I have to confess I do not understand relativity, special or general and I
have trouble with gallilean relativity.

However I do know from experience that ten light years takes about six
months and there is no twin paradox. It was six months on earth and on my
travels. My Ancestor Gulliver Goddard found the same when he gathered the
material for his account in "Gullivers travels" (first edition).

I also know that teleportation is used for huge distance travel
instantaneously over hundreds of light years. As far as I understand it it
is done as a series of hops between space stations.

With Galilean relativity if you are walking at velocity v1,v2,v3 on a boat
and relative to the deck which is moving at a velocity w1,w2,w3 then the
resultant velocity is v1+w1,v2+w2,v3+w3 but if the velocity of the ship is
very high like w=0.9c and the velocity of the walk is high like v=0.9c then
the sum is less than 1.8c and is still less than c. I do not recall the
solution.

Does anyone know what it is?

y=(w-v)/(1-wv/c^2)... (I looked it up).

y=1.8c/(1+.9x.9)=1.8c/1.81=0.9945c

This again due to the phenomina of looking at 4 space in as a projection on
to 3 space. In 4-space y=w-v as usual and 0.9c is in reality .9c/sqr(1-.9^2)
=2.064c and y=4.129c.

Relativity is in reality a form of perspective and an example of affine
geometry.

As with galilean geometry there is no absolute velocity in space and any
point not accelerating can be taken as being at rest.

However it also means that since all objects in space are under the
influence of gravity all objects are accelerating and so nothing is at rest.
You could take the center of gravity of the milky way galaxy as at rest and
take a particular time like AD 0 and work out the position of a particularly
significant star's position at that time and take that as the 0 on the angle
of polar co-ordinates and another star nearly over the centre of gravity of
the hub to be the z axis and give positions as z angle theta for all objects
in the galaxy. However the milky way is accelerating relative to M31 but it
could be taken as to be at rest to a first approximation.