Did Earth get hit by cosmic blast in 8th century?

10 comments to Did Earth get hit by cosmic blast in 8th century?

• BlueCatShip

  January 28, 2013 at 3:02 am Log in to Reply

  So this happened and no one at the time noticed. If it happened during the daytime on the side closest to the event, people might not have seen any visible light. Even at night, people might not notice a very brief flash. They’d wonder a second, shrug, and go about their business.

  This means — Things like this can happen frequently enough to make some difference, but most of the time, we don’t even notice, because the effects don’t *seem* (to us) major.

  But they can be major, now and then.

  Earth’s natural ozone layer and magnetic field are good, natural protections for all life on Earth, whether you’re a human or a microbe, a tree or a fungus, or something cute and cuddly, or smart and sassy.

  But the ozone layer and magnetic field are not protection against everything. If it’s powerful enough, it can blast right through, and perhaps has before.

  If it’s an asteroid or meteor, it can certainly fall and hit somewhere, on land or in the ocean, and it doesn’t take much to do major damage, on the scale of a city or a continent or the entire planet. Just ask the Pre-Cambrian extinction or the dinosaurs. Oops, sorry, can’t, they didn’t make it. (Some did.)

  Yup, throwing rocks at Earth or zapping it with a blast of radiation, not good for anyone’s day.

  Good thing most of the time it’s OK, we dodge the bullet.

  But it’s also a good reason to develop ways to protect our planet — and to get out into space so not every human or critter is on this big blue marble of an oasis in the vast inky desert of space.

  There are good reasons to take a “genetic Noah’s Ark” with us into space, for any ship big enough.

  Neat article. Things to think about.

• paul

  January 28, 2013 at 9:52 am Log in to Reply

  If it were a gamma ray burst there wouldn’t necessarily be anything to see.

  I’ve read that astronomers believe we are under considerale threat from Sirius A. Only 8.6Ly away, Sirius A & B are two of the eight closest stars, the closest visible with the naked eye. Class A1 main sequence (OBAFGKM), white hot, 9940°K, 25 times as luminous as Sol, twice as massive. When it goes, as it’s partner Sirius B already has, we’ll notice!

• CJ

  January 28, 2013 at 9:57 am Log in to Reply

  Sirus B is the one, isn’t it, that the Dogon people of Africa revere as a divine presence, a blinding light? http://dickinsg.intrasun.tcnj.edu/diaspora/dogon.html

  • paul

    January 28, 2013 at 11:21 pm Log in to Reply

    Yes, and IIRC Jonathan Swift may also mention it.

    BTW, the author’s statement, “This companion is a White Dwarf, which is a tiny star of immense mass and density”, is only partly true. Density is considerable, but “immense mass”? Only for modest amounts of immensity. If it were more than ~1.4 solar masses it would have collapsed to a mini-black hole.

• zette

  January 28, 2013 at 3:44 pm Log in to Reply

  I just read this in Discover (which I get for my Nook HD for a whole $1.99 a month — well worth it. National Geographic, too and at the same price) and thought it was interesting. We’re learning so many interesting things!

  • zette

    January 28, 2013 at 3:55 pm Log in to Reply

    I need to correct that. Discover is $1.66 for subscription. National Geographic and Smithsonian are $1.99 for subscription. I really love this!

    • Raesean

      January 28, 2013 at 9:04 pm Log in to Reply

      Really, they are that cheap? I wonder if they are the same on an IPad? I’m not allowed to subscribe to the paper Nat’l Geo because they will accumulate to the point of tipping over one side of the house,so my spouse says (and we have no bookcase space left now anyways), and also I’m cheap.. but maybe an e-Nat’l Geo….

      • BlueCatShip

        January 29, 2013 at 11:13 am Log in to Reply

        National Geographic is available for iPad, though I forget the subscription price. It’s reasonable and tempting, though. The file sizes for e-magazines and e-newspapers can be big (more pictures, more complex content) but for e-magazines and e-comics/manga, the apps I’ve seen allow you to get a few issues downloaded, and to retain access to purchased issues once you’ve deleted them from the device’s local storage. That is, they remain in a collection or library shelf “in the cloud” of whichever publisher or app. It works essentially like Kindle, Nook, and iBooks. Er, I’m subscribed to my local paper, to National Geographic, and to Wired, but I (cough) often don’t look at them enough. I’m tempted by that Discover subscriptoin, though. It’s one I get occasionally in print.

• WOL

  January 29, 2013 at 7:31 pm Log in to Reply

  Oooh! I’m away to investigate this — I’ve always suspected the lion’s share of the cost of a subscription is the postage, which would not be a factor with wireless subscriptions.

• BlueCatShip

  January 30, 2013 at 12:43 am Log in to Reply

  Discover is $20 per year for a digital subscription. I succumbed. I see others like smithsonian Mag, Popular Science, and Popular Mechanics are about the same. Did not look up Scientific American, but I expect from this that it’s affordable.

  Also — What magazines are available for linguists, anthro/archaeo, historians? Professional and academic and geeky, just fine, thanks. I confess I don’t know, but this has me interested.