If our universe were to be undergoing flat expansion (Flat Uniform Granular Expansion, or FUGE) then, I suggest, a lot of what I have
recently identified as “Big Fat Coincidences” would not be coincidences at all
but would rather be the natural consequences of the process of that FUGE. In addition, in the past few posts, I have identified
a couple of problems that, given FUGE, aren’t actually problems – namely the Flatness Problem and the Cosmological Constant Problem. Please note carefully, I am not suggesting
that I have solved the problem, I am merely saying that if FUGE is true, then
these are not problems.
I am going to summarise how I envisage that FUGE works and
try to hit as many big fat coincidences and problems that don’t (seem to) exist
as I can on the way. If I miss any, or
it’s just too awkward to address them at the time as they come up, I’ll list
them at the end.
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First and foremost, we know that the universe expands. We can see evidence of that as we look at
distant galaxies that are receding from us at a rate proportional to their
distance from us. This rate is what we
all the Hubble parameter (H) or, more
often, the Hubble constant (H0) which merely is the value of
the Hubble parameter today (meaning that it isn’t really a constant, since it
changes with time).
Secondly, our measurements of the curvature of the universe imply that
it is flat. This flatness of the universe
(which must be more extreme as we go back in time, per the Flatness Problem) tells us that the density of the universe is
critical and that, per the Friedmann equations, is ρc = 3H2/8πG.
As can be seen above, curvature of the universe and the
Hubble parameter are linked. In the FUGE
model, the universe is expanding and it remains flat throughout that expansion.
The final element of the FUGE model is its granularity. This granularity is at the Planck scale, which is the scale “below which (or beyond which)
the predictions of the Standard Model, quantum
field theory and general
relativity are no longer reconcilable”. To be more precisely, in the FUGE model, the
universe is granular at the Planck length and Planck time.
To expand, the radius of the universe must increase. Note however that this is the radius of a 4D
shape, specifically a glome. The 3D
universe does not have a radius in the same way that a sphere has a radius, but
the volume of the 3D universe is linked to the radius of the glome (r)
thus:
Vsurface = 2π2r3
It is this radius that increases. Clearly the universe, to expand, must expand
at a rate. In the FUGE model, the
expansion is given by:
Δr/Δt=c
At the granular level, this is equivalent to the radius of the universe
(as a glome) expanding by one Planck increment each Planck time. I say one Planck increment because it could
be said that the expansion is time, so the expansion rate is one
Planck time per Planck time however given the interchangeability of space and
time, this is equivalent to one Planck length per Planck time, which is the
value of r that can be used to determine the surface volume of the
universe – r = ct, where t is the age of the universe.
As the universe expands, it is filled with Plank atoms –
where a Planck atom is the 4D equivalent of Planck volume, so lpl3.tpl. The surface volume of the universe is the
current layer of Planck atoms, which appear to us, at the macro level, as 3D
space.
Note that as the surface volume of the glome expands, room
will become available for more Planck atoms.
In other words, gaps will open up.
These gaps will open up everywhere with a random distribution at a rate
proportional to ct. The consequence
of this is that, within the surface volume of the universal glome, for a sphere of rLH =
ct (that is a sphere defined by a radius equal to the light horizon, which
is the distance that light could have travelled in the age of the universe, t,
to reach an observer in the centre of that sphere), the rate of expansion would
be c. The recession of any object
at distance D, as observed from the centre of that light horizon sphere, would
be given by:
v = (c/rLH).D = (1/t).D
= H.D
This accounts for one big fat coincidence, namely that the
value of the Hubble parameter today, Ho, is the inverse of
the age of the universe. In the FUGE
model, the value of the Hubble parameter is always the inverse of
the age of the universe. It also
accounts for the fact that the Hubble length (lH = c/H) is
the same as the light horizon.
Note that our observations are based on the light horizon in
which we exist. The volume of that light
horizon is VLH = 4πr3/3,
where r=c.t.
As mentioned above, is the universe is flat, then ρc = 3H2/8πG. Given that H = 1/t and ρc = M/V and Δr/Δt = c and VLH =
4πr3/3,
consider the change in mass (ΔM)
over a period of Δt:
ΔM/(4π(cΔt)3/3) = 3/8πGΔt2
ΔM/Δt = (c3/G)/2 = (Mpl / tpl)/2
This is telling us that mass (and thus mass-energy) is increasing
within the light horizon at a rate of one half Planck mass per Planck time. This resolves the flatness problem since, if this
is true, the universe will be maintained at precisely critical density forever –
and will be flat forever. Note that this
applies to whichever light horizon we choose, from either here in our current
spacetime location, or from any other event location. This implies that the entire universe is
increasing in mass at rate that is greater by a factor of 3π/2.
Note that this rate of mass increase is not time constrained,
so it would apply even for very small values of t. This means that there is no singularity problem. For
sure, the universe would have been significantly denser at the beginning, when
Hubble parameter values would have been very high, but that density would not
have been infinite.
In the FUGE model, the universe does have a size because,
while it’s not bounded (in 3D), it’s not infinite. The volume of the universe is given by 2π2(ct)3
= 4.39x1079 m3.
It should be noted that the volume inside a sphere defined by a radius equal
to the “comoving distance to the edge of the observable universe” is greater
than this.
The radiation that is received by us today as cosmic microwave background radiation
has travelled across an expanse of space that now has a comoving distance of 46
billion light years despite the fact that the radiation has travelled at precisely
the speed of light for only 13.8 billion years.
Comprehending this difference is a little mind-bending but, in short, it
is incorrect to think of a sphere painted with something like the image below receding
from us at Ho.cd (where Ho is the current
value of the Hubble parameter and cd is the comoving distance to the
origin of the cosmic microwave background radiation (not to the “the
edge” of the observable universe)).
Instead, think of an expanding sphere, on which there is a “flat”
(unbounded but not infinite) 2D surface area and imagine that 2D information travels
along the surface in a straight line (or rather a geodesic or a “straight arc”). Imagine further that the sphere is expanding
in such a way that information can’t quite circumnavigate the sphere:
As said above, the surface volume of a glome of radius ct
is given by 2π2(ct)3. This can be equated to a sphere with a radius
of half the pseudo-radius, or:
(4π/3).(rp/2)3
= 2π2(ct)3
rp3 = 12π.(ct)3
rp = 3√(12π).ct
When ct=13.8Gly, this gives a value of rp = 46.3Gly,
which is (give or take a little) equal to the comoving distance to the “edge”
of the observable universe. Another big
fat coincidence.
As discussed above, mass-energy enters the universe at a rate
of one half Planck mass per Planck time within the light horizon (where the
light horizon can be taken from any location within the surface volume of the universe. Given that M = ((c3/G)/2).t, and V = (4π/3).(ct)
3, this gives us a mass-energy density of:
E/V = M.c2/V = ((c5/G)/2).t / ((4π/3).(ct) 3) = 3c2/(8πG.t 2)
At the current age
of the universe at 13.8 Gy or 4.35x1017s, that gives us a mass-energy
density of 8.48x10-10 J/m3. Noting that baryonic and dark matter make up 32%
of the mass-energy of the universe, that means 68% is dark energy. Specifically, that is 68% of 8.48x10-10
J/m3 which is 5.76x10-10 J/m3. According the WMAP Survey the “positive
energy density (is) about 6 × 10-10 joules per cubic meter”. Another
big fat coincidence.
Above I arrived at ΔM/Δt = (c3/G)/2
= (Mpl / tpl)/2. It can be seen that his
represents the lower bound of the Heisenberg Uncertainty Principle, because:
(ΔE/Δt) = (ΔM/Δt).c2
= (c5/G)/2 = (ℏ/2)/tpl2
Noting that the Planck
time is the smallest division of time (equated with the lower limit of Δt), we can multiply through by tpl2
to find:
ΔE.tpl = ℏ/2
Given that Δt ≥ tpl, then we have ΔE.Δt ≥ ℏ/2, which is the Energy-Time
variant of the Heisenberg Uncertainty Principle equation. Another big fat coincidence.
Finally, there are
some aspects to the fine-tuned universe argument that are addressed by the FUGE
model. I only want to go into two here,
as an example; the value of Ω and the value of Λ as argued by Martin Rees.
Omega (Ω) is the density
parameter and, he argued, its value is very close to 1. If the value of Ω deviated from 1 by any
significant margin then gravity would be either too strong or too weak – too strong
and the universe would collapse, too weak and stars would not have been able to
form. In the FUGE model, the value of Ω
in not “close to 1”, it is precisely 1 as argued above in regard to flatness.
Lambda (Λ) is the cosmological
constant and, Rees argued, its value is very, very small. Making some assumptions, including that the
dark energy density is constant, he arrived at 10-122 as its approximate
value which as a very small, but not zero value is curious. In the FUGE model, however, one of the assumptions
made by Rees does not hold. Dark energy density
is not a constant. Overall mass-density is
inversely proportional to time, so density of dark energy is must be decreasing
albeit at a slower rate than the density of baryonic and dark matter.
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