Vic Stenger

The Fallacy of Fine-TuningHow the Universe is

Not Designed for Life

Is the universe fine-tuned for life? Penrose: 1/10123

Anthropic principle.

If the constants of physics had been slightly different, life as we know it would not have evolved.

Some obvious fallacies of fine tuning claims

Speed of light cPlanck's constant hGravitational constant G

Arbitrary constantsjust establish system of units

Only meaningful parameters are dimensionless ratios

Fine tuned?

Another trivial fallacy

Masses of neutrinosClaim: If slightly bigger or smaller stars and galaxies would not form in ways conducive to life.Assumes number of neutrinos is fixed. Not! Number of neutrinos depends on mass of neutrino. Higher masssmaller number.

Gravitational effect same for wide range of masses.

Hoyle coincidenceHe4 + He4 -> Be8Be8 + He4 -> C12

Hoyle 1953

Be8 + He47.6447.68

7.3667MeV

Livio et al 1989T = 1.393 billion degrees

More carbon

Prediction!

No fine tuning evident

Synthesis of carbon in stars

Carbon energy levels

Strength of Nuclear Force

But this assumes EM strength = constant = 1/137

S lowerno stable nuclei

S higherno hydrogen

S

forbidden

forbidden

allowed

Allow to vary

How fine-tuned is our universe?Four dimensionless parameters determine major large-scale features of universe:

Ratio of electron to proton masses me / mp

Strength of electromagnetic force G =

Gmp2c Strength of gravity

S Strength of strong nuclear force

Note: gives proton mass

Other forms of life

Some other form of life might be possible with many other variations of physical constants.

MonkeyGod

Generates universe for given set of parameters.

Can run from my web site

Num

ber o

f uni

vers

es0

2

4

6

8

10

-10 0 10 20 30 40

logarithm of stellar lifetime in years

10 billion yearsGenerated 100 random universes.

Most universes have stars with long lives (> 1 By) needed for evolution of complex elements.

20 % universes "livable"

Extreme examples

Without which it is claimed any form of life would be impossible.

Ratio of electron to protons! 1/1037Ratio of e-m force to gravity! 1/1040Expansion rate of the universe 1/1055Energy density of the universe! 1/1059Cosmological constant 1/10120

Ratio of number of electrons to number of protons

in universe

Just what it should be if total electrical charge of universe is

Which is just what it should be if the universe came from nothing (zero charge).

ne = np

zero

Not fine tuned.

Gravity and electromagnetism

= 1039 Weyl 1919: Why so big?

is big because masses of particles are smallN1

r

protonelectron

Let m1 = m2 = 1.85x109 kg FEFG

= 1Then

Not fine tuned.

N1 =FEFG

=kEe2r2

G mpmer2=

kEe2Gmpme

Energy density of the universem

M

a

v

Just what you expect if the universe came from nothing (zero energy).

E = 12 mv2

GmMa =

12 mk

Data: k = 0E = KE + PE = 0

Not fine tuned.

Expansion rate of the universem

M

a

v

Expansion rate depends on critical density

H = 1adadt Hubble parameter

H 2 = 83 KE ka2

Data: k = 0 H 2 = 83 KE critical density

Not fine tuned.

Cosmological constant

1ad 2adt 2 =

4G3 mat + 2rad( ) +

3 Friedmann equationc = 1

Cosmol. constant

3 =83Gvac vacuum energy density

dark energy?

120 orders of magnitude lower

dN = gh3 d3kd 3x

x

kphasespace

Energy of the vacuum

Worst calculation in

physics history!

vac =

dEdV

= 12

gh3

d 3k

Assume zero-point energy of particle fields

+ bosons- fermions

=

g16 23c3

Ecutoff4

Ecutoff = Planck energy

vac = 10124 eV

cm3 Observed value < 104

eVcm3

Solving cosmological constant problem

Supersymmetry:ZPE of fermions and bosons exactly cancel

Anthropic principle: multiple universes

SUSY broken in current universe

Ecutoff = 1 TeV vac = 10

64 eVcm3

Only 60 orders of magnitude off!

Include negative energy statesZPE= 0

but...

Early universe?

WAS THE UNIVERSE CREATED FOR LIFE?

The galactic space around Earth is probably not teeming with complex life

Earth is only known planet with life

The underprivileged planet

Earth is not all that well suited for human life oceanWe are restricted to surface Atmosphere does not block UV Natural disasters, disease, famine kill

thousands yearly

An intelligent designer with special regard for humanity would have done a much better job.

Wasted Space

Distances are immense

Nearest star: 4.22 light-years Nearest galaxy: 2.44 million light years Galaxies within our horizon are now 40

billion light-years away

Universe beyond horizon: 10 to the 10 to the 100 times bigger

Wasted time

Universe 13.7 billion years old Earth 4.5 billion years oldModern humans 150 thousand years old

0.001 %

Wasted Matter

Most of the matter of the universe is not atomicthe component of life

Visible atomic matter in galaxies: 0.005 of mass of universe.

Total carbon: 0.0002 Dark matter: 0.22 Dark energy: 0.74

Wasted energy

Only two photons of every billion emitted by sun are used to warm Earth

A tiny pocket of complexity

Most of universe is in random motion

Cosmic microwave backround

Photons are a billion times more numerous than atoms

Random to one part in 100,000

Humans in space

Humans cannot live in space or on any known planet or moon without extensive life support.

Cosmic radiation prevents humans from spending years in space.

Even so-called earth-like planets are not likely to be able to support human life.

We are marooned on spaceship Earth

The universe shows no evidence of being designed with humans in mind

Are we doomed to extinction?

Yes, as a species.

But, perhaps our successors will carry on.