Going the long way

Diziet Sma · Post by **Diziet Sma** » Mon Sep 28, 2009 1:03 pm

And now you mention it DH, I remember that 6.8 - 7.2 lightyear thing too! So THAT'S why I still catch myself double-checking those edge-of-circle distances...

Commander McLane · Post by **Commander McLane** » Mon Sep 28, 2009 1:34 pm

DaddyHoggy wrote:
As an aside and no doubt will be missed in this thread - but where did the 0.4ly resolution come from?

Maths, I guess.

(You see, nothing escapes our attention here.

) The formula for calculating distances has been posted a couple of times these last days and weeks. I think it is rounded in a way that it only moves in 0.4ly steps (like, say, the prices on the commodities screen).

phonebook · Post by **phonebook** » Mon Sep 28, 2009 2:26 pm

back to the corridor thingy- if we agree that the direction traveled in had little bearing on the direction the crosshairs moved, do you think you would have traveled even if you had been stationary, after all, if you are suddenly seeing in real time something taking place in the wormhole, it doesn't mean you aren't traveling along it still.

then again that would preclude the ability to switch destinations- a wormhole within a wormhole perhaps??

haha

Post by **Eric Walch** » Mon Sep 28, 2009 2:43 pm

DaddyHoggy wrote:
I also remember that the C64 had an odd bug - sometimes systems that appeared within the 7ly circle where actually 7.2ly away and some that were definitely outside the circle where only 6.8ly away - so I learned to always check and never actually believe the circle in the local chart!

As an aside and no doubt will be missed in this thread - but where did the 0.4ly resolution come from?

It is rounding because of calculation with integers. Oolite still uses that very inaccurate distance calculation. It also contains a precise calculation, but to give the same results as old elite it uses that old one for calculating jump distances on the F6 screen.

JensAyton · Post by **JensAyton** » Mon Sep 28, 2009 8:21 pm

Like most values in the original Elite calculations, the system coordinates are based on two of the six eight-bit integers in the “system seed”. For the y co-ordinate on the map, the low bit is discarded so that the system is twice as high as it is wide. The final distance value is calculated in the usual way, then scaled by an arbitrary factor of 0.4. (Not entirely arbitrary, of course; for the original implementation, multiplying by 4 and then inserting a decimal point at the right place would use less code than, say, using a factor of 0.6 or 0.35.)

The rounding bug still occurs in Oolite, because the actual shape of your jump range isn’t a circle.

Website · Post by **DaddyHoggy** » Mon Sep 28, 2009 9:47 pm

Ahruman wrote:
Like most values in the original Elite calculations, the system coordinates are based on two of the six eight-bit integers in the “system seed”. For the y co-ordinate on the map, the low bit is discarded so that the system is twice as high as it is wide. The final distance value is calculated in the usual way, then scaled by an arbitrary factor of 0.4. (Not entirely arbitrary, of course; for the original implementation, multiplying by 4 and then inserting a decimal point at the right place would use less code than, say, using a factor of 0.6 or 0.35.)

The rounding bug still occurs in Oolite, because the actual shape of your jump range isn’t a circle.

Thank-you for both the explanation and the pictorial bug example!

Zbond-Zbond · Post by **Zbond-Zbond** » Mon Sep 28, 2009 11:35 pm

I have a vague recollection that it was necessary to kill Thargoids in witchspace (BBC) too, and also left machine running all night - but not in witchspace - to no effect!

I guess that witchspace is the/a Non Local Universe. If so, then all "directions" will be the same direction.

(and all wormholes will be the same wormhole)

From the point of view of the Galaxy Charts, another guess is that you must nominally be @ 1 star or the other, already, despite the immediate witchspace experience, so extended travel would move you imperceptibly along the path to that star???????????? From witchspace. Not from a 2nd star.

phonebook · Post by **phonebook** » Tue Sep 29, 2009 6:20 pm

logic dictates you are right, thats how i was rationalising it too- but its this thing about your destination being out of hyperspace reach!

presumably if thats the case, you are saying (and i am thinking) that thew original planet would still be in hyperspace reach- it must be after all

but then i try to recall what i did on the old suitcase 64, and i dont remember hyperspacing backwards

this is where someone from the original developement team would come in handy

Zbond-Zbond · Post by **Zbond-Zbond** » Wed Sep 30, 2009 1:42 am

There is no connection between stars. But I'm guessing that maybe the destination star system was already generated in some sort of cache on Acorn/BBC or C64 I will investigate further..

Regarding the time taken for travel to alphaCentauri, usually estimated as 40,000 years if we decided to start the project now, that time would reduce significantly if we increased our speed a thousand fold -- a feat we have already achieved in the century since powered vehicles were invented (say, from the Stanley Steam Car to the geo-stationary satellite or something).

By increasing the speed of our proto-spacecraft a mere thousand fold I will be able to travel to alphaCentauri, and - if equipped with hyperlink to Oolite MNSR's - arrive there sane!

The point is that we don't have to achieve a hundred-thousand-million-billion-trillion fold increase in speed, as is often imagined re. astronomical adventure. Just a thousand fold increase.

phonebook · Post by **phonebook** » Wed Sep 30, 2009 2:42 am

hmmmm- ok so you get there in 40 years, who's gonna drive you home?

tho it wont be 40 years to you, it will be ten or something- after all its probly a quarter of the speed of light

no thats wrong!

how far is alpha centauri? 4 and a half light years, so if its 40 years, then you'll be going a tenth the speed of light, sooooooooooo, and this is purely guess/bar room logic, you'll only age 36 years- thats assuming the distortion is linear- it may be closer to 40

but still fast enough to get severe distortion in anything transmitted to you from earth- you may stay sane- but only just!

Chrisfs · Post by **Chrisfs** » Wed Sep 30, 2009 4:13 am

This is what generation ships are for.

Alex · Post by **Alex** » Wed Sep 30, 2009 4:57 am

The speed thing is as always the issue, with most if not all trying to work out the problem of fuel for what ever engine.
Has anyone considered that you wouldn't need fuel if you could focus gravity and point it in any direction? Just like we do with light. Most think there is no gravity in outer space. If that were true there would be no galaxy's. So if you could focus gravity you would have unlimited power and be able to accelerate for as long as you want, ergo attaining any speed you want.
Remember at one time it was said to be impossible to go over 20mph as you would not be able to breath out, then it was impossible to ge over the speed of sound, who's to really say what would happen when you reach the speed of light in your own little gravity bubble?

As always, more questions than answers untill someone actually does it; and as always that just raises more questions..

Post by **Cmdr James** » Wed Sep 30, 2009 7:35 am

Does anyone think there is no gravity in space? I thought it was pretty well understood that you have the inverse square relationship, and that there is gravity everywhere. As you say, gravity is also the glue that holds everything together.

Its not unreasonable to think that even if there were a way to focus gravity you would still need energy to do so, and in any case there is a simple proof (although, as with anything in science there are caveats about the truthiness) that you cannot exceed the speed of light even with unlimited power, and even then the rate of acceleration is limited by the human body.

If we forget about the energy required and relativity for the moment, and look at the human body. If we say that with modern technology the human body can withstand around 10g then asume that future technology can extend that by, what 10 times, you can still only accelerate at 100g so your top speed in any meaningful length of time is limited too. At 100g it takes something like 10 days to get up to the speed of light. And that is highly questionable, even 6 or 7g is pretty uncomfortable.

Website · Post by **DaddyHoggy** » Wed Sep 30, 2009 9:33 am

Cmdr James wrote:
Does anyone think there is no gravity in space? I thought it was pretty well understood that you have the inverse square relationship, and that there is gravity everywhere. As you say, gravity is also the glue that holds everything together.

Its not unreasonable to think that even if there were a way to focus gravity you would still need energy to do so, and in any case there is a simple proof (although, as with anything in science there are caveats about the truthiness) that you cannot exceed the speed of light even with unlimited power, and even then the rate of acceleration is limited by the human body.

If we forget about the energy required and relativity for the moment, and look at the human body. If we say that with modern technology the human body can withstand around 10g then asume that future technology can extend that by, what 10 times, you can still only accelerate at 100g so your top speed in any meaningful length of time is limited too. At 100g it takes something like 10 days to get up to the speed of light. And that is highly questionable, even 6 or 7g is pretty uncomfortable.

And this is the very reason why in shows like Star Trek Inertialess Dampers were "created" - you don't feel the huge accelerations (at Impulse) because there is an exactly opposite force pushing on you and the rest of the ship as it accelerates (and why you lurch about when attacked because the ship's computers take a fraction of a second to compensate for the slight variations in change of vector of the force due to impacts from weapons) and at Warp you're inside a static bubble which itself is being pushed along by the engines manipulating the field that creates the bubble which normal space is trying to squeeze out of existence - so ships in Star Trek don't actually travel FTL, they're sort of pushed along inside something which doesn't really exist either - as techno-babble goes the Star Trek tech manuals are quite self-contained and lots of real scientists have offered advice on the art-of-the-improbable-but-not-necessarily-impossible to support what is seen on-screen which has then become canon.

phonebook · Post by **phonebook** » Wed Sep 30, 2009 9:36 am

true, but we dont need to get to the speed of light, just one tenth of it- so that Zbond can go on his 80 year round trip and come back 5 years younger

at least we have found a way of getting that sod called Gok off the telly