Is Mario Kart’s world scientifically acceptable? I- Relations between weight, speed and acceleration I.1 Light karts have a better acceleration Mario Kart championship has very strong rules : The engine output of all karts must be the same. The only difference between the karts is their weight. In Mario Kart, light karts have a better acceleration than heavy ones. Let's consider two karts : - the one of baby mario and baby luigi which is very light - the one of bowser and baby bowser which is very heavy At the start of a race, we can consider that that the action of the engine is equivalent to a force F that applies to the kart. We can then use the Newton's second law : F = M * a => a = F / M Since M(bowser) > M(mario) a(bowser) < a(mario) Thus, in this field, the behaviour of the karts correspond to reality. I.2 Heavy karts have a high max speed In Mario Kart game, light karts have a better acceleration but heavy ones have a higher max speed. Now we have to take in consideration forces of friction due to the air ans the road. When a kart reaches its max speed, its accelaration (that is to say the variation of its speed) is null. FPD : ma=0=Fengine+Ffrictions When a kart reaches its max speed, it doesn't accelerate anymore. The forces of friction and the force of the engine are compensated. But frictions due to the air are all the more significant as the kart is big. However, the heavy karts of mario kart (such as the ones of Bowser or Wario) are also the largest... It thus seems to exist a contradiction. The only solution is that Bowser and Wario cheat : They use non-authorized engines that are more powerful. II- How can Lakitu fly? 1) a kind of hovercarft ? The role of Lakitu is to film the races. To that, he flies on a small cloud. Of course, this cloud is not a real cloud : The clouds are only accumulations of water vapor. It is impossible to sit on one. It is only a machine that looks like a cloud. But what kind of machine ? The simplest idea is that Lakitu uses a kind of hovercraft. A hovercraft rides on air under pressure. But in the track 'Dry Dry Desert', such a system should throw up sand below it. And it is not the case.. 2) Using magnetic fields? Another solution is to use magnetic fields. If one places face to face 2 magnets with the same polarity (North/North for example), they are pushed back. But, no magnets can be found in Mario Kart tracks.. 3) Another solution.. We have to imagine another solution : It is the action of the gravitational field of the Earth that should prevent Lakitu to fly. The gravitational field has strong similarities with the electromagnetic field. We know that a Faraday Cage can prevent a electromagnetic field to propagate. It can thus be imagined that building a machine able to prevent the gravitational field to propagate is possible. Lakitu is likely to use that kind of machine.. III- The mushroom problem 1 The effects of a mushroom One of the items that you can find on the roads of Mario Kart is the mushroom. Mushrooms provide a little turbo boost. When you use one, your kart will shoot way over its max speed for a few secondes. Let's take the example of mario and luigi ! Their max speed is 80 km per h. When they are using a mushroom, their speed grows up to 100 km/h in only 0.1 s and remains at this level during 2s. 2 The transfer of energy According to the Work-Energy Theorem, the energy that is required for this acceleration is equal to the variation of kinetic energy that is to say : Mmario=Mlugi=50kg (they are not very tall..) Mkart=100kg => m=200kg 80Km/h = 22m/s 100km/h = 28m/s 1/2 M (vf^2-vi^2) = 30 000 J = 30 kJ It is the mushroom that must bring this energy. But how? - the mushroom is burnt. This solution must be forgotten because the released energy would be too low. (only a few kJ) - the mushroom is totally converted in energy. We can imagine that Mario has found the way to transform matter into energy. Indeed, according to the famous formula E=m.c^2, you can transforme energy into matter. m=100g =>E=mc^2=10^13 kJ !! With such an important energy, it seems very strange that the speed of the kart is only 100km/h..... - Mario eats the mushroom. Eating a mushroom of 100g provides 15 kCal, that is to say 63 kJ ! 100g of mushroom = 15 kCal kJ=kcal*4,1868 The most logical explication thus seems to be that mario eats the mushroom and start to pedal top make the kart accelerate thanks to the energy he has received from the mushroom. IV- The problem of the tides The tides on Mario's planet On the Earth, there 2 high tides and 2 low tides a day. This is because of the rotation of the Earth on itself. But in the track 'Peach Beach', you can see that 2 high tides are only separated by thirty seconds ! Another strange fact is that in some track, it is always daylight and in the others, it is always the night. Moreover, the Sun doesn't move at all on the sky of Mario Kart's world. The only solution is that the planet on which Mario and his friends live makes one revolution on itself during one year (like Mercury). On one half of the planet, it is always daylight, and it's always night on the other. A strange moon? Since the planet doesn't turn on itself as fast as the Earth, the tides are a consequence of the rotation of a Moon. But this Moon would have to make one revolution around the planet in 1min ! If we suppose that the distance between the planet of Mario and its moon is equal to the distance between the Earth and the Moon, we can calculate the weight of the planet of Mario thanks to the third law of Kepler : T : period of revolution a : distance planet-moon 3.10^8 G : universal constant of gravitation 6.67 10^-11 M : mass of the planet => M=4.10^33 kg Sun mass = 1,98892 × 10^30 kilogrammes => a thousang times more heavy than the sun ! It's impossible.. A more reasonable solution is to imagine that the planet of Mario has not only one Moon but thousands of differents moons that cause all of these tides.