How to calculate in-system travel times easily

[dragoner]

Here is a Relativistic Star Ship Calculator

You don't need a starship, you have to do relativistic calcs in simple engineering with satellites.

 

[Tom Kalbfus]

Seems to me that anything that would take longer to reach than a Jump Drive would, one should use the jump drive for. After all time is money!

Yes, if travel takes longer than a week - assuming the ship is equipped with a jump drive - it makes more sense to use that to get somewhere that far away instead. There is a precedence for in-system 'microjumps' in Traveller too.

Though yes, jump shadows may be a problem if the destination is on the other side of the sun.

I assume since a jump is through higher dimensional space, all that is important is that the point you jump from and the point you jump to are both outside the 100 diameter limit. Anything within the Sun's 100 diameter limit should be within 5 days travel by maneuver drive in most cases. Also what would be a black hole's "100 diameter limit" A typical stellar black hole is 10 km in diameter, so the 100 diameter limit would be at 1000 km, that doesn't sound right for an object with the mass of a star. The Sun is less dense that the Earth, its "100-diameter" limit should be less than 100 Solar Diameters, the same would be true of Jupiter, Saturn, Uranus, and Neptune. The 100-diameter limit is only an approximation for planets like Mercury, Venus, Earth, and Mars, that is planets made of rock, rather than ice or gas.

 

[sideranautae]

He's right, pretty much.

No.

atomic clocks at differing altitudes (and thus different gravitational potential) will eventually show different times.

Difference being is that I know this stuff.

I already stated that was the case.

 

[Tom Kalbfus]

My own rule is the minimum jump radius is proportional to the cube of the object's mass in Earth masses times 100 Earth diameters.

Mass relative to_(km) Jump Limit (km)______ Orbit
_____Earth Diameter 100 diameters cube root rule Radii (km)
Mercury 0.0553 4880_ 488,000___ 485,452___ 58,000,000
Venus 0.815 13004 1,300,400_ 1,190,210__ 108,000,000
Earth ____1____ 12742 1,274,200_ 1,274,200_ 149,600,000
Mars_ 0.107 6779_ 677,900___ 604,921___ 228,000,000
Jupiter 318__ 139822 13,982,200 8,697,210_ 778,500,000
Saturn 95.2_ 116464 11,646,400 5,818,128_ 1,430,000,000
Uranus 14.5_ 50724 5,072,400_ 3,107,136_ 2,880,000,000
Neptune 17.2_ 49244 4,924,400_ 3,289,125_ 4,500,000,000
Sun__ 333000 1392000 139,200,000 88,318,634
Ganymede 0.0248 5268_ 526,800___ 371,582___ 1,070,400
Titan____ 0.0225 5152_ 515,200___ 359,720___ 1,221,870

So which jump limit rule do you go by?

 

[Wil Mireu]

atomic clocks at differing altitudes (and thus different gravitational potential) will eventually show different times.

Difference being is that I know this stuff.

You clearly don't.

We're not talking about atomic clocks at differing altitudes ("gravitational time dilation") here - we're talking about time dilation that depends on your velocity, which is different and which works as explained on the link I posted. That relation that leads to the calculation of the Lorentz factor is very well known.

 

[dragoner]

I clearly do if I pulled it from your link in two seconds, stop being argumentative.

 

[Wil Mireu]

Do keep up with the conversation, Dragoner:

Both velocity and gravity slow down time as they increase. I know - it's a mind boggler.

You don't get any significant time dilatation until you exceed 72% of the speed of light, in any campaign with Jump Drive technology, this would be rarely done. This doesn't come p in in-system travel.

He's right, pretty much. http://en.wikipedia.org/wiki/Time_dilat ... f_formulae

The time dilation factor is gamma (the Lorentz factor). At 0.7c, it's a factor of 1.4 - at that speed means time runs 1.4 times more slowly as measured on the ship than as measured by an outside observer. At 0.866c, gamma = 2.00. You only get really big time dilation (gamma > 10) really close to c (0.99c or more) - see the chart at http://en.wikipedia.org/wiki/Lorentz_fa ... cal_values

Tom was very clearly talking about travelling at speeds close to c in the quote above, not gravitational time dilation (which was a tangent to the discussion anyway - the thread is about in-system travel times, not how time passes differently with altitude in a gravitational field). As such, he is correct in his statement, as shown by the Lorentz Factor equation and tables that I linked to.

I'm not being 'argumentative' by pointing out your mistakes in reading comprehension. As I said, yes, we've established that clocks will show different times at different altitudes due to 'gravitational time dilation', but that is not what we are talking about here.

 

[dragoner]

Because you aren't know for being argumentative, how many times have you been banned, EDG?

 

[Wil Mireu]

Because you aren't know for being argumentative, how many times have you been banned, EDG?

I think you are mistaking me for someone else.

Regardless, you're still wrong. Trying to hide that behind crazy accusations isn't going to change that.

 

[dragoner]

Okay. :lol:

 

[Tom Kalbfus]

Because you aren't know for being argumentative, how many times have you been banned, EDG?

I don't really care. I take each argument separately without regard for the personal history of the poster. if someone makes a good argument, I don't care about the identity of the person making the argument, just that it makes sense.

 

[dragoner]

Because you aren't know for being argumentative, how many times have you been banned, EDG?

I don't really care. I take each argument separately without regard for the personal history of the poster. if someone makes a good argument, I don't care about the identity of the person making the argument, just that it makes sense.

Ultimately, it is not worth the bother.

 

[Hardwire]

Here is a small spreadsheet that will help.

The calculations came from

Wil Mireu​

 

[boggo2300]

Here is a small spreadsheet that will help.

The calculations came from

Wil Mireu​

Thanks to both of you, I just downloaded this and have already used it