Incorrect Assumptions in Astrophysics
06/01/08
Is all well within the field of astronomy, or have
astronomers been misled by their trusting acceptance of a
myriad of unproven foundational assumptions leading to extreme,
bizarre (and possibly quite wrong) conclusions?
Image Credit:
ScienceCartoonsPlus.com
Reproduced with permission.
In previous commentaries (Ultra Luminous Astronomy
1 and
2), it has been noted that there has been an increasing trend
among astronomers in applying superlative terms to anomalous
astronomical objects, such as "ultra-luminous,"
"beyond bright," "super-massive," among others.
These objects are so labeled due to their extraordinary brilliance,
size, and other attributes. Or are they? On what foundational basis
do these classifications rest? Are they based upon actual
measurements of absolute luminosity,
absolute size, or absolute mass? Or are
they, on the other hand, based upon undisclosed assumptions?
In fact, many stars and galaxies are so distant that accurate
absolute measurements of primary properties are
nearly or completely beyond humanity’s current technological
capability to assess. As such, several of astronomers' "
absolute" measurements are in fact
calculated measurements. They are extrapolated from
related actual data based upon assumptions
about how those data relate to properties that
cannot be directly measured.
This, however, leaves astronomers in the unenviable and
precarious situation of having a trust relationship
with both the properties that can be directly
measured and the assumptions about how those relate to the
properties that cannot be directly measured.
As an example, astronomers can measure the "apparent
luminosity" of stars and galaxies as received at
Earth-based or space-based observatories (how much light the
receiving apparatus was exposed to during a specific interval).
Astronomers do not, however, know the absolute
luminosity of the source (how much light was originally
emitted from the source).
In order to calculate "absolute luminosity" (an
estimation of the quantity of light originally emitted from a
star or galaxy), astronomers must make calculations from the
"apparent luminosity" based upon assumed
distance to the source.
An
article, from Sky and Telescope, appears to recognize the
precarious situation that low-quality estimations of distance
put astronomers in:
A bedrock problem in astronomy is simply figuring out
how far away things are. Practically everything
else about an object - its true size, its energy output
- all the stuff you have to know to understand it - depends
on simply knowing how far away it is. And even now,
the poor quality of many astronomical distances remains
a nagging problem.
[Emphasis added]
However, a pitfall exists in the trust relationship astronomers
have with assumptions used to calculate the data. They trust
that they understand how to calculate the distance to an object
based upon certain assumptions about stellar life cycles, color,
apparent luminosity, etc.
But the question remains as to whether or not astronomers actually
have a valid model of how to calculate
the distance to those objects. One might also ask, what if they’re
wrong? What would the result be in models based upon faulty assumptions?
In the prior articles mentioned above, it was stated that if the
assumed distance was incorrect it would skew the results
of calculations using said incorrect distance as a foundational
assumption. If a normal star or galaxy is placed much further away
than it actually exists due to incorrect assumptions, calculations
based upon the distance will consequently exaggerate its size,
mass, and luminosity. An otherwise "normal galaxy" will
be seen as larger, brighter and more energetic than it actually
is. If the incorrect assumptions are not recognized as such, then
astronomers will continue to accept the larger values and label
those objects "ultra-luminous," "super-massive"
or otherwise "anomalous."
Albert Einstein gave the following sage advice:
"Any fool can make things bigger, more complex, and more
violent. It takes a touch of genius - and a lot of courage -
to move in the opposite direction."
Where astronomers currently see anomalous "super-massive"
and "ultra-luminous" objects, we need a touch of genius
and a bit of courage (like those suggested in Einstein’s quote)
in order to move in the opposite direction.
A recent
news release based upon data from Hubble exemplifies this
principle perfectly, if inadvertently. It appears that researchers
have had to significantly revise down the distance to a
pair of interacting galaxies, from 65 million light years to 45
million light years distant (a 30% reduction in distance).
[T]he scientists found that the Antennae Galaxies are much closer
to us than previously thought: residing at a distance of 45
million light-years instead of the previous best estimate of 65
million light-years.
This surprising conclusion also led to the downward revision of
calculated properties of the interacting pair
of galaxies, bringing them into line with more "normal
" galaxies / mergers:
The previous larger distance required astronomers to invoke
some quite exceptional physical characteristics to account
for the spectacular system: very high star-formation rates,
supermassive star clusters, ultraluminous X-ray sources etc.
The new smaller distance makes the Antennae Galaxies less
extreme in terms of the physics needed to explain the
observed phenomena.
For instance, with the smaller distance its infrared
radiation is now that expected of a "standard"
early merging event rather than that of an ultraluminous
infrared galaxy. The size of the star clusters formed as
a consequence of the Antennae merger now agree with those
of clusters created in other mergers instead of being
1.5 times as large.
It seems that the astronomers have been forced, by the data,
to change the classification of the galaxies from "
ultra-luminous," and "abnormally large" to
"standard in luminosity" and "normal in size,
" in line with other galaxies of similar characteristics
assumed to be at their actual distances.
The implications, however, range further afield than this
isolated case. If a single anomalous "ultra-luminous,
" "super-massive" entity must be revised
downward back to the "normal" range, what might
that say of other "ultra-luminous," "super-
massive" or otherwise "abnormal" / "
unexpected" entities currently requiring a host of
"exotic" unproven explanations?
As noted in the prior TPODs, there is something of a raging
(if muted) debate in the sciences over the foundational
assumption that underpins much of astronomy:
redshift.
Halton Arp has amassed a collection of strong evidence
(published in peer reviewed journals) that the Hubble
relation (redshift ~= recessional velocity ~= distance),
which Hubble himself admitted may not be the only viable
explanation, is not the only interpretation of redshift
and is not necessarily mutually exclusive with other
interpretations (there may be both an intrinsic
and a cosmological component to redshift, with
the intrinsic component being dominant).
Arp’s assertion is that redshift is primarily a measure
of the youth of an object with relation to other nearby
less-redshifted objects, rather than a measure of its
cosmological distance.
If the underpinning assumption of ultra-luminous astronomy
(and much of the Big Bang model) is found to be incorrect,
then it may be necessary for astronomers to radically revise
their understanding of the universe. Objects currently
assumed to be "extremely distant," "super-
massive," "ultra-luminous," or "
extraordinarily fast" based upon Hubble relation
distance assumptions may in fact be found to be far more
local, small, dim, and slow.
It is imperative to once again urge cognizance and caution
with respect to the trust relationships developed with
data and astronomers’ underpinning assumptions. If the
assumptions turn out to be incorrect, the end results may
suffer from "Garbage In, Garbage Out" syndrome
and require significant revision based upon corrected findings.
Permalink to this article.
Public comment may be made on this article on the
Thunderbolts Forum/Thunderblogs (free membership required).
|
Michael Gmirkin is a technology enthusiast with a keen interest
in exploring the electrical nature of the universe.
My Archives
Chronological Archives
Archives by Author
Archives by Subject
Thunderblogs home
|