Recent content by hamischism

We might need to go 3D on this one to make sure we're on the same page. I just don't see how this will work in any modeling software. We will see star circles with the Earth spinning on the spot, or spirals with the Earth moving laterally and spinning.

I get what you're talking about, but please forget about polaris for a second. I shouldn't have mentioned that star, because it would be the only star whose motion could be plausible - if Earth's axis is always pointed directly at it.

Ever tried making a time-lapse sequence from a boat? It's a blurry mess.

I agree with all those diagrams and calculations, but they have nothing to do with what I am talking about. I already asked you not to further complicate this discussion. We're talking about a very simple scenario here. The camera is a point in space. For example, the camera is looking directly...

Relatively speaking, the motion through space (orbiting the sun) compared with the rotation is really fast. 67 times faster. I should see star streaks that curl over into a spiral at a ratio of 1:67 ie really long spirals.

Yes, the camera rotates as it moves laterally with the earth. This combined motion makes a spiral. Yet only we only see circles.

I mean no disrespect. It's just that everything that has been said here is physically impossible. If this were to be modeled in 3D software, none of the scenarios proposed would work because the Earth isn't rotating. It is spiraling. If you were to trace the path of the camera as a point in...

This is not correct. https://en.wikipedia.org/wiki/Star_trail "Star trail photographs are possible because of the rotation of the Earth on its axis. The apparent motion of the stars is recorded as streaks on the film or detector." It's an apparent motion because the motion of the Earth causes...

It is unrelated. Can you imagine if there was only one star in the sky, and we tracked it's path with a star trail sequence? Would it not move in an arc, and therefor reveal the path the camera has taken? Why do you need to talk about some stars being closer and some stars being further? You are...

In the scenario of the camera traveling on a spiraling path, how could you possibly separate the two? Isn't it clear that we're really describing the physical journey of the camera? The camera rotates, but it is also moving sideways 67 times faster. We should be seeing spirals, not concentric...

Could you explain what you mean by the perceived motion of the star?

I don't know why the rotation is more observable, when you consider the physicality of this scenario. It makes no sense. If the stars are too far away, then why do we see any motion from our fixed point at all? And because we see motion, why is it only the rotation and not the much faster...

The stars in star trail sequences clearly reveal the motion of the camera as Earth rotates. I don't understand how you can see one motion without the other.

That's what I am asking. Why does distance not matter for rotational movement, but it does for lateral movement? If I look at a building a mile away, it will move the same relative amount whether I rotate my view or shift it sideways. There is no bias against sideways motion for objects at a...

Yes I used the 1000 mph as the greatest possible speed - how it would be at the equator. In this example, it wouldn't make much difference if you were at a tighter latitude close to the north or south pole. The lateral speed of the Earth still dwarfs any rotational movement that the camera is...