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Just days after NASA released the first cosmic dreamscapes taken by the newly refurbished Hubble Space Telescope (SN: 9/26/09, p. 7) three teams of astronomers have used the rejuvenated observatory to find what appears to be a bounty of the most distant galaxies known.
Analyses of infrared images of these galaxies captured in late August and early September with the newly installed Wide Field Camera 3 suggest there were fewer bright galaxies early in cosmic history and those galaxies formed stars at an unexpectedly low rate.
Because the researchers do not yet have measurements of the wavelengths that make up the starlight from these galaxies, they do not directly know how far away the galaxies lie. But the starlit bodies’ colors suggest that about 16 reside roughly 12.9 billion light-years from Earth and another five or so sit even further, a record-breaking 13.1 billion light-years away.
“We are looking back 13 billion years and seeing galaxies just 600 to 700 million years after the Big Bang, when the Universe was like a 4-year-old,” says Garth Illingworth of the University of California, Santa Cruz, a member of one of the discovery teams.
The galaxies all lie within a small patch of the southern sky, called the Hubble Ultra Deep Field, that has already been imaged by Hubble and a slew of other telescopes.
It’s the new camera’s greater sensitivity, as well as its larger field of view, that has enabled scientists to rapidly find what appear to be extremely remote galaxies, says Richard Ellis of Caltech in Pasadena, a coauthor of two of four papers that the three teams recently posted online at arXiv.org.
“This is a golden moment,” Ellis says. “All the groups independently analyzed the data with different software and broadly speaking, we’re all in agreement.”
A team that includes Illingworth and Rychard Bouwens, also of UC-Santa Cruz, posted its findings on September 11. Ross McLure and James Dunlop of the University of Edinburgh in Scotland, along with Ellis and their colleagues, posted their report on September 15. A team led by Andrew Bunker of the University of Oxford in England, again including Ellis, also posted an analysis of the new Hubble data on September 15.
The researchers all find a marked downturn in the number of bright galaxies as the telescope peers farther away and thus further back in time. That decrease in the galactic population is expected from current models of galaxy formation, comments Harry Ferguson of the Space Telescope Science Institute in Baltimore, who was not a member of any of the teams.
The findings “appear to show that galaxy formation is just starting at these [early times],” comments Simon White of the Max Planck Institute for Astrophysics in Garching, Germany.
Because the Hubble Ultra Deep Field is tiny — one one-hundred-fiftieth the apparent area of the full moon on the sky — and because the Wide Field Camera 3 has only just begun taking pictures, it is difficult to know how representative the findings are of the rest of the universe at these early cosmic times, Ferguson and Ellis both caution.
Ellis notes that the new findings also hint at a puzzle. His team estimates that the distant galaxies, which are too tiny to be clearly resolved by Hubble, are making stars at a puny rate. In some cases, that rate is as low as the mass equivalent of 0.0025 suns per year. According to current models, that rate couldn’t have generated enough ultraviolet starlight for a critical milestone in the evolution of the universe — the wrenching apart of neutral hydrogen atoms into their subatomic constituents.
About 400,000 years after the Big Bang, the cosmos had cooled sufficiently for protons and electrons to recombine into atoms. But the universe has long been reionized, with hydrogen atoms once again split into protons and electrons. Many astronomers have assumed that ultraviolet light from the first galaxies did the splitting.
This is not yet an astronomical crisis, Ellis says. It may be that the first stars were more efficient than expected at producing ultraviolet radiation. Another possibility is that ultraviolet light more easily escaped these early galaxies than it did from later galaxies.
Another possibility, comments White, is that “there might be enough undetected very small galaxies to do the job.”
New data is just starting to pour in that may solve this and other cosmic riddles, Ellis says. “This is a very exciting time.”
Found in: Atom & Cosmos
- Cowen, R. New images and spectra from a rejuvenated Hubble. Science News 176(Sept. 26): 7.
[Go to]
- Oesch, P.A., et al. 2009. z~7 Galaxies in the HUDF: First Epoch WFC3/IR results. [Go to]
- McLure, R.J., et al. 2009. Galaxies at z = 6 - 9 from the WFC3/IR imaging of the HUDF. [Go to]
- Bunker, A., et al. 2009. The contribution of high redshift galaxies to cosmic reionization: New results from deep WFC3 imaging of the Hubble ultra deep field. [Go to]
- Bouwens, R.J., et al. 2009. z~8 galaxies from ultra-deep WFC3/IR Observations over the HUDF. [Go to]
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Two cars have a common starting point. The drive away from each other at 100 mph. After an hour they would be 200 miles apart, but only 100 miles from the original starting point.
Simple question that has always puzzled me. Wouldn't we have to know the exact location of the Big Bang to accurately measure the age of the universe?
Two cars have a common starting point. The drive away from each other at 100 mph. After an hour they would be 200 miles apart, but only 100 miles from the original starting point.
Simple question that has always puzzled me. Wouldn't we have to know the exact location of the Big Bang to accurately measure the age of the universe?
We can see that these galaxies are 13 billion light years away, the images being 13 billion years old.
Now, I imagine a galaxy speeding away from us, both because of our movement and theirs, and I am watching this galaxy emiting light and that light traveling toward every direction in the univese.
Here are my questions:
1) What do they actually look like right now? If galaxies generally form around black holes, wouldn't these most distant galaxies have completely colapsed into their centers by now?
2) how far away are they really? How can we account for the speed of the images through space? As a passing train's whistle changes to a lower pitch when the movement of the train through space both increases the frequency of the sound waves when coming toward us and lowers the frequency of the sound waves when speeding away from us, would light also change in its intensity when traveling faster or slower, relative to the source of the light?
And how would we know this conclusively, when we have only the bending of the light from our own sun to arrive at this so-called constant?
Isn't it possible that these galaxies, speeding away from us, may be alot closer than they appear, and may also have completely colapsed by now?
How can we possibly know ANYTHING that is actually going on in distant galaxies - right now?
I wish these articles, and the scientific community as a whole, would also include the relevancy of our present time in their studies.
======
Quantum and Entropy, Vacuum, Gravity, Star formation . . .etc.
=======...
1.
Henry Poincare named the conception of "entropy "
as a " surprising abstract ".
2.
Lev Landau (Dau) wrote:
" A question about the physical basis of the
entropy monotonous increasing law remains open ".
3.
The mathematician John von Neumann said to
"the father of information theory" Claude Shannon:
" Name it "entropy" then in discussions
you will receive solid advantage, because
nobody knows, what "entropy" basically is ".
=============..
1.
Between 1850 - 1865 Rudolf Clausius published a paper
in which he called " The energy conservation law" as
" The first law of thermodynamics". But in our nature the
heat always flows from the higher temperature to the
lower one and never back. In our everyday life we don't see
the heat itself rises from cold to hot. So, it seemed that
in thermodynamics " The energy conservation law"
wasn’t kept, this law was broken. But Clausius had another
opinion. He thought: I know people believe that this process is
irreversible, but I am sure that " The energy conservation law"
is universal law and it must be correct also for thermodynamic
process. So, how can I save this law ?
Probably, in the thermodynamic process there is something
that we don't know. Maybe, there is some degradation
of the total energy in the system which never disappears .
Perhaps, there is some non-useful heat, some unseen process ,
some unknown dark energy , some another form of potential
energy/heat itself which can transform heat from the cold
body to the warm one. I will call this conception as " entropy"
and it will mean that changes of entropy (dS) can be calculated
for reversible process and may be defined as the ratio of the
quantity of energy taken up (dQ) to the thermodynamic
temperature (T), i.e. dS= dQ /T.
And because I don't know how this process goes I won't call
it as a law but as " The second principle of thermodynamics "
which says that " the entropy of an isolated system always
increases ". Another version: " No process is possible
in which the only result is the transfer of heat from a hotter
to a colder body. It is possible some reversible process which
is unknown now ."
2.
Between 1870 - 1880 Ludwig Boltzmann said:
" Clausius is right. But I can add more to his entropy conception.
First.
According to Classic physics when an isolated thermodynamic
system comes to a thermal equilibrium all particles stop their
moving. From one hand it is correct. But the system cannot be
at thermal equilibrium (in the state of thermo death) all the time.
The situation in the system must change.
Therefore I say that at the thermal equilibrium the entropy
(some unknown dark/potential energy ) of the system will
reach maximum and as a result , the thermal equilibrium
of the system will change.
Second.
I don't know how exactly the thermal equilibrium of the system
changes. But I can give probabilistic / statistical interpretation
of this changing process. I can write " The second principle of
thermodynamics" by a formula: S= k log W and this formula
says:" the entropy ( heat) of the system is the collective result of
mechanical motion and friction of all the particles (k)."
I will call it as " The second law of Thermodynamics."
3
In 1900 Max Planck said:
Clausius and Boltzmann are both right.
But all my life I worked almost exclusively on problems
related to thermodynamics. And I am sure that the " The second
law of Thermodynamics" , concerning entropy, is deeper and it
says more than is generally accepted. I am sure the Boltzmann's
probabilistic /statistical version of "The second law of
Thermodynamics " is not completed, is not final.
Please, look at the graph of the radiation curves of the " black body".
They are very similar to those curves which are calculated
by Maxwell for the velocity (i.e. energy) distribution of gas
molecules in a closed container. Could this black body radiation
problem be studied in the same way as Maxwell's ideal gas....
...electromagnetic waves ? This problem of connection between
radiation of black body and Maxwell's Electrodynamics theory
doesn't give me peace. Maxwell's theory can tell everything
about the emission, absorption and propagation of the radiation,
but nothing about the energy distribution at thermal
equilibrium. What to do? How to be ?
After trying every possible approach using traditional
classical applications of the laws of thermodynamics
I was desperated. And I was forced to consider that the
relation between entropy, Boltzmann's probability version
and Maxwell's theory is possible to solve by suggestion ,
that energy is radiated and absorbed with discrete
individual quanta particle ( E= hf). So, now I must write
" The second law of Thermodynamics " by formula:
hf = k log W.
But if I look to the Clausius inequality I see that entropy
is energy divided per temperature.
So the formula hf = klogW is hf = kT logW I think.
I was so surprised and skeptical of such interpretation
the entropy that I spent years trying to explain this result
in another , less revolutionary way. It was difficult for me
to accept this formula and to understand it essence .
It was hard for me to believe in my own discovery.
==================..
My conclusion.
How to understand this formula?
Which process does formula (hf = kT logW ) describe ?
1.
In 1877 Boltzmann suggested that the energy/mass state
of a physical system (of ideal gas ) could be discreted.
This idea was written with formula: R/N=k. It means:
there are particles with energy/mass state (k) in physical
system of ideal gas . They don’t move, they are in the
state of rest.
2.
In 1900 Planck followed Boltzmann's method of dividing.
Planck suggested that energy was radiated and absorbed
with discrete "energy elements" - " quantum of energy"-
- " Planck's action constant"- (h) . This fact means:
electron produces heat, setting in mechanical motion and
friction all particles. This fact is described with Planck's
formula: hf = kTlogW.
3.
In which reference frame does this process take place?
In thermodynamical reference frame of ideal gas and
black body (M. Laue called this model as Kirchhoff’s vacuum).
Now it is considered that these models are abstract ones which
do not exist in nature. On my opinion these models explain
the situation in the real Vacuum (T=0K) very well.
4.
For my opinion the formula (hf = kT logW ) says:
a)
The reason of " entropy" , the source of thermal equilibrium's
fluctuation , the source of Vacuum fluctuation is an action of
the particle /electron, which has energy: E = hf.
b)
The process of Vacuum fluctuation depends on collective
motions of all particles (k) and will be successful if enough
statistical quantity of Boltzmann's particles ( kT logW)
surround the electron.
c)
Which process does the formula (hf = kT logW ) say about ?
This formula describes the possibility of realization of
macro state from micro state. This formula explains
the beginning conditions of gravitation,
the beginning conditions of star formation.
1.
hf = kT logW.
hf > kT logW.
hf < kT.
2.
hv --> He II --> He I -->
( P. Kapitza , L. Landau , E.L. Andronikashvili theories).
(Superconductivity, superfluidity.)
3.
Plasma reaction... -->
4.
Thermonuclear reactions ...-->......etc.
d)
Thanks to Entropy the homogeneous Vacuum is broken.
Thanks to Entropy the micro process changes into
macro process.
Thanks to Entropy the stars formation takes place.
Thanks to Entropy " the ultraviolet catastrophe" is absent.
Thanks to Entropy our Milky Way doesn't change into radiation.
Thanks to Entropy the process of creating elements takes place.
Thanks to Entropy the process of evolution is going.
e)
One physicist said :" The entropy is only a shadow of energy“.
Maybe now somebody can understand why entropy is a shadow.
And maybe now somebody will understand why
" The Law of conservation and transformation of energy"
is also correct for thermodynamic system.
f)
Why is " The second law of Thermodynamics"
so universal? Because it is based on
" The Law of conservation and transformation of energy"
And this law is not the simple accounting solution of debit and credit.
The sense of this law is dipper and it says more than is usually accepted.
===========..
Best wishes.
Israel Sadovnik. / Socratus.
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