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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.

Experience in the area

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).

What do you like about this subject?

The sheer diversity and range of inquiry from plasma physics to high energy astrophysics, particle physics.

What do you still hope to achieve/learn in this field?

Complete a 2nd book on plasma processes in solar flares. Finish a solar physics textbook.

Something interesting about this subject that others may not know:

The kinetic temperature of a plasma, e.g. 2,000,000 K for solar corona, allows one to insert a hand without getting burned!

Something controversial or provocative about this subject

S. Chandrasekhar's original seminar on compact stellar objects was ridiculed by his advisor, A.S. Eddington.

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Tanya10/25/161010Thank you very much! You definitely provided .....
John 12/04/15101010Enlarging the subject and adding much
Charles05/26/15101010Thank you very much for your amswer

Recent Answers from Philip A. Stahl

2016-10-25 Inflation & the multiverse:

Hello, and thanks for your question.    First, let me point out that the "multiverse" remains a reasonably informed conjecture more than a theory or even hypothesis.  A hypothesis, for example, must at

2016-06-27 help:

Empirical science is concerned with inquiry at every level, and in physics at the most fundamental level. This also entails arranging objects of inquiry in categories for easier differentiation and separation

2016-06-01 Shape of earth:

Hello,    First, planets and stars acquire spherical shapes by different processes. Stars form from the gravitational collapse of large gas clouds (interstellar nebulae like M42 in Orion) and in the process

2016-03-30 Curious:

Hello,    Actually in terms of special relativity it is the mass that is critical not the size. (Which is more related to spatial volume)    The relativistic relation of a moving mass, m, to its rest mass

2016-03-24 Dark matter:

Hello,    The conception of dark matter planets or solar systems for that matter is dependent on how well we can distinguish exotic forms from ordinary forms. In the latter case one might reference Fritz


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