Black Holes seem to have bad press that is largely undeserved. This lecture with professor Ian Morison explains what Black Holes are, how we can discover them even through they cannot be seen and how Stephen Hawking has shown that they are not totally black.
Gresham Professor of Astronomy Ian Morison made his first telescope at the age of 12 with lenses given to him by his optician. Having studied Physics, Maths and Astronomy at Oxford, he became a radio astronomer at the Jodrell Bank Observatory and teaches Astronomy and Cosmology at the University of Manchester.
Over 25 years he has also taught Observational Astronomy to many hundreds of adult students in the North West of England. An active amateur optical astronomer, he is a council member and past president of the Society for Popular Astronomy in the United Kingdom.
At Jodrell Bank he was a designer of the 217 KM MERLIN array and has coordinated the Project Phoenix SETI Observations using the Lovell Radio Telescope. He contributes astronomy articles and reviews for New Scientist and Astronomy Now, and produces a monthly sky guide on the Observatory's website.
British astronomer Ian Morison describes a bleak, yet comical, prognosis should you happen to fall into a black hole. Dubbed "spaghettification" (See: Stephen Hawking's A Brief History of Time), extreme gravitational forces would quickly stretch your body like spaghetti as the event horizon neared.
Cosmic body with gravity (seegravitation) so intense that nothing, not even light, can escape. It is suspected to form in the death and collapse of a star that has retained at least three times the Sun's mass. Stars with less mass evolve into white dwarf stars or neutron stars. Details of a black hole's structure are calculated from Albert Einstein's general theory of relativity: a singularity of zero volume and infinite density pulls in all matter and energy that comes within an event horizon, defined by the Schwarzschild radius, around it. Black holes cannot be observed directly because they are small and emit no light. However, their enormous gravitational fields affect nearby matter, which is drawn in and emits X rays as it collides at high speed outside the event horizon. Some black holes may have nonstellar origins. Astronomers speculate that supermassive black holes at the centres of quasars and many galaxies are the source of energetic activity that is observed. Stephen W. Hawking theorized the creation of numerous tiny black holes, possibly no more massive than an asteroid, during the big bang. These primordial mini black holes lose mass over time and disappear as a result of Hawking radiation. Although black holes remain theoretical, the case for their existence is supported by many observations of phenomena that match their predicted effects.
A black hole can be Vacuum.
A black hole has a temperature within a few
millionths of a degree above absolute zero: T=0K.
/ Oxford. Dictionary./
A stellar black hole of one solar mass has a Hawking
temperature of about 100 nanokelvins. This is far less
than the 2.7 K temperature of the cosmic microwave background.
Previous Picture of the Day articles about black holes suggested that
the terminology used to describe “gravitational point sources”
is highly speculative: space/time, singularities, and infinite density
are abstract concepts, precluding a realistic investigation into
the nature of the Universe.
/ Oct 12, 2011. Black hole theory contradicts itself. By Stephen Smith /
My heretical idea:
The black hole with thermodynamic temperature T= 2,7K - –--> T= 0K.
is a Homogeneous Energy Vacuum Space between Galaxies.
Only Vacuum can have infinite spacetime, infinite energy,infinite density.
Israel Sadovnik Socratus
Black hole and Big bang.
A black hole is a theoretical region of space in which the
gravitational field is so powerful that nothing can escape.
Hawking Radiation theorizes that black holes do not,
in fact, absorb all matter absolutely; they give off some
Once upon a time, 20 billions of years ago, all matter
(all elementary particles and all quarks and their
girlfriends- antiparticles and antiquarks, all kinds of
waves: electromagnetic, gravitational, muons…
gluons field ….. etc.) – was assembled in a ‘single point ‘
The reason of this unity is gravitational force.
How did the ‘single point ‘ create if the matter
can escape from any strong gravitational force?
He made a very silly math mistake from 15:45 to 17:30 . If quarks were a billion times denser than neutrons, then an object of quark matter would have 0.1% the diameter of an equivalent mass neutron star. He over-thought a straightforward problem.
I enjoyed the entire presentation, though.
great video. theoretically surviving an event horizon is a fascinating concept.
my only question came when he estimated how long you would survive before being stretched to death:
is that estimate in relation to an outside observer's perception of time or your own?
i thought special relativity states that a few seconds in the high gravity of a black hole would last beyond the end of our universe/end of time (if there is an end).
and on a side note, could that possibly be a way of human beings surviving until the big crunch [if that happens]