Category Archives: Science

My thoughts on non-physics sciences — like evolutionary biology, cognitive neuroscience etc.

Speed of Light

The speed of light being a constant sounds like a simple statement. But there is more to it, quite a bit more. Let’s look at what this constancy really means. At first glance, it says that if you are standing somewhere, and there is a ray of light going from your right to left, it has a speed c. And another ray of light going from left to right also has a speed c. So far, so good. Now let’s say you are in a rocket ship, as shown in the figure below, moving from right to left.

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Historical Origin of Quantum Mechanics

In this section, we will try to look at the historical origin of Quantum Mechanics, which is usually presented succinctly using scary looking mathematical formulas. The role of mathematics in physics, as Richard Feynman explains (in his lectures on QED given in Auckland, New Zealand in 1979, available on YouTube, but as poor quality recordings) is purely utilitarian.
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Quantum Mechanics

Quantum Mechanics (QM) is the physics of small things. How do they behave and how do they interact with each other? Conspicuously absent from this framework of QM is why. Why small things do what they do is a question QM leaves alone. And, if you are to make any headway into this subject, your best bet is to curb your urge to ask why. Nature is what she is. Our job is to understand the rules by which she plays the game of reality, and do our best to make use of those rules to our advantage in experiments and technologies. Ours is not to reason why. Really.

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Classical Physics

The main difficulty in describing particle physics to general public is the fact that it is built on modern physics. Even if you are physics aficionado and did extremely well in your high school physics, what you have learned and loved is classical physics. The difference between classical physics and modern physics is not just more physics, but a completely new way of looking at the reality around us.
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In all our scientific endeavors, we use similar high-level techniques to understand and study things. The most common technique is reductionism. It is based on the belief that the behavior, properties and structure of large and complex objects can be understood in terms of their simpler constituents. In other words, we try to understand the whole (the universe, for instance) in terms of smaller, reduced constituents (such as particles).

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Particles and Interactions

Recently, I gave a talk on particles and interactions to my daughter’s classmates who were planning on a trip to DESY, Germany and wanted to have an idea of what it was all about. As my first talk of this kind, I was a bit nervous because I didn’t know what level, and background, I should peg the talk at. I didn’t want to make it too basic, which I thought would be a waste of time. Nor did I want to make it too technical, which also would make it useless in a different way.

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