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Episode 68: Christmas Tree Lights, Antigravity Device, Vodka Myths IV

  • Christmas Tree Lights: Heat from Christmas lights can set a Christmas tree on fire. busted
  • Antigravity Device: you can build an antigravity device. busted
  • Can vodka cure a jellyfish sting? confirmed

This episode showed that the MythBusters haven't run out of quacky devices (see Mind Control, Pyramid Power) nor vodka-related myths (see Vodka Myths, Vodka Myths II, Vodka Myths III). For a bit of festive spirit, they threw in a Christmas tree light myth, which can either scare you away from decoratin' the tree or give you more confidence, depending on your point of view.

Christmas Tree Lights

Myth: Heat from Christmas lights can set a Christmas tree on fire.

On December 24-26, there will be about 10,000 fires from Christmas trees, but the MythBusters specifically wanted to test if it was the heat from Christmas lights could be responsible and not some other cause (e.g. electrical short).


Adam and Jamie wanted to test different types of lights as well as normal versus abnormal numbers of lights. They picked up a bunch of C7 3 amp lights and C9 5 amp lights from Fantastico in San Francisco.

Hot boxes and "Maximum Allowable" lights on a tree

Adam stuck each type of Christmas light in a metal box with foil over the top. These "hot boxes" were then left overnight so that the temperature so that they could be measured in the morning.

They also wrapped up the maximum allowable number of lights to leave overnight. The "maximum allowable" amount was dictated by the fuses on the lights. MythTern Jess (Killer Whirlpool/Archimedes Death Ray Revisit) had to watch over the tree and hot boxes overnight.

In the morning, there were no tree fires and the C7 3 amp lights showed no signs of damage in the hot box. The C9 5amp lights got up to 350 degrees, which was enough to melt them together. Adam was excited by this result, as it sets up the conditions for a potential wire short.

Bypassing the safety measures: 500 lights

Adam and Jamie wired the Christmas lights in parallel to bypass the safety fuses. They were able to string up 500 of the 5 amp C9 lights on the Christmas tree. After five hours, they were able to get up to 228 degrees with accompanying dryness, but no fire. After 8 hours, still no fire.

Creating a spark

Adam strung a bunch of lights to a scary stack of three-outlet adapters together and then connected them to an old extension cord. This configuration sent double the rated power through the extension cord. The insulation on the old extension cord began to melt, causing a spark and a brief flame.

Creating a fire

They upped the ante to replicate the results, going with five times as many lights as before -- 2500 -- as well as paper garlands and ornaments. Knowing that they were going for fire, they went out to Pleasanton's fire center and enlisted the help of their fire department. The Pleasanton Fired Department was familiar with Christmas tree fires: in 1997, a child turned on the Christmas lights and the tree immediately ignited.

After 21 minutes, their tree was already at 240 degrees. At 40 minutes, it started getting smoky, but there was no fire.

At this point they decided if 2500 lights hadn't set things on fire by this point, they would go to their standby ignition: a neon transformer that boosts the voltage to 5000-6000 volts. Jamie: "straightforward, always works, way of getting a fire"

With the Pleasanton Fire Department at the ready, they were able to immediately spark the tree. The fire quickly consumed the entire tree.

Adam: "Firemen have the best toys, ever"

busted. The heat from Christmas lights cannot set the tree on fire, but other things can.

Antigravity Device

Myth: you can build an antigravity device

See also: Mind Control, Pyramid Power

Gravity: tendency of objects with mass to accelerate towards one another. For the purposes of the myth, the device must modify the gravitational fields, not simply exert some other force. For example, airplanes do not count, as they are generating lift to counteract gravity, not actually modifying gravitational fields.

The build team surveyed commercial products and numerous antigravity device patents.

Spinning Magnet

Kari played with a spinning magnet -- a fun device that spins in midair. The spinning keeps it stable while the magnet keeps it suspended in midair.

Antigravity lifter kit

The "antigravity lifter kit' (larger design here) is a triangular device made of foil that makes use of electromagnetic field to produce lift. They claimed that 30,000 volts through a wire creates a new gravitational field. The build team selected the device because of "interest from NASA" as well as documentation on Internet. They weren't sure how the "bifield ground effect" worked, so they set it up and put it to the test.

After a bit of debugging with the manufacturer, Grant was ready to give the device its first flight. Grant and Kari both screamed as the device floated off the table and flew towards them. They soon had it floating stably in midair.

Although they didn't fully understand how the device worked yet, there were signs it was not antigravity. They were able to measure 1.6mph of wind from the device, which meant that it was generating thrust, not antigravity. They retested the lifter in a vacuum: no flight, no antigravity.

They were able to figure out that the 30,000V one the wire ionized their air. The ionized air was attracted to the foil below it, creating thrust.

Hamel Generator

The Hamel generator was designed by man "abducted by aliens," who then copied their designs. This was the most comical and complex-looking of the devices they selected. It used 1000 magnets lining 3 cones set inside one another. Unlike the other devices, it wasn't even capable of generating lift.

Tory: "I really wish the aliens were here to show me how to build this thing"

Measuring Antigravity

Derek Van Westrum and Tim Niebauer from Micro-G Lacoste brought a very accurate gravity meter to MythBusters HQ so that the build team could test each of the devices against it. The device looked very complicated, but the principles it worked on were very simple: 1. Motor lifts mirror 2. Motor releases mirror 3. Mirror free falls 4. Laser is bounced off mirror 5. Read tracking information from laser to determine acceleration of gravity

They also brought Bob Jacobson, professor of physics at UC Berkeley, on site to supervise their experiments.

They took each of their antigravity devices and positioned it next to the gravity meter:

  • Magnetic top: no antigravity effect (duh). Actually magnetic force countering gravity force,
  • Antigravity Lifter: no antigravity effect (duh). Actually thrust generating by moving air particles.
  • Hamel generator: no antigravity effect (duh)

busted (for now)

Can vodka cure a jellyfish sting?

See also: Vodka Myths, Vodka Myths II, Vodka Myths III)

Kari got a Pacific Sea nettle/Chrysaora fuscescens from the Monterey Bay Aquarium. According to the expert there, it would sting, but not be fatal. The sea nettles at Monterey are a popular subject for photographers. Here is one of my photos:

Monterey Cliches-2

The test was simple: sting both of Kari's arms. Treat one arm with a traditional mixture of warm water, antihistamine gel, and brush scrubbing. Treat the other arm with vodka and brush scrubbing. Kari was eager to get the treatment started once she was stung; the relief from both came rather quickly and she didn't feel any lingering effect from the sting.

Kari's judgment was that both treatments were effective.



there was not a control for the jellyfish test

Actually, there was a control. In reality, there were three subjects - Kari's arm, unstung, Kari's arm, stung, and Kari's arm, stung + vodka.

I've personally built a lifter and was also astonished that it really flew without moving parts. I'm having a hard time reconciling the MythBuster test with NASA's test in 2003 where thrust was observed even in a full vacuum. Did MythBusters miss something? Link to NASA's test:

jonny: a link to the experiment on NASA's site would be more credible.

actually the mythbusters did this wrong in the 20's a guy named Thomas Townsend brown made anti-gravity saucers that flew around a track at 12 mph then he made the experiment larger and that went a few hundred mph he also tested his effect in a vacuum and it still worked.

I am still not taking any chances with our Christmas tree. A house burning down once is enough!!!!!