Relativity calculator for interstellar journeys

[Vertigo]

Well I did mention it's existence to a couple of sites that have some of this kind of thing like Atomic Rocket ( http://www.projectrho.com/rocket/index.php ) but got little interest. However I would have no problem with Brian doing something like promoting it if he was interested. However consider also the possibility that Brian (and the mods) may specifically not want that sort of traffic.

Appropriately enough, my prologue starts with the data from just such a probe returning to the ship in-transit.

Yeah I've often thought it seems such an obvious way to do it but I've rarely encountered it being done in SF books. Actually the story that started me off down this route may start with the launch of such a probe Although I may go back a little earlier.

And I've actually stumbled on another bug tonight. I think it is a rule of software that as soon as you've launched a new release you will find an error! I'll try and get a fix up tomorrow morning.

I entered one set of data and it looked good. I'll play around with it in time.

Thanks for that; good to know!

[Abernovo]

Originally Posted by Vertigo

Oh one little thing:

Abernovo, if you did these calculations recently by hand it would be interesting to compare the answers you got with what my program produces. One of the things I failed to find were any decent validated examples that I could check my results against.

I no longer have my workings and I'm still playing around with your programme (it's excellent, by the way, thank you) to finesse the minutiae of the trip, but it's producing figures close to those that I worked out by hand.

The difference is that your programe makes it much easier to factor in acceleration and deceleration, which I did have problems with - those blessed curves which determine whether or not the contents/passengers are crushed like bugs inside the vessel.

I'm getting figures of 305 years compared to my own original figures of 303, which I think is pretty close - <1%. I'm presently clapping myself on the back for not being so useless at maths, after all (bear in mind, I'm a lowly environmental scientist who only scraped through on the statistics modules at uni). The time relevant to traveller is also coming out to within a few months of my own figures and, with Star Traveller, I can play around a lot more with different numbers.

The fact is that the voyage is not in itself relevant to my story (which concerns events after the trip), but I needed figures to be accurate about the times and distances involved, which are relevant. So, once again, a big thank you.

[Vertigo]

New version released which fixes a bug that was somtimes preventing subsequent stages from being updated after an earlier stages had been modified.

Originally Posted by Abernovo

The difference is that your programe makes it much easier to factor in acceleration and deceleration, which I did have problems with - those blessed curves which determine whether or not the contents/passengers are crushed like bugs inside the vessel.

This was essentially the motivation to writing the program. I can work these things out by hand, sure, but that was so slow when you wanted to play around with "what if's".

[Jacob Larch]

Like this a lot! Definitely a missing aspect of science fiction for writers who wish to ground their work in reality.

[Vertigo]

Thank you Jacob! Please feel free to pass it around!

There are some other things I want to do with it but I just haven't had the time to work on it recently

I have actually been thinking of another a simple formula calculator. By that I don't mean a 2 x 3 = 6 type of thing but rather one that calculate all sorts of general formulae for stuff like: area, volume, force, mass, acceleration, velocity etc.

Many will be easy and familiar but this is just to make them quicker so that you don't have to rearrange them for different unknowns. So for example most would know that final velocity from time, initial velocity and acceleration are related by:

Vf = at + Vo

But it's a little more of a pain to then figure that:

t = (Vf - Vo) / a

Not much I admit but then what about distance covered etc.

It would also have conversions for lots of different units in it.

[Paul Whipp]

Thanks Vertigo,

I just found your program and, after digging up a laptop that runs windows, I've got it running and providing the journey times I need. Very handy indeed!

Is there a source for the formulae you use that someone like me with only 'A' level math could cope with?

I'd like to do some playing around with the effects of varying accelerations, calculating energy requirements etc. and everything I've googled seems a bit confusing.

[Vertigo]

Sorry Paul, I completely missed your question. Not sure how!

I got my formulae from a variety of places and to be frank it took a bit of work to whittle them into something easily usable. Here's a couple of pages I bookmarked in the process:

http://www.projectrho.com/rocket/index.php Actually I've been going to this one for a while - very very good site
http://math.ucr.edu/home/baez/physic...SR/rocket.html This has formulae and some stuff on fuel requirements

Again, apologies I didn't see your post before!

[Paul Whipp]

No worries. Thanks for the info.

I'm struggling to make sure my stories involving Generation Ships are plausible and this information is really helpful.