Quantum physics

The study of the laws that govern microscopic objects like atoms and electrons and even photons which are particles of light. You may heard of another little invention called the LASER, a quantum device. So this amazing scientific theory called quantum mechanics has transformed our lives today. The fundamental laws of nature are accessible to everybody male or female, young or old, known or unknown.

We cannot actually directly see an atom , it's far to small. But we can setup experiments where we can shine a laser beam at a cloud of atoms. And the atoms will interact with the laser light, and they will leave a shadow of that interaction in the light, and we can collect that light and analyze is and extract that shadow, and from that, we can actually construct a picture to see the atom. Here's the first ever picture of hydrogen atom.

 So you can see picture shows us the world of atom which is represented by a sphere. The laws which govern this kind of world is the laws of quantum physics. And that's actually a very strange set of laws. For example:- there's something called 'the uncertainty principle' which says that we cannot known how exactly where the atom is located  on this surface. So what you are seeing here is actually an image of likelihood. Red shows where the the atom is most likely to be and blue where it is least likely to be.

 The other thing we that we can do is we can actually engineer the surface of this sphere, so actually create a world for the atom, how do we do that? Well, we use lasers and magnetic fields to control this world and one of the thing we can do is we can insert barriers  and change the shapes of the islands on the surface of this atomic world.

If you look deep in to the heart of star- the core, it is actually a powerful fusion reactor. That's where all of the sunlight and energy is produced, and some that comes to earth as sunlight from our star. Of course, we know that it is critical for life on earth. But how does that nuclear reactor work? Well thanks to gravity, the hydrogen nuclei in the core combine, they fused together to create helium and that release enormous amount of energy. But her is the problem. Hydrogen nuclei, they have protons which have positive charges. You know that like charges repel each other. So as you try to bring these hydrogen nucleus close together, they push against each other. There is a barrier an energy barrier, and hydrogen atom cannot cross that barrier. But yet they can. The reason they crosses is exactly because of quantum tunneling. Quantum tunneling or tunneling in quantum mechanics atoms from one side of a potential barrier and appears on the other side without any probability current (flow) appearing inside the well. The hydrogen atom tunnel through the barrier and are able to complete the fusion process form which we get light and energy. So sunlight on earth and reason that we have life on earth, because quantum particles can walk through walls.

Now we have understand the physics behind quantum tunneling, we can control it and build amazing devices like scanning tunneling microscopes and tunneling diodes and these are amazing devices and cutting age technologies, but we are just scratching the surface.

 Tunneling is in one of the many incredible quantum effects that we are exploring now, to try to build future quantum technologies. For example:- Quantum particles can connect with each other in a powerful connection that we call entanglement. So if you make change to one of the quantum particles, it instantly affect all the other particles, no matter how far they are in the universe. And again we find that in order to understand an quantum theory and what is saying about entanglement. We have to question our fundamental ideas about the nature of reality and space and time itself. That's amazing, but here's a nice side effect. By exploring entanglement we have found that like tunneling it's a resource that we can use to build

So it is a fuel that we must have in order to build future cutting technologies like quantum  computers or teleportation or may be some