Astrophysics/Questions
| Subject | Date Asked | Expert |
| physics | 12/3/2011 | James Gort |
| Q: sir why the value of g gets changed when it suddenly stops spinning?and sir by any mean can the ... A: An object which is spinning is in an accelerating reference frame. "g" is the "gravitational ... | ||
| black holes | 11/28/2011 | Steve Nelson |
| Q: i was wondering if it was possible to see into a black hole.lets say we had the worlds most powerful ... A: No, it's not possible. Wireless cameras broacast via light (radio waves are light) and light can't ... | ||
| microgravity | 11/26/2011 | Steve Nelson |
| Q: Sir,what do you mean by microgravity please explain? & sir what type of experiments can be performed ... A: I didn't coin the term, so it's kind of improper to ask me what *I* mean by it. Experiments in ... | ||
| matter/dark matter ratio | 11/23/2011 | Steve Nelson |
| Q: I am just wondering; do we know whether the ratio between matter and dark matter is constant? Does ... A: I'll say it this way: 1) People in physics are ABSOLUTELY obsessed with dark matter and come up ... | ||
| Maxwell and the Speed of LIght | 11/4/2011 | Philip A. Stahl |
| Q: Did James Maxwell's calculation of the speed of light state that light's speed would vary inversely ... A: Bear in mind that the density of interstellar gas in a black hole’s vicinity is likely to be ... | ||
| Maxwell and the Speed of LIght | 11/4/2011 | Philip A. Stahl |
| Q: Did James Maxwell's calculation of the speed of light state that light's speed would vary inversely ... A: Maxwell's key wave equations actually say nothing about light propagating with a velocity that will ... | ||
| Gliese 581 | 10/30/2011 | James Gort |
| Q: Dr. Gort, Although I am not formally educated, I am, like many others, a fan of cosmology. I am ... A: Although your son may eventually be able to get there, please explain to him that we'll have to ... | ||
| Expansion of the universe trough diffusion | 10/20/2011 | Philip A. Stahl |
| Q: After viewing an episode of "trough the wormhole" I was left pondering about dark matter and dark ... A: The problem with comparing the diffusion of ink spreading through water with the accelerating cosmic ... | ||
| Polar Lights | 9/30/2011 | Steve Nelson |
| Q: I'm not sure if you're the right person to ask, but I didn't see anyone who seemed like a definite ... A: I somehow answered this and it never got posted. In a nutshell, there are no specific frequency ... | ||
| electromagnetic waves | 9/30/2011 | Philip A. Stahl |
| Q: sir pls tell why radio waves are non polarizing while light waves are A: I'm not sure where exactly you got the idea that radio waves are not polarized, but they are. For ... | ||
| Ref: question | 9/11/2011 | Philip A. Stahl |
| Q: Good day How does spectroscopic analysis work and how do we know what we know about the light from ... A: This is simply too vast an area to casually address in a forum like this, so I post several links ... | ||
| titans | 9/10/2011 | Philip A. Stahl |
| Q: Titan, one of Saturn's many moons, has an atmosphere, but our own Moon does not. What is the ... A: The bottom line is there's no easy explanation. ON the face of it, given Titan is about the same ... | ||
| speed of light | 9/6/2011 | James Gort |
| Q: It is said that nothing,even information,can exceed the speed of light in this universe.However if ... A: What you're missing is that no rod is truly "rigid". For instance, steel has a carbon and iron ... | ||
| waves | 9/6/2011 | Steve Nelson |
| Q: sir please tell me the difference and similarities between radio signals(waves) and light waves A: Radio waves are a form of electromagnetic waves, just like light waves. By light waves, I'll assume ... | ||
| Cosmological Expansion or Transition? | 8/19/2011 | James Gort |
| Q: Is the Hobble observation conclusive evidence that our universe is expanding? Would there be an ... A: Yes, I think there would be an observable difference, but let me go through your scenario: If a ... | ||
| scientific notation | 8/17/2011 | James Gort |
| Q: My basic question is if it okay to write scientific notstion without using superscripts. For example ... A: There are basically three ways that I know of. But there should be a footnote or other explanation ... | ||
| light | 6/21/2011 | Philip A. Stahl |
| Q: 1]Can the speed of light be increased? 2]Is it possible for light to move objects? ANSWER: ... A: This site is rich in information, more than I could ever give at one time, and also full of ... | ||
| light | 6/20/2011 | Philip A. Stahl |
| Q: 1]Can the speed of light be increased? 2]Is it possible for light to move objects? ANSWER: ... A: No one knows 'why' light moves 'so fast', but that is also because in science we give more emphasis ... | ||
| light | 6/20/2011 | Philip A. Stahl |
| Q: 1]Can the speed of light be increased? 2]Is it possible for light to move objects? A: Answers: 1) No, the speed of light can't be increased. But, an addendum and proviso. In a paper ... | ||
| Dark energy | 6/13/2011 | Philip A. Stahl |
| Q: Can dark energy/dark matter be created? How can we detect dark matter/dark energy? Are there ... A: Whether dark energy can be created will depend on exactly what its nature is. So far this is an open ... | ||
| universe | 5/27/2011 | Philip A. Stahl |
| Q: (could be a stupid question) scientist say they see an explosion 13 billion light years from earth, ... A: Okay first, true - in general when one looks out at objects in space, e.g. stars, star clusters, ... | ||
| Two fluid theory | 5/18/2011 | Philip A. Stahl |
| Q: I'm not a student but just interested in plasma physics and have done lots of work on it, mostly ... A: Classification of differing fluid regimes is far beyond the scope of this answer, but you can find ... | ||
| Alien spacecraft | 5/17/2011 | Steve Nelson |
| Q: Can astrophysics explain the possibility of their existence utilizing cold plasma, electromagnetism ... A: "Astro"physics is just a subspecializition of physics. Physics Today (the professional magazine we ... | ||
| Astronomy | 5/4/2011 | James Gort |
| Q: I want to know that what will happen if Two Neutron stars or Two Black holes or a Neutron star and a ... A: If two neutron stars, two black holes, or a neutron star and a black hole came close to each other ... | ||
| average mass per particle | 4/12/2011 | Steve Nelson |
| Q: This is a follow up question - when calculating the Jeans mass to determine when a cloud will ... A: I don't answer homework question, and this isn't a follow-up to any question I've been asked before, ... | ||
| density terminology | 4/11/2011 | Steve Nelson |
| Q: In re "The possibility of recollapse of the universe..." I was doing okay until undefined p's and ... A: If you look at the units the author of the answer to your original question gave you, the answers ... | ||
| density terminology | 4/11/2011 | Steve Nelson |
| Q: In re "The possibility of recollapse of the universe..." I was doing okay until undefined p's and ... A: No, your question is absolutely too short and without detail to mean anything at all. What do the ... | ||
| astrophysics | 4/9/2011 | Philip A. Stahl |
| Q: sir I went through following link ... A: The answer to your first question isn't very clear, and certainly not from the link! (where it ... | ||
| aurora | 3/29/2011 | Philip A. Stahl |
| Q: What is an aurora? A: One can visualize the Earth as a giant spherical magnet, with magnetic field lines extending from ... | ||
| tachyons & photons | 3/13/2011 | Philip A. Stahl |
| Q: Sorry for bombarding you with all those questions in one email. Here's two that I would appreciate ... A: In answer to your questions: 1) The prcise speed at which tachyons travel isn't known, only that ... | ||
| How to solve complex problems | 2/20/2011 | Philip A. Stahl |
| Q: I was wondering if you could provide some advice on how to solve problems.When solving problems i ... A: You don't really specify what physics subject you are dealing with, whether General Physics, or ... | ||
| Beloved In Christ | 2/19/2011 | Steve Nelson |
| Q: Beloved In Christ, Greetings in name of our Lord Jesus Christ. I am a new Christian convert, ... A: I wanted to answer this one to ask how stupid you think I am. I mean, you sought out an expert in ... | ||
| is the solar system merely an atom in a much larger structure? | 2/6/2011 | Philip A. Stahl |
| Q: hope you can help me and that this is not a silly question. firstly, it has been prompted by an old ... A: The old "solar system" (Bohr model) of the atom basically fell through once the modern wave ... | ||
| angular momentum of a black hole | 1/31/2011 | Philip A. Stahl |
| Q: Your Question was: why is the maximum angular momentum of a black hole limited to G * M^ 2 / c.? A: The key aspect to consider here is that a black hole assigned some mass M can’t have any arbitrary L ... | ||
| Quark-Gluon Plasma | 1/31/2011 | Steve Nelson |
| Q: If the Big Bang initially resulted initially in a quark-gluon plasma, when and how did electrons ... A: I'm more of a low-energy nuclear astrophysics guy, I mean that your answer is in the subfields of ... | ||
| Expanding Universe | 1/25/2011 | Philip A. Stahl |
| Q: After seeing Science programs on TV and reading articles, it seams that the Universe will just keep ... A: Your explanation (or interpretation) of why there won't be a "big Crunch" is one way to think of it. ... | ||
| Gravity - Thought Experiement | 1/19/2011 | Philip A. Stahl |
| Q: This is a bit of a thought experiment question, hope it makes sense, If a void could be created at ... A: Okay- thanks for clarifying your question. Several problems here: first, the definition of "weight" ... | ||
| Gravity - Thought Experiement | 1/18/2011 | Philip A. Stahl |
| Q: This is a bit of a thought experiment question, hope it makes sense, If a void could be created at ... A: I'd have to say that a 0 G experience would not be so produced, given that no matter how large your ... | ||
| hadron collider | 1/11/2011 | James Gort |
| Q: my question is could the hadron collider be causing all the bird and fish deaths. Could it be doing ... A: The Super Hadron Collider was the cause of some concern by some people - such as possibly creating ... | ||
| Gravity wave experiment | 12/13/2010 | Steve Nelson |
| Q: I am the inventor of the Solar plasma meter pat# 6,234,013 a mechanical radiation detector. If you ... A: I'm not carrying out an experiment for you, especially one so utterly ridiculous. There's no ... | ||
Philip A. Stahl
Top Expert on this page
Expertise
I specialize in stellar and solar astrophysics. Can answer any questions pertaining to these areas, the spectroscopic analysis of stars – as well as the magneto-hydrodynamics of sunspots and solar flares. Sorry – No homework problems done or research projects! I will provide hints on solutions.
Experience
Have published papers on the relationship between sunspot morphology and solar flares; discovery of SID flares related to this, constructed computerized stellar models; MHD research.
Organizations
American Astronomical Society (Solar physics and Dynamical astronomy divisions), American Geophysical Union, American Mathematical Society, Intertel.
Publications
Solar Physics, Journal of the Royal Astronomical Society of Canada, Journal of the Barbados Astronomical Society, Meudon Solar Flare Proceedings (Meudon, France). Books: 'Selected Analyses in Solar Flare Plasma Dynamics', 'Physics Notes for Advanced Level'.
Education/Credentials
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
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