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Monthly Archives: February 2011

Teaching vs Learning [pedagogy]

I came across an excellent talk by Carl Wieman (2001 Physics Nobelist) on how to teach the ability to do science, Science Education in the 21st Century: Using the Tools of Science to Teach Science (@MIT; @iTunesU). This lecture was apparently delivered in 2008, but I just stumbled across it in iTunes. The actual lecture […]

Supernova [Q&A]

Krishna of Canara College asks, how do supernovae occur? There are two kinds of Supernovae. One that occurs due to the build-up of accreting matter on the surface of a white dwarf, and another that occurs due to a collapse in the core of a giant star. The former is thought to occur as a […]

residue of stars [Q&A]

Vibha (Poornaprajna PU College) and Tilak (SDM College) ask, there is a lot of stuff in the Universe, especially Hydrogen, where did they all come from? How did they form? Hydrogen is easy (well, in a manner of speaking). It is just an electron paired with a proton. A lot of these were produced during […]

polar lights [Q&A]

Sathwika of SDM PU College asks, what is the mechanism of the formation of aurora? Aurorae, aka polar lights, form when plasma from the solar wind gets funneled into the Earth’s atmosphere around the magnetic poles, and collide with Oxygen and Nitrogen atoms and ions in the upper atmosphere. The collision causes the electrons in […]

Venusian day [Q&A]

Vibha of Poornaprajna PU College asks, why is the Venusian day longer than its year? Venus takes ≈225 days to revolve around the Sun, but takes ≈243 days to rotate around its axis. What is more, it rotates backwards, along an axis that is opposite to the orbital rotation axis, so compared to North as […]

geomagnetism [Q&A]

Madhusoodan of Poornaprajna College asks, what causes the Earth to have a magnetic field? Typically, magnetic fields in astronomical objects are generated via a natural dynamo. Starting from a seed field which is embedded in the medium, the object first amplifies this field by wrapping it around via rotation, and then rearranges it via convection. […]

about the Q&As [meta]

Whenever I have had the opportunity to talk with non-astronomers about astronomy and astrophysics, or science in general actually, I have always been amazed at the level of interest and curiosity among people at all levels and ages. They are always brimming with questions, and invariably highly intelligent and perceptive questions. In fact, I’ve found […]

the reach of black holes [Q&A]

Gautham of Poornaprajna College wonders what keeps black holes from disrupting the stability of the Universe and gobbling up everything? It is a misconception to think that black holes are somehow more “powerful” at gravitational attraction than other objects. Black holes have mass, and they continue to obey the inverse square law at large distances. […]

Comoving Distance [Q&A]

Atul of Canara College asks, how is it possible that we can see quasars that are 28 billion light years away, when the Universe itself is only 13.7 billions years old? How can light have traveled farther than the Universe has existed? This can happen because the Universe is expanding. Distances to quasars and similar […]

Theory of Law [epistemology]

I was talking with a Botanist friend of mine, and the question came up, what is the difference between a Law and a Theory? Is Evolution a Theory, just like Gravity? Isn’t Gravity a Law? Are Laws just Theories with simple mathematical proofs? Simply put, Laws are the codifications of existing observations. Theories are our […]