The golden anniversary of black-hole singularity

Related Articles

When a star collapses forming a black hole, a space-time singularity is created wherein the laws of Physics no longer work.

In 1965 Sir Roger Penrose presented a theorem where he associated that singularity with so-called ”trapped surfaces” that shrink over time. That hypothesis -one of the results of the general theory of relativity- is now celebrating its anniversary.

Exactly 50 years ago, the physicist and mathematician Sir Roger Penrose, currently Professor Emeritus at the University of Oxford (United Kingdom), formulated a theorem in which he associated two concepts related to relativity. One of these concepts is gravitational singularity, an ‘error’ in space-time where physical quantities cannot be defined.

 

The other concept is that of so-called ”trapped surfaces”, areas that inevitably shrink over time. These surfaces are formed by the explosion of a star at the end of its life, thus causing its collapse and the subsequent formation of a black hole. At that moment, a gravitational singularity is created where time ceases to exist and the laws of known Physics can no longer be applied.

Penrose’s theorem relates both concepts and is considered the first major mathematically rigorous result of Einstein’s general theory. Shortly after presenting his theorem, Penrose and the acclaimed Stephen Hawking tested another theorem which indicates that an expanding universe -such as ours- must have its origin in an instantaneous singularity: the Big Bang, the mysterious initial state which has infinite density.

”What these two theorems are saying is that the general theory of relativity predicts the existence of singular and catastrophic occurrences, such as that which happens inside a black hole or the great initial expansion of the universe, under certain physically reasonable conditions,” explains José M. M. Senovilla, theoretical physicist at the University of the Basque Country and co-author of a study concerning these theorems.

“But they also indicate that Einstein’s theory includes and describes its own limitations -he adds-, since said theory no longer seems valid in certain situations under extreme conditions due to the occurrence of totally unacceptable ‘infinite’ singularities”.

The theorems in and of themselves do not imply that catastrophic events such as black holes have to occur. Singularity could be averted if the hypotheses of the theorem were nullified. “An example in which this would occur would be if the energy density of the entire Universe were, on average, null; but the problem is that this case seems to be highly unrealistic, so singularities prevail,” the researcher notes.

FECYT – SPANISH FOUNDATION FOR SCIENCE AND TECHNOLOGY

Download the HeritageDaily mobile application on iOS and Android

More on this topic

LATEST NEWS

Archaeologists Excavate 1,600-Year-Old Burial Containing Ornate Treasures

Archaeologists excavating a burial ground have discovered a grave containing ornate grave goods from the 5th century AD, a period of instability during the collapse of the Western Roman Empire.

Archaeologists Discover Ancient Settlements Associated With “Polish Pyramids”

Archaeologists conducting a detailed study of the area near the Kujawy megalithic tombs, dubbed the “Polish Pyramids”, have identified the associated settlements of the tomb builders.

Rocky Planet Discovered in Virgo Constellation Could Change Search For Life in Universe

A newly discovered planet could be our best chance yet of studying rocky planet atmospheres outside the solar system, a new international study involving UNSW Sydney shows.

Sungbo’s Eredo – The “Queen of Sheba’s Embankment”

Sungbo’s Eredo is one of the largest man-made monuments in Africa, consisting of a giant system of ditches and embankments that surrounds the entire ljebu Kingdom in the rain forests of south-western Nigeria.

Woolly Mammoths May Have Shared the Landscape With First Humans in New England

Woolly mammoths may have walked the landscape at the same time as the earliest humans in what is now New England, according to a Dartmouth study published in Boreas.

Prehistoric killing machine exposed

Judging by its massive, bone-crushing teeth, gigantic skull and powerful jaw, there is no doubt that the Anteosaurus, a premammalian reptile that roamed the African continent 265 to 260 million years ago - during a period known as the middle Permian - was a ferocious carnivore.

Noushabad – The Hidden Underground City

Noushabed, also called Oeei or Ouyim is an ancient subterranean city, built beneath the small town of Nushabad in present-day Iran.

10 British Iron Age Hill Forts

A hill fort is a type of earthworks used as a fortified refuge or defended settlement, located to exploit a rise in elevation for defensive advantage.

Popular stories

Noushabad – The Hidden Underground City

Noushabed, also called Oeei or Ouyim is an ancient subterranean city, built beneath the small town of Nushabad in present-day Iran.

Ani – The Abandoned Medieval City

Ani is a ruined medieval city, and the former capital of the Bagratid Armenian kingdom, located in the Eastern Anatolia region of the Kars province in present-day Turkey.

Interactive Map of Earth’s Asteroid and Meteor Impact Craters

Across the history of our planet, around 190 terrestrial impact craters have been identified that still survive the Earth’s geological processes, with the most recent event occurring in 1947 at the Sikhote-Alin Mountains of south-eastern Russia.

The Sunken Town of Pavlopetri

Pavlopetri, also called Paulopetri, is a submerged ancient town, located between the islet of Pavlopetri and the Pounta coast of Laconia, on the Peloponnese peninsula in southern Greece.