thebigdog

Thanks, amigo; I should have checked that reference in the first place; I hope it helps! Thanks again, Stan Thank you, swansont; that reference should help me out. Thank you for your time and patience, Stan

Thanks for your response, Mordred; it is greatly appreciated. Yes, I DO understand that any numbers are inherently "model dependent." However, WikiPedia got their numbers SOMEWHERE. (I am assuming the model used to be Glashow's SO(5) model.) So I guess what I am asking is..... "Using WikiPedia's figures of 27^10K at the beginning of Inflation and 10^22K at the end of Inflation, what would the temperature have risen to at the beginning of the Electroweak Epoch, and what would the temperature have been at the end of the Electroweak Epoch?" Thanks again for your courtesy, my friend, and have a great day! Stan

Now, I understand that any discussion of the very early Universe is entirely hypothetical and to say it is extremely speculative is being generous. However, there are a few concepts regarding the Grand Unified Epoch, the Inflationary Epoch, and the Electroweak Epoch that I am hoping someone will have the patience to explain… According to http://en.wikipedia.org/wiki/Inflation_(28cosmology) “Reheating” “Inflation is a period of supercooled expansion, when the temperature drops by a factor of 100,000 or so. (The exact drop is model dependent, but in the first models it was typically from 10^27K down to 10^22K.) This relatively low temperature is maintained during the inflationary phase. When inflation ends the temperature returns to the pre-inflationary temperature; this is called reheating or thermalization because the large potential energy of the inflaton field decays into particles and fills the Universe with Standard Model particles, including electromagnetic radiation, starting the radiation dominated phase of the Universe.”​ My question is this: If, “during the period of supercooled expansion during the Inflationary Epoch the temperature dropped from 10^27K down to 10^22K, and when inflation ends the temperature RETURNS to the pre-inflationary temperature in the process called reheating....” Does mean that, at the beginning of the next epoch – the Electroweak Epoch – the temperature ROSE BACK TO 10^27K (the temperature at the start of Inflation)? If that is correct, then what would the temperature have been at the END of the Electroweak Epoch? Thanks in advance for your time and consideration, Stan

Thank you, my friends, for taking the time to reply to my post. I found your responses most helpful. I view discussion of the Planck Epoch as merely a preamble to more interesting (and complex!) epochs, since so little can definitively said about it; but I had to start SOMEwhere. I look forward with great enthusiasm to being educated on the less speculative eras of Big Bang cosmology. Thanks again, and have a terrific day, Stan

Questions Concerning The Planck Epoch I must begin this thread with an apology. I am NOT a physicist nor astronomer; in fact, my degree is in biology. However, for decades I have had a deep interest in what is commonly referred to as Big Bang Cosmology and have an “educated layman’s” knowledge and appreciation for this field. My eventual goal is to establish a “best-guess” or “theoretically-acceptable” step-by-step chronology of the Big Bang. I have found WikiPedia’s Chronology of the Universe to be an extremely useful starting point. However, a number of areas in their Chronology are in need of clarification for my humble intellect. In addition, in cross referencing WikiPedia’s information with other sources, both on and off the Internet, I have found that there exists no concensus of opinion regarding certain data and concepts. I am hoping that the intellect and benevolence of the members of this forum will see fit to display a little patience and assist me in my understanding. So allow me to begin at the beginning… with the Planck Epoch: Five Basic Parameters of the Planck Epoch (Time 0 to 10^-43 second) PARAMETER ONE: Time Time at BEGINNING of Epoch: 0 Time at END of Epoch: 10^-43 second (1 Planck Time) PARAMETER TWO: DIAMETER Diameter of Universe at BEGINNING of Epoch: 0 Diameter of Universe at END of Epoch: 10^-35 m (1 Planck Length) PARAMETER THREE: TEMPERATURE Temperature at BEGINNING of Epoch: ∞ Temperature at END of Epoch: 10^32 K (Planck Temperature) PARAMETER FOUR: MASS Mass at BEGINNING of Epoch: ∞ Mass at END of Epoch: 10^19 GeV (Planck Mass) PARAMETER FIVE: DENSITY Density at BEGINNING of Epoch: ∞ Density at END of Epoch: 10^97 g/m3 (Planck Density) Now I DO understand that (to quote http://www.whillyard.com/science-pages/planck-epoch.html):“The equations of General Relativity suggest that the Universe started as a singularity; that is, infinite density in an infinitely small space. Scientifically, this is not acceptable, and most scientists agree that General Relativity breaks down below the Planck Length due to random quantum mechanical fluctuations. Quantum physics places limits on size and density, and suggests that the expansion started with the entire Universe in a space with the diameter of the Planck length, and with the density at around 10^94 grams per cubic centimeter.” (Please understand that I am using time=0 (the “singularity”) solely as a metaphorical starting point.) Now for my for my humble (and no doubt naïve) questions regarding this initial Epoch: Question # 1: Are my (rounded to the nearest factor of 10) numbers for the Planck Epoch even remotely accurate and theoretically acceptable? Question # 2: During the Planck Epoch all four of the forces observable in the present-day Universe were combined into a single, unified force, sometimes referred to as the Superforce, Supergravity, or Mother-Force. Am I correct in stating that eventually (at t = 10^-43 second after the beginning) the gravitational force condensed out from the Superforce, and this symmetry-breaking event marked the END of the Planck Epoch and initiated the BEGINNING of the next epoch, the GUT Epoch? Thanks in advance, my friends for your time and consideration, Stan