Sunday 31 October 2010

Johnald's Fantastical Daily Link Splurge

Johnald's Fantastical Daily Link Splurge


What the Frak? Battlestar Galactica’s Science Explained

Posted: 30 Oct 2010 04:00 AM PDT

When the science fiction drama Battlestar Galactica ended in 2009, it left some geeks wanting answers. How can a humanoid robot plug directly into a spaceship? How does Galactica's faster-than-light travel work? And what the frak was up with the mitochondrial Eve thing?

Read a Wired.com exclusive excerpt from the new book by Patrick Di Justo and Kevin Grazier, The Science of Battlestar Galactica.

To find out, Wired.com spoke with Patrick Di Justo, Wired magazine contributing editor and co-author of the new book, The Science of Battlestar Galactica. Together with the show's science advisor, NASA scientist Kevin Grazier, Di Justo jumps beyond the red line to delve into the science behind the story — and discovers that some things lie beyond what science can reach.

Spoiler alert: Major plot points ahead.

Wired.com: What was the purpose of this book?

Patrick Di Justo: Battlestar Galactica has been called "a science fiction show without the science." There are some episodes of Galactica that are almost like The West Wing, they dealt more with politics…. They never really highlighted the science in the show unless it drove the plot. That was very good from a dramatic point of view, but it did leave a lot of science unexplored and unexplained in the show.

So we thought, hey, no one's really building up the science in the show, and it's there. Why don't we do it?

Wired.com: So in the show's philosophy, who wins in the science-versus-drama battle?

Di Justo: There's actually a quote in the book, where it says, "Drama wins every time." That's essentially it. It's not that they completely threw science out the airlock. It's just that there would be times when they wouldn't mention or play up the science.

 

Wired.com: Can you give an example?

DiJusto: Very basically, how could Cylons pass medical tests? They never explained that, never went into any detail about it. It was just accepted that Cylons could be so wonderfully indistinguishable that it would take a demented genius like Gaius Baltar to build a special type of machine that could differentiate the two. You wouldn't tell them apart from a standard medical test. And the show never explains how that works, how that happens — it just happens.

Same thing with the FTL drive. They never explain how it happens, it's just spin up the drives and whoosh — off you go.

Wired.com: It seems like sometimes the physics of how the FTL drive works changes to fit what would be the most dramatic thing.

Di Justo: In the book, we explain that they never really locked down how the FTL drive worked, until they actually needed the details for a plot point. As long as you could reasonably say, okay, let's FTL jump out of here, that's all you needed to know — until an aspect of the drama required you need to know how it works.

Wired.com: People have raised parallels between Battlestar Galactica and our own world, and not just in the way the final episode plays out. Can you talk a bit about that?

Di Justo: Think about what the mood in this country was like in 2003. We were still scared from the Sept. 11 attacks. We had this problem of, who can you trust? People were seeing terrorists under every bridge, it seemed.

And here you had a science fiction property from nearly 25 years before that covered almost all of those fears and feelings that we were having. So the show, it did what I believe science fiction is supposed to do. It takes us to the future, out in space. It takes us away from our current day, so that we can turn around and look at ourselves through a different lens.

Wired.com: What kind of messages or cautionary tales do we get from the treatment of these questions in Battlestar?

Di Justo: One of the show's executive producers, David Eick, said, "We're not doing our jobs if, at least once a week, the viewer doesn't ask. 'Am I rooting for the wrong team?'"

Here, at least in America in 2003 when the show first came on, so many people were insisting that they knew this was right, these people were evil, we are the right people.

Then this show came along, which paralleled or mirrored that. You've got these Colonials who we're sure are right, and the Cylons who we're sure are evil and bad. But over the course of the first couple of seasons, sometimes maybe the Colonials aren't right all the time. Sometimes maybe the Cylons aren't evil all the time. Eventually you get to the point where the Colonials are doing suicide bombings against the Cylons. Here we are saying suicide bombing is just plain-out bad, and before you know it the good guys are doing it. Are they still the good guys?

My opinion is, if you had done that on American television with Americans and Muslim terrorists, and if you had blurred the line between the two, my God, the show would have been off the air before the episode had ended.

Yet by putting it in outer space, by making the bad guys manufactured robots, you could tell that same story, you could blur those lines. But you're not doing it in such an obvious way that would make people get their defenses up. That's what science fiction has been doing since the very, very beginning.

Wired.com: What are some other parallels and differences between Colonials, Cylons and Earth humans?

Di Justo: Well, we talked about blood type at Comic Con in New York. Another key thing is, in the episode "A Measure of Salvation," a subgroup of Cylons come across an old beacon that happens to be contaminated with lymphocytic encephalitis. They're sickened, they're on the verge of death. If they're not helped soon, they're all going to die.

Doctor Cottle explains that the Colonials are immune to this disease. They're just absolutely fine, while the Cylons are dying.

That sounds really cool, but when you start to look into it, we, the people on the planet Earth in 2010, we are not immune to lymphocytic encephalitis. We get sick. Sometimes if we're not careful, we die.

Right there in the third season, we did not know how the show was going to end. But we got a really strong clue that Colonials are one type of people, Cylons are another type of people, and we humans really do seem to be halfway between both of them. We do seem to be a link, somehow, between them. And eventually at the end of the series we found out that we are the descendants of both groups.

Wired.com: What about Cylon neural structure? Are there brain differences between Cylons and humans?

Di Justo: At the very beginning, in the miniseries, where Commander Adama says that the radiation on Ragnar is affecting the Cylon's silica pathways to the brain: For myself, I was thinking of dark silicon, like the stuff a CPU is made out of.

Until Dr. Grazier pointed out that a fiber-optic cable is also a silica pathway. Instead of dark silica, like a CPU, what is more likely is that they have fiber optics jacking up their neural systems. Which is how, when you see one of the Number Eight Cylons jam a fiber-optic cable into her arm and reprogram a computer, that's how that happens. They have fiber-optic nerves.

Wired.com: And that lets them interface with any computer like a USB?

Di Justo: That's what we're seeing, yeah.

Exclusive Excerpt: The Science of Battlestar Galactica

Posted: 30 Oct 2010 04:00 AM PDT

Spoiler alert: This excerpt contains details of the final scene of the final episode. If you don't know why Hera Agathon is important, you may want to finish watching the series before reading.

Mitochondrial Eve

In the last scene of the last episode of Battlestar Galactica, Angel Six and Angel Baltar appear behind a bearded man (Ron Moore, in a goodbye cameo) at a New York newsstand, reading an issue of National Geographic magazine over his shoulder. Angel Six, in voiceover, reads, "Mitochondrial Eve is the name scientists have given to the most recent common ancestor for all human beings now living on Earth." We're supposed to assume they're referring to Hera, Helo and Athena's half-Colonial, half-Cylon daughter.

Find out more about the science of Battlestar Galactica in a Q&A with Patrick Di Justo.


Patrick DiJusto is co-author of the new book The Science of Battlestar Galactica. He is a contributing editor at Wired magazine and has written for Popular Science, Scientific American, New York Magazine and The New York Times tech blog, Circuits.

Lords of Kobol! An actual admitted scientific mistake!

The problem arises from the conflation of two very different terms: "Mitochondrial Eve," and "most recent common ancestor." The Most Recent Common Ancestor is, as the name suggests, the most recent common ancestor of all humans alive on this planet. Mitochondrial Eve is the most recent common ancestor of all humans along the matrilineal line. And to explain the difference—as always—we need a little background.

Biological cells come in two main types: prokaryotes and eukaryotes. For our purposes, the most important difference is that eukaryotes have a distinct nucleus and distinct organelles with their own membranes, while prokaryotes generally have neither. Mitochondria are tiny organelles embedded deep in the cytoplasm of almost every cell in your body. They have been called biological batteries or powerhouses because their chief task is to convert glucose into adenosine triphosphate (ATP), the energy unit of cellular metabolism.

Though mitochondria are embedded in your cells, they are self-contained entities, very similar to prokaryotes. For this reason, biologist Lynn Margulis suggested in 1966 that billions of years ago, primitive mitochondria actually were prokaryotes that entered into a symbiotici relationship with other cells. That hypothesis was reinforced in the 1980s when researchers showed that mitochondria have their own set of DNA, different from their parent cell.

Geneticists almost immediately realized that DNA from the mitochondria (mtDNA) could help them to track evolution and heredity along the female line. Since sperm do not contribute mitochondriaii to the developing embryo, an analysis of mtDNA can help to track matrilineal descent through the use of specific DNA markers. And because mtDNA isn't repaired as efficiently as nuclear DNA, it mutates approximately ten times faster.

Since mtDNA comes only from the mother, you will have that same code sequence in your DNA; if you are female, you'll pass that code sequence to your children. If you happen to have a mutation to your mtDNA, you'll pass that mutation, which will be shared with all of your subsequent descendants. By tracking layers of mutations backwards, geneticists can determine which populations are ancestors to which other populations.

 

Mitochondrial Eve is the term given to the woman who was the matrilineal most recent common ancestor for all humans living on planet Earth today. Passed down from mother to offspring, the mitochondrial DNA of every human is directly descended from hers. Although they lived thousands of years apart, Mitochondrial Eve has a male counterpart in Y-chromosomal Adam, the patrilineal most recent common ancestor. By tracking mtDNA mutations, scientists have determined that Mitochondrial Eve lived approximately 170,000 years agoiii, give or take a few tens of thousands of years. She most likely lived in East Africaiv, when modern Homo sapiens was branching off as a species distinct from other humans.

It's important to emphasize that Mitochondrial Eve and her contemporaries had offspring, and those offspring had other offspring. But throughout the subsequent generations, for one reason or another, the lineages of Eve's contemporaries all died out. Of all the women alive then (and in our case, that means the entire female population of Galactica and the fleet), only one has offspring alive today. We know her as Hera Agathonv.

This does not necessarily mean that Hera is our Most Recent Common Ancestor (MRCA). Hera populated today's Earth solely through her daughters and daughters' daughters. The MRCA is the person who, while no doubt descended from Hera, populated today's Earth via their daughters and/or sons. By adding males to the mix, the MRCA almost certainly cannot be the same as Mitochondrial Eve. In fact, most researchers today feel that the MRCA lived only about five thousand years ago, 145,000 years after Hera.

Does such a recent MRCA imply that the human race was once nearly wiped out, where it had to bring itself back with a small number of survivors after almost going extinct? Not necessarily. If cousins mate with each other, as has been known to happen in tightly knit tribal societies, then the number of ancestors each person could have would be constrained. In some societies, even more recent MRCAs are possible.

There was a real population bottleneck in our history. It took place seventy-five thousand years ago and was called the Toba catastrophe.

Somewhere in our deep past, a giant volcanic eruption—most probably of Mt. Toba on the island of Sumatra—created the volcanic version of a nuclear winter. The supercolossal explosion was the equivalent of one trillion tons of TNT, and sent volcanic debris more than twenty-five miles into the stratosphere. The resulting ash cloud covered much of the world, causing temperatures to drop as much as 5 degrees and possibly triggering an ice age. The number of humans, already relatively small, dwindled to approximately fifteen thousand, spread throughout Africa and southwest Asia. Yet those fifteen thousand managed to regroup and repopulate Africa within a few tens of thousands of years, and to move out into the rest of the world thirty thousand years later.

Population biologists talk of something called a minimum viable population, which is the smallest number of individuals that can survive "in the wild." For terrestrial vertebrates, that number is around four thousand. Of course, more individuals are always better for the species, as long as the food holds out, because they bring more genetic diversity into the population. As long as there are at least four thousand souls in a single population group, then Hera's children should have survived.

i. Sym = together, bio = life; a symbiotic relationship is one in which at least two different organisms live together, usually (but not always) providing a benefit to both creatures. For example, we provide cats with shelter and a steady food supply; cats provide us with rodent control and aloof companionship.

ii. Specifically, the sperm's mitochondria are marked for elimination by the egg's cytoplasmic destruction machinery. Talk about being a ballbuster.

iii. Incidentally, the use of the term "Eve" is not meant to indicate that she was the only human female of the time, simply that she was mother to us all.

iv. The article that Angel Six reads over Ron Moore's shoulder purports to say Tanzania.

v. Or do we? Angel Baltar gleefully said, "Along with her Cylon mother . . . and human father!" It's totally reasonable to think that once the fleet settled on Earth, other Cylon-Colonial pairs had offspring in the same generation as Hera, perhaps even Six and Baltar. Imagine if their child was Mitochondrial Eve!