What shall we explore today?

Position, velocity, acceleration

Position tells where an object is; velocity describes how quickly and in which direction position changes; acceleration describes how velocity changes.

Uniform linear motion

In uniform linear motion, an object travels along a straight line at constant velocity; distance grows in proportion to time.

Uniformly accelerated motion

Constant acceleration makes velocity change uniformly with time and position vary quadratically with time.

Pressure in fluids and atmospheric pressure

Pressure in a stationary liquid rises with depth; atmospheric pressure is the force per area exerted by the weight of the air.

Motion in a central field, the Kepler problem

The Kepler problem describes motion under an inverse-square gravitational potential. Symmetry reduces it to radial dynamics and classifies trajectories as ellipses, parabolas, or hyperbolas.

Optical trapping and laser cooling

Photon scattering provides Doppler cooling, while intensity gradients create dipole potentials that trap atoms.

Condition for a standing wave on a string fixed at both ends

$L = n\lambda/2$, $n = 1, 2, 3, \ldots$ — the string length L must equal an integer number of half-wavelengths for a stable standing wave.

Newton's first law (inertia)

An object remains at rest or in uniform straight-line motion unless acted on by a force, or as long as the net force acting on it is zero.

The first law of thermodynamics

$\Delta U = Q - A$ — the change in a system’s internal energy equals the heat it absorbs minus the work it performs.

Mohammad Abdus Salam

Pakistani theoretical physicist who independently formulated the electroweak unification and founded the ICTP to support scientists in developing countries.

Adam Guy Riess

American astrophysicist whose analysis for the High-z team led to the accelerating-universe conclusion.

Alain Aspect

French physicist who performed the first stringent Bell tests — proving quantum entanglement is real.