Dark Energy Overtaking GravityBy Jim Hartsell, Aug. 17, 2010.Last sentence added May 28, 2011. BACK TO HOME PAGE Dark energy is a repulsive force that causes the universe to expand. It was inadvertantly predicted mathematicaly by Albert Einstein while developing his theory of General Relativity, when he introduced his Cosmological Constant into his equations. Dark energy is also called negative pressure, negative vacuum, and vacuum energy. It originated from the decay of a Higgs field that caused the Big Bang. For a week I thought I had come up with a breakthrough idea. I had not seen it in any of my readings of Astronomy, Discover, and Scientific American magazines. We know that expansion of the universe began accelerating about 5 billion years ago. The thought hit me that the repulsive force, or negative pressure, of dark energy increases with distance (a better way to say it is "increases with cosmological expansion"), and 5 billion years ago, the repulsive force of dark energy finally overtook the mutual gravitational attraction of galaxies, and thus expansion began to accelerate. I was so sure this was a new idea that in order to "publish" it, I emailed "Ask Astro" of Astronomy magazine with the following question: "Gravity DECREASES with distance. Could it be that the repulsive force of dark energy INCREASES with distance, thus causing expansion of the universe to accelerate? Could it be that when accelerated expansion kicked in 5-6 billion years ago, it was when dark energy overtook gravity? - Jim Hartsell, Sunnyvale, California." "Astro" replied saying "It is my understanding that dark energy's effects did kick in around 5 billion years ago. I'm not sure if this answered your question, however." I was crushed, but at least I had an email reply for proof it was my idea. So, I wrote back and mentioned my degree in Math/Physics, that I worked 6 years with Clyde Tombaugh, etc. "Astro" wrote back with: "I'm not sure if dark energy increases with distance, but it sounds quite plausible. I'll forward this on to a cosmologist and include it in Ask Astro in a future issue." Before this second reply from "Astro", thinking my idea was dead in the water, I began plan B. Being a subscriber of Astronomy magazine, I joined the online discussion forum at astronomy.com with the topic "Dark energy overtaking gravity", as follows: "Expansion of the universe began accelerating 5 or 6 billion years ago. I'm wondering if this was when the repulsive force of dark energy overtook the mutual gravitational attraction of galaxies (when the universe got large enough). I'm wondering if the repulsive force of dark energy INCREASES with distance, where gravity DECREASES with distance." See cs.astronomy.com/asycs/forums/t/47760.aspx. I got a reply from Dave Mitsky, a moderator for the "Planet Earth" series on the Science Channel. He said "That is exactly what some cosmologists believe. The repulsive force of dark energy grows in strength as cosmological expansion increases." He gave me the link www.universetoday.com/11933/has-dark-energy-always-been-constant/. Wow. So then I started Googling for the words: dark energy overtake gravity. I found www.redorbit.com/news/science/1085903/mysterious_dark_energy_winning_cosmic_tug_of_war/. It says "But in the last 5 billion years, dark energy - a sort of "negative gravity" or "repulsive" force - has overcome gravity and is driving galaxies apart at an ever-increasing rate." Then, coincidence of all coincidences, the Science Channel had a program "Morgan Freeman's Through The Wormhole - Beyond the Darkness". It was about dark matter and dark energy, where the statement was made that 5 billion years ago dark energy overtook gravity and expansion of the universe began to accelerate. So, it was not a new idea. They won't be calling it "The Hartsell Effect". I won't be on the Oprah Winfrey show. But at least it was something I independently thought of that turned out to be correct. My question finally made it into the "Ask Astro" section of the July 2011 Astronomy magazine. But, they left off the important second part of my question, and I wasn't happy with the answer to the first part. |