CaptainPanic

Pfft. People deliver a max. of about 400 W. Assume that passing a gate takes 1 second. Assume that 100 million people (all of Japan) pass the gate daily. That delivers 400*1*1e8 = 40 GJ of energy, or an average of 460 kW... which is nothing for a whole country's rail system. One modern electric locomotive consumes 4.5 MW (megawatt!)... so this environmentally friendly gate will provide about 10% of the power consumption of 1 locomotive (at peak power).

A priest and a hunter go out for a walk. A few minutes outside the village, the hunter spots a little bunny. As it's the natural thing for him to do, he immediately takes aim and pulls the trigger of his rifle... Seeing the result he mutters: "Goddamn, I missed". The priest replies: "You shouldn't be saying this, the Lord will not be pleased". They continue their walk, and just a few minutes later, there's a beautiful deer staring at them. The hunter doesn't hesitate and shoots... but he says: "Goddamn, I missed!!". The priest gets annoyed and replies in a firm voice: "You really should watch your mouth, the Lord has ways to make you understand!". They continue their walk in silence, and after some time, there is a large bear... a target that cannot be missed. The hunter aims, shoots, and: "Goddamn, damn, damn, [beep] god, goddamn!! I missed again!!". The priest gets really angry, then sad and says: "Don't say I did not warn you!"... As the priest says this, dark clouds gather, and a blinding bolt of lightning shoots down from the sky. The priest drops dead. A voice from the heaven says: "Goddamn, I missed".

Can you write down which reactions we're talking about? I propose to "model" the cookies as glucose (sugar): [ce] C6H12O6 + 6 O2 -> 6 CO2 + 6 H2O [/ce] And TNT can be itself. Let's also assume that TNT detonates in stead of burning up... [ce] 2 C7H5N3O6 -> 3 N2 + 5 H2O + 7 CO + 7 C [/ce] Before I spend any time on this, I want to reach a conclusion about the TNT-reaction. We can also agree on complete combustion: The remaining CO and C will also burn. [ce] 7 CO + 7 C + 10.5 O2 -> 14 CO2 [/ce] If we can agree on this (detonation or combustion, and also if glucose is satisfactory to model the cookie?), then we can proceed to calculate the heat of reaction. If the cookie is to be represented by another molecule, or even a group of them, please provide a heat of formation or combustion. Note that although the TNT contains oxygen, it is not oxidized. It's like gunpowder... it contains the oxygen (in the form of nitrate) but it will only oxidize when you ignite it. On TNT, the oxygen atoms break their bond with the nitrogen atom, and form another one with hydrogen to form water. This releases quite a bit of energy. I still think we're talking about the digestion-energy... that I cannot calculate, but I wouldn't recommend to eat TNT anyway.

That's probably "energy from digestion"? It's like the question: which has more energy: a relatively fresh yellow/green banana or a ripe and brown/yellow banana? Answer: for total energy it's the greenish banana. The banana burns some of itself while it ripens. It produces CO2. However, it also produces more free sugars (monomeric), and those are easy to digest. So for us people, a ripe banana "contains more energy"...

The few seconds of the clip are the intro of a cartoon. I am not sure that the "air gear rollerblade thing" actually exists. Just to make it clear, we're discussing the thing that is in the pictures below, aren't we? p.s. If you want to make a cool movie with a loop (I think it's a .gif), I can't help you, but Google might help. If you want to extract info from a movie in youtube, I suggest using the pause-button. Copy-paste the picture of the movie is done (in Windows) by pressing ctrl-print screen, then opening MS Paint, and pressing "paste".

I think you need to ask more specific questions to get some help. Nobody is going to give you a complete design, and I doubt anyone has experience with making motorized rollerskates (for example, all my "experience" is from watching Jackass, and that made me decide never to try it).

New too. I'm a chemical process engineer, recently started working after finishing uni. (Where are the engineering threads?)