lightbulbs, 50–51
lightning, 162–63
light pollution, 121
light-year, 26n
Limited Test Ban Treaty, 161–62
lithium, 27, 119–20
Lowell Observatory, 131
Lucretius, 17
Macy’s Thanksgiving Day Parade, 119
Magellan, Ferdinand, 63
Magellanic Clouds, 63, 66
magnetic fields, 170–71, 174
mammals, 31
Manhattan Project, 52
Mars, 128, 137, 167–68, 180, 204
methane on, 189
mass, Conservation of, 43
Massachusetts Institute of Technology, 108
Mather, John C., 56
matter, 18, 20–21, 23, 48, 59–60, 75–76, 85, 107, 109
accumulation of, 58–59, 86
ultimate source of, 26
see also dark matter
matter-antimatter pairs, 74
matter-antimatter particle pairs, 20–21
McKinley, Mount, 137
mercury (element), 129
Mercury (planet), 129, 167
meteors, 165–68
methane, 189, 190
Michelson, Albert, 88
microwave ovens, 160
microwaves, 50, 51, 52, 53–57, 151, 156, 159, 163, 184–85
military, U.S., 119
Milky Way, 29, 55, 63, 78, 89, 114, 205
dwarf galaxy consumed by, 66
exoplanets in, 192
flatness of, 139–40, 144
radio waves emitted by, 157
supernovas in, 153–54
“missing mass” problem, 76, 80
MK 1 (radio telescope), 158
momentum, conservation of, 43, 46
Moon, 35, 128, 168, 170, 171–72
formation of, 166–67
view of Earth from, 180
moons, 85, 171–74
Morley, Edward, 88
mountains, 136–37
multiverse, 32, 89, 145–46
Nagasaki, 132