REAP 2015 – Class 2 (Introduction to Mechanics) by Prof. Vijay K. (ICTS, TIFR)


Prof. Vijay has also done REAP-Physics course in  2003-2004.

He took class on explaining basics of physics and mechanics.

Physics – Study of matter and its interaction.

2 Imp. questions:

  1. What is the world made of?
  2. How is  the world put together.

Emergence is very important concept in physics where big object is emerged from smaller components (e.g. atoms or molecule).

Can we do calculations for big object (e.g. ball, how it will move or bounce if you calculate the movement of individual components – individual atoms) from its components. This is very difficult.

Mechanics – Behaviour/Dynamics of system subjected to interaction/forces.

Kinematics – description of motion without knowing about interaction.

Then straight line motion was explained where d (distance) = v*t was plotted on different graphs.


REAP 2015 – Class 1 (Introduction to Physics) by Prof. Bala R. Iyer (ICTS, TIFR)


Dr. Bala explained about the basics of physics and different direction a researcher can take in physics. He also explained the seriousness in the research and value of mathematics in the research.

  • Constituent of matter
    •    Small scale: Atom -> Nuclei + Electron -> Quarks -> ? (Strings)
    •    Big scale: Objects -> Planets -> Star -> Galaxy -> Universe
  • Direction in physics:
    • Classical Mechanics (first year of REAP)
    • Special Relativity (2nd year of REAP)
    • Quantum Mechanics (2nd year of REAP)
    • Quantum Field Theory (QFT) or Particle Physics or High Energy Physics – Needs special tools like CERN LHC.

image source: wikipedia

  • Forces present in the nature
    • S – Strong interaction (responsible for binding the neutrons and protons inside the nuclei of atom)
    • W – Weak Interaction (responsible for beta decay)
    • G – Gravitation
    • E – Electromagnetic

Only theory proposed for electromagnetic force is complete, for other 3 fundamental forces, their theories are incomplete.

Daily life is dominated by electromagnetic force.

Universe is dominated by gravity.

Two charges at static gives coulomb equation ~ 1/r2 * q1 * q2

Charges at movement gives rise to the current.

Acceleration in current gives rise to Radiation (EMW) – Light.

Electricity + Magnetism + Optics = Considered one in modern physics.

Different theories are formulated to provide answers for different speed and size scale such as

EM + W = Electromagnetic + weak

EW + S = Unified Grand Theory

EW + S + G = Super string theory