Has the expansion of the universe effected navigation when you are navigating by use of the stars?

Question

It would seem to me that it would. Or is it so slight that we just can't notice it. How long before we do notice it?

Answer 1

The stars apparent movement is less than 1 arc-minute a year. That's close enough to navigate to better than 1 mile. If you make the daily corrections like you're supposed to, you can get within 60 yards accuracy -- except that there are no practical navigation instruments that can take a star sighting better than 0.1 arc-minutes.

The expansion of the universe does not affect the position of navigation stars, since they are all in our own galaxy. The smallest unit for the universal expansion is super-clusters of 1000's of galaxy. Inside a super-clusters, the galaxies move around each other.

Answer 2

The expansion of the universe is too slow to cause a measurable change in the position of anything. In any case, since it is moving everything straight away from us, it has no effect on apparent position.

For the local stars we can see in the sky, their own motions through the galaxy are many orders of magnitude larger than the minuscule effect of expansion, but even those are too small to affect navigation.

The largest effect is the precession of Earth's axis, which causes star positions with respect to a specific time and date to change at the rate of about 50 arc-seconds per year. Software will correct for this automatically; otherwise, if you're using a printed almanac, it needs to be reasonably recent.

Answer 3

The relative position of the stars in the sky has changed slightly, but this has more to do with the "wobble" in the earths orbit. The expansion of the universe is so slow that any change would take dozens of generations to witness. however if you were to sit and stare at the "plough" constellation (ursa major/the big dipper) for a couple of millenia or so, the two end stars would appear to move inwards.

Answer 4

its slight and at the same time its not. the galaxies are moving very fast relative to how fast we can go. but at the same time other galaxies are thousands of lightyears away. so any movement we can detect takes days of observation or time lapse cameras, and that movement is small (its actually quite large, but it seems small cuz were so far away.)

Answer 5

Yes ,it's because it is so slight.