Download Checklist for Geo- vs. Heliocentric Model of Universe

Checklist for Geo- vs. Heliocentric Model of Universe
1st Century A.D.
Criterion
Geocentric Model
Success Heliocentric Model
Success
1. Common Sense
It seems obvious that all
objects revolve around the
Earth
We do not detect any
motion, therefore the
Earth cannot be moving
Yes
X
Objects appear to be
attracted to the center of
the Earth, which is
considered to be the center
of the universe
There is no detection of
stellar parallax, absence of
which is compatible with a
static Earth and a
stationary observer
Yes
5. Predicting
planetary orbits
Very close agreement- the
best yet
Yes
6. Retrograde
path of planets
Explained with epicycles
and deferents
Yes
7. Simplicity
Very complicated –
epicycles, deferents,
equants and eccentrics
X
2. Awareness of
motion
3. Falling to the
ground
4. Stellar parallax
Yes
Yes
Adapted from Singh, 2004, Table 2 on pages 34-35
It requires a leap of
imagination and logic to see
that the Earth orbits the Sun
We do not detect any
motion, which is not easy to
explain if the Earth is
moving
The is no obvious
explanation for why objects
fall to the ground in a model
in which the Earth is not
centrally located
The Earth moves, so the
apparent lack of stellar
parallax must be due to
huge stellar distances;
hopefully parallax would be
detected with better
equipment
Good agreement, but not as
good as in the geocentric
model
A natural consequence of
the motion of the Earth and
our changing vantage point
Very simple – everything
follows circles
X
X
?
?
Yes
Yes
Checklist for Geo- vs. Heliocentric Model of Universe
Year 1610, after Galileo’s Observations with the Telescope
Criterion
Geocentric Model
Success Heliocentric Model
Success
1. Common Sense
It seems obvious that all
objects revolve around the
Earth
We do not detect any
motion, therefore the
Earth cannot be moving
Yes
X
3. Falling to the
ground
Objects appear to be
attracted to the center of
the Earth, which is
considered to be the center
of the universe
Yes
4. Stellar parallax
There is no detection of
stellar parallax, absence of
which is compatible with a
static Earth and a
stationary observer
Yes
5. Predicting
planetary orbits
6. Retrograde
path of planets
Very close agreement- the
best yet
Explained with epicycles
and deferents
Yes
7. Simplicity
Very complicated –
epicycles, deferents,
equants and eccentrics
Fails to predict the
observed phases
Problematic – this model
emerges from an
Aristotelian view, which
also claims that the
heavens are perfect
Problematic – everything
is supposed to orbit the
Earth
X
It still requires a leap of
imagination and logic to see
that the Earth orbits the Sun
Galileo was attempting to
explaining why we do not
sense the Earth’s motion
around the Sun
The is no obvious
explanation for why objects
fall to the ground in a model
in which the Earth is not
centrally located; only later
would Newton explain
gravity in this context
The Earth moves, so the
apparent lack of stellar
parallax must be due to
huge stellar distances;
parallax should be detected
with better telescopes
Perfect agreement, after
Kepler’s contributions
A natural consequence of
the motion of the Earth and
our changing vantage point
Very simple – everything
follows ellipses
Successfully predicts the
observed phases
No problem – this model
makes no claims about the
perfection or imperfection of
heavenly bodies
Yes
No problem – this model
tolerates multiple centers
Yes
2. Awareness of
motion
8. Phases of Venus
9. Blemishes on
Sun and Moon
10. Moons of
Jupiter
Yes
Yes
X
X
X
Adapted from Singh, 2004, Table 3 on pages 68-69
?
X
?
Yes
Yes
Yes
Yes
Checklist for Geo- vs. Heliocentric Model of Universe
After Newton’s Discoveries: Post 1704
Criterion
Geocentric Model
Success Heliocentric Model
Success
1. Common Sense
It seems obvious that all
objects revolve around the
Earth
X
Yes
2. Awareness of
motion
We do not detect any
motion, therefore the
Earth cannot be moving
X
3. Falling to the
ground
Objects appear to be
attracted to the center of
the Earth, which is
considered to be the center
of the universe
There is no detection of
stellar parallax, absence of
which is compatible with a
static Earth and a
stationary observer
Very close agreement- the
best yet
Explained with epicycles
and deferents
X
Newton’s explanation of
inertia and gravity can
support the notion of objects
revolving around each other.
Newton’s explanation of
inertia aids understanding of
why we don’t feel ourselves
rotating on the Earth.
Newton explained gravity in
this context.
X
Detection of small stellar
parallax angles indicates
that the Earth is not
stationary.
Yes
X
Yes
Very complicated –
epicycles, deferents,
equants and eccentrics
Fails to predict the
observed phases
Problematic – this model
emerges from an
Aristotelian view, which
also claims that the
heavens are perfect
Problematic – everything
is supposed to orbit the
Earth
X
Perfect agreement, after
Kepler’s contributions
A natural consequence of
the motion of the Earth and
our changing vantage point
Very simple – everything
follows ellipses
Successfully predicts the
observed phases
No problem – this model
makes no claims about the
perfection or imperfection of
heavenly bodies
Yes
No problem – this model
tolerates multiple centers
Yes
4. Stellar parallax
5. Predicting
planetary orbits
6. Retrograde
path of planets
7. Simplicity
8. Phases of Venus
9. Blemishes on
Sun and Moon
10. Moons of
Jupiter
X
X
X
X
Adapted from Singh, 2004, Table 3 on pages 68-69
Yes
Yes
Yes
Yes
Yes
Checklist for Big Bang vs. Steady State Model
Based Upon Data Available In 1950
Criterion
Big Bang Model
Success Steady-State Model
Success
1. Redshift and the
expanding
universe
Expected from a universe
that is created in a dense
state and then expands
Yes
Yes
2. Abundances of
the atoms
Gamow and colleagues
showed that the Big Bang
predicts the observed
ration of hydrogen to
helium, but fails to explain
the other atomic
abundances
The Big Bang expansion
would perhaps have
pulled apart baby galaxies
before they could grow;
nevertheless, galaxies did
evolve, but no one could
explain how
Young galaxies existed in
the early universe and
should therefore be
observable only at great
distances, which effectively
provides a window onto
the early universe
This echo of the Big Bang
should still be detected
with sufficiently sensitive
equipment
The universe is apparently
younger than the stars it
contains
There is no explanation of
what caused the creation
of the universe
?
Expected from an eternal
universe that expands, with
new matter created in the
gaps
Matter is created in between
the galaxies moving apart,
so somehow this material has
to be transformed into the
atomic abundances that we
observe
X
There is more time and no
initial violent expansion; this
allows galaxies to develop
and die, to be replaced by
new galaxies built from
created matter
Yes
?
Young galaxies should
appear to be evenly
distributed, because they
can be born anywhere and
at any time out of the
matter created in between
old galaxies
There was no Big Bang so
there was no echo, which is
why we cannot detect it
?
The universe is eternal, so the
age of the stars is not a
difficulty
There is no explanation of
the continuous creation of
matter in the universe
Yes
3. Formation of
galaxies
4. Distribution of
galaxies
5. Cosmic
microwave
background
(CMB) radiation
6. Age of the
universe
7. Creation
?
X
?
Adapted from Singh, 2004, Table 4 on pages 370-371
?
?
?
Checklist for Big Bang vs. Steady State Model
Based Upon Data Available In 1978
Criterion
Big Bang Model
Success Steady-State Model
Success
1. Redshift and the
expanding
universe
Expected from a universe
that is created in a dense
state and then expands
Yes
Yes
2. Abundances of
the atoms
The observed proportions
of light atoms (e.g.,
hydrogen and helium) are
very close to the Big Bang
prediction by Gamow and
colleagues; heavier atoms
are produced in the stars
The Big Bang expansion
might have pulled apart
baby galaxies before they
could grow; nevertheless,
galaxies did evolve, but no
one could explain how
The distribution of galaxies
varies with distance, as
shown by Ryle; young
galaxies (e.g., quasars) are
observed but only at great
distances, as they would
have existed only just after
the Big Bang
This echo of the Big Bang
was predicted by Gamow,
Alpher and Herman, and
was found by Penzias and
Wilson
Recent age measurements
show that the objects in
the universe are younger
than the universe itself, so
everything is consistent
There is still no explanation
of what caused the
creation of the universe
Yes
Expected from an eternal
universe that expands, with
new matter created in the
gaps
Cannot really explain the
observed abundances of
light atoms; heavier atoms
are produced in the stars
There is more time and no
initial violent expansion; this
allows galaxies to develop
and die, to be replaced by
new galaxies built from
created matter
Young galaxies should be
evenly distributed, because
they can be born anywhere
and at any time out of the
matter created in between
old galaxies, but this is not
backed by observation
Yes
Yes
Cannot explain the observed
CMB radiation
X
Yes
There is no evidence for
anything older than 20
billion years, yet the universe
is supposedly infinitely old
?
?
There is still no explanation
of the continuous creation of
matter in the universe
?
3. Formation of
galaxies
4. Distribution of
galaxies
5. Cosmic
microwave
background
(CMB) radiation
6. Age of the
universe
7. Creation
X
Yes
Adapted from Singh, 2004, Table 4 on pages 370-371
X
X