Logarithmic Maps of the Universe (2005) | Hacker News Reader

Logarithmic Maps of the Universe (2005)

astro.princeton.edu

139 pointsautoditype34 comments

I got one of these printed by a banner-printing service who could do prints two metres tall and 60 cm wide or something. It came back with the bottom third blank - there are so many objects in the postscript file, it crashed their rasteriser. This was a cheap service, so they didn't check it before printing it out.

I rasterised it in software, and sent them the image, and that was fine.

If anyone looked for Andromeda and couldn't find it: M31 is Andromeda and it's around 765 kiloparsecs away.

The lower bound on this map’s logarithmic scale is ~1000 km. I’d love to see it extended down to the Planck length.

Yeah, and then the origin should be moved to somewhere on the surface of the earth, instead of it's core.

what do you mean? There's no "origin" on a logarithmic map, it's infinite both ways

The map is relative to one location. You don’t want to see « rocks » and « rocks » for any distance smaller than 6000km, you want to see everyday objects. So you want the origin to be on earth surface

ok, I get it. It could be centered on a cell of your own body!

https://www.youtube.com/watch?v=0fKBhvDjuy0

Yes! Maybe centered on an up quark in a proton of a carbon atom in the DNA in the nucleus of a brain cell.

compare (1957) https://ned.ipac.caltech.edu/level5/Boeke/frames.html "The Universe in 40 jumps"

10e-13 cm to 10e26 cm

Not quite the same concept, but close: https://htwins.net/scale2/

Neat map.

The page's link to the journal article is broken. The abstract can be viewed on NASA's ADS[0] or directly via the DOI link[1] (which connects to the current home of the Astrophysical Journal).

[0] https://ui.adsabs.harvard.edu/abs/2005ApJ...624..463G/abstra...

[1] https://ui.adsabs.harvard.edu/link_gateway/2005ApJ...624..46...

And here's the corrected arXiv link: https://arxiv.org/abs/astro-ph/0310571

Can someone ELI15 the horizontal axis to me (24h..6h)?

The "longitude" of astronomy is called "right ascension" and is traditionally counted as a 24 hour circle: https://en.wikipedia.org/wiki/Right_ascension

Why is there a band of decelerating matter right near the top? I thought it was all accelerating outwards?

Also what's the gap between the blue bits?

The gap is part of the universe we have trouble seeing because it is obscured by Milky Way.

The early universe's expansion was not accelerating, as the early universe was not dominated by dark energy. I don't know off the top of my head exactly when that changed, but z=0.76 seems about right. So I'm pretty sure that is what that is.

The reason the dominant form of matter changes is fairly simple. As the universe expands, the amount of matter doesn't change, so the matter density goes as 1/r^3. The amount or radiation goes as 1/r^4 as there is an extra loss of energy due to redshifting (E = hc/wavelength). Dark energy though is (we think) a constant, so as the universe expands, the amount of it stays constant.

That took a long time to process! What's z? Your username checks out :-)

It is interesting to see that the biggest distance, in terms of orders of magnitude, is between Sol system and nearest stars.

I would like to see a map of the universe scaled by population, similar to http://www-personal.umich.edu/~mejn/election/2016/

Opening that link, I just get presented with a login page.

Your browser is probably redirecting to the broken HTTPS version.

https://www.businessinsider.com/2016-election-results-maps-p... has the same maps.