chapter  19
22 Pages

What New Telescopes Can Tell Us about “Other Worlds”

In the Western tradition, the “Many Worlds” concept goes back to pre-Socratic thought, with Epicurus asserting in his Letter to Herodotus (ca. 300 BCE) that “[T]here are inœnite worlds both like and unlike this world of ours. … We must believe that in all worlds there are living creatures and plants and other things we see in this world. …”

Such thoughts are to be found in Chinese history as well, with philosophers debating the nature of the Universe and the existence of other worlds. Around 100 BCE, the Hun Thien ( ) School advocated a single celestial sphere, while Hsüan Yeh ( ) taught of inœnite empty space. One modern-sounding explication of the “Many Worlds” hypothesis comes from the philosopher Deng Mu ( ) (1247-1306 CE):*

Introduction ....................................................................................................................................309 Modern Science, but Still Some Speculation ................................................................................. 310 Planet Detection Methods .............................................................................................................. 310

Radial Velocity .......................................................................................................................... 312 Transits and Precision Photometry ............................................................................................ 314 Microlensing ............................................................................................................................. 317 Direct Imaging of Giant Planets ................................................................................................ 317

Observing from the Ground ................................................................................................. 317 Observing Giant Planets with the James Webb Space Telescope (JWST) ............................ 318

Astrometry................................................................................................................................. 319 The Search for Life on Other Worlds ............................................................................................. 322

What to Look For ...................................................................................................................... 323 How to Look for Life ................................................................................................................ 324

Transit Experiments.............................................................................................................. 324 Direct Imaging of Earths with the Terrestrial Planet Finder (TPF) .................................... 325

Concluding Remarks ...................................................................................................................... 327 Acknowledgments .......................................................................................................................... 327 References ...................................................................................................................................... 327

Renaissance and Enlightenment Europe offer numerous examples of natural philosophers proclaiming a belief in multiple worlds and even other worlds with life. Deng Mu sounds exactly like Italy’s Giordano Bruno, who asserted in De L’innito universo e mondi (On the Innite Universe and Worlds) (1584) that “[T]here are countless suns and countless earths all rotating around their suns in exactly the same way as the seven planets of our system. … The countless worlds in the universe are no worse and no less inhabited than our Earth.”