Category: mechanics

Just my summary of classical mechanics that made me pass the exam in the first semester. Nostalgia.




** The reason why this is awesome is because one does need to worry about the unit vectors in the r and theta directions, which makes the algebra so much more simpler

You might have seen animations like this that show an electron undergoing a transition from a lower energy to a higher energy state and vice versa like so:


There is something really important about this image that one must  understand clearly.

The diagram represents the transition in energy of an electron BUT this does not mean that the electron
is magically jumping from one position and respawning at another


                        The electron’s position is NOT doing this i

If you want to know about the probability of finding an electron around the nucleus at a certain energy level, you look at its wavefunction and not at the energy diagram.

Here is the wavefunction of a hydrogen atom and each stationary state defines a specific energy
level of the atom.


This might not sound like a big deal but one might be surprised to know that there are a lot of people who think that the electron is magically transported from energy level to another which most certainly is not true.

Have a good one!

– A2A

Thank you so much! Well.. There is an amazing playlist on YouTube compiled by  Ludwig Maximilian University of Munich featuring a set of 27 frequently asked questions about Bohmian Mechanics. It is definitely a rich source of information on the topic.

Thanks for asking! *

PDF Version: Click here

Home page: Department of Mathematics, Ludwig Maximilian University of Munich

* NOTE:  You guys have been asking us a ton of interesting questions over the past month or two and we have been trying our very best to get to all of your questions ASAP. It would help if you did not ask Anonymously since it’s hard to address some personal questions on a global platform. Thanks!


TBH cleaning your car is a rather mundane task. But when you fill your head with some interesting physics the task actually gets rather pretty interesting. Here’s some good for thought on such an occasion :

The dust on your windshield might actually be from the Sahara desert

To understand how, lets start with some simple physics.

The stacked ball drop

You basically take couple of balls, align them up and drop them to the ground. The ball at the top reaches the most highest due to the subsequent transfer of energy from the other balls.


                                    Source Video : Physics Girl

Here is an exaggerated but amazing slow motion of the same energy transfer with a water balloon. Notice how the transfer of energy takes place between the water balloon and the tennis ball.


                                     Source Video : Slow Mo Lab

Sandstorms in the desert


Sandstorms/ Dust storms as you might be aware, are pretty common in the desert. . Dust storms arise when a gust front or other strong wind blows loose sand and dirt from a dry surface.


And this can cause something phenomenal to happen:

If the wind speed is sufficient then larger sand particles can propel finer ones high into the atmosphere. ( just like the stacked ball )

Then these fine particles are caught in the global wind pattern and are transported across the globe until they fall down to the earth as rain.

How cool is that !

* Tracking saharan dust in 3D – NASA video

** All the World’s a Stage … for Dust – NASA article

** Wiki on Saltation


This animation shows a cinemagraph of a breaking wave photographed by Ray Collins. The motion was

inferred and digitally added by a second artist, Jersey Maria. The result is hypnotic, as if we are traveling beside the wave and watching it tear apart ever so slowly. The wave seems to be poised on a tipping point, only breaking up along its back edge, when instinct tells us it will keep steepening and tipping forward until its top curl crashes down in a wave of white foam. Surf photography like Collins’ work shows us an alternative perspective on waves, their power frozen into a single instant. Reanimated, it feels like we’re seeing the wave in hyper-slow-motion, watching every tiny movement of water before everything crashes down. Even if it’s not physically realistic, it is an awesome view.  (Image credit: R. Collins / J. Maria, source, original; via Iwan A.)