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