Astrophysical journal of the 20th century was agog with Einsteins’ general theory of Relativity and this century is astir with Black holes. In our known universe the idea that no particle can pass faster than light was sacrosanct. Every theory had to fit in order to pass approval. In 2011 was a debate going on about faster-than-light neutrinos. Imagine the notion of the universe having internal boundaries! Only that we have not had any convincing proof to support this quirky idea. It has now been ditched.
What makes a black hole special is its event horizon. If you pass through you are lost forever, in the most complete way, from the universe you left behind. It’s a boundary to the knowable universe. Extraordinary claims require extraordinary evidence. The claim that the universe has internal boundaries is extraordinary. So what’s the evidence for event horizons? One may point to observations of hot matter around the postulated event horizon and say that matter is at least as far from the horizon as the size of the black hole itself. Einstein’s theory of gravity, describes these hot matter observations well, and if it continues to do so all the way down to the event horizon then black holes exist. But we’ve yet to see evidence for that.
Our theoretical explanations may require the existence of things for which there is no direct evidence. It happens all the time in physics. If you accept the Standard Model of Particle Physics then you probably believe in the Higgs boson even though it took a while in order to prove its existence. Similarly, if you believe general relativity then you probably believe in event horizons.
At best we may conclude the best theoretical model of the observational data implies a black hole. But that model includes general relativity, which we expect does not completely describe black holes, as it predicts a singularity – a point of infinite density and infinitesimal volume, at which space and time become infinitely distorted. Things can become quite weird is it not?
So when you come across the term “infinite” in physics it is more like the white spaces in old maps with a notation, ‘terra incognita’, meaning we have reached the limits of our understanding.
Thanks to Stephen Hawking who jiggered with black hole predicts small event horizons eventually explode due to’Hawking radiation.’
So it’s possible event horizons are where quantum mechanics first requires significant modifications to general relativity. Speculating further, it’s also possible that such modifications would prevent event horizons from forming. That might save us from living in a universe with parts that are unknowable.
‘Black holes are a bit like free will. Irrespective of the evidence, most of us live as if free will exists. And most astrophysicists live as if black holes exist’.
(The Conversation/ Black holes might exist, but let’s stay skeptical-Prof.craig savage, Theoretical Physics- Au.NU/ Nov.29, 2011)
(To be concluded)
Read Full Post »
From ashes to ashes, dust to dust’ so runs the line in Book of Common Prayer. In death of a star there is no burial service but it signals processes that resonate for us on earth as well. Now for some scientific facts.
Volcanic ash is inert but rain makes it active. Think of clouds of dust behaving in similar fashion. Gas released by death of stars when come into contact with these grains- analogous to sand, silicates, and infusion of stellar radiation are instant factories, churning out complex molecules. Atoms and molecules from the gas condense onto their surfaces and then interact with one another to form even more complex species. Water, a particularly abundant species, tends to form a layer of ice on the grain surfaces. New stars leave dramatic outflows of material disrupting environments and produce shocks when they collide with the processes begun in the wake of stellar radiation. This includes dislodging surface molecules from grains and prompting the molecules to radiate. The shocks can also fracture the grains, thereby injecting silicon oxide molecules (SiO) into the gas. A cluster of processes are set into motion. At speeds of 20-25 kilometers per second the grain surfaces are completely vaporized, returning all the ice to the gas as water vapor. Then, once the surface has been completely eroded, the grains begin to release SiO into the gas. By using Millimeter telescopes scientists have found that SiO gas emission is a ubiquitous signal around young stars.(Ack: Harvard-Smithsonian Center for Astrophysics/Jan 7,’13)
We are nothing but dust but what grandeur is invested even in dust or in ashes? Life makes even inert body capable of thinking and doing things great many things. The shock process of living is to gather all the benign influences so we also radiate as it happens in space. When whatever happens are more or less played elsewhere life we need to rethink of life and death. Should we worry if we were come to death alone or in the midst of our loved ones? We are not lost among strangers or our family members since the whole cosmos is with us for company. Think of cosmos as our home to which the earth is our cradle.
Read Full Post »
Astronomer Edwin Hubble demonstrated that all galaxies and distant astronomical objects were moving away from us, as predicted by a universal expansion. Using the redshift of their electromagnetic spectra to determine the distance and speed of remote objects in space, he showed that all objects are moving away from us, and that their speed is proportional to their distance.
Similarly how far each of us is far from the Truth absolute can be understood by scanning *Energy Profile of each. Like the red or blueshift our actions hold certain permanence in the Cosmos.
Permanence in this universe? One may ask. It all depends what you think of your soul. If my soul or essential Self is permanent my Energy profile also matters.
Nucleons have same mass as fermions and are two different states of the same particle. In similar fashion whether as spiritual being or as physical being each of us shall go on about the plane of soul till we are perfect. Pure energy as light in the Cosmos.
* I have already covered the topic of Energy profile. Any shift of truth of my actions from the absolute is set in space-time coordinates.
Read Full Post »