have, for example, a rock outer layer and a gas core, when, in fact, the opposite is true.
Title: Re: Speed in Nebulas
Post by: Retsof on February 04, 2008, 03:58:36 pm
 :jaw: He actually beat me in a physics debate.  ... Guess I'll get rid of my "science nerd" sign.  :blah: Dang... *goes to read a physics book*
Title: Re: Speed in Nebulas
Post by: Flipside on February 04, 2008, 04:16:36 pm
LOL Ironically enough, I was only reading up on it a few days ago, because I was actually discussing it with someone, so I sort of had an advantage ;)
Title: Re: Speed in Nebulas
Post by: Wanderer on February 05, 2008, 04:00:25 am
I would have kinda said that gravity was not the only factor... more like combination of gravity and heat eg. volatility of molecules (snow line)...
Title: Re: Speed in Nebulas
Post by: Flipside on February 05, 2008, 08:43:46 am
Yep, there is a lot more involved with what actually causes the creation of the planets themselves, but their constituent materials were mostly put in their orbital planes by the effects of gravity.