I have been challenged by one David Randall to complete Randall's Challenge of Deceit. This challenge consists of three individual challenges in which I must write an article on three separate subjects defined by the taskmaster himself. Those were the grounds laid down, and without further delay I would like to tackle my first subject: "Air Balloons".

Air Balloons.
Now Mr Randall did not specify whether these balloons are hot air balloons that fly or just balloons filled with air. Therefore I think it is important to tackle both, starting with the basics, and try to find out which is better - and just what is all the hype about!?

Essentially, hot air is lighter than cool air, because it has less mass per unit of volume. A cubic foot of air weighs roughly 28 grams (about an ounce). If you heat that air by 100 degrees F, it weighs about 7 grams less. Therefore, each cubic foot of air contained in a hot air balloon can lift about 7 grams - this isn't much. This explains one aspect of their aesthetics, a hot air balloon is so large in size because of the weight it needs to carry - to lift 1,000 grams you would need approximately 65,000 cubic feet of hot air and a large balloon to put it in.

Then we must consider how they take advantage of the basic principle of gravity + air pressure = buoyancy. The most obvious thing that is lighter than air is nothing at all. A vacuum can have volume but does not have mass, and so, it would seem, a balloon with a vacuum inside should be lifted by the buoyancy of the air around it. This doesn't work however because a vacuum inside the balloon would have no outward pressure, and the air outside of it would easily crush the balloon inward resulting in terrible if not dire consequences in which many, many people could die. The way to overcome this problem is to decrease the air density of the particles within the balloon whilst maintaining air pressure, which can simply be achieved by heating up the air within. Cold air balloons on the other hand, are a completely different kettle of fish:

Cold air balloons involve the principle of 'air in balloon = balloon filled with air'. Unlike hot air balloons, the air in cold air balloons, or simply: Balloons, is often not hot and quite often not air. Helium balloons for example became popular because they were filled with a gas with a lower density then the air surrounding it causing them to try and escape upwards. Helium only has a lifting force of 1 gram per 1 litre, so you would need 5 litres of helium to lift 5 grams off the ground. A normal helium balloon is roughly 30 centimetres or 1 foot in diameter, and therefore the calculation to determine how many litres it can hold would be 4/3*pi*r*r*r. In this case the radius is 15cm so:

4/3 * pi * 15 * 15 * 15 = 14,137 cubic centimetres / 14 litres

So we can then conclude that a balloon of roughly 30 centimetres or 1 foot in diameter can lift 14 grams. Say you weight 50Kg (50,000 grams) then you would simply divide that by 14 to find out how many balloons filled with helium you need to lift you off the ground, which in this case is 3,572. You might wish to add more balloons on top of this, i.e. 500 - 1000 to ensure you lift as a fairly decent pace. However 4 balloons of 3 metre diameter could also lift you with the same force - you can get these from your nearest army-surplus store.

In conclusion, you can take off with both hot and cold air balloons, which proves inconclusively that living in a country where the average temperature is -14 degrees C will lower your sperm count.

Article Written by Jay