Cosmic Coincidences If these cosmic traits were just slightly altered, life as we know it would be impossible. A few examples: • Stars like the sun produce energy by fusing two hydrogen atoms into a single helium atom. During that reaction, 0.007 percent of the mass of the hydrogen atoms is converted into energy, via Einstein’s famous e = mc2 equation. But if that percentage were, say, 0.006 or 0.008, the universe would be far more hostile to life. The lower number would result in a universe filled only with hydrogen; the higher number would leave a universe with no hydrogen (and therefore no water) and no stars like the sun. • The early universe was delicately poised between runaway expansion and terminal collapse. Had the universe contained much more matter, additional gravity would have made it implode. If it contained less, the universe would have expanded too quickly for galaxies to form. • Had matter in the universe been more evenly distributed, it would not have clumped together to form galaxies. Had matter been clumpier, it would have condensed into black holes. • Atomic nuclei are bound together by the so-called strong force. If that force were slightly more powerful, all the protons in the early universe would have paired off and there would be no hydrogen, which fuels long-lived stars. Water would not exist, nor would any known form of life.
Posted on: Sat, 19 Apr 2014 22:56:28 +0000