Fun, ghoulish activities for this Halloween.

Looking for what to do this Halloween weekend? Here are several activities for technology and science enthusiasts that can please both families and adults alike.

For the family

Halloween Afternoon at the Exploratorium
Sunday, October 31, 2010
Noon–4pm

Celebrate Halloween at the Exploratorium where they will have a variety of activities for the family. Creepy crawlies will be on display thanks to The San Francisco Bay Area Tarantula Society. If insects aren't your thing, check out the garden of carnivorous plants or join local artist Irma Ortiz as she demonstrates how to handcraft Calaveras, or sugar skulls, in preparation for Dia de los Muertos.

Lawrence Hall of Science
Weekend, October 30-31
1:30 – 4pm

Visit the Animal Discovery Room and hang out with all the creepy animals LHS has to offer. Touch or hold some of the slimiest, hairiest, creepy-crawliest creatures and learn more about those animals, and why they may not be as creepy as you think.

Academy of Sciences
Saturday, October 30, 9:30 -5:00 pm
Sunday, October 31, 11:00-5:00 pm

Celebrate Halloween with chills and thrills at the Academy. Enjoy ghoulish music, join a costume parade, or take in the performances by Velocity Circus. Check out the live animal demonstrations and get up close with cockroaches, snakes, and other creepy crawly critters.

For the inner child

Instructables
Friday, October 29
6pm

Instructables invites you to come to their headquarters in Downtown SF and join in a costumed show and tell. Bring your own DIY creation to show off and meet other makers. This is a participatory event, so if you're not bringing an item to show, please bring food or drink to share. Costumes are encouraged!

Journey to the End of the Night
Saturday, October 30
7pm, Justin Herman Plaza

While not strictly a science or technology event, this event is definitely worth a mention. Engage in a citywide game of tag, as you run from location to location with Journey to the End of the Night. Players race through San Francisco to a series of checkpoints, while avoiding being caught by chasers. Those who fall will become chasers themselves, out to pursue their former friends and allies.

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European Garden Spider, Araneus diadematus.

UC Berkeley professor Rosie Gillespie and her grad student Steve Lew identified my backyard spider as the European Garden Spider, Araneus diadematus. It is really common here in the Bay Area, and can be easily identified by the white cross on its back. These spiders aren’t especially numerous this year, although their numbers have increased over the past few decades. Initially from Europe, as their common name suggests, this spider appeared in the Puget Sound region in the 1970s. By the mid-90s, they were firmly established in the Bay Area. Araneus diadematus is an invasive species, an organism that is not native to the area and has a detrimental effect on the native organisms or ecosystem. And, there are quite a few invasive spider species in the Bay Area.

Another common invasive spider is Zygiella x-notata. They spin a very distinctive web—it looks as though a piece of the web is missing, as though someone has removed a single slice of pie. Other invasive spiders are actually displacing native spiders. For instance, the false widow, Steatoda grossa, is displacing the native black widow spider, Latrodectus hesperus. (This may not be such a bad thing, as the false widow’s bite, while venomous, is not nearly as harmful to humans as the real thing.) Another California spider, Theridion californicum, is being displaced by Enoplognatha ovata, which also hails from Europe. And, the native Funnel Weaver Spider, Hololena spp., may be facing some competition from the invasive Badumna longinqua, initially from Australia and New Zealand.

Certainly some of the spiders my friends and I are seeing are invasive. But, it is also the time of year when spiders build their webs. As my spider expert friend Joe Spagna put it, spiders “do the Charlotte’s Web thing” in the fall—the females spin a big web, make an eggcase, and then die. The baby spiders hatch in the spring. If you’ve been out and about over the past few weeks, you’ve no doubt noticed Halloween decorations all over the place. Along with vampires and mummies, you’ve surely seen a spider web or two. Joe brought up a really interesting question: “for a long time, I've wondered if the prominence of big, hairy orbweavers in Halloween folklore and imagery was actually a recognition of what was going on in nature this time of year.”

Joe and I spent some time digging through the some literature on Halloween folklore, but we didn’t find anything that specifically links Halloween spider imagery to the seasonality of spider web-weaving. Halloween folklore buffs out there, please comment if you know of any connection!

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Light up costumes are creative ways to celebrate Halloween.

We're all familiar with the notion of getting a bedsheet, cutting out a couple holes for eyes and draping it over ourselves in a pinch. With a little more time you could light that costume up and dazzle friends, neighbors and fellow trick-or-treaters.

Cool Costumers with EL Wire

Electroluminescent wire (EL wire) is incredibly easy to work with and in great supply in the Bay Area, thanks to all our Burning Man friends. There is an excellent Instructables on creating glowing fairy wings out of EL Wire by SewLolita. Follow their instructions and you'll have a one of a kind creation to light up any fairy costume.

If fairies aren't your thing, consider making a TRON costume, outlining the edges of the costume in EL Wire and voila, you've created a TRON outfit.

Check out Cool Neon, a Bay Area company that specializes in EL wire, and all kinds of things that light up. They have an online store and you can also pick up from there warehouse in the East Bay. Furthermore, they have a great guide to soldering with EL wire that is indispensable if this is your first time soldering.

Light up using LED's

Like EL wire, LED costumes allow you to stretch you imagination to create unique light shows and funky designs. You can build your own light saber, make all kinds of illuminated clothing and even turn yourself in a live fireworks display! Believe it or not, using an umbrella and programmable LED's you can do just that thanks to this Instructables from Chris Huebner.

Resources

Noisebridge offers their space to the public for free use of their equipment including soldering irons and sewing machines. Wednesday nights they host a sewing and craft night that welcomes anyone to come and work on a craft project and get help from others.

The Crucible is offering an EL Wire workshop on October 23rd to get you ready to create illuminated costumes.

Good luck with your Halloween costume and let us know what you're planning on making in the comments!

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Prion diseases are neurodegenerative, attacking the brain. Could they be responsible for the recent wave of Zombie attacks across the globe? Original photo: digitalsextant.

But what if there existed a substance that acted like a virus or bacteria but wasn’t living? Medicine made a revolutionary leap during the time of Louis Pasteur in the mid 1800's. The inventor of food pasteurization and one of the founding fathers of microbiology – he was able to prove germ theory. Food spoiled and organisms got sick because of the growth of bacteria and viruses within them. Within sterile environments, viruses and bacteria could be killed off and food could be preserved or organisms could recover from illness or infection. Sterilization works on living micro-organisms. Prions, however, are not living organisms.

Prions are infectious proteins. For unknown reasons, these proteins refold abnormally and cause a domino effect in surrounding proteins which in turn mutate into stable structures. Prions will then cause tissue damage and cell death to surrounding areas. Prion diseases are neurodegenerative, attacking the brain and are characterized by "holes" in the tissue. The incubation time for Prion diseases is quite long. They usually surface later in life but after they surface, the diseases are rapid and fatal. Such examples of Prion diseases include Mad Cow Disease in cattle, Scrapie in sheep and Fatal Familial Insomnia in humans. FFI is a disease that literally takes away the ability to sleep and in a few months leads to death. The Book “The Family That Couldn’t Sleep” by journalist D.T. Max follows a family in Italy that passes this disease from one generation to the next over subsequent centuries.

Prions have been and still are a medical mystery. What causes them to mutate and aggressively eat away at the brain? How can they be stopped? Because they are not living they are highly resistant to sterilization methods. While viruses and bacteria can be eradicated on equipment through heat, radiation or chemical reagents, Prions are strongly immune. Maybe Zombies are not so far off after all – lurking in the shadow of medicine has been a mutation that is resistant, brain-eating and neither alive or dead. It has some serious similarities to the zombies I have watched over and over again on the big screen.

If you want to learn more about Prions and their history, check out Down to a Science’s next reading group which is focusing on the book The Family that Couldn’t Sleep or check out the book Deadly Feasts: The "Prion" Controversy and the Public's Health by Richard Rhodes. And one more thing – Happy Halloween!

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So we visited zookeeper Andrea Dougall at the Oakland Zoo to learn about their Malayan and Island Flying Fox. Both are a type of fruit bat, and I couldn’t readily see the difference between them. There are many fascinating things that Andrea taught us about these bats that we couldn't fit into our two minute segment (and honestly, this producer wouldn't mind making a half hour special on these critters!). For instance, they have a lot of blood vessels in their wing tissue, so they make excellent thermo-regulators. If the bat is cold, he wraps himself up in his wings so that the heat from his blood vessels can keep him warm. Likewise, when it's hot out the bats flap their wings to cool off.

When Andrea told us that bats are the only mammals that can have sustained flight by flapping their wings, someone said "but what about the flying squirrel?" Nope– they glide.

These bats don't actually swallow the fruit that they eat, instead they chew it into small pieces, push it up against the roof of their mouth to ring out the juice, which they then swallow, and spit out the leftovers. This is something that Andrea reminded me of when I told her I'd like to take one of these cute critters home as a pet… the amount of rotten fruit pulp that you have to pick up is really unappealing. Plus, of course, it would be illegal.

Perhaps the most intriguing thing to me is the simple fact that these animals spend all of their time hanging upside down. I asked Andrea about that too– how is it possible that they wouldn't experience some sort of leg fatigue and let go of their grip? She told me what's in the scientific literature on other kinds of bats (and we're assuming it applies to fruit bats as well). The deal is that the tendon of the muscle that flexes the claw passes through a tough sheath that consists of 19-50 rings, oriented at an angle so that the inside surface is ridged. So there's some ratchet-action going on in the sheath that holds the claw in a grasping position even after the muscle has relaxed, and it's the tension on that tendon from the body weight that holds the ratchet in place. When the bat wants to move, the tension is released and therefore the claw releases its hold. So basically, the clenched position is the "at rest" position, and the releasing of the foot is the part that takes energy.

If you haven't yet, I highly suggest you make a trip over to the Oakland Zoo to see these highly captivating animals for yourself.

Watch the Cool Critters: Fruit Bats television story report online. Also, if you’d like to see close-up photos of these bats, please visit our photo set over on Flickr.

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