How Big Is The Solar System?

(Hint: Really big)

I took a trip to one of Austin’s famous moontowers so I could put the enormity of our solar system into perspective. With the help of a grapefruit, and a lot of walking, you’ll get an idea of just how tiny everything is out there!!

Do it yourself! Calculate sizes and distances, and then make your own solar system model using this calculator.

I’m serious about that part, make your own and send them to me! I’ll feature them here on the blog so everyone can see your crafty science awesomeness.

Click here to SUBSCRIBE and get more great science, it’s FREE!


Joe’s new episode of It’s Okay To Be Smart got me all choked up. I am always full of goosebumps and a few tears when I think about the absolutely unbelievable fact that we have sent people to space and we continue to explore as far out as we do, mostly for the sake of curiosity. 


NEW SHOW FROM PBS DIGITAL STUDIOS! So make sure you tell everyone and their mom(s).

There’s now more than 7 billion human beings on Earth, and that got me wondering: How successful are we compared to other species? I take a look at out how our numbers stack up to some other domains of life. It turns out that biomass, or what things weigh, can be more important than how many of something there are. Find out how our numbers stack up against everything from bugs to bacteria, and get ready for some mind-blowing numbers!

Have an idea for an episode or an amazing science question you want answered? Leave a comment below!

Tweet at me: @jtotheizzoe
Email me: itsokaytobesmart [at] gmail [dot] com
For more awesome science, check out:

Written and hosted by Joe Hanson
Produced by Painted On Productions (


Clips from this episode via:
“Aspens” by Altitude Filmworks:
“Golden Aspen Meadow” by David Huting:
Red-billed queleas by Antero Topp: 
Bacterial growth:
Dengue virus infection:


The science of… OH GOD IS THAT A SPIDER?!
Subscribe to It’s Okay To Be Smart: 


The Odds of Finding Life and Love

You guys ready for the next episode of It’s Okay To Be Smart? This is a fun one, with a little Valentine’s Day theme. 

It’s about what the search for extraterrestrial life in our galaxy can teach us about our odds of finding that special someone. Starting with the Fermi Paradox and the Drake Equation, we’ll explore the odds of finding a human to love that meets your criteria. There’s a special cosmic love story involving a couple named Carl and Ann that I think you guys will like too :)

If you’d like to learn more about the science behind the numbers that went into calculating the odds of alien life for this video, check this doc

Don’t forget to share it with every human being you know, and be sure to subscribe

Here’s last week’s video.


It’s Okay To Be Smart. Also okay? Making a fool of yourself with a blooper reel. 

“Hoooman. Hooman. WHAT IS GOING ON. This is really awkward. There is grandeur in this way of YouTube life.”

There’s more spitting involved in making a YouTube series than I ever thought there would be. And voguing. 


Like A Bee Sees

By now you’ve probably all watched the latest It’s Okay To Be Smart video  about the amaaaaazing ways that bees are able to sense flowers. (actually I know a few of you haven’t so go do that, mmkay? Thanks!)

Beyond the electric field sensing part (which is cool in its own right), it’s the fact that bees see into the “invisible” that just blows my mind. Bees (and butterflies too, actually) have photoreceptors that respond to wavelengths down in the UV range (see chart above). They use that vision to zoom right in on the important part of the flower: the sweet, sugary nectar pot.

Spoiler alert: As much as we love flowers, they don’t really give a crap about us. But they do love bees. In return for giving the bees the sugary yum-yums, flowers get pollinated. And in the name of the evolutionary game, that’s the most important thing. To help get the gene-passing-on done, flowers have evolved certain pigments near the center of the flower that absorb UV light. That paints a big, fat bulls-eye for the bee to land on, right where the flower needs them (next to all the flower-sex bits). To us, the whole flower may look yellow or orange. To a bee. BIG “land here” spot in the middle. 

THAT IS AMAZING!!! Nature, you are just too cool.

Thanks to camera technology, we can take UV filtered photos of flowers and see those patterns pop out. It’s a pretty advanced technique, but some of my favorites are above. Check out those photographers’ galleries at the links below:

UV floral photography by Klaus Schmitt and Bjørn Rørslett.  Click to subscribe to IOTBS on YouTube.


It’s Okay To Be Smart Episode 1: Life by the Numbers

Check out the first episode of my new YouTube science series from PBS Digital Studios! I’m practically co-workers with Big Bird now!

This episode is all about the scale of life on Earth. So there’s now over seven billion people on Earth, but does that make us a successful species by numbers alone? And while humans may be getting heavier every day, how does our weight stack up to the rest of biology?

We’ll learn about “biomass” while we take a trip through some forests, a spoonful of soil and deep into the oceans to find out just how much stuff there is out there. 

Click here to subscribe to It’s Okay To Be Smart on YouTube.

Have an idea for a future episode or have a question for me (Joe)? Tweet me, leave a comment on YouTube or email me.


Space Sounds - Sounds of the Big Bang

It’s time for another Episode Extra! (which is where you special blog readers get to check out really cool stuff to go along with my YouTube videos, like special features on a DVD, only way more special-er)

I’ve got another extra feature to go along with my latest Space Sounds video! I’m full of ‘em this week.

The very first radiation to escape after the Big Bang has been traveling outward for 13.8 billion years. This cosmic microwave background has been literally stretched over time, it’s frequency and temperature lowering as the universe, and everything in it, expands.

John G. Cramer from the University of Washington took the measurement data of the cosmic microwave background from ESA’s Planck space telescope and converted the energy frequencies of the first 760,000 years of the universe into audible sound. He had to multiply each frequency by 10^26 so we could hear it!

More “space sounds” episode extras here. Click here to subscribe on YouTube!

Time for a science-tastic, carboniferous Episode Extra™ to accompany my latest YouTube vid!

In the most recent episode of It’s Okay To Be Smart on YouTube, about how we all share the same air, the #1 question from People Who Are Watching was about a number I mentioned in the beginning: We hoomanz are emitting 33-34 billion tons of CO2 a year. If the atmosphere is so dang big, is that amount of CO2 a lot?

A few people were subsequently all “Wait a sec, is Joe referencing climate change here?! Rabble rabble rabble!!!” Congrats. You caught me. Guilty as charged. But there’s science on my side, and you know what they say about science:

Where the carbon comes from: the primary people-caused CO2 sources are fossil fuels, deforestation, and cement production. Since 1850, over one thousand billion (AKA “a trillion”) tons of CO2 have been added to the atmosphere. We put about 34 billion tons of CO2 into atmosphere in 2011, the latest year I could find data. These are not debatable facts, minus a few decimals of statistical error. We can measure them, we have the technology. 

Where does it go? Only 55% of this is removed by the oceans (dissolved CO2 and photosynthetic organisms) and the plants in our jungles and forests. Fifty years ago, as much as 60% of that CO2 would have been removed by oceans and plants. That means that not only are we increasing the amount of CO2 we emit every year, but plants and oceans (the carbon “sinks”) can’t keep up with the rate that we are adding it to the atmosphere.

Sure, as more carbon is put into atmosphere, plants and plankton can reproduce and take more of it up. But if we pump it out faster than they proliferate, it’s still a net loss. Oceans might actually be less able to absorb CO2 as the world warms (it’s simple chemistry, think about warm carbonated soda).

Then we get to the warming part. CO2 makes up less than one tenth of one percent of Earth’s atmosphere. So it can’t be that big of a deal to increase that by like 0.01% right? Wrong. Sure, for every million molecules of air, only ~391 of them will be CO2, but carbon dioxide is an amazingly powerful molecular mirror for solar energy, reflecting it back down to Earth and heating our planet. The math is complex, but tenths of tenths of percent changes in CO2 concentrations can lead to full degree changes in global temperatures. This doesn’t even include the effects of methane, which is almost 1,000 times less abundant as CO2, but contributes a whopping 1/5th of greenhouse gas effects.

For more: A paper in PNAS about carbon emissions and carbon sinks. A summary of emissions, warming and greenhouse gases from NOAA. Finally, you might need this: How to talk to a climate skeptic.

We do share the same small atmosphere, just like the video says. So keep it clean, because it’s mine too, dammit! (PS - If you read this far, you should totally subscribe)


Why does music make us feel happy or sad? Or angry or romantic? How can simple sound waves cause so much emotion?

First things first, this is the best t-shirt I’ve worn in any episode.

I went from my comfy chair to the streets of Austin to investigate whether it might be written into neural evolution. Modern neuroscience says our brains may be wired to pick certain emotions out of music because they remind us of how people move!

Humans are the only species we know that creates and communicate using music, but it’s still unclear how or why we do that, brain-wise. Is it just a lucky side effect of evolution, like Steven Pinker says? Or is it a deeper part of our evolutionary history, as people like Mark Changizi and Daniel Levitin argue?

Some brand new evolutionary psychology research says that we may read emotion in music because it relates to how we sense emotion in people’s movements. We’ll take a trip from Austin to Dartmouth to Cambodia to hear why music makes us feel so many feels. The connections between movement and music go far beyond dance moves!

Mike over at Idea Channel has a different opinion, that our emotional reactions to music are purely learned and cultural. Head on over and check it out. Do you agree?

For more reading on this awesome topic, check out these references.


Whose Air Would You Share?

In response to the latest episode of It’s Okay To Be Smart, “Whose Air Do We Share?” many of you shared with me who you were most excited to share air molecules with.

There were plenty of Carl Sagans and other great minds offered, as well as Amy Poehler and even a horse (Secretariat). But many of you also sent in touching answers, like grandparents you’ve never gotten to meet, or people who left us too soon.

When we step past all the atmospheric science and interesting math about just how small and shared our atmosphere is, I think this bit of poetic connection will prove to be my favorite part of this episode.

I mean, science providing us with a profound sense of connection, true links to the past, true community with those we can no longer see and with those we have never met? That’s a breath of fresh air.

Click here to subscribe and to check out more episodes.


New episode of It’s Okay To Be Smart! Let’s all do the “new video” dance:

My latest creation is an ode to space exploration, from its rather war-themed beginnings, to the pure adventure of Apollo, to the golden age of the shuttle era, to the curiosity of Curiosity.

Where do we go from here? Special thanks to the National Air and Space Museum for letting me hang out with a real-life space shuttle for a few hours.

Episode Extra: Behemoths of Biomass

(This post helps explain some of the science in the latest episode of my YouTube show, which is called, you guessed it, It’s Okay To Be Smart. It’s impossible to get all the details into a few minutes, so I dig into the them here. Watch the episode here if you haven’t already. Seriously, watch it already!)

Lots of the “scale of life” stuff that I talked about in my latest episode “Life by the Numbers” dealt with the mind-boggling multitudes that make up populations of things like birds, bacteria and viruses. But being numerous isn’t all there is to success. What about enormous single organisms?

Individual life forms may not have much influence on the world around them all by their lonesome selves, but when they come together on enormous scales like billions, trillions or quadrillions they can have huge influence their ecosystems because of … well, their sheer numbers. Trillions of bacteria crawling around in forest soil possess an incredibly diverse set of genes that they can share and transfer between each other like salesmen trading business cards. That drives evolution into the fast lane. These “big number” populations can also eat a lot, or provide food for a host of other organisms, as ocean viruses do as their infected dead sink to the bottom of the ocean to feed hordes of tiny creatures. Circle of life, man.

Now for the behemoths. Large single individuals can also have huge advantages from being large and independent, but that brings its own set of risks.

Take the Aspen tree grove named Pando that I talked about in the video. It gains an advantage by being one single, genetically identical, physically connected organism. It is literally a single tree that looks like tens of thousands. Wrap your mind around that. If one side of the grove is near water or minerals, it can transfer those nutrients to an area of grove that is dry or in less fertile soil, like a big city plumbing system. This underground connection is also a defense against forest fires, because all the above-surface parts can burn away and new trees can grow back quickly. Environmental adaptation, folks!

Several people didn’t like how I compared an underground fungus (it lives in Oregon’s Malheur National Forest) to the weight of 75 space shuttles. Well, there’s no number I can give you that will make any sense to our petty human brains. How about 7,000 tons? What’s even crazier is that the underground fungal web is nearly invisible. We’re used to seeing the fruiting bodies of fungi, those mushroom things. But it’s the threadlike hyphae and mycelium that reach like fingers through the forest floor, digesting dead plant matter so that it doesn’t pile up over the treetops (because it would, seriously). It’s a massively interconnected fungal buffet, and these decomposers help keep an area the size of 1,600 football fields clear.

Unfortunately, being genetically identical means they are extra-sensitive to disease and environmental disruption. That’s why WE need to be so careful about how we treat these giants of biomass.

So these big boys and girls can serve as cornerstones of ecosystems, be incredibly resilient, and attain great mass and reach because they are a single, large organism. But this is also their Achilles’ heel, and makes them incredibly sensitive to the destructive forces of man, beast and bug. Being bigger and broader is an immense accomplishment in terms of evolution, but evolution never reaches perfection. This is proof of species success, but success is perhaps never complete in the living world.

How do you think “bigger” compares to “numerous” in species success?

HA! So, today’s my last day working in my lab, today’s Dilbert is amazingly appropriate, eh? :)

On to bigger and better things! I’ll be working the science beat at Wired Magazine in San Francisco this summer, and my PBS YouTube show continues on and on.

Thanks, everyone. In a way, I feel like we did this together. Let’s see what else we can learn! (Or at least pretend to learn)

-Dr. Joe

Who would you most like to share a breath with?

Since shooting the latest episode of It’s Okay To Be Smart, “Whose Air Do We Share?”, I haven’t been able to escape those poetic feels that come with knowing we all really do share the same air. I mean, our atmosphere’s 1044 molecules of air is a lot, but given enough time we will share at least a few of those with everyone, living or dead. That’s pretty awesome.

Not only does it give me a wonderful sense of connection with people I’ll never get to meet, but it reminds me that we have to be careful about what we’re putting in the air up there.

My answer is pretty obvious (just look at the GIF above), but I want to hear from you all (it will make sense after you watch the video at the link, of course): Living or dead, science-y or not, famous or anonymous, whose air are you most excited to share?

Watch on

I’ve been making YouTube videos for 7 months now and I STILL get messages from people on Tumblr or Twitter or wherever saying “Heywhahuh I didn’t know you had a YouTube channel!!

Well I do have a YouTube channel, and it would be cool if you watched it and subscribed and shared it with your friends, because I know you love science and this my job now and when you watch I get to, like, eat :) 

How can I make sure all of my Tumblr followers know this? Maybe I should rent one of those planes that uses smoke to write in the sky? Except that would be expensive to get it to all of your cities … hmm …

Here’s the new trailer for the channel we just put up. New videos are starting up next week!