Wanna freak out your friends? Here is a cool trick, AND a cool science experiment you can do to tonight to really scare the crap out of them…and possibly question your sanity!
Step 1: Take a banana and cut the ends off as shown above.
Step 2: Shave the sized off of the banana so that it resembles a small, wax candle.
Step 3: Make sure to place it into a real candle-holder otherwise no one will believe it’s a real
Step 4: Slice an almond so that it looks like a candle wick!
Step 5: Place the almond wick into the center of the banana!
Step 6: Light the almond wick!
There you have it! Your very own banana candle!
Now, freak out your friends and blow out the candle…then eat it!!!!! They won’t believe that you ate a candle…but you know that it was just a banana! Science!
Wanna know how it works? Below the explanation from ABC Science. Wanna see more cool science? Don’t miss the new episode of Cosmos on FOX Sunday at 9pm, or you can join us at Mobius Science Center in Downtown Spokane to experience it on the big screen!
See ya there!
What’s going on?!
“Many foods can be set alight. In fact, all food is combustible but the high water content of fresh fruits and vegetables and the low surface area of just about everything means most of our tucker isn’t usually much of a fire hazard.
Almonds, peanuts and nuts all have a relatively high fat and low water content which makes them burn rather readily while bananas and carrots are impossible to fire up. Olive oil and vegetable oil are almost nothing but fat (of the unsaturated variety) and will famously burn spectacularly well under the right (or wrong) conditions. Ask a chef.
But it’s not just fats that’ll fry you to a crisp. Dry flour can become notoriously hazardous as the citizens of Minneapolis in Minnesota, USA, discovered in 1878 when the Washburn A Mill exploded, killing 14 workers. The problem with flour is the large surface area to volume ratio of each tiny grain which, combined with its combustibility and ability to form dust clouds make it a potentially very dangerously explosive substance. The Washburn A Mill was the largest flour mill in the world at the time and the explosion that rocked the city was heard more than 15 kilometres away. The fire spread to two adjacent mills which also exploded killing four more workers.
The flammability of food has been well known for a long time and is, in fact, used to derive those numbers on the nutrition panels two in three Australians now appear to be ignoring).
The energy content of food is calculated using the Atwater system, named after Wilbur Olin Atwater (1844 – 1907.) Atwater invented the Atwater-Rosa calorimeter with help from physicist Edward Bennett Rosa (1973 – 1921.) This device was large enough to hold a person for more than a day so that their total energy expenditure could be accurately measured. Atwater’s work resulted in a data set called the Atwater factors which are used to calculate the ‘metabolisable energy’ in other foods by measuring their ‘gross energy’ content in a ‘bomb calorimeter’ and then applying the Atwater factor for that food.
To measure ‘gross energy’, a food sample is placed inside a sealed ‘bomb’ which is submerged in a water vessel which, in turn, is sealed inside a larger chamber. The food is then burnt inside the sealed bomb and the change in the temperature of the water is measured. One calorie is the energy it takes to raise the temperature of one kilogram of water by one degree (oh, and one calorie is 4.2 kilojoules, which is the unit of energy we prefer in Australia.) Apply the relevant Atwater factor and, hey presto, you’ve got a number to put on your packet.
Atwater’s system has been in use for more than 100 years and it is still remarkably accurate, but recent research has shown that it often overestimates the energy content of food available to humans. One study published in the American Journal of Clinical Nutrition in 2012 showed that the Atwater system overestimates the energy content of fake candle wicks (aka “almonds”) by almost 30 per cent.
Grab a packet of almonds in the supermarket and you’ll be led to believe that your body will gain 2500 kilojoules per hundred grams of almonds. When the researchers fed real almonds to real human beings and painstakingly measured how much energy they actually obtained, they found the figure to be more like 1900 kilojoules per hundred grams. Why the discrepancy? Well, the human digestive system is incredibly sophisticated and complicated and variable and dependent and interdependent on a the micro biome of critters (bacteria) that live in our guts and there is clearly much more still to be learnt.
Atwater’s factors for carbohydrates, proteins and fats are terrific, but calculating the metabolisable energy content for any particular food has turned out to be much more complicated than simply adding together the combined energy of those three components.
But please don’t now turn around and fool yourself into thinking you can now just ignore the whole idea of ‘kilojoules in versus kilojoules out’ and start eating as much as you like. The numbers on nutrition panels are still a very excellent guide for deciding how much of something you should eat. For example, at 1900 kilojoules per hundred grams, you should still avoid overindulging in almonds! Compare them to pickled cucumbers, which come in at a paltry 50 kilojoules per hundred grams, and you can probably see why. Baked beans hover around the 300 kilojoules per hundred gram mark so you can see that a 30 per cent error doesn’t mean you can now go nuts on nuts… like almonds… which aren’t actually nuts at all.
Luckily, it is better to overestimate the energy content of food than it is to underestimate it because, if you work with the overestimated amount, it means you’ll eat less of that food.
And on that note, I wish you happy snacking.”