## How to calculate in-system travel times easily

Discuss the Traveller RPG and its many settings
Tom Kalbfus
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### Re: How to calculate in-system travel times easily

I was wondering. Would anyone like to calculate in-system travel times for this system?
http://en.battlestarwiki.org/wiki/The_T ... s_of_Kobol
Of most interest would be the travel times between the twelve colonies
Aerilon
Aquaria
Canceron
Caprica
Gemenon
Leonis
Libran
Picon
Sagittaron
Scorpia
Tauron
Virgon
You could also use this map of the System as a guide
http://en.battlestarwiki.org/wiki/Battl ... 2_Colonies
http://en.battlestarwiki.org/wiki/File: ... _Kobol.jpg
http://media.battlestarwiki.org/images/ ... _Kobol.jpg
It is quite a complex system.
So a 12 by 12 tables with near and far travel times for acceleration from 1-g to 6-g would be a great help, it would decide for instance when you use a standard Traveller Jump drive or not, as those take 5 days no matter what.

Basically this is for my Battlestar 3.0 scenario using Traveller starships as opposed to the 2003 Series starships. For instance a scout/courier instead of a raptor.
Wil Mireu
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### Re: How to calculate in-system travel times easily

Tom Kalbfus wrote:I was wondering. Would anyone like to calculate in-system travel times for this system?
If you can figure out the actual distances between each body (which don't appear to be mentioned there, so good luck with that), then is there any reason you couldn't calculate it yourself? If you've got the measurements, and you've got the simple formulae here, then you should be able to do it.

Though it's not as if you can come up with a travel time table for 'a system' anyway, because it doesn't work like that - you need to know the exact distance between the two points you're travelling between, and since planets move in their orbits that distance is going to be changing all the time.
Tom Kalbfus
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### Re: How to calculate in-system travel times easily

Wil Mireu wrote:
Tom Kalbfus wrote:I was wondering. Would anyone like to calculate in-system travel times for this system?
If you can figure out the actual distances between each body (which don't appear to be mentioned there, so good luck with that), then is there any reason you couldn't calculate it yourself? If you've got the measurements, and you've got the simple formulae here, then you should be able to do it.

Though it's not as if you can come up with a travel time table for 'a system' anyway, because it doesn't work like that - you need to know the exact distance between the two points you're travelling between, and since planets move in their orbits that distance is going to be changing all the time.
I'll probably do it eventually, as time permits. This system has four stars and 12 habitable planets, about three habitable planets in the life zone of each star. They are two pairs of binaries orbiting at a distance of 0.16 light years according to the map. Each binary orbits around a common center in a nearly circular orbit, which is unusual for a binary as they usually orbit in elliptical orbits.

For a single star in a system its very simple to find the minimum distance and the maximum distance, for example for the distance between Earth to Mars the minimum distance is arrived at by subtracting the distance of the Earth to the Sun from the distance from Mars to the Sun, the maximum distance if found by adding the distance from the Earth to the Sun to the distance from Mars to the Sun. In a binary, assuming circular orbits, the minimum distance is the distance between the stars minus the planet's distances from those stars if each planet orbits a different star, the maximum distance is the distance between the two stars plus each planet's distance from their separate star, in a four star system the minimum distance if the distance between the pairs of stars, minus the distance of the star from the barycenter minus the distance of each planet from each star. The maximum distance is the distance between the pairs of stars plus the distance of each star from each pair's barycenter plus the distance of each planet from each star. This can get rather complicated.
sideranautae
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### Re: How to calculate in-system travel times easily

Wil Mireu wrote:
Though it's not as if you can come up with a travel time table for 'a system' anyway, because it doesn't work like that - you need to know the exact distance between the two points you're travelling between, and since planets move in their orbits that distance is going to be changing all the time.
Sometimes what I'll do is roll 2 D 12's if considering two planets in the same system. Apply like the hour hand on a clock. Sun in the middle of course. Gives a quick idea of how long a trip.
Reynard
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### Re: How to calculate in-system travel times easily

Amazing how a Stellar Unit equals an Astronomical Unit!

To get an idea of scale, with the two binaries 10,091 AUs apart and let's use a super fast(relative) ship of 6gs. Using the formula T= 4 x Sqrt(5045/6), T would equal 116 days or 17 weeks! Pack a LOT of fuel or there must be routine microjumping. One binary is 140 AUs apart so about 14 days at 6gs and the other binary is 126 AUS for about 13 days travel from one system to the other.

Checking the map for the series, I see two K class and two G class stars. The 12 worlds would need to be in or very near the habitable zones and that's tight! I'd say travel time is not great within each of the four systems measured in a few days.
ShawnDriscoll
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### Re: How to calculate in-system travel times easily

What typically happens in a game after getting such information?
Reynard
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### Re: How to calculate in-system travel times easily

For me, travel times are the fade in/fade back periods unless I plan to use travel time for an event or encounter or the time factors into a subsequent future event as part of a scenario. Same for that one week jump time.
Tom Kalbfus
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### Re: How to calculate in-system travel times easily

Reynard wrote:For me, travel times are the fade in/fade back periods unless I plan to use travel time for an event or encounter or the time factors into a subsequent future event as part of a scenario. Same for that one week jump time.
They are important in determining when you need to use a jump drive in system.
Wil Mireu
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### Re: How to calculate in-system travel times easily

ShawnDriscoll wrote:What typically happens in a game after getting such information?
Do stop trolling.
ShawnDriscoll
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### Re: How to calculate in-system travel times easily

Reynard wrote:For me, travel times are the fade in/fade back periods unless I plan to use travel time for an event or encounter or the time factors into a subsequent future event as part of a scenario. Same for that one week jump time.
I like using travel times for in-ship role-playing. Especially when it's a well thought out ship design.
Last edited by ShawnDriscoll on Sun May 04, 2014 10:56 pm, edited 1 time in total.
GypsyComet
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### Re: How to calculate in-system travel times easily

Some ships are inexplicably designed with only two weeks of fuel. Travel times are really important on that sort of timetable.
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Tom Kalbfus
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### Re: How to calculate in-system travel times easily

T20 Rules design trips for 4 weeks of fuel. As a matter if physics, the two-week rule is probably more realistic. A fusion drive should not easily get past 1%-10% of the speed of light without resort to multiple stages 1% is probably more realistic for starships that aren't mostly fuel. 1% of light speed is 3000 km/sec or 3,000,000 meters per second, that's 300,000 seconds to reach such a speed at 1g. A harshly realistic fusion drive would allow for 1 week of maneuvering fuel, this will allow 3.5 days of 1g acceleration to get up to 1% of the speed of light and 3.5 days of 1g acceleration to slow down again. If you want to go faster than that, you need to resort to a more exotic drive option, such as antimatter.
sideranautae
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### Re: How to calculate in-system travel times easily

Tom Kalbfus wrote: As a matter if physics, the two-week rule is probably more realistic. A fusion drive should not easily get past 1%-10% of the speed of light without resort to multiple stages
MGT doesn't use fusion drives. It uses Gravity drives. No need for "multiple stages".

What IS interesting is that NASA conducted tests showing that the more acceleration (independent of actual speed) something is experiencing, the slower time goes. A person living on the 1st floor has time move slower than a person on the 20th floor (where grav, aka acceleration is less). NOW, if a grav drive created a grav well and that' how it worked in deep space a ship would be accelerating in Free fall and NOT be experiencing the acceleration. THUS, not experiencing the time dilation.
sideranautae
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### Re: How to calculate in-system travel times easily

Wil Mireu wrote:
ShawnDriscoll wrote:What typically happens in a game after getting such information?
Do stop trolling.
He did the same thing a few days ago. I searched his posts and a majority of them are just trolling. He trolls under this name on many sites. A Google check showed that.
sideranautae
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### Re: How to calculate in-system travel times easily

If travelling to Sol-3,beware:

Internet trolls are sadists and psychopaths according to scientific study.
Tom Kalbfus
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### Re: How to calculate in-system travel times easily

sideranautae wrote:
Tom Kalbfus wrote: As a matter if physics, the two-week rule is probably more realistic. A fusion drive should not easily get past 1%-10% of the speed of light without resort to multiple stages
MGT doesn't use fusion drives. It uses Gravity drives. No need for "multiple stages".

What IS interesting is that NASA conducted tests showing that the more acceleration (independent of actual speed) something is experiencing, the slower time goes. A person living on the 1st floor has time move slower than a person on the 20th floor (where grav, aka acceleration is less). NOW, if a grav drive created a grav well and that' how it worked in deep space a ship would be accelerating in Free fall and NOT be experiencing the acceleration. THUS, not experiencing the time dilation.
Seems to me 7 days of 1g acceleration is all you need to get anywhere in the Solar System. if you have an FTL Jump Drive, you have no need to get anywhere near the speed of light either.
GypsyComet
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### Re: How to calculate in-system travel times easily

We are all playing different games that happen to have the same name on the cover.

Not everyone cares about the hours and minutes spent in flight.
Last edited by GypsyComet on Tue May 06, 2014 1:45 pm, edited 2 times in total.
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dragoner
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### Re: How to calculate in-system travel times easily

sideranautae wrote: NOW, if a grav drive created a grav well and that' how it worked in deep space a ship would be accelerating in Free fall and NOT be experiencing the acceleration. THUS, not experiencing the time dilation.
What?
Wil Mireu
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### Re: How to calculate in-system travel times easily

GypsyComet wrote:Shawn is just one of several people here who apparently have trouble with the idea that you or I play Traveller differently than they do. Some of those people, such as one often-grumpy astronomer, have a habit of getting banned for their resulting behavior. Shawn has not gotten that bad so far, IMO, though his behavior on the G+ Traveller community last year came close.
Making personal attacks against those people doesn't make you any better than they are.
Wil Mireu
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### Re: How to calculate in-system travel times easily

sideranautae wrote:What IS interesting is that NASA conducted tests showing that the more acceleration (independent of actual speed) something is experiencing, the slower time goes. A person living on the 1st floor has time move slower than a person on the 20th floor (where grav, aka acceleration is less). NOW, if a grav drive created a grav well and that' how it worked in deep space a ship would be accelerating in Free fall and NOT be experiencing the acceleration. THUS, not experiencing the time dilation.
Cite please. As far as I'm aware, time dilation occurs for things travelling near the speed of light - their acceleration isn't what slows it down, it's their velocity.

I think you're confusing this with something else - maybe you're thinking of frame-dragging or something?

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