Questions Concerning The Planck Epoch

[thebigdog]

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

[Sensei]

Question # 1: Are my (rounded to the nearest factor of 10) numbers for the Planck Epoch even remotely accurate and theoretically acceptable?

IMHO, not really.

 

Take for example: "Mass at END of Epoch: 10^19 GeV (Planck Mass)"

 

It's less mass than in 1 gram of water.

[imatfaal]

IMHO, not really.

 

Take for example: "Mass at END of Epoch: 10^19 GeV (Planck Mass)"

 

It's less mass than in 1 gram of water.

 

Actually those figures are those often give:

 

You take Shu's idea about the fact that the Planck time is that before which we can make no observations and look to see what size event horizon that entails (gonna be in same ballpark as blackhole ev)

 

[latex]R =\frac{2Gm}{c^2}[/latex]

 

But we also know (or at least wildly surmise) from deb broglie and heisenburg that the smallest size will be at the compton wavelength

 

[latex]\lambda = \frac {\hbar}{mc}[/latex]

 

Set wavelength equal to diameter and you get

 

[latex]\frac{GM}{c^2} = \frac{\hbar}{Mc}[/latex]

 

Solve for Mass you get

 

[latex]M= \sqrt{\frac{\hbar c}{G}}[/latex]

 

Which is the Planck Mass - add back in the missing 4 and 2pi and you will get the reduced planck mass.

[thebigdog]

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

[Sensei]

But we also know (or at least wildly surmise) from deb broglie and heisenburg that the smallest size will be at the compton wavelength

But Compton wavelength is typically calculated using electron mass m=m_e=9.11*10^-31 kg.

 

[latex]\lambda_c = \frac {h}{m_ec}=2.426 pm[/latex]

 

If we will use different particle mass f.e. m=m_p=1.67*10^-27 kg, we will get much smaller Compton wavelength for protons..

 

[latex]\lambda_p = \frac {h}{m_pc}=1.323 fm[/latex]

 

Then how could Compton wavelength for electrons being the smallest size? Falsified instantly.

 

Which is the Planck Mass - add back in the missing 4 and 2pi and you will get the reduced planck mass.

 

Yes, I know how to derive Planck mass from other constants.

 

My point was that if we have Universe with radius r, existing for time t, it should have mass of current Universe, otherwise mass-energy equation would be violated.

Edited January 20, 2015 by Sensei

[imatfaal]

But Compton wavelength is typically calculated using electron mass m=m_e=9.11*10^-31 kg.

 

[latex]\lambda_c = \frac {h}{m_ec}=2.426 pm[/latex]

 

If we will use different particle mass f.e. m=m_p=1.67*10^-27 kg, we will get much smaller Compton wavelength for protons..

 

[latex]\lambda_p = \frac {h}{m_pc}=1.323 fm[/latex]

 

Then how could Compton wavelength for electrons being the smallest size? Falsified instantly.

 

 

"Falsified instantly." Well it might have been if you had followed same procedure - but you decided that you wanted to use the compton wavelength for an electron; you can have a compton wavelength for anything. If you set the compton wavelength to equal the width of the event horizon you get an equation you can solve for mass.

 

This is the Shu formalism for the Planck epoch - there are lots of versions and they are all different; but this is the one the OP had the figures for, so I provided the derivation.