Why is the expansion of the universe not measurable inside a classroom?

Why is the expansion of the universe not measurable inside a classroom?

The sun's orbital period

The Sun moves in a roughly circular orbit around the center of our galaxy (Milky Way), at a distance of 26, 500 light-years. The orbital speed is ~ 230 km/s. Calculate the Sun's total orbital period and estimate the mass of the galaxy?

The sun's total power output

According to Stefan's law, how much energy is radiated into space per unit time by each square meter of the Sun's surface? If the Sun's radius is 700,000 km, what is the total power output of the Sun?

Comparing the energy of a gamma ray to a radio photon.

What is the energy (in Joules) of a 450-nm blue photon? How many times more energy does a 0.0001-nm gamma ray have than a 10-MHz radio photon?

Calculating Venus's diameter given the distance from Earth and its angular size.

Given that the angular size of Venus is 53" when the planet is 44 million km from Earth, calculate Venus's diameter (in kilometers).