Keywords: Hubble, cosmology, redshift, cosmological principle, homogeneity, isotropy
The cosmological principle is the foundation of modern cosmology. The cosmological principle states that the universe is both homogeneous and isotropic. Homogeneity means that the universe appears the same to all observers, while isotropy means that the universe looks the same in all directions. Of course, the cosmological principle cannot be demonstrated in the general case, which is why it is an assumption. However, the cosmological principle is consistent with a wealth of observational data. The cosmological principle very well may contradict biblical cosmology. For instance, several proposed biblical cosmologies posit that the universe has a center and that the earth is near that center (Faulkner 2016; Hartnett 2003a, 2003b, 2004, 2007, 2015; Humphreys 1994, 2002, 2017). If the universe has a center, then the cosmological principle cannot be true. However, there is yet no clear observational data that contradict the cosmological principle. Until such data are obtained, to the most neutral observer it appears that the rejection of the cosmological principle is the more unwarranted assumption. Of course, other recent creationists disagree with my assessment on this matter. However, it is not my purpose here to discuss this topic further. Rather, I am concerned with the way some creationists of late have used quotes by Edwin Hubble to demonstrate a nearly desperate attitude on Hubble’s part in introducing the cosmological principle.
It has become common in creationist circles to reference quotes by Edwin Hubble that suggest extreme bias on Hubble’s part in introducing the cosmological principle. For instance, Hartnett (2005, 96) has quoted from Hubble thus:
Such a condition would imply that we occupy a unique position in the universe . . . . But the unwelcome supposition of a favoured location must be avoided at all costs. Such a favoured position, of course, is intolerable; moreover, it represents a discrepancy with the theory, because the theory postulates homogeneity.
On the same page, Hartnett also quoted Hubble:
Therefore, in order to restore homogeneity, and to escape the horror of a unique position, the departures from uniformity, which are introduced by the recession factors, must be compensated by the second term representing the effects of spatial curvature.
These quotes certainly suggest an almost desperate attitude on Hubble’s part, that his data had led him to an unpalatable conclusion that we were near the center of the universe, and that to avoid this conclusion, Hubble concocted the cosmological principle and other rescuing devices to avoid this conclusion. These quotes seem to live down to the lowest expectations of many creationists, confirming many of their suspicions about modern cosmology. However, as the saying goes, “When something sounds too good to be true, it probably is too good to be true.” Let us investigate the context of these quotes to determine if they truly represent Hubble’s thoughts.
The source of these quotes come from Hubble’s second book, The Observational Approach to Cosmology, published in 1937. The year before, Hubble had published his first book, The Realm of the Nebulae (Hubble 1936). Both books were based upon different lecture series that Hubble gave. It isn’t clear how much either set of lectures were edited for publication. Hubble’s first book is much longer than his second book. The earlier book is referenced much more than the latter book, and copies of Hubble’s earlier book are more easily found. Both books were based upon Hubble’s work with galaxies and redshifts, though the books read very differently. As the title of Hubble’s earlier book suggests, it gives more details of his work on galaxies (in Hubble’s day, galaxies were still referred to as “nebulae”). Hubble’s latter book also lived up to its title in that it focused on an observer’s view of the cosmological ramifications of Hubble’s work. That distinction is very important.
Hubble had published his original work on the
relationship between galaxy redshift and distance
a little less than a decade prior to his two books
(Hubble 1929). In the intervening years, Hubble
and his colleagues used the largest telescopes in the
world to expand our understanding of galaxies. Many
people erroneously assume that Hubble’s summary
of cosmology in his second book related to measured
redshifts of galaxies. However, the significant part
of the discussion in that book centered around
measurements of galaxy brightness. There is a very
good reason for this. Redshift measurements come
from spectroscopy. Because it requires dispersing
light into its constituent wavelengths, spectroscopy
is a very inefficient use of light. Given the size
of telescopes and the sensitivity of photographic
emulsions in Hubble’s day, Hubble had pushed
spectroscopy to the limits of what they could reveal.
However, imaging is a much more efficient use of
light, and the brightness of galaxies measured from
their images can be very useful in discerning proper
cosmology. Astronomers express brightness of a
galaxy as its integrated apparent magnitude.1
Hubble had pioneered the use of Cephid variables
and the brightest supergiant stars in galaxies to
measure the distances of galaxies. Hubble also
had noted that the overall brightness of a galaxy
could be used to gauge a galaxy’s distance. This is
because there is uniformity in the brightness of the
largest and brightest galaxies. This is readily seen in
clusters of galaxies, groups of hundreds of apparently
gravitationally bound galaxies. Within an individual
cluster of galaxies, there is obvious uniformity in
apparent magnitude among many of its members. The
differences in the apparent magnitudes of galaxies
from cluster to cluster appeared to be the result of
varying distances of the clusters. Thus, large galaxies
have about the same absolute magnitude. Knowing
that absolute magnitude, one could determine the
distance of an individual galaxy by measuring the
galaxy’s apparent magnitude. Since there is some
variation in the absolute magnitude of galaxies, at
best this would be a crude way to measure galaxy
distances. Furthermore, this method of distance
determination requires the proper calibration of the
average absolute magnitude of galaxies. It is clear now
that Hubble did not yet have that proper calibration.
However, Hubble found a clever way to avoid
these difficulties. Hubble and his collaborators at
Mt. Wilson Observatory had taken photographs of
many galaxies across the sky, from which they had
measured apparent magnitudes. From this data,
Hubble had constructed a table of Nm, the number
of galaxies per square degree observed to magnitude
limit m. Since magnitude increases with decreasing
brightness, then Nm increases with increasing m.
The use of Nm avoided the two objections just raised.
While the brightness of individual galaxies varies,
the use of a large sample size cancels out, because
in a large sample size one is just as likely to include
galaxies that are brighter than average than to
include galaxies that are fainter than average. Not
having the proper calibration is of no consequence,
because recalibrating merely adjusts the scale, not
the conclusions with regards to cosmology.
There was one other necessary correction. Proctor
(1878, 44–45) is generally credited with the discovery
of the zone of avoidance, the region along the Milky
Way plane where few spiral nebulae (now called
galaxies) are found. The reason for this zone of
avoidance was not understood until about 1930. It
is due to vast clouds of dust along the Milky Way
plane that scatter light, thus rendering galaxies that
lie close to the plane of the Milky Way very faint or
altogether unobservable. Astronomers define galactic
latitude using the plane of the Milky Way as the
reference circle. The amount of extinction (how much
light is dimmed) is a function of galactic latitude.
Since the positions of all the galaxies at Hubble’s
disposal were well known, Hubble was able to correct
measured magnitudes for extinction.
Hubble’s Conclusions About
Homogeneity and Expansion2
From his tabulated values of Nm, Hubble concluded:
The homogeneity indicated by the reconnaissance,
even as a rough approximation, is very significant.
The uniform distribution extends out to the limits
of our telescopes. There is no trace of a physical
boundary, no evidence of a super-system of nebulae
isolated in a larger world. As far as the observations
can be interpreted, the realm of the nebulae may be
the universe itself, and the observable region may be
a fair sample.
This is very different from what the above quotes
supposedly attributed to Hubble suggest. Hubble
went on to say:
Let us, then, follow the principle of tie uniformity
of nature and accept the observable region as a fair
sample of the universe. The assumption will serve
as a reasonable working hypothesis until it leads to
contradictions. Then it can be revised or replaced to
conform with our new information.
Again, this does not jibe with the attitude implied
by the quotes attributed to Hubble above.
Hubble then discussed redshifts. Based upon his
1929 paper, Hubble deduced his law of redshifts,
z = kr, where z is redshift, r is distance, and k is
some constant. Of course, this law of redshift is now
known as the Hubble relation, or Hubble law,3 with
the constant of proportionality called the Hubble
constant. Of redshifts, Hubble wrote in his 1937 book,
To anticipate, the investigations lead to alternative
pictures, depending upon the alternative possible
interpretations of red-shifts. If red-shifts are the
familiar velocity-shifts, systematic variations do
exist in the observable region, and they suggest an
expanding universe that is finite, small, and young.
On the other hand, if red-shifts are evidence of some
unknown principle of nature, which does not involve
actual motion, then variations are not appreciable
in our sample, and the observable region is an
insignificant fraction of the universe as a whole. Thus,
in a certain sense, we again face a choice between a
small finite universe and a universe indefinitely large
plus a new principle of nature.
Apparently, Hubble was aware that in 1931
George LeMaître had interpreted his law of redshifts
as indicating the universe had a beginning in the
finite past. Hubble’s caution here is indicative of the
thinking of many other astronomers at the time. They
were steeped in the idea that the universe was eternal,
so they were repulsed by the thought that expansion
led to a finite age for the universe. Hence, Hubble
seriously considered other options. The situation
would change a decade later with publication of the
steady state model (Bondi and Gold 1948; Hoyle 1948),
for it offered the possibility of an eternally expanding
universe. This discomfiture probably explains why,
for the rest of his life, Hubble harbored doubts about
the expansion explanation for the Hubble relation.
But at least within An Observational Approach to
Cosmology, Hubble provisionally accepted expansion
as the best explanation, for he further wrote:
When first observed the red-shifts were immediately
attributed to radial motion away from the observer,
to recession of the nebulae. This interpretation
still remains the only permissible explanation that
is known. It is true that other ways are known by
which red-shifts might be produced, but in each case
they would be accompanied by other phenomena
which would be conspicuous and, actually, are not
found. We may state with some confidence that redshifts
are the familiar velocity-shifts, or else they
represent some unrecognized principle of nature.
We cannot assume that our knowledge of physical
principles is yet complete; nevertheless, we should
not replace a known, familiar principle by an ad
hoc explanation unless we are forced to that step by
Most of the theoretical investigators adopt this
point of view, and accept without question the
interpretation of red-shifts as velocity-shifts. They
are fully justified in their position until evidence
to the contrary is forthcoming. But these lectures
will present a remarkable situation. The familiar
interpretation of red-shifts seems to imply a strange
and dubious universe, very young and very small. On
the other hand, the plausible and, in a sense, familiar
conception of a universe extending indefinitely in
space and time, a universe vastly greater than the
observable region, seems to imply that red-shifts are
not primarily velocity-shifts.
Clearly, Hubble saw conflict between his great
discovery of the Hubble law and his preferred view of
an eternal universe. Hubble continued:
When Slipher, in his great pioneering work,
assembled the first considerable lists of red-shifts,
the observations were necessarily restricted to the
brighter, nearer nebulae. Consequently, the shifts
were moderately small (less than 1 per cent.), and
they were accepted without question as the familiar
velocity-shifts. Attempts were immediately made to
study the motions of the nebulae by the same methods
used in the study of stellar motions. But later, after
the ‘velocity-distance relation’ had been formulated,
and Humason’s observations of faint nebulae began
to accumulate, the earlier, complete certainty of the
interpretation began to fade.
And Hubble further said:
The observer seems to face a dilemma. The familiar
interpretation of red-shifts leads to rather startling
conclusions. These conclusions can be avoided by
an assumption which sounds plausible but which
finds no place in our present body of knowledge.
The situation can be described as follows. Red-shifts
are produced either in the nebulae, where the light
originates, or in the intervening space through which
the light travels. If the source is in the nebulae, then
red-shifts are probably velocity-shifts and the nebulae
are receding. If the source lies in the intervening
space, the explanation of red-shifts is unknown but
the nebulae are sensibly stationary.
Therefore, rather than boldly asserting the
expansion of the universe, Hubble clearly was
troubled by its implications.
Hubble’s Quotes in Context
What I have quoted from Hubble so far merely
provides background of what Hubble was thinking.
What about the two quotes attributed to Hubble by
Hartnett in the Introduction, the central issue of this
paper? Notice that the first quote consists of three
sentences separated by ellipses. The ellipses indicate
that additional text was omitted. Indeed, this is the
case, as the first two sentences appear in separate
paragraphs with a paragraph in between, while
the third sentence appears in an entirely different
section of The Observational Approach to Cosmology.
Furthermore, that third sentence, along with the
second Hubble quote by Harnett constitute much of
a paragraph in that section. Hartnett’s separation of
those lines is misleading.
What is the context of the first two sentences?
They appear under the heading “The Law of Nebular
Distribution when Red-Shifts are not interpreted
as Velocity-Shifts.” Therefore, the context is under
the assumption that the universe is not expanding.
Hubble pointed out that his data showed that the
galaxies are uniformly distributed in space. He then
The assumption of uniformity has much to be said
in its favour. If the distribution were not uniform, it
would either increase with distance, or decrease. But
we would not expect to find a distribution in which
the density increases with distance, symmetrically
in all directions. Such a condition would imply
that we occupy a unique position in the universe,
analogous, in a sense, to the ancient conception of a
central earth. The hypothesis cannot be disproved
but it is unwelcome and would be accepted only
as a last resort in order to save the phenomena.
Therefore, we disregard this possibility and consider
the alternative, namely, a distribution which thins
out with distance [emphasis added to indicate the
portion of the paragraph quoted by Hartnett].
Notice that Hubble was not concerned with the
clumping of matter in the universe, for clumping of
matter smooths out on large scales. Rather, Hubble
was concerned with the possibility of an increase or
decrease in matter distribution as distance increased.
Here Hubble was most concerned about the galaxy
density increasing with increasing distance, but he
seemed unconcerned about the opposite possibility,
that galaxy density might decrease with increasing
distance. And why was Hubble concerned with these
two possibilities at all, since his data indicated that
neither was the case?
In the next paragraph, Hubble explained that an
observed thinning of galaxies with increasing distance
might be due to two possible mechanisms other than
a true thinning of galaxy density with increasing
distance. One possible mechanism was dimming of
light due to an intergalactic medium just as dust in
the Milky Way dimmed light, producing the zone
of avoidance. Since the data showed no thinning in
galaxy density with increasing distance, Hubble was
confident that there was no intergalactic medium
capable of doing this. However, being a very careful
scientist, Hubble could not definitely rule out the
possibility that an intergalactic medium might dim
the light of galaxies so that it exactly compensated
and hence masked a true increase in galaxy density
with increasing distance. It is in this spirit that
Hubble made the above statement that some people
find a shocking admission when taken out of context.
Hubble continued in the next paragraph, where the
second sentence of the supposed shocking quote
Both explanations seem plausible, but neither
is permitted by the observations. The apparent
departures from uniformity in the World Picture
are fully compensated by the minimum possible
corrections for redshifts on any interpretation.
No margin is left for a thinning out. The true
distribution must either be uniform or increase
outward, leaving the observer in a unique position.
But the unwelcome supposition of a favoured location
must be avoided at all costs. Therefore, we accept
the uniform distribution, and assume that space is
sensibly transparent. Then the data from the surveys
are simply and fully accounted for by the energy
corrections alone—without the additional postulate
of an expanding universe [emphases again added to
indicate the sentence quoted by Hartnett].
Hence, in context, these first two sentences quoted
from Hubble are not bold assertions at all. Rather,
Hubble was considering a possibility, a possibility
that he found wanting.
What of the third sentence? As I previously stated,
this sentence, along with the second portion quoted
by Hartnett are from a paragraph in an entirely
different section of Hubble’s book. That paragraph
appears under the heading of “Spatial Curvature.”
That section is preceded by a section entitled
“Comparison of Observations with Theory.” Here is
that section’s text in its entirety:
Now let us return to the surveys, and reduce them all
to the epoch, now, in accordance with the principles
of relativistic cosmology. We wish to know the
relative numbers of nebulae which an observer, in an
expanding universe, would count to successive limits
of apparent faintness. The problem is intricate but it
has been thoroughly investigated, and the necessary
formula is available in quite simple terms. Actually,
the expression is just that previously derived for
uniform distribution in a stationary universe, plus
two extra terms. One of the terms represents the
recession factor, the other represents effects of spatial
If the use of a logarithm is permitted, the situation
may be clearly represented by a pair of equations.
If nebulae are uniformly distributed through a
non-expanding universe in which red-shifts are not
primarily velocity-shifts, then the numbers should be
proportional to the volumes, and the surveys should
conform (and actually do conform) with the relation
where mc is the limiting faintness expressed as a
magnitude, corrected for local obscuration and for
the energy-effects required by the mere presence
of redshifts. The corresponding relation for a
homogeneous, expanding universe, obeying the
relativistic laws of gravitation, is
where dλ/λ is the recession factor and Cv is the effect
of spatial curvature. We wish to know whether or not
the surveys can be fitted into the latter expression.
If both of the extra terms (for recession and for
curvature) were absent, the surveys would clearly
fit the formula because the situation would be
precisely that in a stationary universe. Now suppose
we introduce only one of the extra terms, namely,
the recession factor. In this way we pass from a
stationary universe to an expanding universe with
negligible curvature, but we destroy the agreement
with the observations. The distribution is no longer
uniform. The recession factors introduce departures
from uniformity in the law of distribution, just as
they introduced departures from linearity in the law
Notice what Hubble is saying here. The first
equation is the fit to his data. The second equation
is the prediction of general relativity applied to the
universe. The two match only if CV = Δλ/λ. Remember
that the title of Hubble’s book is An Observational
Approach to Cosmology. Speaking from an observer’s
viewpoint, Hubble asked some questions. He pointed
out that if both CV and Δλ/λ were zero, then his
data reduced to a static universe. Hubble then asked
what if we consider only one of the terms, Δλ/λ,
which is the interpretation of redshifts as indicative
of motion (a non-static universe). But that results
in a contradiction with observation, unless we also
consider curvature, CV.
It is this context that Hubble began his section
entitled “Spatial Curvature”:
The departures from uniformity are positive; the
numbers of nebulae increase faster than the volume
of space through which they are scattered. Thus
the density of the nebular distribution increases
outwards, symmetrically in all directions, leaving
the observer in a unique position. Such a favoured
position, of course, is intolerable; moreover, it
represents a discrepancy with the theory, because the
theory postulates homogeneity. Therefore, in order
to restore homogeneity, and to escape the horror of
a unique position, the departures from uniformity,
which are introduced by the recession factors, must be
compensated by the second term representing effects of
spatial curvature. There seems to be no other escape.
Observations demonstrate that
Relativistic cosmology requires that
The curvature of space is demonstrated and
measured by the postulated recession of the nebulae
[again with emphasis highlighting the portion quoted
Again, taken in context, the quote by Hubble
does not indicate a desperate attempt to salvage
theory or to impose unwarranted assumptions onto
the universe. Rather, they are the words of a very
careful scientist trying to assess the current state
of cosmology of his time from the viewpoint of an
observer rather than a theoretician. Indeed, that
spirit is captured well by the remainder of the last
paragraph started above:
To the observer the procedure seems artificial. He
has counted the nebulae to various limits, applied
only the corrections that are necessarily required
(energy-corrections), and derived the quite plausible
result of uniform distribution. Now, in testing the
relativistic theory, he introduces a new postulate,
namely, recession of the nebulae, and it leads to
discrepancies. Therefore, he adds still another
postulate, namely, spatial curvature, in order to
compensate the discrepancies introduced by the first.
The accumulation of assumptions is uneconomical,
and the justification must be sought in the general
background of knowledge. The outstanding
argument is the fact that velocity-shifts remain the
only permissible interpretation of red-shifts that is
known at the present time.
Clearly, this is from the perspective of an observer.
Hubble concluded his short book with a brief
discussion of the expanding universe model as then
known. He expressed disappointment that the data
implied a relatively small radius for the curvature
of the universe, 470 million light years, and an age
for the universe of only 1.86 billion years, less than
the estimated age of the earth at the time. Some of
this has been cleared up by changes in the expansion
rate of the universe. Hubble initial measurement
of the Hubble constant was over 500 km/s/Mpc.
Over the years, the value of the Hubble constant
declined to about 50 km/s/Mpc before rising again in
the currently accepted value of about 70 km/s/Mpc.
Lower values for the Hubble constant translate into
a much larger, older universe.
Hartnett has misinterpreted Hubble’s quotes.
Part of the problem may be that creationists have
misunderstood the viewpoint of Hubble’s latter
book, An Observational Approach to Cosmology. It
reads very differently from Hubble’s earlier book
from just a year before. In his latter book, Hubble
attempted to convey his work from the perspective
of an observational astronomer. When read apart
from their context, the oft-quoted words of Hubble
sound like a damning admission of extreme and
even desperate bias. But when considered in
context, Hubble’s words amount to an honest and
open exploration of many possibilities. I discourage
creationists from using these quotes from Hubble
any other way.
Bondi, H., and T. Gold. 1948. “The Steady-State Theory of
the Expanding Universe.” Monthly Notices of the Royal
Astronomical Society 108, no. 3: 252–270.
Faulkner, Danny R. 2013. “Astronomical Distance
Determination Methods and the Light Travel Time
Problem.” Answers Research Journal 6: 211–229.
Faulkner, Danny R. 2016. “Thoughts on the rāqîa‘ and a Possible Explanation for the Cosmic Microwave Background.” Answers Research Journal 9: 57–65.
Hartnett, John G. 2003a. “A New Cosmology: Solution to the
Starlight Travel Time Problem.” TJ 17, no. 2: 98–102.
Hartnett, John G. 2003b. “Look-Back Time in our Galactic
Neighbourhood Leads to a New Cosmogony.” TJ 17, no. 1:
Hartnett, John. 2004. “New Evidence: We Really Are At the
Centre of the Universe.” TJ 18, no. 1: 9.
Hartnett, John. 2005. “Cosmological Expansion in a Creationist
Cosmology.” TJ 19, no. 3: 96–102.
Hartnett, John. 2007. Starlight, Time, and the New Physics:
How We Can See Starlight in our Young Universe. Powder
Springs, Georgia: Creation Book Publishers.
Hartnett, John G. 2015. “A Biblical Creationist
Cosmogony.” Answers Research Journal 8:13–20.
Hoyle, F. 1948. “A New Model of the Expanding Universe.”
Monthly Notices of the Royal Astronomical Society 108,
no. 5: 372–382.
Hubble, Edwin. 1929. “A Relation Between Distance
and Radial Velocity Among Extra-Galactic Nebulae.”
Proceedings of the National Academy of Sciences of the USA
15, no. 3: 168–173.
Hubble, Edwin. 1936. The Realm of the Nebulae. New Haven,
Connecticut: Yale University Press.
Hubble, Edwin. 1937. The Observational Approach to
Cosmology. Oxford, United Kingdom: Clarendon Press.
Humphreys, D. Russell. 1994. “A Biblical Basis for a Creationist
Cosmology.” In Proceedings of the Third International
Conference on Creationism, edited by R. E. Walsh, 255–266.
Pittsburgh, Pennsylvania: Creation Science Fellowship.
Humphreys, D. Russell. 2002. “Our Galaxy is the Centre
of the Universe, ‘Quantized’ Red Shifts Show.” TJ 16,
no. 2(August): 95.
Humphreys, D. Russell. 2017. “Biblical Evidence for Time
Dilation in the Cosmos.” Creation Research Society
Quarterly 53, no. 4 (Spring): 297–305.
Proctor, Richard Anthony. 1878. The Universe of Stars:
Presenting Researches into and New Views Respecting the
Constitution of the Heavens. London, United Kingdom:
Longmans, Green, and Co.
https://answersingenesis.org/astronomy/cosmology/misquoting-hubble/ This article originally appeared on answersingenesis.org