Gravitational Time Dilation

Excessive contemplation works in mysterious ways, I didn’t wake up pondering gravitational time dilation. Placing blame squarely on GPS strikes me as a reasonable explanation. I brought it on myself – putting a monotone tyrant in charge before first coffee rubbed sleep from my eyes, obviously explains an inexplicable need to understand Einstein’s theory of relativity. With each directive – turn left, right, merge – absolute faith in GPS freed my mind to concentrate on time and space.

We think of GPS as an absolute tool, one linking position of our device with that of some imagined all seeing eye. Few of us realize GPS constantly recalculates and adjusts readings based on Einstein’s theory of special relativity. If left unchecked, navigational errors of 10 km per day would quickly topple getting from point A to B.

Einstein’s theory of relativity describes the effect of gravity on space and time. Time is relative to mass and proximity of gravitational pull – speeding up as it moves further away. Time passes at different rates according to gravitational potential. Space-time depends on proximity to forces of gravity.

GPS satellites orbit 20,000 Km above, with gravitational forces four times weaker than Earth. Science proves Einstein knew what he was talking about – satellite clocks tick 38 microseconds faster a day than clocks on our planet. I urge you to read the link below. It explains gravitational time dilution – I’m still digesting my first dip in the relativity pond.




Super Massive Black Hole Encounter

Super massive black holes are the cement holding galaxies together. Massive is a word fitting extremely large objects – preface it with “super” and you have unimaginable size. Asking anyone to visualize something hundreds of thousands, perhaps millions or billions times larger than our sun is pointless. If a super massive pimple came up in conversation – few in the room would struggle over mental images.  Super massive black holes defy common understanding, they elude definable points of reference. Ridiculous vastness aside, black holes are considered fictional science fiction devices rather than concrete science fact.

Princeton physicist John Wheeler came up with “black hole” in 1967. Albert Einstein surmised their existence as part of his theory of relativity – simply put, when a star “dies” it collapses in on itself, resulting in a core of dense mass. Picture New York city instantly compressed onto a pin head and you have “baby steps” towards visualizing just how dense is dense. If the “remnant core” exceeds three times the star’s mass, gravity screams “oh hell no” – a black hole is born.

Galaxies cluster around the extreme gravitational pull of black holes. The Milky Way galaxy boasts a respectable super massive behemoth over four million times the mass of our sun. Indiscriminate cosmic glue, responsible for galactic rotation, orbits, and sealed fates for anything passing the “event horizon” – a  gravitational point of no return, the threshold of absorption by forces so powerful, not even light can escape.

Astronomers are buzzing over an opportunity to witness a black hole in action. In 2011 German astronomers noticed a gas cloud  oblivious to its ill fated path, speeding up as it neared the event horizon. Recent data indicates part of the cloud has begun “spagettification”, a certified sign of black hole might –  gravity elongates as it pulls towards oblivion. The main body of this cloud is expected to succumb by April.

To actually observe an object, to see how it behaves as it vanishes into mystery – how cool is that?  Ponder a moment capable of catapulting science fiction into fact.

Image via ESO/MPE/M. Schartmann/L. Calçada

Image via ESO/MPE/M.Schartmann/L.Calcada

Dark Matter

The universe is made of matter, normal matter is the matter we understand. Normal matter makes up only around 5% of the universe. The rest – about 70% is dark energy, and 25% dark matter.  We have no idea how dark energy or matter work, we only know it’s there. To understand them we may have to throw Einstein’s theory of relativity out the window, as his theory on gravity holding the universe together doesn’t seem to apply to 95% of our universe.

.Albert Einstein