CHAPTER 1: Relativity

According to the theory of relativity, nothing can travel faster than light. Although today’s spacecraft can exceed 10km/s, they are far from this ultimate speed limit.

In 1905 a young physicist of twenty-six named Albert Einstein showed how measurements of time and space are affected by motion between an observer and what is being observed. To say that Einstein's theory of relativity revolutionized science is no exaggeration. Relativity connects space and time, matter and energy, electricity and magnetism-links that are crucial to our understanding of the physical universe. From relativity have come a host of remarkable predictions, all of which have been confirmed by experiment. For all their profundity, many of the conclusions of relativity can be reached with only the simplest of mathematics.

1.1 SPECIAL RELATIVITY

All motion is relative; the speed of light in free space is the same for all observers

1.2 TIME DILATION

A moving clock ticks more slowly than at rest

1.3 DOPPLER EFFECT

Why the universe is believed to be expanding

1.4 LENGTH CONTRACTION

Faster means shorter

1.5 TWIN PARADOX

A longer life, but it will not seem longer

1.6 ELECTRICITY AND MAGNETISM

Relativity is the bridge

1.7 RELATIVISTIC MOMENTUM

Redefining an important quantity

1.8 MASS AND ENERGY

Where E_o= mc² comes from

1.9 ENERGY AND MOMENTUM

 How they fit together in relativity

1.10 GENERAL RELATIVITY

Gravity is a warping of spacetime

APPENDIXI: THE LORENTZ TRANSFORMATION

APPENDIXII: SPACETIME