What a clown show from Schroeder!
Let's show how the slight of hand works.
Well lets look at his calculations.
From your link.
The equation A = Aₒexp(-Lt) apart from being pulled out of thin air without derivation has the highly questionable constant Aₒ (Aₒ = the instantaneous ratio of the threshold rest energy of a proton {the proton is the first stable form of matter following the big bang creation of the universe that defines the element} to the current energy of space corrected for the increase in the rate of expansion of space.)
This weird little factor "A" is the instantaneous ratio of "genesis time" (t) to real time (no symbol given). (You might think all you need to do is divide 13.7 Gyr / 6 days and get a ratio, but instead Schroeder tries to get fancy by using "physics" (it isn't physics). [Spoiler: the original ratio will do, the rest is all razzle dazzle to distract the marks.]
If you integrate the equation over all of chapter 1 (up to day 6 or so) you get the observable age of the universe (if it works, and shockingly it works less well than he portrays).
So first Schroeder wants the A to decay by halving every genesis day so that the "progress of real time" slows down. (Yes, I am aware this makes no real sense.) Why? Who knows. It seems arbitrary. Now because there are 5.5 days (according to old Gerald for some reason) the "speed of time" slows down by 2^5.5 or about 45-fold. That isn't really all that much "slowing down" given that
we're he's (keep the rest of us off your crazy train "Doc Schroeder") already trying to squeeze 13.7 billion years in to less than a week. (And I thought *my* vacation plans were ambitious.) This means that when the train comes to a halt when "Adam gets a soul" time abruptly "slows down". (Be careful not crack the time rotor, Doc!)
So let's set the constants in the exponential (uncited quotes taken from earlier cut-and-paste from the Schroeder web page):
L = natural log of 2 {usually referred to as ln2} = 0.693 divided by the half period;
Half period = t1/2 = one Genesis day
Schroeder is working in units of days, so the factor "L" is just ln(2)/(1 day).
Essentially, what he want is A_o * 2^(-t/days), a very simple "half-life formula" with a 1 day halving. Cool. The exponential makes it easier to integrate.
t = time in Genesis days and goes from 0 to 5.5 days; each day 24 hours duration; 5.5 and not 6 because Adam receives the human soul – the neshama – half way through the 6th day. In the calculation, the difference between using 5.5 or 6 is minute.}
Minute it is indeed. (As we shall see.)
If we now:
Integrate A = Aₒexp(-Lt) with t going from 0 to 5.5 days
We get a [age] from 5.5 genesis days equal to the real age of the universe (or so he would have you believe):
Integral ∫A = Integral ∫Aₒexp(-Lt) = (-Aₒ/L)exp(-Lt)
And this is that integral correctly computed (OK, it's literally 1st semester calculus.)
Note that the units of the right side of the integrated equation is days
Yes, because (1/L = 1 day/0.693...)
The definite integral looks like this [age] = [-Aₒ/L] [2^{-5.5} - 2^{0}]
Since we all know what 2^0 is, let's do a little more simplification to see things a bit more clearly:
[age] = [Aₒ/L] [1 - 2^{-5.5}] = [Aₒ/L] 0.978
Dirty secret number one:
After a few days, the total number of days doesn't matter. 4, 5, 6, 43 all give ~1 for that [1-2^{#days}] factor. The only purpose the exponential really serves is to get the "days" unit out and make things look "fancy". It's all just numerology in a pseudophysics wrapping.
In the next line the indefinite integral is repeated with the "constants" inserted
Integral ∫A = -((10.9 x10¹² /3) x ( 1 day/0.693))exp(-0.693 t) /1 day| with t going from 0 to 5.5 days
Why (10.9 x10¹² )/3? Well that's just because he wants to get the right number of days when multiplying this unitless constant by (1 day/0.693) = 1/L. So it's time to go hunting for a "plausible" physical ratio.
Ol' Gerry chooses the ratio of the temperature of the Universe at the beginning and end of creation. For the latter, he uses the measured cosmological value, for the former he chooses (quite arbitrarily, but that's how numerology works) the rest mass energy of the proton and sets it equal to kT (k is Boltzmann's constant, and kT has units of energy, kT is all over real physics, so why not use it here in this fake physics). If you use the proton rest mass energy for kT you get T = 10.9 x10¹² K, so our ratio
Aₒ = (10.9 x10¹² K)/(3 K)
[age ] = (10.9 x10¹² K)/(3 K) * (1 day / 0.693) * 0.978
to get this:
Integral ∫A = 5.12 x10¹² days = 14 x 10⁹ years
after converting days to years. 14 Gyr isn't too far off 13.7 ( about 2% to high). Not bad... but we have another problem
The current temperature of the Universe *isn't* 3 K, it's 2.71 K.
Dirty secret number two: Lowering the 3 K by 10% *increases* the ratio Aₒ and the age of the universe by 10%. Now the "age" of the universe comes out as 15.5 Gyr. (Not good, MIT super genius.)
[We could actually fix it by changing the number of days to 3 or using 6 days with a 2 day "half-life" as 1 - 2^{-3} give a majik special age of 13.8 Gyr. It's a miracle! Numerology, full of numbers, meaning nothing.]
But wait, MIT man, you made another mistake...
Dirty secret number three: In smashing his religion and science-y things together he managed to explain his variables *wrong* on his web page.
On the web page he claims that
A = earth time in number of days
But it's not. It can't be. As is stated above:
A = Aₒexp(-Lt)
Since both Aₒ and the exponential are unitless A is also unitless. As I stated before, A is the "speed of time" (just go with it) the ratio of genesis time to real time and it slows down with time during "creation week". If we take the web page seriously that A is the "earth time in days" (I must also assume he means universe, or at least the parts outside "the garden".), then as creation progresses, the current time decreases. (It's what decaying exponentials do, after all.)
Instead, it is the *INTEGRAL* of A that give the age of the universe during creation, up to when the non-uniform time flow abruptly stops. While A is the "speed ratio" and Aₒ is a constant needed to make the numerology "work out".
(It would seem that the guy with the physics Ph.D. from [large state university] can indeed find errors in the work of the MIT/Harvard guy. Ha!)
Why use the rest energy of the proton?
It *almost* works. Almost as well as physics by chatbot.