As someone who writes about astronomy, I know that figuring out the universe is tough. There's all these weird things — dark matter, quasars, cosmological expansion — that are genuinely difficult to get a good handle on.

So anything that helps come to terms with how the cosmos works is commendable, and for that reason I really like this new 3-D map assembled by scientists working with the National Astronomical Observatory in Japan using data from the Subaru Telescope. The graphic places more than 1,000 galaxies in their respective positions out in the universe, taking the flat starry night sky that we normally experience and giving us a new perspective. These galaxies are between 8 and 10 billion years old.

There's something actually user-friendly about the scale, which covers a mere 2.5 billion light-years in distance backwards and 600 million light-years across (yes, that's huge but this is the universe we're talking about). Other 3-D cosmic maps have plotted out some 500 million objects at distances up to 7 billion light-years from Earth. While cool-looking, you tend to miss the trees for the forest when inundated by so much information.

So what are we looking at? Well the bottom left shows you the field of view: That is, the flat night sky that you would see from Earth if you had an enormous telescope like the Subaru. That view is then expanded so that we can see each galaxy's position out in space relative to one another. The nice thing is that this view lets you get a good handle on the concept of cosmological redshift, or what astronomers call z.

Distances out in the universe are really wonky. If you look at the graphic, you'll notice that the galaxies are roughly 9 billion years old and yet all are more than 12 billion light-years away. If you think about that for a minute, it's a little crazy. Distance is a function of how fast you travel for a given amount of time. If these galaxies are only 9 billion years old and even if they've been traveling at the speed of light, by definition they should be no more than 9 billion light-years away.

And yet they're not. The reason is that these galaxies aren't traveling at the speed of light — they're traveling faster than it. To answer your first question, yes, that is possible, and to answer your second, no, you still can't build a time machine.

You might already be familiar with the fact that the universe and the fabric of space-time are expanding. All galaxies in the universe are moving away from all other galaxies in the universe at a particular rate. But the expansion of the universe doesn't care too much about Einstein's nothing-goes-faster-than-light dictum, it proceeds at any speed it wants. Because the rate of expansion gets faster and faster the farther away any two galaxies are, there is a certain point where two galaxies are so far apart, they are moving faster away from one another than the speed of light.

So astronomers, being precision scientists, need to know what other astronomers mean when they say "distance." There is the light travel distance, which is based on the speed of light and would be 9 billion light-years in this case. And there's the comoving distance, which is based on the expansion of the universe and is larger. Astronomers sidestep this confusing problem with z.

Light, being a thing that is inside the universe, is also subject to the expansion of space-time. Let's say a photon of light is emitted by a distant star. As that photon travels, the space it exists in expands, lengthening its wavelength and shifting it toward the longer, redder end of the electromagnetic spectrum. Over billions of years, that wavelength shift, called redshift, becomes noticeable. Astronomers use the difference between the wavelength of light when it was emitted and the wavelength of light as it appears now to come up with z, a dimensionless quantity indicating how much redshift that light has been subjected to.

As you can see in the 3-D map, the wavelength of light for a galaxy at the farther end of the graphic is 1.52 times longer than it was when it was emitted. The light from galaxies at the nearer end of the map are only 1.23 times longer than when they were emitted. I think that's pretty cool.

This map also contains some other good information, such as the rate of star formation. In the earliest days of the universe's history, galaxies were producing many stars. These more middle-aged galaxies have a wider variety of star formation. Some continue to be star factories while others have slowed down. Our own Milky Way galaxy is thought to have formed around this time.

The gauzy haze around the galaxies also stands in for the total mass around them, which is mostly made of unseen dark matter. If we could see this dark matter, it would form the filaments and gaps in this map. The hope is that by looking at this large-scale structure, astronomers may be able to figure out a bit about how dark energy works.

Finally, displaying the positions of galaxies in this way reminds me of this graphic (below), released by NASA for their WMAP satellite, which looked at the earliest light that we can see in the universe, and projected the history of the universe forward. It would be cool to see the next maps coming from the NAOJ that will position more than 5,000 galaxies in their respective places.