Date post: | 02-Jun-2018 |
Category: |
Documents |
Upload: | lahsivlahsiv684 |
View: | 227 times |
Download: | 0 times |
of 27
8/10/2019 Origin universe
1/27
Was the Universe Created?
Vic Stenger
8/10/2019 Origin universe
2/27
Not handed down fromabove.
Not restrictionson thebehavior of matter.
Restrictions on the way
physicists may formulatetheir mathematicalstatements aboutobservations.
Physics models mustpossesspoint-of-viewinvariance.
Where do the laws of physics come from?
8/10/2019 Origin universe
3/27
For every continuous symmetryof
the laws of physics there exists aconservation law and vice versa.
That is, the most important lawsof physics:
Conservation ofEnergy
Linear momentum
Angular momentumFollow from point-of-viewinvariance.
-Emmy Noether(1915)
Gauge symmetry
generalizesNoethers theorem
Noethers Theorem
The laws of physics are just what they would be
expected to be if they came from nothing.
8/10/2019 Origin universe
4/27
The Kalam CosmologicalArgument
Everything that beginshas acause.
The universe had a beginning
(big bang).Therefore the universe had a
cause.
William Lane Craig
8/10/2019 Origin universe
5/27
Related claim:
Hawking and Penrose (1979)
:Universe began as a singularity.
Craig and other theologians:Therefore time and space beganwith the big bang and there was
no before.Only a supernaturalorigin is
possible.
8/10/2019 Origin universe
6/27
Refutation
Noteverything that begins hasa cause. Quantum transitions.
The universe did notbeginwith a singularity. Quantummechanics. (Hawking 1988)
Therefore the universe neednothave had a beginning or acause. No creator needed.
8/10/2019 Origin universe
7/27
A Natural Scenario forthe Origin of Our
Universe
References:
Hartle, J.B. and S.W. Hawking, "Wave Function of the Universe,"
Physical ReviewD28 (1983): 2960-75.Atkatz, David. "Quantum cosmology for pedestrians,"American
Journal of Physics62 (1994): 619-27.
8/10/2019 Origin universe
8/27
Quantum tunneling
8/10/2019 Origin universe
9/27
da
dt
!
"#
$
%&
2
'8()G
3
a2='kCosmological
Friedmann equation
! ="
8#G
ao
2=
3
!
Assume emptyuniverse
cosmologicalconstant
a(t) = aocosh
t
ao
!
"#$
%&Inflation
Note that tcan be negative
Let
ao
2=
3
8!"G
closeduniverse
Let k = 1
8/10/2019 Origin universe
10/27
Quantizing we get
d2
da2!
3"
2G
#$%
&'(
2
a2
1!a
2
ao
2
#
$%
&
'(
)
*++
,
-../ = 0
Wheeler-DeWittequation
Wave function of the universe
Schrdingerequation for particle with m= 1/2, E =0
V(a) =3!
2G
"#$
%&'
2
a2 1(
a2
ao
2
"
#$
%
&'Potential energy
! = c = 1
8/10/2019 Origin universe
11/27
Potential energy
/3!
2G
"#$
%&'
2
Unphysical
region
Physical
region
a(!) = ao
cos !
ao
"
#$
%
&'t = i! imaginary
8/10/2019 Origin universe
12/27
!HH
(a > ao) = K(a)"1/ 2 cos #
2ao
2 a
2
ao
2"1$
%& '
()
3/ 2
*+,,
-.//
K(a) =3!
2G
"#$
%&'
2
aa2
ao
2(1"
#$
%&'
1/ 2
No boundary solution of Hartle and Hawking:Equal amounts of incoming and outgoing waves
!HH
(0 < a < ao) = K(a)"1/ 2 exp
#2ao
2 a2
ao
2"1
$
%&
'
()
3/ 2*
+
,,
-
.
//
8/10/2019 Origin universe
13/27
Wave function of the universe
unphysical region(nothing)
physical region
8/10/2019 Origin universe
14/27
8/10/2019 Origin universe
15/27
our time
prior time
space
"nothing"
time imaginary
8/10/2019 Origin universe
16/27
P! exp "2 dx2mV(x)"E1/ 2
a
b
#
$
%&
'
()2m = 1 E = 0 a = 0 b = a
o
P! exp "3
8G2#
$
%&'
()
#! G"2
* P=
exp "
3
8
$
%&
'
() =
0.687
something 2x as likely as nothing
Tunnelingprobability
8/10/2019 Origin universe
17/27
Entropy ofuniverse
Maximumentropy
TimeOrigin at Planck Time
(10-43sec)
Room fororder
Maximumchaos
The universe contains nomemory of a creator
8/10/2019 Origin universe
18/27
8/10/2019 Origin universe
19/27
Why is there something
rather than nothing?
Why should nothing bemore natural than
something?
8/10/2019 Origin universe
20/27
Symmetry and Stability
Symmetric systems tendto spontaneouslyundergo phase
transitionsto lesssymmetric systems inabsence of energy.
Nothing is moresymmetric thannothing.
WaterIce
8/10/2019 Origin universe
21/27
Nothing is unstable.
Frank Wilczek
SciAm 1980
8/10/2019 Origin universe
22/27
Fine-tuning?
Other forms of life?
Multiple universes?
How estimate probabilities?
Not all constants are
constant.Not all that fine-tuned
8/10/2019 Origin universe
23/27
V d l
8/10/2019 Origin universe
24/27
Vary!, me,m
prandomly over
10 orders of magnitude
8/10/2019 Origin universe
25/27
For God so loved the
human race that He wentto the expense ofbuilding a hundred billion
trillion stars andcarefully shaped andcrafted them for
[fourteen] billion years sothat at this brief momentin time we could all havea nice place to live.
--Hugh Ross
8/10/2019 Origin universe
26/27
We no longer have anyneed of a god to explain
what is no longermysterious.
ChristopherHitchens
8/10/2019 Origin universe
27/27
Was the Universe Created?
NO