Hi Simon
Thanks for your interest.
I dont know how we can resolve what NASA uses to guide space craft but I have heard on many occassions that Newtonian gravity is what they use.
But that is heresay and neither of us seem to actually know so hopefully someone can come forward and clear the matter up.
I believe you are correct re GPS in so far as I think both Special Relativity and General Relativity are used for positioning for Earth locations...but again I have read neither are used for space flight but unfortunately I cant provide authority and that I must do given I have made the claim I must back it up.
I will see what I can do. ..email NASA I guess☺
I must pull you up in one aspect...You are entitled to believe that I dont understand gravity (which I reject as you assume that I have no understanding of General Relativity which although limited is sufficient for me to say I understand it better than most laymen) but please do not say I have a theory for I have never ever claimed my ideas about gravity was a theory because ideas are not a theory they are mere ideas fit for no more than a chat at the pub I recognise that about my ideas and I want you to understand that...you must know the meaning of the word theory...you may as well substitue the words "established fact representing our current scientific position that rules supreme unless a better theory or model is presented, tested and its predictions observed" and that "theory" is not applicable to my ramblings.
But you are right about going on about push gravity and all I can say is I dont know what came over me...I have not thought about it for years.
Re aether..
We both know there is no aether or ether in physics but to me that paints a picture that is probably different to the reality which I believe must be that space is full of stuff flying about and I mention nutrinos to indicate but one particle that we could assume there would be sufficient to call an eather and you could make a list to add I expect...my point is I suppose there is no doubt enough stuff flying about to label it as an ether.. ..certainly not the lum ether but enough something to fit a loose term ether.
And you can say that is unscientific and unsupported but I have not claimed it is.
Or lets approach it another way..take a cubic foot of space in the remotest part of space you can think of and consider what passes thru it...if you think about it you find it is less than empty and I feel calling the stuff we find in there an ether not hard to do.
Empty space is far from empty so what will we call whats in it...I choose ether.
It is true that we can barely measure nuetrinos but I think it is accepted they are somewhat plentiful although I can not defend the statements I have tead that there abillions of them passing thru our body as we speak.
I dont know what their life span is and frankly I have not thought about that until now and their life span is entirely relevant to my ether call in temote space as I have up till now assumed they would reach such remote places...well if they have a long life space will be full of them...if they gave a short life the question becomes into what form do they decay.
Again thank you for your interest and thought provoking comments.
I will think about how we can resolve the issue of the use or no use of Relativity in space flight...you would think they must use GPS in at least landing craft on Earth...
Alex
From the little research I have done so far a general statement could be...Newtoian gravity is used in most situations as it does the job but General Relativity is used to fine tune.
So it seems you would plpt your course to the edge of the Solar System using Newtoian gravity but perhaps employ General Relativity to manage a booster rocket firing.
Anyways rather than put too fine a point upon the matter it is clear that Newtonian Gravity works well and although General Relativity is now the best model it takes little away from the usefulness of Newtonian gravity which is simply a recognition of the brilliance of Newton.
But it would be great if someone could provide more information as to exactly how they plan a route for a space craft...
Alex
Neutrinos as Dark Matter. This decay has a mean life of 887 seconds or a half life of 10.25 minutes. ... Thus a 1 MeV neutrino could travel through about 35 light years of water before interacting.
Sorry I need to give a link and acknowledge the site but I must go...does this mean a nutrino can travell 35 light years?
Back later.
Alex
Credit to
http://www.astro.ucla.edu/~wright/neutrinos.html
And that site reminded me that we observe nutrinos from supernova which means there must be plenty flying around not only from supernova but from each and every star.
Alex