We’re Back!

After an absence of over a year the Battlestar Galactica Tech Blog is officially back… with a new, more permanent, home! With so much time past we have plenty of fun topics saved up! Before we get really technical, though, let’s start with…

Dragon*Con 2007

Boyoboyoboy! Was Dragon*Con a blast this year, or what?! I ended up doing thirteen panels/presentations and one podcast, and still, no kidding, wound up drinking more in one long weekend than I normally do in an entire year (in fact, I think the same held for my con roommate, John). Special thanks goes out to The Colonial Fleet on this last point — awesome parties, guys!

The first topic for Tech Blog v 2.0 is, fittingly, the second-most-common TECH issue about which fans have inquired of me since the season three Battlestar Galactica episode "A Day in the Life" aired. My first exposure, pun partially intended, to the fact that fans took issue with the episode "A Day in the Life" occurred shortly after I did an interview for Caprica City (English translation here). After the interview went live, I received a follow up email from the site’s webmaster, mentioning that on their forum several fans took issue with the science behind what we did with both Galen Tyrol and Cally Henderson-Tyrol in that episode.

SPOILER ALERT

To refresh your memories, in “A Day in the Life” Chief Tyrol had to perform maintence — to fix a slow leak — on a battle-damaged airlock. Because he saw an opportunity to spend some time with his wife, he assigned Cally to assist (you never know when small hands will be useful). While working in the airlock a malfunction causes the inner airlock door to trigger, trapping the two in a compartment with a slowly-dwindling air supply along with the prospect that their son, Nicky, may be an orphan by day’s end.

The plan to save the Chief and Cally involves blowing the explosive bolts on the outer airlock door, with explosive decompression expelling the Tyrols out of Galactica, and through the open hatch of a waiting Raptor.

END SPOILER ALERT

Battlestar Galactica is, I believe, one of the few TV shows/movies which accurately depicted the physiological effects of exposure to the near-vacuum of space. The movie 2001: A Space Oddysey is also a good example of doing it right, but in some aspects we did still better. Fans, poisoned by 50 years of sci-fi addressing the topic poorly, had two major complaints.

Everybody Knows They’d Freeze


Contrary to popular belief, the ambient temperature of space is not absolute zero (also, contrary to popular belief, atomic motion does NOT stop when a substance is at absolute zero — if an atom were held motionless it would violate the Heisenberg Uncertainty Principle). In the absence of a nearby star, or other heat-producing object, the ambient temperature of space is 2.7 Kelvins (about -455 degrees Fahrenheit).

It’s THAT cold, and you claim they wouldn’t feeeze?

That’s what I’m saying, yes. First, let’s define heat transfer. Succinctly, heat is the transfer of energy between a body, or a body and its environment, merely as a result of temperature differences. There are three primary methods of heat transfer: conduction, convection, and radiation. The concept of convection is only applicable when you have a fluid heated from beneath, so we can rule that out. That leaves conduction and radiation. Let’s examine conduction first. Conduction is a way of temperature equalization when two objects, of differing temperatures, are in contact. When you touch a hot stove with your finger, energy is conducted from the stove to your finger. Ouch! Alternately, when you hold a cold beer, heat is conducted from your hand to your drink.

Space is not a perfect vacuum, it has an average density of about 16 atoms per cubic inch. While that’s not a perfect vacuum per se, it’s close and, more to the point, is far better than can be reproduced by modern technology. Have you ever noticed that room temperature air feels comfortable, but room temperature water feels cool? That’s because, by virtue of being denser, water conducts heat 22 times more efficiently than air. If there’s little or no medium surrounding your body, there’s no conduction to make you freeze — at least not quickly.

That leaves radiation. Any body above absolute zero radiates its heat to its environment, assuming the environment is cooler. Obviously, we are aware of this because we have radiators on cars to shed excess engine heat, while we use radiators and space heaters to warm rooms in our homes. This is a much slower process than conduction, and certainly is not instantaneous. If Tyrol and Cally were left in space, their bodies would freeze eventually, but it would occur long after they perished by asphyxiation.

I will admit that I disagree slightly with the description on the Battlestar Wiki. In the description of the episode “The Captain’s Hand”, it is written:

The depictions of the airlock getting colder as it depressurizes are not entirely accurate. Contrary to common belief, space is an insulator. In low-pressure environments, convection is ineffective and the only way to lose heat is by radiating it.

We are in agreement that in low pressure environments, the only way to lose heat is by radiation and, taking that a step further, this is a slow process. Our heroes certainly would not freeze upon exposure to the space environment. I have two minor issues with the above, however. The first is “convection is ineffective”. This is almost certainly a typo, and what is meant here is conduction. More importantly, the airlock certainly would have been getting colder — due to the leak, the airlock was neither in thermal nor mechanical equilibrium. In essence, it was acting like a big refrigerator, and would have been cooling down. It was also established in the episode that the Tyrols were in there for a fairly long time — long enough that they could radiate a nontrivial amount of their body heat.