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Astrophysics/cosmic background radiation


I'm confused on cosmic background radiation regarding the "glow" from the big bang. Wouldn't the glow (initial radiation or such) from the onset of the big bang move ahead of ordinary matter when the big bang occurred? Such that it would be impossible to detect any of it today since the glow is well out of our reach? Much like a supernova, the initial photons from the explosion are well ahead of the other elements of the explosion so how can we measure the glow of the big bang if it is well ahead of us?


A great deal of your confusion can be dispelled by clearing up some of the basic concepts. One is that the 'Big Bang' (despite the name) is not an 'explosion'. A good source if you can get it is May, 2007 issue of ASTRONOMY, which features an extensive article ('Cosmology: 'Five Things You Need to Know', pp. 28-33) dispelling a number of common myths or perceptions.

The article cites Charles Bennett (lead researcher on the Wilkinson Microwave Anisotropy Probe) who avers:

"There is nothing in the physics of the Big Bang that talks about an explosion."

He goes on to state:

"Big Bang is not an accurate term for the theory. What it describes is the expansion and the cooling of the universe. It doesn't describe an explosion at all."

Hence, there is NO analogy which can be made to a supernova, which is an explosion.

The article goes on to point out that Bennett's WMAP project has "produced the most accurate picture of the cosmic microwave background" (the 'glow to which you refer) and that "these photons have been traveling through space since neutral hydrogen first formed some 380,000 years ago."

That time frame is often referred to as the phase of "decoupling"  i.e. matter decoupling from the (hitherto) hot radiation background, since by then the temperature had cooled enough to permit electrons and protons to combine.

Thus, again, the photons arise from no "explosion" but from the atomic transitions (i.e. between energy levels in atoms) first made possible after the atoms have formed at the decoupling stage. Since the photons "have been traveling through space since the protons and electrons first combined" - i.e. at the decoupling, then there is no chance they would be "out of our reach".

Hopefully, this makes sense!  


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Philip A. Stahl


I specialize in stellar and solar astrophysics. Can answer questions pertaining to these areas, including: stellar structure and evolution, HR diagrams, binary systems, collapsars (black holes, neutron stars) stellar atmospheres and the spectroscopic analysis of stars as well as the magnetohydrodynamics of sunspots and solar flares. Sorry No homework problems done or research projects! I will provide hints on solutions. No nonsense questions accepted, i.e. pertaining to astrology, or 'UFOs' or overly speculative questions: 'traveling through or near black holes, worm holes, time travel etc. Absolutely NO questions based on the twaddle at this Canadian site: purporting to show a "new physics". Do not waste my time or yours by wasting bandwidith with reference to such bunkum.


Have constructed computerized stellar models; MHD research. Gave workshops in astrophysics (stellar spectroscopy, analysis) at Harry Bayley Observatory, Barbados. More than twenty years spent in solar physics research, including discovery of SID flares. Developed first ever consistent magnetic arcade model for solar flares incorporating energy dissipation and accumulation. Developed first ever loop-based solar flare model using double layers and incorporating cavity resonators. (Paper presented at Joint AGU/AAS Meeting in Baltimore, MD, May 1994)

American Astronomical Society (Solar physics and Dynamical astronomy divisions), American Geophysical Union, American Mathematical Society, Intertel.

Papers appearing in Solar Physics, Journal of the Royal Astronomical Society of Canada, Journal of the Barbados Astronomical Society, Meudon Solar Flare Proceedings (Meudon, France). Books: 'Fundamentals of Solar Physics', 'Selected Analyses in Solar Flare Plasma Dynamics', 'Physics Notes for Advanced Level', 'Astronomy & Astrophysics: Notes, Problems and Solutions', 'Modern Physics: Notes, Problems and Solutions'

B.A. degree in Astronomy; M.Phil. degree in Physics - specializing in solar physics.

Awards and Honors
Postgraduate research award- Barbados government; Studentship Award in Solar Physics - American Astronomical Society. Barbados Astronomical Society award for service (1977-91) as Journal editor.

Past/Present Clients
Caribbean Examinations Council (as advisor, examiner), Barbados Astronomical Society (as Journal Editor 1977-91), Trinidad & Tobago Astronomical Society (as consultant on courses, methods of instruction, and guest speaker).

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