ok, really, the habitable zone is not that small

January 6, 2011 — 5 Comments

For the last week or so, there’s been a new meme making its way across the web, a Failbook post in which a particularly devout and ignorant person declares that a mere ten foot difference in our orbit is all it would take for Earth to become either an uninhabitable hothouse, or a frozen ice cube of a world. Someone with a shred of sanity and some basic knowledge replied to his friend to politely explain why that’s impossible, and in what can only be described as cementing one’s idiocy, the original poster demanded not to be corrected again. It’s truly a frightening display of imbecility to behold, and it may have served as an inspiration for Phil Plait to give us a basic rundown of the 3 million mile change in our orbit from aphelion to perihelion, and end it with an odd and out of place invitation which dealt with something that wasn’t even mentioned until then…

Oh, and hey, one more thing. Every now and again I’ll hear from a kid or parent who tells me that they had a teacher or friend claim that if the Earth were just a few thousand miles closer or farther from the Sun we’d burn up or freeze. That’s clearly silly, since over the course of six months the Earth’s distance to the Sun changes by 3 million miles! Not only that, but the Earth is 8,000 miles across and spins once a day. That means at noon you’re 8,000 miles closer to the Sun than you are at midnight, and I don’t general see people bursting into flame and then freezing in a block of ice every 12 hours. So if you ever hear that particular bit of silliness, refer ‘em here.

Now far be it from me to say that Phil was responding to this massive failure of critical thinking featured on an offbeat blog cataloging people’s inability to self-censor on the web, but it’s certainly up his alley. And really, if all it takes is ten feet from one perfect spot to either freeze or burn up, then we should be all extinct three times over. As noted by the voice of sanity in that thread, all those recent quakes in the Indian Ocean, Pakistan, Haiti, China, and Chile should’ve moved us so far off our ideal orbital niche that our planet would be utterly devoid of all life. Since this hasn’t happened, I could only assume that her assertion is wrong, and if she quotes such a ridiculous and easily debunked claim with a straight face, attributes this supposed fact to God’s powers, then growls at being corrected while managing to have friends who approve, it’s actually a very scary indictment of her and her friends’ education. I’m sorry, I meant lack of education. And it really does scare me to know that a whole lot of people go on to parrot nonsense like this without a second thought and choose to remain proudly ignorant when confronted with the facts because admitting that they’re wrong is an alien notion to them.

Share
  • Pierce R. Butler

    Do earthquakes really cause a measurable (is 10 ft measurable?) change in our planet’s orbital path?

  • Greg Fish

    After a really strong quake, the Earth wobbles on its axis, and that’s thought to affect the planet’s orbit a few feet here and there over years of powerful tremors. Again though, the Earth moves millions of miles closer and farther from the sun in its orbit so arguing that a 10 ft. difference in it would kill us all can only be described as ridiculous.

  • Pierce R. Butler

    Oh, there’s no question at all that the original premise here is absurd to Colbertian levels.

    I can’t recall seeing any quake-aftermath photos showing a fissure 10 feet wide, nor a change in elevation on either side of the fault line that high (or even half as much). The amount of energy required to shift the mass of the planet as a whole that far would be easy to calculate, though I suspect translating it to the Richter scale would produce a number well beyond the range of any seismometer now in use.

  • Greg Fish

    Well, actually, the Indian Ocean tsunami caused a 50ft slip between two tectonic plates along a nearly thousand miles long path, and the Chile quake created a 435 mile long rupture with a 32 ft. slip in the local plates, so a 10 ft. change in elevation along a fault line after a massive quake isn’t nearly as impossible as you think…

  • Pierce R. Butler

    Hey, I didn’t use the word “impossible” (and I appreciate the links to back up yr numbers).

    Did anyone measure changes in earth’s orbit or rotation following either of those shakes?