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Thursday, February 21, 2013
We've got eight episodes up and a backlog of 12+ that will go up gradually as I clear it. Most of the start is kind of random, but it's gradually settling down and getting more structure.
Tuesday, December 4, 2012
So in my last post, I described why faster-than-light travel might cause some problems with causality itself, and therefore might be physically impossible. In this one, I'm going to walk that back a little.
The core of the argument I used before is something called the "ansible paradox". As I said before, it has nothing to do with the method that allows you to move faster than light - it's actually a problem with any information at all traveling faster than light. And it's not actually a problem of traveling faster than light per se, but rather then creation of closed timelike curves, which I'll explain after the fold.
Thursday, November 29, 2012
The general idea behind the Alcubierre Drive is that while you can't locally move an object faster than the speed of light, you can stretch and squish spacetime itself. So if you stretch spacetime behind a spaceship and squish it in front, the ship can effectively "move" without actually moving, or violating the speed of light (at least in its own local "warp bubble" of space).
It's ingenious. It also requires something called "exotic matter" to function, which effectively has negative mass. A lot of people have focused on this as being the biggest problem with the drive system, as such matter probably don't exist in our universe. I actually don't think that's the biggest problem. We've proven with things like metamaterials that you can do bizarre things that shouldn't be "legal" under normal physics if you get creative enough - for example, make light travel backwards or even "freeze" the waves in place.
No, the problem with all faster-than-light travel is that it violates causality.
Monday, July 9, 2012
So let's talk about the difference between skepticism and "skepticism". Skepticism - the kind of philosophy I practice - says that all claims should be backed by concrete evidence and that all claims must be able to stand up to rigorous inquiry.
It is fundamentally a materialistic and non-spiritual philosophy, and therefore not particularly appealing to many people. But it's also a very useful, practical approach to life. The fundamental principles are that we inhabit a common reality governed by rules (like physical laws) and that past experience can be used to predict future behavior. This is a simple thing, really - if the sun has risen every day so far, it's likely to rise again tomorrow. An object dropped from a height accelerates towards the ground, whether it's dropped yesterday, today, or in a thousand years.
Tuesday, April 10, 2012
Not sure how I ended up on the sperm whale Wikipedia page (something to do with today's XKCD) but... man. Sperm whales kind of kick ass. They're like the Chuck Norris of the ocean.
Here are a few awesome facts about sperm whales:
Monday, February 6, 2012
Evidently, some scientists figured out how to put mammalian nerves back together, so full or nearly full function is restored in a few weeks after serious damage. The article is light on details, and it's not clear if the severing of the nerve needs to be clean for it to work (or what the window for repairing it is), but this is pretty cool stuff nonetheless.
Wednesday, December 14, 2011
Contrary to what games and movies will tell you, you can't actually sink in lava.
Falling into lava involves (a) bursting into flame just before you hit the surface and (b) sitting on the surface until you are reduced to ash, which shouldn't take very long at all. The ash itself might later sink or dissolve.
In fact, hitting lava at any great velocity would be more like hitting a slightly mushy brick wall than falling into water. The reason is that lava is made of molten rock, which is three times denser than you, and way, way thicker than water (or molasses or pudding or whatever). In contrast, you're only a little bit denser than water, and water isn't very gooey at all. And even a long fall into water can kill you just from the impact, so... you get the idea.
What this also means is that, with properly insulated clothing, it would be possible to actually walk on lava, though you'd have to devise a system to protect yourself from the superheated air around it.
Tuesday, December 13, 2011
According to a new study, differences in performance in mathematics between the sexes are entirely attributable to cultural and social factors, and not to any inherent aptitude or greater variability in skill set on either side of the gender binary.
The study appears to disprove two common theories, one which states that men are just better at math than women are, and one which states that while men and women are on average equally good at math, men have more variation in ability and are therefore overrepresented at the top (and bottom).
What the study actually found was that, the more equal the genders were in a given society, the closer their math scores were for high, low, and average achievers. Also, the more equal the genders were, the higher the scores were for everyone - not just women. This suggests that advanced countries with better education systems and more gender equality are doubly advantaged, as they will have not only better-performing women, but also better-performing men.
This study shows that people tend to live up to the expectations that their society sets for them, and those expectations can have unexpected and far-reaching effects. If the same principle applies to other classes of people who are often seen to be under-performers like racial and ethnic minorities - and I expect it does - it's a very good, pragmatic argument for fighting for greater equality for all people.
Tuesday, November 22, 2011
Someone did a geographical analysis of reviews of the "Twilight" books, and the novels appear to be considerably more popular in red states.
This should come as no surprise. The parts of the country where Twilight was well-reviewed are dominated by religious conservatives. They're places where people marry young and have traditional notions of gender roles. A woman (and let's face it, men aren't reading these books) who married her high school sweetheart and never had an adult life outside the home is much more likely to see Edward as a hopelessly romantic bad boy. A lawyer who married a man that her accountant friend set her up with in her thirties (after four years of dating and living together, of course) is probably going to get a more creepy-stalker vibe from sparkle dude.
But at least people in the red states are reading, right?
Friday, October 21, 2011
So this is a no-brainer, but there are lots of people out there who are still "skeptical" about global warming, despite enormous scientific consensus. A little while ago, a bunch of big-money organizations on both the left and right (including the infamous Koch brothers) got together to fund an independent scientific inquiry into whether the warming trends detected by previous studies were in fact accurate.
The results are in, and global warming is real. Not that we didn't know that, but when a Koch-funded panel comes to that conclusion, you kind of have to sit up and look. Now, it won't stop conservatives from arguing that the confirmed warming trend isn't caused by humans and that there isn't anything we can/should do about it. But it's certainly the first step.
The thing is, if the trend is real, regardless of whether it's purely our fault or not, we can still make a decision to try to counter it. That's not to say that people in industry won't continue to oppose any change in policy which could hurt their short-term profits, but that's always a struggle, regardless of the policy involved. And with the future of our farms and coastal cities in the balance, it's probably a fight worth having.