Cosmic Sightseeing 5

Feeling Small


I stopped liking amusement park rides a long time ago. Back when I was a kid, I loved getting spun around and hung upside down, but my inner ears must have changed since then. Now, those rides feel like torture.

Anyway, who needs thrill rides when you have the Cosmos? It’s kicky enough just letting your mind wander through the bizarreries of the Universe. Like a Tilt-a-Whirl for the mind.

The Omega Nebula in the constellation Sagittarius. A nebula is a giant dust and gas cloud in interstellar space. The different colors correspond to different chemical elements or temperatures. This picture shows a 3-light year wide area.
Image: NASA, ESA, J. Hester (ASU)


I think many people find things like the sheer size of the universe too unsettling…it makes them feel small and insignificant. But, I find it energizing. I like to ponder how small I really am: one person on a planet of 7 billion people, among millions of other species, in a galaxy with billions of stars, in a universe with billions of galaxies.

Also known as “The Pillars of Creation”, this is a picture from the Hubble Telescope of the Eagle Nebula in the constellation Serpens. These towers of cold gas and dust are light-years long.


Last week, on Cosmic Sightseeing 3, I gave you a puzzle: to figure out what a series of images had in common. The answer was so easy it was hard! Everything I showed you was composed of matter.

Oh, duh, right?

The Cat’s Eye Nebula. This image shows a star experiencing the phase of stellar evolution similar to what our Sun will experience in a few billion years. This is a combination of an optical image from the Hubble Telescope, and an X-ray image from the Chandra X-ray Observatory.
Credit: X-ray: NASA/CXC/SAO; Optical: NASA/STScl


But, as with most things, if you look closer—matter gets more interesting. Consider that you and I and the moon and all the stars are made of the same basic ingredients—the same 12 particles of matter—just combined in different ways. Take 12 miniscule particles, mix them up in various ways with the 4 Forces of Nature, add the elusive and mysterious Higgs Boson, and voilá…you’ve got everything from a fruit fly to the planet Jupiter.

And most of matter is—by far—empty space. If you could look close enough, with a microscope more powerful than anything we can dream of, you would see tiny particles surrounded by vast oceans of empty space.

And, the particles themselves—the very ones inside you and me right now—were almost certainly once part of something else very different…a tree, a dinosaur, a rock, or the inside of a distant star.

Stars are the furnaces where most matter is forged, after all.

I’ll never forget my favorite quote by Carl Sagan: “We are all made of star-stuff.”


The Hourglass Nebula, with its central star in its last throes as it becomes a white dwarf. This is a picture from the Hubble Space Telescope.
Image Credit: NASA, WFPC2, HST, R. Sahai and J. Trauger (JPL)


And, another thing about matter: it’s everything and practically nothing at the same time. Only about 5% of the mass of galaxies is actually composed of matter. The rest is either Dark Matter, or Dark Energy: stuff that is a complete unknown. We know it’s there, but we have no idea what it is.

95% of the Universe is made of stuff that is “not us”.

Feel like crawling back into bed and hiding under the covers? Not me. I’m going to keep sightseeing as long as I can.


The Boomerang Nebula, about 5,000 light years from Earth in the constellation Centaurus. This incredibly cold nebula has two symmetrical cones of matter that are being ejected from the central star. Another great image from the Hubble.
Image credit: NASA, ESA and The Hubble Heritage Team (STScI/AURA)



A wonderful and amusing explanation of matter and the Higgs Boson

The BBC’s very awesome “Wonders of the Universe”


Next week…we’ll take a break from the Cosmos and dive into the Pacific Ocean. I’ll be pondering ancient sea creatures and I’ll also feature some wonderful student artwork by Miranda Andersen, guest artist to next week’s blog!


And, I’m giving you another few days to solve the TIME AND LIFE AND THE UNIVERSE puzzle from Cosmic Sightseeing 4.

Here’s a review. Just to be nice, I’ll make it easier this time:

Life in the Universe is possible for only a short period of time, relative to the total duration of the Universe itself. The numbers are astronomical, so I want to get a visualization of them by drawing a timeline.

But, I want the timeline to be to-scale. Timelines are just bogus if they’re not to-scale

I’ll show the entire duration of the universe (from the Big Bang at zero, to the time in the distant future when the Universe dissipates into nothingness) as a red bar, and the time period during which the universe is hospitable to life as a blue bar. I’m setting the size of the blue bar to be 1 centimeter. How wide does my paper need to be to fit the entire red bar?

Blue is one-thousandth of a billion billion billionth, billion billion billionth, billion billion billionth, of one percent of red.

So, how wide does my paper need to be?

Select the closest width:

a. 10 meters

b. 10 kilometers

c. 10,000 kilometers

d. 1 million kilometers

e. Fuggeddaboudit…the paper would not fit into the observable Universe (10 to the 27th power meters – give or take)

It’s a Tilt-a-Whirl for the mind.


Cosmic Sightseeing 3

I was working on this week’s blog post, and I got a little distracted. I was just floating around, not quite grasping the subject.














So, I’m splitting the post in two.Today, we’ll have a pop quiz!

And in a day or two, another post with the answers and more sightseeing.


Take the Quiz:

What would you say the following things have in common:

An ancient Native American Village…


Pioneer homesteaders…


A gray whale…


Prairie flowers, a damselfly, a monarch caterpillar…


An alligator lizard, its prey, and the rocks that give them both shelter…


The City of Reno, the Truckee River and Lake Tahoe…



NASA photo.


And all the planets, stars, asteroids and cosmic structures in the observable Universe.

Image Credit: ESA/Herschel/PACS/SPIRE/Hill, Motte, HOBYS Key Programme Consortium


Leave a comment with your answer! (remember…you can leave comments without giving your real name if you want to.) And tune in to the blog tomorrow to see how you did.

I’ll just give you one hint: the answer is not 42.

Cosmic Sightseeing 2


Falling Up

Whenever I get the chance, I like to sleep outside under the stars. On a clear, dark night, far away from the city…it takes me out of ordinary day-to-day life and plunks me down where I really am: clinging to a tiny rock floating around somewhere in an immense and complex Universe. It gives me perspective.

Artwork this week is provided by artist (and my mother) Barbara Dahn. I think her work is rather cosmically-inspired, don’t you?


Several times, though, while I’ve been looking up and pondering all the countless other stars and planets Out There, I’ve had a strange sensation of reverse-vertigo, almost as if gravity were letting go and I was floating up into the limitless black of the night sky.

It’s a weird feeling of falling up.

Drawing by Barbara Dahn


Falling up is an unsettling feeling…but in a good way, kind of like riding a roller coaster. I’m sure it stems from somewhere in my inner-ear—something about losing sight of the horizon. Or maybe it’s just the starry sky… a reminder of just how small I am and how big the Universe really is.


How far out into space can we see? 

Last week on this blog, we pondered Andromeda, the most distant thing any of us can see with our naked eyes—a mere 2.5 million light years away. But with a wide variety of different telescopes, we can look much farther, as far as 13.7 billion light years.

Drawing by Barbara Dahn


Looking into space is not always a visual “seeing”, especially at the greater distances. (Remember how limited the “visual” portion of the electromagnetic spectrum is?) Often, we are detecting other wavelengths that are invisible to our eyes but detectable by a variety of telescopes: infared, radio, ultraviolet, gamma rays, microwave, etc.


How big is the Universe?

13.7 billion light years is the farthest distance we have detected. At that point, all we detect is microwave background ‘noise’ left over from the Big Bang. We’re basically looking back to the beginning of time. But we’re not seeing all there is…the Universe is likely at least 160 billion light years in size. Or bigger.*

And as far as we can tell… it’s probably flat.**

And it may be only one of many, many, many Universes.***

Drawing by Barbara Dahn


I’m falling up again. How about you?


Drawing by Barbara Dahn


PS – Happy Birthday Voyager 1!

Today is Voyager’s 35th birthday.

The most-distant human-made objects, Voyager 1 and Voyager 2 are on their way out of the solar system. Sometime soon, they will enter interstellar space, where they will wander our galaxy, the Milky Way until one of the following happens:

a. they get picked up by some extraterrestrial life form

b. our entire galaxy gets swallowed into a black hole

c. unknown

d. other


For more information:


*The size of the Universe

**The shape of the Universe

***Multiverse (more than one Universe)

To see The Powers Of Ten—a very cool 10-minute film that takes you to the edge of the Universe and back



Go ahead, make my day…leave a comment! Anything at all…ask a question, make an observation, tell me if you’ve ever fallen up, or down, or sideways…