How long will our oil last?
GIVEN that the Earth’s endowment of oil is about 3 trillion barrels AND GIVEN that current production is 85 million barrels a day IF world consumption remains at this level CALCULATE how many years we can continue to use oil. Further work GIVEN that the world population is 6.7 million in 2010 IF world population … Read more
Now that there are one billion cars on the planet
With one billion cars on the planet it might be prudent to consider our oil use. Most cars run on the stuff. GIVEN that there are today one billion cars on the earth. the average car travels 15,000km a year and uses 1 liter to travel 12km. Global oil reserves were calculated to be 1,383 … Read more
Children can learn complex mathematics on their own new study suggests
A recent news article on Kurzweil suggests that schoolchildren can independently develop strategies for solving complex mathematical tasks, with weaker students proving just as capable as their stronger classmates.
The horse and oat cart challenge
I maintain that this little problem will illustrate how the maximum size of a city is well below that experts currently state. In fact, this problem shows that without fossil fuel the sizes of cities will be severely restricted. This little problem sets a benchmark for how large a city can be, as it is … Read more
The horse and oat carts problem
Although horses eat grass, they need oats. Imagine then a horse carrying food from the area of production to the city where the oats will be consumed. The driver feeds the horse the oats from the cart. Is there a way the answer to this problem could illustrate for us the maximum size of a … Read more
City density
An average city in Europe may show a population density of about 5000 inhabitants per km2. City centres have much more, from 12,000 upwards. However, around 40% of the area of these cities is allocated to car transport system – for example, roads, garages, parking spaces, car showrooms, repair shops and so on. If the … Read more
Holding hands around the world
This problem was given to me during the Future Perfect festival I thought I would post it… If we who live on Earth stand and hold hands with each other, would we be able to form a circle around the Earth? Given that the average comfortable reach is about 1,2 meters hand to hand. Given … Read more
If all the world lived in one city… how big would it be?
Given the population of Earth is 7 billion And that the density of cities ranges from Mumbai – nearly 30,000 per square km Through Sao Paolo at 9,000 Through London at 5,000 to Copenhagen at 1,800 How much space would be needed for these different variants? For inspiration see the website PER MILE. For the … Read more
The land use of cities
Given a large city of one million. Given that the agricultural land needed to feed a family of four is about one hectare. Given that only about 30 % of land can be farmed. Given that the population density of cities can be around 5000 inhabitants per square kilometre. Calculate: If the city is circle-shaped, … Read more
Climate impact of cars
GIVEN: The average car in Europe weighs 1.5 metric tons (1500kg)and in the US: 2 tons (2000kg). GIVEN: One litre of petrol weighs 0.737 kg and one litre of petrol gives rise to 2.32kg of carbon dioxide. GIVEN: The European Fuel Efficiency Regulations demand maximum 5 litres per 100km. Calculate: How far must you drive … Read more
How much carbon is there in carbon dioxide?
GIVEN THAT The atomic weight of carbon is 12 and oxygen 16. As carbon dioxide has two oxygen molecules (CO2): The total weight of carbon dioxide is 12+16+16 =44 CALCULATE: if your car emits one ton (1000kg) of carbon dioxide, how much of this is carbon? READ MORE: calculate how far you must drive to … Read more
