Walking and third law of motion

I realised one fine day that apart from trampoline and rockets there is an example of Newton's third law of motion that I missed all my life!

When we want to move forward, we push our foot backward, and earth as a reaction pushes our foot forward!

Same happens when we want to move backward, we push our foot forward!

Now I understand why children take so much time to learn to walk! :)

If atom is mostly empty space, why don't we pass through things ?

 We know the atom is mostly empty space, with nucleus accounting for a very small portion of atom. Nucleus can be compared to like a grain of sand with atom as a large room. Then why don't we pass through things, how can we sit on a chair ... why do we bump onto things ?

• Things are held up even with the vast amount of emptiness in an atom only due to fact that electron cloud in outer space of atoms in me are negatively charged- > So do the electrons in the atoms of chair, they are also negatively charged

• We know negative charges repel each other -> And we also know electrical forces are very STRONG-> So we are able to Sit, Walk, Do things that we do, See things as we see

• Without Electrical forces-> Everything will crumble into fine dust -> There will be no matter or no things as we see in Universe -> Only Clouds of Protons, Neutrons, Electrons !

What is meaning of Ampere as unit of current , and what exactly is a 'unit' of electric current ?

 Some history behind why Ampere is unit of current :

• While it was known that force is imposed -> and subsequent motion between two bodies each having an electric charge,

• Known through columb's law- > Electric force between two static bodies is directly proportional to product of charges and divided by square of distance,

• Which was somehow just like the gravitational law !,

• Marie Ampere observed that -> when electricity is passed between two adjacent wires- > it imposes a force on each other

• If currents are in same direction-> Wires attract each other,

• Unit of current was made in honour of his research,

• Definition of current - A hypothetical case of 2 thin and infinite wires , 1 m apart , 1 Amp is 'current' that generates 2x 10^-7 N of 'force' per 'every m' of wire

• Very small force and strange definition indeed, but this is what is behind the definition !