phlip wrote:Depends what you call a "step"... Going up about 1cm will double the height, going up about 3-4cm will be 10 times the height.
I'm confused. Someone please explain?
A logarithmic scale means that a constant distance in the vertical direction in the chart, rather than representing a constant distance IRL, actually represents a constant multiplication
of the height.
So, for instance, if an object at 200m is shown, say, 1cm above an object at 100m (which it's close to, depending on your monitor's resolution), then an object at 400m will be 1cm above an object at 200m... an object at 10 light years will be 1cm above one at 5 light years... the same distance on the chart everywhere means a doubling.
Now, there's nothing special about doubling... if 1cm means the height is doubled, then 2cm means the height is multiplied by 4 (that is, doubled twice)... and about 3.3cm would mean the height is multiplied by 10 (3.3 = log2
10). The distances between the 1 billion light years line, the 1 million light years line, the 1 thousand light year mark (which is unlabeled, but it's between Rigel at 800ly and the Horsehead Nebula at 1500ly) and the 1 light year line, are all the same distance, which represents a multiplication by 1000.
I'd recommend ignoring the actual scale on the right from 100m to 1km... it's badly misaligned.