The Universe is a stunningly big place.

If you find yourself needing a little perspective today then take 2 minutes to watch the following YouTube video:

Now consider this: Those dots aren’t individual stars. They’re individual galaxies.

This animated flight through the universe was made by Miguel Aragon of Johns Hopkins University with Mark Subbarao of the Adler Planetarium and Alex Szalay of Johns Hopkins. There are close to 400,000 galaxies in the animation, with images of the actual galaxies in these positions (or in some cases their near cousins in type) derived from the Sloan Digital Sky Survey (SDSS) Data Release 7. Vast as this slice of the universe seems, its most distant reach is to redshift 0.1, corresponding to roughly 1.3 billion light years from Earth. SDSS Data Release 9 from the Baryon Oscillation Spectroscopic Survey (BOSS), led by Berkeley Lab scientists, includes spectroscopic data for well over half a million galaxies at redshifts up to 0.8 — roughly 7 billion light years distant — and over a hundred thousand quasars to redshift 3.0 and beyond.

I find this both awe inspiring and a little sad. That’s just a small slice of the universe we know about and it is mind bendingly huge on its own. When you stop to consider the distances between those galaxies it’s hard not to be awed by it.

And that’s also what makes me a little sad. Proxima Centauri is the next closest star to our solar system and it is roughly 4.24 light years away pretty much putting it out of our reach for visiting unless we find some way to bend the laws of physics. The closest known galaxy to ours is the Canis Major Dwarf Galaxy which is roughly 25,000 light years away from the Sun. That’s a difficult number to fathom on its own. When you realize that a light year is 5.87849981 × 1012 miles (roughly 6 trillion miles) it becomes even more so.

Now consider how close everything looked in that video. There’s just tons of places to go and see! Except that you’re looking at literally billions of light years of distance which means we’ll probably never see any of it up close. We’ll be lucky if we ever make it to Proxima Centauri given the distance involved, going to a neighboring galaxy is likely to forever remain a dream of science fiction writers. Not that NASA isn’t still considering the possibility, but the challenges of just getting to our neighbor star are overwhelming.

So much stuff out there and no real chance of seeing it. Guess I’ll have to settle for watching sci-fi movies for the time being.

4 thoughts on “The Universe is a stunningly big place.

  1. Hopefully future generations will come up with a method to reach other galaxies, but it won’t be ours.

    Another way of visualizing light speed is to consider sunlight; roughly seven minutes to reach Earth, a few minutes more to reach Mars, but (as Les noted) a little over four years to reach Proxima Centauri. It was thrilling that the Curiosity rover reached Mars, but imagine the difference between a few minutes and one presidential term. That is why the notion of alien visitors is absurd. It also reveals how trivial our planet is in the wider picture; if our galaxy disappeared, much less our planet, it wouldn’t be at all noticeable to the wider universe. That wipes out the pretensions of anthropocentric religions (namely, all of them) in one stroke.

    The universe is relatively uniform, so at least we have a vague sense of what it is like. Emphasis on vague. I look forward to the James Webb telescope, which will show us a bit more.

  2. The furthest I ever got in science education was Astronomy 101 in college, where I learned the info and skills necessary to read the spectral lines of light from stars to help determine their composition. It was awesome, but 20 years later most of the specifics are all but forgotten. But I have never stopped thinking about the ideas involved and what we could possibly learn.

    For me it’s a very bittersweet subject. I generally choose to take a cautiously optimistic, Saganesque view of future possibilities. I have no good reason or evidence to think that we will ever get around the limitations of the speed of light. I have no reason to think that we will ever fully explore the galaxy. But if the human race lives long enough, I still think we could construct and send ships, manned or more likely unmanned, and at least map our small section of the galaxy, which to me would be interesting enough to be worth the effort. Over a century or two, we could at least get working probes out to a circumference of a few light years, and keep learning about our galactic neighborhood, if we can achieve a stable enough civilization. If we can’t get to that level of stability within the next 100-200 years or so, I don’t think we will be able to maintain a technological society for very long anyway.

    In my complete and utter amateur view, open to correction, at least the following may be possible:
    Decide on a goal. Personally, I think the most interesting goal would be to look for evidence of life-bearing or habitable planets within our observable range. (We are already doing this, and have made huge leaps forward in just a decade, but I don’t think we are living up to our potential.) I would not waste too many resources on planetary systems that only contain, say, a hot Jupiter and a star, unless it was close, easy to observe, and good practice for future attempts.

    Keep trying to advance our instruments- larger, more powerful telescopes, more sensitive light detectors, anything that might help observation. Get more of them out into space, eventually trying to get them closer to possibly habitable systems. We may get to the point where we could read the spectral lines of a planet from a realistically achievable distance, and find evidence consistent with life.

    Narrow the search to planets with orbits in the habitable range for their star, and as we move outward, look along the parts of the galaxy that resemble our own…I recently read an article presenting the theory that, like the “habitable zone” of a star, there may also be areas of the galaxy like ours that are more likely to harbor life.

    I know that all this is being done already, at least slowly, by smarter and more dedicated people than I…but I wish either more of the people on this planet took it seriously, or at least influential people took it more seriously. I consider the likelihood of finding solid evidence of another life-bearing or even habitable planet within my lifetime (another 40 years or so, tops) to be about the same as me winning the lottery if I bought a ticket once a week. As close to zero as makes no difference. It would probably require that we increase our worldwide investment tenfold at least, including improving our instruments and detection techniques, making the search our main focus, and that we get very, very lucky.

    I am resigned to the reality that I will most likely never live to see the search truly get up to speed, much less reach any goals. I am a naturally content person for the most part…I have never had to deal with serious emotional problems…but to be perfectly honest, coming to terms with this reality is the closest I have ever experienced to real depression. But I just can not stop thinking about it. If nuclear war sent us back to the stone age tomorrow, but I survived, I would spend the rest of my life cursing the human race for the opportunities we lost. I’ve gone through periods of a few years where I didn’t obsess over it, yet I always return to my hopes and speculations. Even though I will never live to see the discovery of life on other planets, just the thought that someone a bit like me might get to…or that they might get to realize that there is no life close by, and realize how precious the earth is…the thought of either outcome is the closest thing I have to a religious sentiment. I don’t let it get in the way of reality, but it helps keep me open-minded and generally thrilled to just be alive.

    Sorry to go on so long….in my opinion, this general subject is the biggest field of mind-altering, humbling, awe-inspiring questions that humans have ever asked. It’s like when other people talk about god or the meaning of life, except that in this quest for understanding, there just might be some achievable answers- if we can hold out long enough and better teach ourselves, from our own experiences, how to learn.

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