When we hear the word radiation, it's tempting to picture huge explosions and frightening mutations, but that's not the full story.
Radiation also applies to rainbows and a doctor examining an x-ray.
So what is radiation really, and how much should we worry about its effects?
The answer begins with understanding that the word radiation describes two very different scientific phenomena: electromagnetic radiation and nuclear radiation.
Electromagnetic radiation is pure energy consisting of interacting electrical and magnetic waves oscillating through space.
As these waves oscillate faster, they scale up in energy.
At the lower end of the spectrum, there's radio, infrared, and visible light.
At the higher end are ultraviolet, X-ray, and gamma rays.
Modern society is shaped by sending and detecting electromagnetic radiation.
We might download an email to our phone via radio waves to open an image of an X-ray print, which we can see because our screen emits visible light.
Nuclear radiation, on the other hand, originates in the atomic nucleus, where protons repel each other due to their mutually positive charges.
A phenomenon known as the strong nuclear force struggles to overcome this repulsion and keep the nucleus intact.
However, some combinations of protons and neutrons, known as isotopes, remain unstable, or radioactive.
They will randomly eject matter and/or energy, known as nuclear radiation, to achieve greater stability.
Nuclear radiation comes from natural sources, like radon, a gas which seeps up from the ground.
We also refine naturally occurring radioactive ores to fuel nuclear power plants.
Even bananas contain trace amounts of a radioactive potassium isotope.
So if we live in a world of radiation, how can we escape its dangerous effects?
To start, not all radiation is hazardous.
Radiation becomes risky when it rips atoms' electrons away upon impact, a process that can damage DNA.
This is known as ionizing radiation because an atom that has lost or gained electrons is called an ion.
All nuclear radiation is ionizing, while only the highest energy electromagnetic radiation is.
That includes gamma rays, X-rays, and the high-energy end of ultraviolet.
That's why as an extra precaution during X-rays, doctors shield body parts they don't need to examine, and why beach-goers use sunscreen.
In comparison, cell phones and microwaves operate at the lower end of the spectrum, so there is no risk of ionizing radiation from their use.
The biggest health risk occurs when lots of ionizing radiation hits us in a short time period, also known as an acute exposure.
Acute exposures overwhelm the body's natural ability to repair the damage.
This can trigger cancers, cellular dysfunction, and potentially even death.
Fortunately, acute exposures are rare, but we are exposed daily to lower levels of ionizing radiation from both natural and man-made sources.
Scientists have a harder time quantifying these risks.
Your body often repairs damage from small amounts ionizing radiation, and if it can't, the results of damage may not manifest for a decade or more.
One way scientists compare ionizing radiation exposure is a unit called the sievert.
An acute exposure to one sievert will probably cause nausea within hours, and four sieverts could be fatal.
However, our normal daily exposures are far lower.
The average person receives 6.2 millisieverts of radiation from all sources annually, around a third due to radon.
At only five microsieverts each, you'd need to get more than 1200 dental X-rays to rack up your annual dosage.
And remember that banana?
If you could absorb all the banana's radiation, you'd need around 170 a day to hit your annual dosage.
We live in a world of radiation.
However, much of that radiation is non-ionizing.
For the remainder that is ionizing, our exposures are usually low, and choices like getting your home tested for radon and wearing sunscreen can help reduce the associated health risks.
Marie Curie, one of the early radiation pioneers, summed up the challenge as follows: "Nothing in life is to be feared, it is only to be understood.
Now is the time to understand more, so that we may fear less."
Companies are losing control.
What happens on Wall Street no longer stays on Wall Street.
What happens in Vegas ends up on YouTube.
(Laughter) Reputations are volatile.
Loyalties are fickle.
Management teams seem increasingly disconnected from their staff.
(Laughter) A recent survey said that 27 percent of bosses believe their employees are inspired by their firm.
However, in the same survey, only four percent of employees agreed.
Companies are losing control of their customers and their employees.
But are they really?
I'm a marketer, and as a marketer, I know that I've never really been in control.
Your brand is what other people say about you when you're not in the room, the saying goes.
Hyperconnectivity and transparency allow companies to be in that room now, 24/7.
They can listen and join the conversation.
In fact, they have more control over the loss of control than ever before.
They can design for it.
But how?
First of all, they can give employees and customers more control.
They can collaborate with them on the creation of ideas, knowledge, content, designs and product.
They can give them more control over pricing, which is what the band Radiohead did with its pay-as-you-like online release of its album "In Rainbows."
Buyers could determine the price, but the offer was exclusive, and only stood for a limited period of time.
The album sold more copies than previous releases of the band.
The Danish chocolate company Anthon Berg opened a so-called "generous store" in Copenhagen.
It asked customers to purchase chocolate with the promise of good deeds towards loved ones.
It turned transactions into interactions, and generosity into a currency.
Companies can even give control to hackers.
When Microsoft Kinect came out, the motion-controlled add-on to its Xbox gaming console, it immediately drew the attention of hackers.
Microsoft first fought off the hacks, but then shifted course when it realized that actively supporting the community came with benefits.
The sense of co-ownership, the free publicity, the added value, all helped drive sales.
The ultimate empowerment of customers is to ask them not to buy.
Outdoor clothier Patagonia encouraged prospective buyers to check out eBay for its used products and to resole their shoes before purchasing new ones.
In an even more radical stance against consumerism, the company placed a "Don't Buy This Jacket" advertisement during the peak of shopping season.
It may have jeopardized short-term sales, but it builds lasting, long-term loyalty based on shared values.
Research has shown that giving employees more control over their work makes them happier and more productive.
The Brazilian company Semco Group famously lets employees set their own work schedules and even their salaries.
Hulu and Netflix, among other companies, have open vacation policies.
Companies can give people more control, but they can also give them less control.
Traditional business wisdom holds that trust is earned by predictable behavior, but when everything is consistent and standardized, how do you create meaningful experiences?
Giving people less control might be a wonderful way to counter the abundance of choice and make them happier.
Take the travel service Nextpedition.
Nextpedition turns the trip into a game, with surprising twists and turns along the way.
It does not tell the traveler where she's going until the very last minute, and information is provided just in time.
Similarly, Dutch airline KLM launched a surprise campaign, seemingly randomly handing out small gifts to travelers en route to their destination.
U.K.-based Interflora monitored Twitter for users who were having a bad day, and then sent them a free bouquet of flowers.
Is there anything companies can do to make their employees feel less pressed for time?
Yes.
Force them to help others.
A recent study suggests that having employees complete occasional altruistic tasks throughout the day increases their sense of overall productivity.
At Frog, the company I work for, we hold internal speed meet sessions that connect old and new employees, helping them get to know each other fast.
By applying a strict process, we give them less control, less choice, but we enable more and richer social interactions.
Companies are the makers of their fortunes, and like all of us, they are utterly exposed to serendipity.
That should make them more humble, more vulnerable and more human.
At the end of the day, as hyperconnectivity and transparency expose companies' behavior in broad daylight, staying true to their true selves is the only sustainable value proposition.
Or as the ballet dancer Alonzo King said, "What's interesting about you is you."
For the true selves of companies to come through, openness is paramount, but radical openness is not a solution, because when everything is open, nothing is open.
"A smile is a door that is half open and half closed," the author Jennifer Egan wrote.
Companies can give their employees and customers more control or less.
They can worry about how much openness is good for them, and what needs to stay closed.
Or they can simply smile, and remain open to all possibilities.
Thank you.
(Applause) (Applause)
When I was in the fifth grade, I bought an issue of "DC Comics Presents #57" off of a spinner rack at my local bookstore, and that comic book changed my life.
The combination of words and pictures did something inside my head that had never been done before, and I immediately fell in love with the medium of comics.
I became a voracious comic book reader, but I never brought them to school.
Instinctively, I knew that comic books didn't belong in the classroom.
My parents definitely were not fans, and I was certain that my teachers wouldn't be either.
After all, they never used them to teach, comic books and graphic novels were never allowed during silent sustained reading, and they were never sold at our annual book fair.
Even so, I kept reading comics, and I even started making them.
Eventually I became a published cartoonist, writing and drawing comic books for a living.
I also became a high school teacher.
This is where I taught: Bishop O'Dowd High School in Oakland, California.
I taught a little bit of math and a little bit of art, but mostly computer science, and I was there for 17 years.
When I was a brand new teacher, I tried bringing comic books into my classroom.
I remember telling my students on the first day of every class that I was also a cartoonist.
It wasn't so much that I was planning to teach them with comics, it was more that I was hoping comics would make them think that I was cool.
(Laughter) I was wrong.
This was the '90s, so comic books didn't have the cultural cachet that they do today.
My students didn't think I was cool.
They thought I was kind of a dork.
And even worse, when stuff got hard in my class, they would use comic books as a way of distracting me.
They would raise their hands and ask me questions like, "Mr. Yang, who do you think would win in a fight, Superman or the Hulk?"
(Laughter) I very quickly realized I had to keep my teaching and my cartooning separate.
It seemed like my instincts in fifth grade were correct.
Comic books didn't belong in the classroom.
But again, I was wrong.
A few years into my teaching career, I learned firsthand the educational potential of comics.
One semester, I was asked to sub for this Algebra 2 class.
I was asked to long-term sub it, and I said yes, but there was a problem.
At the time, I was also the school's educational technologist, which meant every couple of weeks I had to miss one or two periods of this Algebra 2 class because I was in another classroom helping another teacher with a computer-related activity.
For these Algebra 2 students, that was terrible.
I mean, having a long-term sub is bad enough, but having a sub for your sub?
That's the worst.
In an effort to provide some sort of consistency for my students, I began videotaping myself giving lectures.
I'd then give these videos to my sub to play for my students.
I tried to make these videos as engaging as possible.
I even included these little special effects.
For instance, after I finished a problem on the board, I'd clap my hands, and the board would magically erase.
(Laughter) I thought it was pretty awesome.
I was pretty certain that my students would love it, but I was wrong.
(Laughter) These video lectures were a disaster.
I had students coming up to me and saying things like, "Mr. Yang, we thought you were boring in person, but on video, you are just unbearable."
(Laughter) So as a desperate second attempt, I began drawing these lectures as comics.
I'd do these very quickly with very little planning.
I'd just take a sharpie, draw one panel after the other, figuring out what I wanted to say as I went.
These comics lectures would come out to anywhere between four and six pages long, I'd xerox these, give them to my sub to hand to my students.
And much to my surprise, these comics lectures were a hit.
My students would ask me to make these for them even when I could be there in person.
It was like they liked cartoon me more than actual me.
(Laughter) This surprised me, because my students are part of a generation that was raised on screens, so I thought for sure they would like learning from a screen better than learning from a page.
But when I talked to my students about why they liked these comics lectures so much, I began to understand the educational potential of comics.
First, unlike their math textbooks, these comics lectures taught visually.
Our students grow up in a visual culture, so they're used to taking in information that way.
But unlike other visual narratives, like film or television or animation or video, comics are what I call permanent.
In a comic, past, present and future all sit side by side on the same page.
This means that the rate of information flow is firmly in the hands of the reader.
When my students didn't understand something in my comics lecture, they could just reread that passage as quickly or as slowly as they needed.
It was like I was giving them a remote control over the information.
The same was not true of my video lectures, and it wasn't even true of my in-person lectures.
When I speak, I deliver the information as quickly or slowly as I want.
So for certain students and certain kinds of information, these two aspects of the comics medium, its visual nature and its permanence, make it an incredibly powerful educational tool.
When I was teaching this Algebra 2 class, I was also working on my master's in education at Cal State East Bay.
And I was so intrigued by this experience that I had with these comics lectures that I decided to focus my final master's project on comics.
I wanted to figure out why American educators have historically been so reluctant to use comic books in their classrooms.
Here's what I discovered.
Comic books first became a mass medium in the 1940s, with millions of copies selling every month, and educators back then took notice.
A lot of innovative teachers began bringing comics into their classrooms to experiment.
In 1944, the "Journal of Educational Sociology" even devoted an entire issue to this topic.
Things seemed to be progressing.
Teachers were starting to figure things out.
But then along comes this guy.
This is child psychologist Dr. Fredric Wertham, and in 1954, he wrote a book called "Seduction of the Innocent," where he argues that comic books cause juvenile delinquency.
(Laughter) He was wrong.
Now, Dr. Wertham was actually a pretty decent guy.
He spent most of his career working with juvenile delinquents, and in his work he noticed that most of his clients read comic books.
What Dr. Wertham failed to realize was in the 1940s and '50s, almost every kid in America read comic books.
Dr. Wertham does a pretty dubious job of proving his case, but his book does inspire the Senate of the United States to hold a series of hearings to see if in fact comic books caused juvenile delinquency.
These hearings lasted for almost two months.
They ended inconclusively, but not before doing tremendous damage to the reputation of comic books in the eyes of the American public.
After this, respectable American educators all backed away, and they stayed away for decades.
It wasn't until the 1970s that a few brave souls started making their way back in.
And it really wasn't until pretty recently, maybe the last decade or so, that comics have seen more widespread acceptance among American educators.
Comic books and graphic novels are now finally making their way back into American classrooms and this is even happening at Bishop O'Dowd, where I used to teach.
Mr. Smith, one of my former colleagues, uses Scott McCloud's "Understanding Comics" in his literature and film class, because that book gives his students the language with which to discuss the relationship between words and images.
Mr. Burns assigns a comics essay to his students every year.
By asking his students to process a prose novel using images, Mr. Burns asks them to think deeply not just about the story but also about how that story is told.
And Ms. Murrock uses my own "American Born Chinese" with her English 1 students.
For her, graphic novels are a great way of fulfilling a Common Core Standard.
The Standard states that students ought to be able to analyze how visual elements contribute to the meaning, tone and beauty of a text.
Over in the library, Ms. Counts has built a pretty impressive graphic novel collection for Bishop O'Dowd.
Now, Ms. Counts and all of her librarian colleagues have really been at the forefront of comics advocacy, really since the early '80s, when a school library journal article stated that the mere presence of graphic novels in the library increased usage by about 80 percent and increased the circulation of noncomics material by about 30 percent.
Inspired by this renewed interest from American educators, American cartoonists are now producing more explicitly educational content for the K-12 market than ever before.
A lot of this is directed at language arts, but more and more comics and graphic novels are starting to tackle math and science topics.
STEM comics graphics novels really are like this uncharted territory, ready to be explored.
America is finally waking up to the fact that comic books do not cause juvenile delinquency.
(Laughter) That they really do belong in every educator's toolkit.
There's no good reason to keep comic books and graphic novels out of K-12 education.
They teach visually, they give our students that remote control.
The educational potential is there just waiting to be tapped by creative people like you.
Thank you.
(Applause)