Revise: Modern Physics
Radioactivity and its uses, nuclear energy and its environmental impact, wave-particle dualism, and the principle of special relativity.
After n half-lives, (1/2) to the power n remains.
I-131 (half-life 8 days) after 24 days: 12.5% remains.
E = mc squared — tiny mass, enormous energy.
0.001kg converts to 9e13 J.
lambda = h/(mv) — every particle has a wavelength.
A fast electron has lambda approximately 0.36nm.
delta t = gamma times delta t_0. Moving clocks run slow.
v=0.8c → gamma=1.667.
A sample never reaches exactly zero mathematically.
Carbon dating measures the fraction of C-14 remaining.
Never forget to square the speed of light.
Nuclear fuel has millions of times the energy density of coal.
Confirmed experimentally via electron diffraction.
Electron microscopes resolve far finer detail than light ones.
The effect is never exactly zero, just usually tiny.
GPS satellites correct for time dilation daily.