Dark energy : More than two-thirds of the total energy of the universe is in a form we don’t yet understand. Two popular models for it are known as the cosmological constant and quintessence.
Why We Have Already Found Extraterrestrial Life
In this first of three books that I’ve coauthored with astrobiologist Dirk Schulze-Makuch, we build a strong case for the existence of life on other worlds in the solar system and beyond. Taking weird organisms on Earth as our starting point, including ice-loving bugs and microbes living in boiling hot acid, we explore what forms life might take and where it is likely to reside. From the noxious clouds of Venus to the methane rains of Titan, We Are Not Alone considers the biological credentials of alien worlds within range of our spacecraft, and the possibilities for detecting life on exoplanets.
"Packed with facts and written in an absorbing style, this book leaves you in no doubt that extraterrestrial microbes could yet be found in our Solar System." - BBC Sky at Night
"Well-written and provocative." - New Scientist