"Want me hit you with a bolt of lightening?"

 

"Want me to hit you with a bolt of lightening?"

Think about that question for a second what would your reaction be?  I was asked just this question a number of years ago as I sat inside a Van der Graff generator with a few of my coworkers.  We all looked back and forth at each other in nervous silence for a minute before someone offered up a feeble sounding "sure."

The Museum of Science's Van der Graff Generator (Photo from the Museum of Science Boston)

I should probably explain how we all got to be sitting in the top of the generator in the first place.  One afternoon at lunch the man in charge of the lightening shows at the Museum of Science, I'll call him Len,  mentioned to us he was going to be cleaning out the insides of the generators and if any of us were curious what they looked like on the inside to meet him there tomorrow morning.  The next morning my boss and I along with some other curious coworkers gathered at the agreed on time in the lightening theater.  Len popped open the door at the bottom and instructed us to climb up the ladder to the ball at the top so we could see it innards.  One by one we climbed up the ladder next to a very long conveyer belt which had little brushes over it at the very top.  Once Len had joined us in the big ball at the top he proceeded to explain the generator worked like a big static electricity producer. The faster the conveyer belt ran the more static was produced by the brushes and the extra charge would build up on the outside of  the metal before discharging to create the lightening bolts we saw in his demonstrations.  After a few more minutes of questions from us Len then looks at us with a glint in his eye and asks "want me to hit you with a bolt of lightning?" After agreeing he slips back down the ladder and closes the door at the bottom.  We all let out a nervous giggle as the conveyer belt began to build up its static charge.  "Should this be open?" I shouted down to Len who now sat inside the Faraday cage at the controls.  "You're fine just keep your heads inside" he reassured us.

After a few tense minutes there was an audible crack and we all looked out the hole as the lightening hit the cage Len sat inside.  Cool we all thought as the belt began to spin faster now. After a few minutes of watching rather small lightening bolts hit the cage Len called up "Close the window." We did as instructed an sat completely enclosed in our metal sphere and waited.  Then there was another loud crack and a sound like someone throwing a tennis ball against the side of the metal.  On and on this went for a few minutes the belt spinning faster and faster, the cracks and bangs against the metal getting louder and louder.  When the banging reached deafening proportions we pounded on the sides of the metal sphere, our agreed on signal for Len to stop.  We waited for the belt to stop moving and the door at the bottom to be opened before descending back down the ladder.

"So?" Len asked after we had all safely made it out of the generator.  "Cool!" was our response. "How many volts was that last strike?" someone asked. "Enough to blow up a large redwood." Len casually responded.   

If your trying to figure out how we were all not blasted in to millions of little pieces the answer is simple and complex at the same time; we put our faith in the skin effect. Since I never took physics I can't really explain how this works, but because of the frequency of a bolt of lightening the charge was spread over the surface of the copper metal in which we sat and never penetrated the metal sphere. 

The same idea works if your sitting inside your car in a lightening storm as long as you DON'T touch anything inside the car, just sit there with your feet flat on the floor and hands in your lap. See this in action on BBC's Top Gear.

To see the Museum of Science's Van der Graff Generator in action check out this YouTube Video. https://www.youtube.com/watch?v=1-mFl_YXqiA  But it is MUCH cooler in person!

For More information:

For a great explanation on how the generator works and why Van der Graff created them in the first place see the HowStuffWorks website.
For a really in-depth explination of how the skin effect works. http://fermi.la.asu.edu/w9cf/skin/skin.html
More information on cars and lightening http://www.lightningsafety.com/nlsi_pls/vehicle_strike.html
How to be safe outside in a lightening storm. http://www.ready.gov/thunderstorms-lightning

For a brief glimpse inside the generator I sat in watch Since Bob's video. http://www.sciencebob.com/experiments/videos/video-van_de_graaff.php

What is it about chocolate?

Quick run to your kitchen throw open the cupboards and the refrigerator and look to see how many pieces of chocolate you find. Go on I'll wait.

So what did you find?  If your like me there is a lot of chocolate in your house or in my case there was until this last weekend when things when from good to poop in a rather short period of time. 

I was listening to the TED Radio hour on NPR over the weekend like I normally do and something caught my attention.....the mention of chocolate. This was kinda weird since the topic of the day was about success.  I perked up to hear Ron Gutman talk about smiling your way to success. "A smile, he reported, has the same brain stimulation as eating 2,000 bars of chocolate."  This was not the first time I had heard some scientific research related in terms of chocolate, but since I don't know who is reading this I will refrain from posting it because it is not appropriate for all age groups.

I started looking for fun sort of motivational facts about chocolate and here is what I came up with:

1)  "One chocolate chip can give a person enough energy to walk 150 feet.^"
                        (Bring on the chocolate chip cookies I say. )
2) "A Hershey's bar was dug up after 60 years from Admiral Richard Byrd’s cache at the South Pole.  Having been frozen all those years, it was still edible."
3) "Chocolate melting in a person’s mouth can cause a more intense and longer-lasting “buzz” than kissing."
                        (On the same note I read once that there are 22 calories in a Hersey Kiss and you burn 25 calories in a passionate one minute kiss. Not a bad way to burn calories if you ask me.)

4)   "Chocolate is a perfect food, as wholesome as it is delicious, a beneficent restorer of exhausted power. It is the best friend of those engaged in literary pursuits. – Baron Justus von Liebig (1803-1873), German chemist"
                         (I'm not sure exactly how these go together.)
5)  "Chocolate is a Vegetable: chocolate is derived from cocoa beans. Bean = vegetable. Sugar is derived from either sugar cane or sugar beets. Both are plants, which places them in the vegetable category. Thus, chocolate is a vegetable. To go one step further, chocolate candy bars also contain milk, which is dairy. So candy bars are a health food."
                          (It isn't but I like the logic here)

Why are we so enamored with chocolate is it the way it melts on the tongue, the fact that it gives us the same chemical happy feeling in our brains that other pleasurable things do, or is something coded in our DNA from way way back. Imaging being the Aztecs your trying to make something like beer and come up with chocolate were you bummed out by this or after some taste testing by your friends did you decide it was the best thing on earth?

Ruth Wakefield, who invented the  chocolate chip cookie, sold her recipe to Nestle for a lifetime supply of chocolate. You go girl! 

Whatever it is that has us so addicted may it never be factored out of chocolate.  I tip my hat to you Aztecs for your mistake is one of my favorite things.

Want more chocolate?
http://www.facts-about-chocolate.com/chocolate-quotes/
Even local bears love chocolate.  http://www.youtube.com/watch?v=_3GiXckb9z0
http://facts.randomhistory.com/chocolate-facts.html
http://www.webmd.com/food-recipes/rm-quiz-chocolate

It's Raining Antlers?

As I was returning home from a walk last week I saw a sight which just made me stand there and laugh. The one antlered elk. Try as the pour guy might he just could not make the other one fall off. Each year around the middle of March our antlered friends, the deer, elk, caribou, and moose loose their antlers. A hormonal change causes their antlers to fall to the ground. Sometimes they both fall off at once and other times.... Well let's just say there are some funny looking elk walking around. Why would you want to loose your antlers each year you ask? Simple to win over the girls. Imagine that during a particularly rough mating season you smashed heads with another make of your kind and broke off part of an antler. Now, since the females of your kind look for antlers which are the same on both sides you have just lost your chance at mating.  

                                            Copyright Peter Zuzga

 However, since antlers fall off each year as long as the animal has not damaged the part of the skull where the antler grows next year his rack will come back good as new.  Antlers unlike horns are made from bone and are shed each spring. Within a few weeks our antlered friends start to regrow their antlers and while they are in velvet antlers act as a built in cooling system for the animal. There is blood circulating underneath the velvet. It is hard to imagine an animal growing an antler of this size in just one season (April-early September), but they do.  Antlers are the fastest growing bone known to man and can grow as much as an inch a day at the height of the growing season.

                                                                   My Final Antler

Their weight is pretty impressive too. A full grown healthy male elk can have a rack which weighs a total of 40 pounds. That's a lot of weight to be carrying on your head all the time.

Since I am on the topic of antlers why don't I tell you about some of the differences between antlers and horns.

Antlers	Horns
Made out of bone	Made out of keratin (like your fingernails)
Are solid	Are hollow in the middle
On an elk they can weigh 40 pounds	On a Bighorn Sheep up to 30 pounds
Shed every year	With the animal for life

Just remember if you see a shed antler out in the woods it is best to leave it where it is there are many small rodents out there which eat the antlers to get much needed nutrients to help them grow. Think of shed antlers as vitamins for wildlife.  Happy antler spotting.