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No Shadow From the Big Bang?
ultracool writes "In a finding sure to cause controversy, scientists at The University of Alabama in Huntsville (UAH) found a lack of evidence of shadows from "nearby" clusters of galaxies using new, highly accurate measurements of the cosmic microwave background (WMAP). Other groups have previously reported seeing this type of shadows in the microwave background. Those studies, however, did not use data from WMAP, which was designed and built specifically to study the cosmic microwave background."
How do we know that the ±0.0001 K (or whatever it is exactly) fluctuations in the CMB isn't just from nearby galaxies? How do we know it is truly background information? No subtraction algorithm is THAT perfect.
Quid festinatio swallonis est aetherfuga inonusti?
Africus aut Europaeus?
Shadows require light, an object and an observer. The 'observer' is us here at the earth. The 'object' is this (from TFA):
Galaxy clusters are the largest organized structures in the universe.[snip] The gravity created at the center of some clusters traps gas that is hot enough to emit X-rays.
This gas is also hot enough to lose its electrons (or ionize), filling millions of cubic light years of space inside the galactic clusters with swarming clouds of free electrons. It is these free electrons which bump into and interact with individual photons of microwave radiation, deflecting them away from their original paths and creating the shadowing effect. This shadowing effect was first predicted in 1969 by the Russian scientists Rashid Sunyaev and Yakov Zel'dovich.
And the 'light' is the background microwave radiation, until now assumed to be from the edges of the universe, beyond these clusters.
I can explain it for you, but I can't understand it for you.
First get this in your head. At this point in history, evolutionary biology is a certainty in the way that gravity is a certainty. We may reconceptualize certain parts of it from time to time, but it is clear and obvious that it is there and happening.
The big bang is NOTHING like this. This is because, unlike in biology, in physics at the moment we have massive unknowns (dark matter, dark energy, no clue what the elementary building material of the universe is, no way to connect quatum mechanics to relativity). At this point the best we can say is all clues seem to hint toward a big bang and that seems the most likely explanation to explain currently observed phenomena.
Big difference!
P.S.: Most Christian fundimentalists don't actually understand the difference between evolution and the big bang. They often see the two in their own heads as linked and think by argueing against one, they are arguing against the other as well. See Kent Hovind and his crazyness, for example.
Big apple, new Yorik, undig it, something's unrotting in Edenmark.
A B-Grade Sci-fi thriller
My Aurora : http://www.youtube.com/watch?v=o91ZsGwJYyg
FB : https://www.facebook.com/TanveersPhotography
Evolution is a phenomenon that has been observed directly. The big bang is not. The problem with the big bang is one similar to the problem plaguing black holes: the singularity. It's the elephant in the room.
Quid festinatio swallonis est aetherfuga inonusti?
Africus aut Europaeus?
As a physicist (but no cosmologist or astrophysicist), I'm surprised that shadowing was expected. As far as I understood the article, the shadowing effect is expected not due to absorption/inelastic scattering (where I could understand the shadow effect), but due to elastic scattering (the photons just change their direction).
Now it is obvious that the number of photons reaching us from behind is reduced by the elastic scattering process. However one of the basic properties of the cosmic background radiation is that is is nearly isotropic. And that means there should be an about equal amount of radiation scattered into our direction which would not have reached us otherwise.
So is there anything I'm missing?
The Tao of math: The numbers you can count are not the real numbers.
A little shadow anomaly isn't going to seriously dent the Big Bang theory. There is so much evidence for the Big Bang and predictions based on it have been observed that it will take more than a little inconsistency to make the theory suspect. You need something more substantial than shadows to expect a rehauling of the Big Bang.
Remember that there were serious questions about the applicability of Newtonian Dynamics on a large scale too when it was determined that galaxies could not have kept their structure if calculations were based on ND only. However, rather than modify ND, scientists chose to posit an unseen dark matter just to save ND. As it turns out, there is indeed dark matter!
Don't sound the death knell on the big bang yet.
I think the big bang gets attacked more in the sense of attacks on exactly what the initial thingy was. There's no real doubt that the universe is exploding and has been for most of physically evident history. It may not be the initial event, the universe could be eternal, cyclical, or whatever -- but it's certainly exploding now, and seems to have been for at least 12 billion years.
There isn't so much an attacking of the big bang as trying to nail down what exactly the big bang was. In other words, it's the same kind of attacks that people like Stephen Gould and Lynn Margulis make on evolution. They don't doubt that evolution is a real phenomenon for a second; they just want to nail down what exactly evolution is, what makes it tick, how it happens. It's the good kind of attacking, and it's what makes science jump.
Fundies, in turn, seem to assume that the big bang was invented for the sole purpose of trying to support evolution, which is so ridiculous that it defies the belief of real people. In fact, they seem to think that every branch of science exists solely to provide support for an otherwise untenable theory of evolution. This despite the fact that many of these ideas preceded Darwin (in a few cases by millenia).
The theory, if I understand it, is that since the CMB and the energy from the nebula should have taken the same time to reach from where they were then to where we are now, and assuming that the CMB was not somehow generated "in front of or "at" nebula (which we currently deduce from its very red-shifted frequency and distribution), then we should see the nebula's emissions, but not the same strength of CMB that is measured from the "background" at very small angular displacements from the nebula.
I need to read the REAL article, since the "Science Daily" was a joke, but, here are some issues with the research as described:
#1 the universe has no "edge" in any layman's sense of word. We're no more in the middle than some galaxy 8 billion light years away in any direction.
#2 the CMB is NOT "pointed at" the Earth. It's going in every direction at the same time, including very, very small angles to "straight away" in any direction.
#3 the WMAP antenna is very good, but it is NOT 100% unidirectional, so it will pick up energy from a very narrow cone, not a line straight away.
Therefore the WMAP data will rarely show a "shadow" of much change in intensity, since the antenna will pick up significant CMB from off-axis of the line between the Earth and the nebula, even if the nebula is resolved to nearly all of the sample point. For that matter, it could be lensing on- or off-axis causing some of the intensity variation described in the artice.
The variations in CMB are incredibly small in the first place, and we don't have THAT many significant digits of intensity in the measurement range. We only really detected them when we got WMAP up there. Any additional small variation in CMB co-incident with an ionized nebula is going to be difficult to unambiguously assign to "shadowing", and the even smaller variations of variations from nebula to nebula are very close to the statistical noise values of the original samples.
As I said, maybe the "Astrophysical Journal" article is better presented, but so far, this doesn't sound well thought-out.
What exactly is wrong with observing "natural selection" cases? Aren't these exactly cases of evolution in action?3 27083737.htm)
* peppered moth: selection for wing coloring
* mutations in HIV after it jumped species to humans. Many other mutations are observed in bacteria and other pathogens that make them resistant to drugs. We are currently waiting in fear for the birdflue to undergo such a change.
* Invasive species: many mutations are observed in invasive species that make them more adapted to the environment.
* Recently, direct observation of the evolution of beak size in Darwin's finches was reported (Science 14 July 2006: Vol. 313. no. 5784, pp. 224 - 226)
* Evolution of RNA sequences: many experiments have evolved RNA sequences that perform various functions. One example among many is converting an RNA enzyme to a DNA enzyme (http://www.sciencedaily.com/releases/2006/03/060
* Artificial evolution: in many experiment run in computers, evolution is able to create new structures, from bridges to sorting algorithms
Finally, I think it is worthwhile to mention one important piece of evidence that has recently been completed. When Darwin suggested in the 19th century that humans and apes had a common ancestor, he was ridiculed. Till then humans were seen as different from all animals, having been created on a different day of creation. In that time, nothing was known of the DNA. Today, we managed to sequence the human and the chimp genome. We know that humans and chimpanzees differ in 1% of their DNA sequence. In fact, the DNA sequence of a human is closer to that of a chimp than the chimp is to an Orangutan, or than the chimp is to any other living species, with the exception of the bonobo. The human is the chimp and bonobo's closest relative.
I think that is quite an amazing prediction to make more than 100 years in advance. In fact, predictions like this are the strongest corroborations in science: making a prediction that is absolutely unthinkable based on the current belief.
* HIV is not still HIV. HIV did not exist 100 years ago, SIV existed in apes, and jumped to humans, and then changed. It has a different name, whether you want to call it a different species is upto you, because HIVs don't mate, so the regular definitions do not aply. It is different, and occupies a different niche, though.
Lets jump over your yawns to darwin's finches. How many species of finches live on the galapagos islands? I think it is wrong to call them all "one species". What about the different species of giant tortoises, are they also all one species? How come we can not recreate the species from which we have a single male left over - (lonesome george)? Before Darwin, people had no problem with calling all the different finches on the Galapagos island different species. It is just that on the Galapagos island it is so obvious that they all had a common origin, that Darwin had to conclude that species can not be stationary, they must change. And, after "on the origin of species" was published, people had to change the concept of species in order to try to still hold the immutable species concept. The changes that are observed now in one species of finches on the galapagos are similar to the changes that lead to the evolution of the different species. Are they a new species? Not yet. Will the become a new species? Who knows, but our current observations and thought do not provide any barrier that would prevent them from doing so.
* In vitro evolution, or artificial evolution are models. Just as we compute the path of a spaceship or the planets, or an atomic bomb in a model, we do a model of evolution. Without models, science would not exist. A model turns theory into predictions. These models tell us that conceptually, Darwin's idea of natural selection works. This is not clear to begin with, and certainly not all types of natural selection work.
The in-vitro models of evolution allow us to understand how the process of evolution works. There actually is a branch of the philosophy of science that believes that one can not test theories using observations. That one always needs a controlled experiment, and that observations in nature can never be controlled enough. (But I don't buy into this)
One needs to distinguish between concepts.
* Common descent
* Natural selection
* Speciation
* Evolution
Common descent is what tells us that chimps and humans had a common ancestor. Do you have any other reason for explaining why the DNA of chimps and humans are so close?
Natural selection is what creates functions in organisms. As was stated above, this is observed often - though the timescale at which things happen is quite long.
Speciation is a complicated concept. It seems that there are different ways in which a new species can arise - it can first use a different niche, and then stop being able to mate, or fist stop being able to mate (maybe because of a mountain in the middle), and then diverge in function. We do observe all stages of speciation separately, but the concept of the species is not defined well enough to point at cases where we observed a new species arising (see HIV example above).
Evolution includes all the concepts above. You seem to want to talk about evolution as speciation - I have no problem with that. Let us talk about that for a second. However, I'll drop the species concept. I think the species concept is a historical artefact that we inherited from pre-darwinian biology. Instead I'd like to know which two organisms that we observe on earth, according to your opinion are so different that they do not share a common ancestor.
So, you do accept that HIV and SIV share a common ancestor, right? As do the finches with the shorter beaks and those with the longer beaks mentioned above?
What about the other finches on Galapagos island? Do they have a common ancestor? Which of them do?
What about the chimpanzees? Currently we have chimps living in Africa all the way from the Kongo to the western shores of Africa. It is debated