How is it that so many intergalactic species in movies and TV just happen to speak perfect English?
The short answer is that no one wants to watch a starship crew spend years compiling an alien dictionary.
But to keep things consistent, the creators of Star Trek and other science-fiction worlds have introduced the concept of a universal translator, a portable device that can instantly translate between any languages.
So is a universal translator possible in real life?
We already have many programs that claim to do just that, taking a word, sentence, or entire book in one language and translating it into almost any other, whether it's modern English or Ancient Sanskrit.
And if translation were just a matter of looking up words in a dictionary, these programs would run circles around humans.
The reality, however, is a bit more complicated.
A rule-based translation program uses a lexical database, which includes all the words you'd find in a dictionary and all grammatical forms they can take, and set of rules to recognize the basic linguistic elements in the input language.
For a seemingly simple sentence like, "The children eat the muffins," the program first parses its syntax, or grammatical structure, by identifying the children as the subject, and the rest of the sentence as the predicate consisting of a verb "eat," and a direct object "the muffins."
It then needs to recognize English morphology, or how the language can be broken down into its smallest meaningful units, such as the word muffin and the suffix "s," used to indicate plural.
Finally, it needs to understand the semantics, what the different parts of the sentence actually mean.
To translate this sentence properly, the program would refer to a different set of vocabulary and rules for each element of the target language.
But this is where it gets tricky.
The syntax of some languages allows words to be arranged in any order, while in others, doing so could make the muffin eat the child.
Morphology can also pose a problem.
Slovene distinguishes between two children and three or more using a dual suffix absent in many other languages, while Russian's lack of definite articles might leave you wondering whether the children are eating some particular muffins, or just eat muffins in general.
Finally, even when the semantics are technically correct, the program might miss their finer points, such as whether the children "mangiano" the muffins, or "divorano" them.
Another method is statistical machine translation, which analyzes a database of books, articles, and documents that have already been translated by humans.
By finding matches between source and translated text that are unlikely to occur by chance, the program can identify corresponding phrases and patterns, and use them for future translations.
However, the quality of this type of translation depends on the size of the initial database and the availability of samples for certain languages or styles of writing.
The difficulty that computers have with the exceptions, irregularities and shades of meaning that seem to come instinctively to humans has led some researchers to believe that our understanding of language is a unique product of our biological brain structure.
In fact, one of the most famous fictional universal translators, the Babel fish from "The Hitchhiker's Guide to the Galaxy", is not a machine at all but a small creature that translates the brain waves and nerve signals of sentient species through a form of telepathy.
For now, learning a language the old fashioned way will still give you better results than any currently available computer program.
But this is no easy task, and the sheer number of languages in the world, as well as the increasing interaction between the people who speak them, will only continue to spur greater advances in automatic translation.
Perhaps by the time we encounter intergalactic life forms, we'll be able to communicate with them through a tiny gizmo, or we might have to start compiling that dictionary, after all.
What's your sign?
In Western astrology, it's a constellation determined by when your birthday falls in the calendar.
But according to the Chinese zodiac, or shēngxiào, it's your shǔxiàng, meaning the animal assigned to your birth year.
And of the many myths explaining these animal signs and their arrangement, the most enduring one is that of the Great Race.
As the story goes, Yù Dì, or Jade Emperor, Ruler of the Heavens, wanted to devise a way to measure time, so he organized a race.
The first twelve animals to make it across the river would earn a spot on the zodiac calendar in the order they arrived.
The rat rose with the sun to get an early start, but on the way to the river, he met the horse, the tiger, and the ox.
Because the rat was small and couldn't swim very well, he asked the bigger animals for help.
While the tiger and horse refused, the kind-hearted ox agreed to carry the rat across.
Yet, just as they were about to reach the other side, the rat jumped off the ox's head and secured first place.
The ox came in second, with the powerful tiger right behind him.
The rabbit, too small to battle the current, nimbly hopped across stones and logs to come in fourth.
Next came the dragon, who could have flown directly across, but stopped to help some creatures she had encountered on the way.
After her came the horse, galloping across the river.
But just as she got across, the snake slithered by.
The startled horse reared back, letting the snake sneak into sixth place.
The Jade Emperor looked out at the river and spotted the sheep, the monkey, and the rooster all atop a raft, working together to push it through the weeds.
When they made it across, the trio agreed to give eighth place to the sheep, who had been the most comforting and harmonious of them, followed by the monkey and the rooster.
Next came the dog, scrambling onto the shore.
He was a great swimmer, but frolicked in the water for so long that he only managed to come in eleventh.
The final spot was claimed by the pig, who had gotten hungry and stopped to eat and nap before finally waddling across the finish line.
And so, each year is associated with one of the animals in this order, with the cycle starting over every 60 years.
Why 60 and not twelve?
Well, the traditional Chinese calendar is made up of two overlapping systems.
The animals of the zodiac are associated with what's called the Twelve Earthly Branches, or shí'èrzhī.
Another system, the Ten Heavenly Stems, or tiāngān, is linked with the five classical elements of metal, xīn, wood, mù, water, shuǐ, fire, huǒ, and earth, tǔ.
Each element is assigned yīn or yáng, creating a ten-year cycle.
When the twelve animals of the Earthly Branches are matched with the five elements plus the yīn or the yáng of the Heavenly Stems, it creates 60 years of different combinations, known as a sexagenary cycle, or gānzhī.
So someone born in 1980 would have the sign of yáng metal monkey, while someone born in 2007 would be yīn fire pig.
In fact, you can also have an inner animal based on your birth month, a true animal based on your birth date, and a secret animal based on your birth hour.
It was the great race that supposedly determined which animals were enshrined in the Chinese zodiac, but as the system spread through Asia, other cultures made changes to reflect their communities.
So if you consult the Vietnamese zodiac, you may discover that you're a cat, not a rabbit, and if you're in Thailand, a mythical snake called a Naga replaces the dragon.
So whether or not you place stock in what the zodiac says about you as an individual, it certainly reveals much about the culture it comes from.
Just between your chest and abdomen is where you’ll find one of the most important muscles you probably didn't know you had: the lower esophageal sphincter, or LES.
When functioning properly, this ring of tissue plays a crucial role in helping us eat.
But when the LES malfunctions, it becomes the main player in heartburn --a searing, sometimes sour-tasting chest-spasm that many people will experience at some point in their lives.
We know that humans have been battling heartburn for hundreds, if not thousands of years.
But recently the incidence has risen, making it a common stomach complaint worldwide.
When the symptoms of heartburn become more more regular and intense —such as twice a week or more-- it’s diagnosed as Gastroesophageal Reflux Disease, or GERD.
But what causes this problem, and how can it be stopped?
Heartburn starts in an area called the gastroesophageal junction, where the LES resides.
This smooth, muscular ring of the LES is moderated by an intricate tree of nerve roots that connect to the brain, the heart, and the lungs.
After food enters the stomach from the esophagus, the muscle’s task is to stop it from surging back up again.
The LES contracts, squeezing the stomach entrance and creating a high pressure zone that prevents digestive acids from seeping out.
But if the LES relaxes at the wrong moment or gradually weakens, it becomes like a faulty, ill-fitting lid, causing the area to depressurize.
That allows burning stomach acid-- and even chunks of food--to spurt into the esophagus, sometimes going as far up as the mouth.
The cause of all this internal drama has long been put down to diet.
Foods like caffeine and peppermint contain ingredients that may have a relaxing affect on the LES, which makes it incapable of doing its job.
Other acidic foods, like citrus and tomatoes, can worsen irritation of the esophagus when they leach out with stomach acid.
Carbonated beverages can similarly bubble up in the stomach, forcing open the valve.
But researchers have discovered that food isn’t the only trigger.
Smoking poses a risk, because the nicotine in cigarettes relaxes the LES.
Consuming excessive amounts of alcohol may have a similar effect.
Pregnant women often experience more heartburn due to the pressure of a growing baby on their stomachs.
and the levels of certain hormones in their bodies.
Obesity can cause hernias that disrupt the anti-reflux barrier of the gastroesophageal junction that normally protects against heartburn.
Numerous medications, including those for asthma, high blood pressure, birth control, and depression can also have unintended effects on the LES.
An occasional bout of heartburn isn't necessarily something to worry about.
But, if heartburn starts happening regularly, it can weaken the LES muscle over time, letting more and more acid escape.
And if it goes untreated, this can cause bigger problems.
Over time, constant acid leakage from heartburn may form scar tissue which narrows the esophageal tube, making it harder to swallow food.
Ongoing reflux can also damage the cells lining the esophagus--a rare condition called Barrett’s esophagus, which can elevate the risk of esophageal cancer.
Luckily, heartburn is often treatable with a range of medicines that can help neutralize or reduce stomach acid.
In extreme cases, some people have surgery to tighten the LES to minimize their distress.
But we can often stop heartburn before it reaches that point.
Reducing the consumption of certain foods, not smoking, and maintaining a healthy weight can all dramatically reduce reflux.
With proper care we can help our LES’s keep the chemical fountain of our stomachs in proper order and avoid having to feel the burn.
If you look deep into the night sky, you see stars, and if you look further, you see more stars, and further, galaxies, and further, more galaxies.
But if you keep looking further and further, eventually you see nothing for a long while, and then finally you see a faint, fading afterglow, and it's the afterglow of the Big Bang.
Now, the Big Bang was an era in the early universe when everything we see in the night sky was condensed into an incredibly small, incredibly hot, incredibly roiling mass, and from it sprung everything we see.
Now, we've mapped that afterglow with great precision, and when I say we, I mean people who aren't me.
We've mapped the afterglow with spectacular precision, and one of the shocks about it is that it's almost completely uniform.
Fourteen billion light years that way and 14 billion light years that way, it's the same temperature.
Now it's been 14 billion years since that Big Bang, and so it's got faint and cold.
It's now 2.7 degrees.
But it's not exactly 2.7 degrees.
It's only 2.7 degrees to about 10 parts in a million.
Over here, it's a little hotter, and over there, it's a little cooler, and that's incredibly important to everyone in this room, because where it was a little hotter, there was a little more stuff, and where there was a little more stuff, we have galaxies and clusters of galaxies and superclusters and all the structure you see in the cosmos.
And those small, little, inhomogeneities, 20 parts in a million, those were formed by quantum mechanical wiggles in that early universe that were stretched across the size of the entire cosmos.
That is spectacular, and that's not what they found on Monday; what they found on Monday is cooler.
So here's what they found on Monday: Imagine you take a bell, and you whack the bell with a hammer.
What happens?
It rings.
But if you wait, that ringing fades and fades and fades until you don't notice it anymore.
Now, that early universe was incredibly dense, like a metal, way denser, and if you hit it, it would ring, but the thing ringing would be the structure of space-time itself, and the hammer would be quantum mechanics.
What they found on Monday was evidence of the ringing of the space-time of the early universe, what we call gravitational waves from the fundamental era, and here's how they found it.
Those waves have long since faded.
If you go for a walk, you don't wiggle.
Those gravitational waves in the structure of space are totally invisible for all practical purposes.
But early on, when the universe was making that last afterglow, the gravitational waves put little twists in the structure of the light that we see.
So by looking at the night sky deeper and deeper -- in fact, these guys spent three years on the South Pole looking straight up through the coldest, clearest, cleanest air they possibly could find looking deep into the night sky and studying that glow and looking for the faint twists which are the symbol, the signal, of gravitational waves, the ringing of the early universe.
And on Monday, they announced that they had found it.
And the thing that's so spectacular about that to me is not just the ringing, though that is awesome.
The thing that's totally amazing, the reason I'm on this stage, is because what that tells us is something deep about the early universe.
It tells us that we and everything we see around us are basically one large bubble -- and this is the idea of inflation— one large bubble surrounded by something else.
This isn't conclusive evidence for inflation, but anything that isn't inflation that explains this will look the same.
This is a theory, an idea, that has been around for a while, and we never thought we we'd really see it.
For good reasons, we thought we'd never see killer evidence, and this is killer evidence.
But the really crazy idea is that our bubble is just one bubble in a much larger, roiling pot of universal stuff.
We're never going to see the stuff outside, but by going to the South Pole and spending three years looking at the detailed structure of the night sky, we can figure out that we're probably in a universe that looks kind of like that.
And that amazes me.
Thanks a lot.
(Applause)