The wavelengths of the electromagnetic radiation emitted by an ideal blackbody radiator depends only on the temperature.

Jul 27, 2007 – Paul A. Heckert

Both the steady state and big bang cosmological theories are based on certain fundamental cosmological assumptions and observations.

Jun 13, 2007 – Paul A. Heckert

The steady state theory was a mid 20th century alternative to the big bang theory. It suggested that there was no moment of creation. The universe has always existed.

Jun 13, 2007 – Paul A. Heckert

You are recycled stardust. The atoms in our bodies were manufactured in stars or supernovae and recycled by supernova explosions.

Jun 11, 2007 – Paul A. Heckert

Astronomers use high resolution spectroscopy and the Doppler effect to discover extrasolar planets, which are planets outside our solar system.

Apr 30, 2007 – Paul A. Heckert

Spectroscopy allows astronomers to deduce the chemical compositions of distant astronomical objects. What is astronomical spectroscopy and how does it work?

Apr 28, 2007 – Paul A. Heckert

In early April 2007 astronomers announced the discovery of water on a planet orbiting the star, HD 209458. How is it possible to detect water on an extrasolar planet?

Apr 28, 2007 – Paul A. Heckert

Bohr's atomic model explains how electrons jumping between orbits in atoms cause emission and absorption line spectra and why each element has its own spectral signature.

Apr 28, 2007 – Paul A. Heckert

Time Travel has been a favorite subject for science fiction enthusiasts. Yet scientists do have an idea on how it can be done. Some of these ideas will be discussed.

Apr 23, 2007 – Cyrus Dehkan

How do we know stars must evolve? The fundamental law of conservation of energy, when applied to stars, tells us that they must run out of fuel and therefore evolve.

Apr 1, 2007 – Paul A. Heckert

Astronomers and biologists both frequently use the term evolution, but don't mean exactly the same thing.

Mar 18, 2007 – Paul A. Heckert

The "Big Bang" is commonly described as an explosion, but this is not really a good analogy. In fact, the universe was created through an expansion of space.

Mar 16, 2007 – Paul A. Heckert

Stellar spectral classification helps astrophysicists understand the lives of stars.

Feb 25, 2007 – Katharine M. J. Osborne

Throughout history, humans have tried to explain how everything came to be. The theories we came up with were conjecture based on intuition and imagination.

Feb 10, 2007 – Katharine M. J. Osborne

Solstice occurs twice a year. It happens when either the northern or southern hemisphere is tilted towards the Sun so that the hemisphere has the longest day of the year.

Dec 22, 2006 – Katharine M. J. Osborne

A Wormhole is a theoretical shortcut through spacetime that connects two distant locations.

Jun 29, 2006 – Katharine M. J. Osborne

Each star is unique, and the lifespan of every star is determined primarily by it's mass. The more massive a star is, the shorter its lifespan.

Apr 7, 2006 – Katharine M. J. Osborne

Gamma ray bursters are among the most violent phenomena in the visible universe. In fact, if one occurred near the Earth it would incinerate the atmosphere in seconds. Fi

Mar 10, 2006 – Katharine M. J. Osborne