Mainly Cosmology and Gravitation, some quantum theory
Here are some challenging riddles that I put forth to two different sets of students. One was a group of 4th graders (8-9 year olds) – and the other was a group of 14-16 year olds.
I am something no one … Continue reading
A small bag is lying on the floor. The room is big – with high ceilings. Yet, no one can jump over the bag. Why?
I posed this to several grown-ups. No one got it. Next, I posed it to my … Continue reading
People tend to use ‘laws’ interchangeably with ‘principles’. In reality, there is an important difference between the two – as described in this short post.
A law encompasses a specific area – e.g. mechanics is fully described by Newton’s ‘laws’ – … Continue reading
Consider the 24 presidents (and their corresponding 24 terms in office) in the 19th century. A student was asked to match the president to his term. Not knowing the answers, the student resorted to guessing. He had two possible strategies … Continue reading
One of the things I never fully grasped in college was the ‘Michelson Morley’ experiment. I understood what it was for (proving the constancy of the speed of light) – and understood that it proved that very well – but … Continue reading
Two friends decide to meet at a definite place between 9 AM and 10 AM. The first to arrive waits for his friend for 15 minutes and then leaves. If each of them arrives at an arbitrary moment between 9 … Continue reading
This is an excerpt from the introduction to the collection of stories (Nebula Award Stories) below (edited by Isaac Asimov). Asimov remains one of the most prolific writers of all time, having written everything from textbooks, science fiction, literary critiques … Continue reading
Probably the most startling revelation of Quantum Theory was the postulate that all particles have a waviness to them. Initially, when this was proposed for photons, physicist were more open to accepting it – since light was already clearly a … Continue reading
Traffic flow is not that different from the flow of anything else. Imagine heat flow along an iron rod or water flowing down a pipe. If you observe the traffic (on a highway) from a far enough distance, the mass … Continue reading
Quantum Mechanics starting point – The Schrodinger Equation
All laws of physics are required to be Lorentz Invariant . The above equation is not. To try and make it Lorentz invariant, we start with looking at … Continue reading