A Cosmic Affair that Defies Logic

"We've known that it exists for more than 25 years. But we don't know what the hell it is." - Virginia Trimble, Astronomer, University of California, Irvine.

Darkness. No matter how much you abhor it, that doesn't wipe out your curiosity in it; over time, it grows ten folds, more so when it bedevils Science and what follows is varied degrees of cerebrations, inspiring revolutionary - or at worst, controversial theories. Let's cite an example.

Over a century back, scientists agreed upon the occurrence of ether, something that fills an apparently void space and defined by Wordweb dictionary as: "The fifth and highest element after air and earth and fire and water; was believed to be the substance composing all heavenly bodies". Luminous ether was a mysterious stuff that had never been sighted; it was only through mathematics that an existence of ether was proved, which explained the varying effects of mutual gravity between the celestial bodies. However, as the 19th century drew towards its end, the concept of luminous ether earned the prefix of mis- and we hope, what beguiles today's astronomers though existing at the cutting edge of cosmological theories shall face the same destiny as ether has now. The concept of Dark Matter is what we are discussing.

Modern astronomers vouch for it; they accept that the greater part of the universe comprises dark matter. The thought pattern opposes directly the scientific mindset that bars humans from being certain of anything that eludes the five senses. However, from observations performed on the movement of stars, nebulas and galaxies for over half a century, theoretically, there's no ground to refuse an existence of the same.

Such observations took into account the spiral galaxies. An individual star or the nebular clouds orbit at speeds faster than if affected only by the inter-galactic visible matter. It applies for the galactic clusters as well, for individual galactic motions are incomprehensible if judged by gravity alone. This is where the concept of the vast halos comes; they are formed out of a matter that's mysterious, different and unseen. It complies with the definition of dark. Unenlightened and secret, for there's present no radiation of energy from it.

However, it has mass, which proves it has gravity, enough to hold in its embrace the galaxies and the galactic clusters together. And cosmology, even being a subject as outré as it can be, finds this proposition hard to digest. It still asks - "Can't there be another explanation?" The answer depends on understanding properly the way gravity functions, but Chris Impey, from University of Arizona did cast some light. Let's quote him here.

"Definitely most astronomers are extremely unwilling to give up Newton's law (on gravity), so it's essentially a choice of two evils: You either hypothesize that Newton's law is wrong and that our knowledge of the gravity theory is incomplete; or, you hypothesize a fundamental microscopic particle that has never been detected in any physics lab, whose properties are only constrained by these astronomical observations, which is a pretty uncomfortable position for physicists to be in."

That makes the dark matter - requiring fewer variations on accepted physics - a less evil phenomenon, even with its 10:1 ratio with the matter we know.