div class=ts-pagebutton class=gotoPage data-page=1Page 1button div class=ts-imageimg data-url=background-radiation-isotropic-microwaveshtmlpage=1 data-page=1 class=ts-thumb lazyload alt=Page 1: Background Radiation: Isotropic Microwaves loading=lazy src=data:imagegifbase64iVBORw0KGgoAAAANSUhEUgAAAAIAAAACCAQAAADYv8WvAAAAD0lEQVR42mP8X8AwAgiABKBAv+vAXklAAAAAElFTkSuQmCC data-src=https:reader031vdocumentsmxreader031viewer20220204055750683e1a28ab0f07af424bhtml5thumbnails1jpg width=140 height=200 divp© 1969 Nature Publishing Grouppdiv