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Scale of the Universe (primaxstudio.com)
181 points by btilly on Oct 26, 2010 | hide | past | web | favorite | 46 comments

As pointed out by others, the largest scales on this animation are completely wrong. The figure given for the Observable Universe, 14 billion light years, is actually only half of the distance between us and the HUDF.YD3 galaxy. The figure given for the total size of the Universe is actually the estimated size of the Observable Universe: 93 billion light years. The size of the Universe itself is not known with any certainty.

If you're wondering to yourself how anything can be further away than (age of Universe) * (speed of light), read up on comoving distance and the metric expansion of spacetime. I wrote a fairly lengthy series of comments on this six months ago: http://news.ycombinator.com/item?id=1317907

One point of note is that distances beyond 100M ly are difficult to measure and prone to large errors. Beyond 1Bn ly there is nothing but the Hubble Law. It could be that objects observed to have a large redshift (and hence appearing far away by the Hubble Law) are in fact nearby objects.

I'm wondering what you think about Wun-Yi Shu Universe (http://byrev.org/tech/wun-yi-shu-universe/). I saw a post about his paper here on HN a while ago.

Without looking too hard at it, this seems to be nonsense. Shu pulls parameters out of the air all over the place and makes wild philosophical claims about the nature of time without explanation. He selectively ignores basic physics, and makes up nonstandard formulas for various quantities whenever they're needed.

Further, he repeatedly draws conclusions that, if proven, would win him a Nobel Prize. The biggest is that black holes can't exist. Others include having solved both the flatness problem and the horizon problem and ruling out the only known explanation of the CMBR without replacing it with anything else.

But, rather than take my word for it, you should just apply the Baez Index: http://math.ucr.edu/home/baez/crackpot.html

It could be wrong, but it gets across the point. The scrollbar would still be the same width, the rate of change of scale would be a little higher (in visual perception)

I spent probably half an hour reading those comments. Good stuff. Do you have a background in cosmology?

No, none. I never went past General Relativity in school but I read a few textbooks on my own. Don't take anything I say with authority.

The man who invented the Total Perspective Vortex did so basically in order to annoy his wife.

Trin Tragula--for that was his name--was a dreamer, a thinker, a speculative philosopher or, as his wife would have it, an idiot.

And she would nag him incessantly about the utterly inordinate amount of time he spent staring out into space, or mulling over the mechanics of safety pins, or doing spectrographic analyses of pieces of fairy cake.

"Have some sense of proportion!" she would say, sometimes as often as thirty-eight times in a single day.

And so he built the Total Perspective Vortex--just to show her.

And into one end, he plugged the whole of reality as extrapolated from a piece of fairy cake, and into the other, he plugged his wife: so that when he turned it on she saw in one instant the whole infinity of creation and herself in relation to it.

To Trin Tragula's horror, the shock completely annihilated her brain, but to his satisfaction he realized that he had proved conclusively that if life is going to exist in a Universe of this size, then one thing it cannot afford to have is a sense of proportion.

I really hope no HN reader misses the reference, but:

  -- Douglas Adams, _The Hitchhiker's Guide to the Galaxy_

I think he'd have appreciated this site.

Every time this toy shows up, I try to remind people that it doesn't have the grandest scale right.

First, the observable universe. From WP:

The comoving distance from Earth to the edge of the observable universe is about 14 billion parsecs (46.5 billion light-years) in any direction. The visible universe is thus a sphere with a diameter of about 28 billion parsecs (about 93 billion light-years). Assuming that space is roughly flat, this size corresponds to a comoving volume of about 3×10^80 cubic meters. This is equivalent to a volume of about 41 decillion cubic light-years short scale (4.1 × 10^34 cubic light years).

Now for the whole universe:

According to the theory of cosmic inflation and its founder, Alan Guth, if it is assumed that inflation began about 10^-37 seconds after the Big Bang, then with the plausible assumption that the size of the Universe at this time was approximately equal to the speed of light times its age, that would suggest that at present the entire Universe's size is at least 10^23 times larger than the size of the observable Universe.

Ah, but in the earliest part of the big bang, time didn't exist. Now what?

You are incorrect. There is no concept of time or space "before" the Big Bang; I say "before" in quotes because there is no "before" the Big Bang.

In the earliest part of the Big Bang time did exist. The Big Bang created time.

This really ought to be phrased something more like "According to the best current model of the universe, there was no time until the big bang occurred. However, this model has known flaws; it is the best because we haven't got anything better, not because it is actually correct. Many competing models have been proposed, many of which include some form of time before the big bang." It really should not be stated as unassailable fact that time started with the big bang. It isn't even unassailable fact that the big bang must have erased all information about the previous universe.

Simple question here, when did I ever say before?


In the early universe, before the plank epoch when we had particles of plank length or less, you know, things with a schwarzschild radius? The entire universe made of things that are black holes, nothing but black holes? Those time-ending particles that disappeared in their own hawking radiation? The first early 10^−43 seconds, where time didn't actually exist? Those were the good old days.

The first early 10^−43 seconds, where time didn't actually exist?

If time didn't exist, then how did the universe know when those 10^-43 seconds were up?

Seriously, I think this discussion is proceeding at a level which probably shouldn't be attempted by non-cosmologists. We all probably have a bunch of misconceptions we've picked up from popularizations about the Big Bang, and would only embarrass ourselves if any cosmologists happen to show up.

You didn't. Sorry, my phrasing was poor. You said that time didn't exist at the earliest part of the Big Bang, and I was trying to clarify that time didn't exist "before" the Big Bang but did immediately after.

Darn American measuring system. I wish I wasn't metric system handicapped... After slowly and sensibly dragging from small to large, it's cool to whip rapidly too! :)

Edit: Uh oh, I seem to have angered the downvote police. Sorry, uh... yay fractions?

At these scales, the difference between meters and feet (or really, between cm and miles) is insignificant.

Interesting that we seem to fall about in the middle.

Or perhaps that suggests we've only been able to observe so far in either direction.

Richard Dawkins has talked about this phenomenon. He says we live in a "middle world" and make all of our important judgments based on our size. (He says that our view of the universe would be fundamentally different if we lived on a different scale.)


Because humans can only observe the universe from Earth's point of view, our perception is that we are in the middle of the cosmos. Yet we are only in the middle of what we can observe from our point of view at any angle. As you said, we can only observe so far in either direction or any direction as it were.

I was referring to the middle of the scale, rather than the middle of the universe.

Ah, thank you for clarity. The concept still applies I think.

We're not really in the middle considering this scale goes from 10E-35m to 10E26m and we're in the 10E0 range. Looks like Pollen Grain and Silt are in the middle. OTOH, if you got rid of the ridiculous levels below the neutrino we'd be closer to the middle logarithmically.

We're probably not in the center of the universe.

From having listened to Dr Pamela Gay on Astronomy Cast for the last few years, I thought the general line of thinking now was that there is no center (or if there is, it's "everywhere") due to way it loops around on itself.

There is no "general thinking" because no one's measured the edge of the universe to see what it's like. And certainly no one has seen the universe "wrap" around itself. In the absence of evidence, everyone just picks the model that looks best to them on paper.

At the smallest scale it claims: Plank's length -- any length shorter makes no physical sense

Is this actually true? According to wikipedia (http://en.wikipedia.org/wiki/Planck_length): The physical significance of the Planck length, if any, is not yet known.

A video which gives perspective of distance, in appreciable way. The powers of ten http://www.youtube.com/watch?v=0fKBhvDjuy0&feature=playe...

I found it incredibly annoying that the numbers are formatted with the power of ten magnitude first, and the actual measurement last.

So, 3 cm is formatted as 10^-2 * 3 m, rather than the (in my opinion, correct) 3 * 10^-2 m. The power of ten is what is given a shorthand as "centi" in "cm", so it just disrupts it totally when they're swapped.

I realize the point is probably to make the order of magnitude more important than the actual value ("cm" is more interesting than "3 cm"), to get a sense of scale. Still, I found it ugly and hard to read.

Another one with much limited scope:


Fascinating how large the gap is from Neutrinos to Quantum Foam/Strings. I can't help but wonder if it's filled with stuff we don't yet know about.

Also, a Giant Earthworm that's the length of a small car? What what what?

Really great data viz, thanks for posting it.

Absolutely fantastic and soothing. My thoughts are made of such things, this example helps to sooth my mind.

A technical question: How was relative scale so efficiently kept between all those objects?

Isn't it odd that there is _no_ physical structure between 10^-35 (Planck length) and 10^-24 (neutrino)?

That's a massive gap compared to scales larger than the neutrino. Is there are reason?

They may not have been discovered yet. Things on this scale would be incredibly difficult to detect.

I want to know what's hiding between 0.1 yoctometers and Planck length, it seems like a big blank according to the Flash app thing...

Yeah, we have no instruments to really get to that scale. Probably won't for some time, either.

Well done! Edutainment at its finest. You should publish that for physics teachers.

there might be entire civilizations of life forms billions of years ahead of us technology wise inside the atoms that make up the particles in the air we breath. Our entire universe may be an atom that makes up a single blob unit of a cell inside an entity that is larger than our known universe.

It would make an interesting sci-fi movie, to finally make contact with an advanced race that lives inside an electron.

Men In Black? (although I guess contact wasn't actually made, unless you count a game of marbles)

Horton Hears a Who

too good..i've added it to my favorites.

We are so small yet think so big. We are interesting creatures...a bit mad though.

Only /a bit/ mad?

The only way this could've been better is if a large, screaming face appeared at the smallest scale.

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