Scientists expected to release landmark image of black hole

Author: 
Reuters
ID: 
1554872594876380000
Wed, 2019-04-10 05:00

WASHINGTON: An international scientific team is expected on
Wednesday to unveil a landmark achievement in astrophysics — the
first photo of a black hole — in a feat that will put to the test
a pillar of science: Albert Einstein’s theory of general
relativity.
Black holes are phenomenally dense celestial entities with
gravitational fields so powerful no matter or light can escape,
making them extraordinarily difficult to observe despite their
great mass.
News conferences are set in Washington, Brussels, Santiago,
Shanghai, Taipei and Tokyo to disclose a “groundbreaking
result” from the Event Horizon Telescope (EHT) project, begun in
2012 to directly observe the immediate environment of a black hole
using a global network of telescopes.
A black hole’s event horizon is the point of no return beyond
which anything — stars, planets, gas, dust and all forms of
electromagnetic radiation — gets swallowed into oblivion. The
project targeted two supermassive black holes residing at the
center of different galaxies.
The Washington news conference convened by the US National Science
Foundation is scheduled for 9 a.m. (1300 GMT) on Wednesday. Among
those due to speak are astrophysicist Sheperd Doeleman, director of
the Event Horizon Telescope at the Center for Astrophysics, Harvard
& Smithsonian.
The research will test the theory of general relativity put forward
in 1915 by Einstein, the famed theoretical physicist, to explain
the laws of gravity and their relation to other natural forces.
Einstein’s theory allows for a prediction of the size and shape
of a black hole. If the prediction turns out to be off the mark,
the theory may need rethinking.
This is separate from another key component of Einstein’s broader
theory of relativity: his 1905 theory of special relativity, part
of the basis of modern physics. The theory of special relativity
explaining the relationship between space and time.
One of the black holes — Sagittarius A* — is situated at the
center of our own Milky Way galaxy, possessing 4 million times the
mass of our sun and located 26,000 light years from Earth. A light
year is the distance light travels in a year, 5.9 trillion miles
(9.5 trillion km).
The second one — M87 — inhabits the center of the neighboring
Virgo A galaxy, boasting a mass 3.5 billion times that of the sun
and located 54 million light-years away from Earth. Streaming away
from M87 at nearly the speed of light is a humongous jet of
subatomic particles.
Black holes, which come in different sizes, are formed when very
massive stars collapse at the end of their life cycle. Supermassive
black holes are the largest kind, growing in mass as they devour
matter and radiation and perhaps merging with other black
holes.
The fact that black holes do not allow light to escape makes
viewing them difficult. The scientists will be looking for a ring
of light — disrupted matter and radiation circling at tremendous
speed at the edge of the event horizon — around a region of
darkness representing the actual black hole. This is known as the
black hole’s shadow or silhouette.
The scientists said the shape of the shadow would be almost a
perfect circle in Einstein’s theory of general relativity, and if
it turns out that it is not, there is something wrong with the
theory.
The project’s researchers obtained the first data in April 2017
using telescopes in the US states of Arizona and Hawaii as well as
Mexico, Chile, Spain and Antarctica. Since then, telescopes in
France and Greenland have been added to the global network. The
global network of telescopes has essentially created a planet-sized
observational dish.

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Source: *FS – All – Science News Net
Scientists expected to release landmark image of black hole