Scientists expected to release landmark
image of black hole
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[April 10, 2019]
By Will Dunham
WASHINGTON (Reuters) - 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 U.S. 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).
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The world's largest milimetric telescope (50 metres in diameter) is
seen in the Sierra Negra Volcano, at an altitude of 4,600 m (15,000
ft.), which lies between the states of Puebla and Veracruz in
Mexico, June 20, 2011. REUTERS/Henry Romero/File Photo
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 U.S. 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.
(Reporting by Will Dunham; Editing by Sandra Maler)
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