Despite of the astronomical community’s over 200 year
fascination of the concept, does the recent true picture ever captured of a
black hole truly an astronomical breakthrough?
By: Ringo Bones
Maybe we should be thanking first Katie Bouman, a former computer
science student at MIT, now at Cal Tech, who developed the sophisticated
computer algorithm that made possible the first ever interferometer-based
photograph of a black hole. Although it was entirely a team effort, the
astronomical community’s fascination of these enigmatic astronomical objects
that are commonly referred to as black holes dates back over 200 years.
Now largely forgotten many credit the English clergyman and polymath
John Michell for theorizing the existence of black holes, which he then referred
to as dark stars and he does it using only Newtonian Physics. During 1783,
geologist John Michell wrote a letter to Henry Cavendish outlining the expected
properties of dark stars that got published by The Royal Society in their 1784
volume. Michell calculated that that when the escape velocity at the surface of
a star was equal to or greater than the speed of light, the generated light would
be gravitationally trapped so that the star would not be visible to a distant
astronomer. The Sun’s escape velocity = 1/500th that of the speed of
light, would a star with more than 500 times more massive than our Sun has an
escape velocity greater than that of the speed of light and would therefore be
invisible to nearby astronomers?
It was when Albert Einstein published his General Relativity
when our modern understanding of black holes gained widespread popularity.
Popular enough that many science fiction writers often used it in their
action-adventure scenes. The black hole’s popularity to the general public
gained more impetus back in 1964 during the discovery of Cygnus X-1, a strong
X-ray source in the constellation Cygnus. His work on stars and how they could
become black holes got Subrahmanyan Chandrasekhar the 1983 Nobel Physics Prize.
The recent Event Horizon Telescope breakthrough image shows
a halo of dust and gas, tracing the outline of a colossal black hole at the
heart of the Messier 87 galaxy, which is 55-million light years from Earth and
about 6-billion times the mass of our Sun. The Event Horizon Telescope (EHT) is
composed of a network of eight radio telescopes spanning locations from
Antarctica to Spain and Chile – was made possible by the involvement of more
than 200 scientists. The Event Horizon Telescope achieved the necessary
resolution by combining data from the eight of the world’s leading radio
observatories, including the Atacama Large Millimetre Array (ALMA) in Chile and
the South Pole Telescope, creating a virtual telescope akin to the size of
planet Earth.
Despite of the renewed fascination of anyone interested in
astronomy and theoretical physics, a number of science fiction writers and Hollywood
visual special effects artists were a bit “underwhelmed” because the recently
published “true pictures” of the super-massive black hole at the heart of the
M 87 galaxy only confirms that their visual representation or artist’s rendering
of black holes were right all along. Nonetheless, the resulting astrophysical
data obtained by the Event Horizon Telescope may prove to be more useful than
the iconic M 87 galaxy super-massive black hole image.
