Centauro event
Encyclopedia
A Centauro event is a kind of anomalous event observed in cosmic-ray detectors since 1972. They are so named because their shape resembles that of a centaur
: i.e., highly asymmetric
.
If some versions of string theory
are correct, then high-energy cosmic ray
s could create black holes when they collide with molecule
s in the Earth's atmosphere
. These black holes would be tiny, with a mass
of around 10 microgram
s. They would also be unstable enough to explode in a burst of particle
s within around a billion-billion-billionth of a second
(10−27 of a second).
Theodore Tomaras, a physicist
at the University of Crete
in Heraklion
, Greece
, and his Russia
n collaborators hypothesize that these miniature black holes could explain certain anomalous observations made by cosmic-ray detectors in the Bolivia
n Andes
and on a mountain in Tajikistan
.
In 1972, the Andean detector registered a cascade that was strangely rich in charged, quark
-based particles; far more particles were detected in the bottom portion of the detector than in the top portion. It was called a "Centauro" event, because it resembled the half-man half-horse
beings of Greek mythology
.
In years since, the detectors in Bolivia and Tajikistan
have detected more than 40 Centauro events. Various explanations have been suggested. One possible explanation might be if the strong force between particles behaves unusually when they have extremely high energies.
Exploding black holes are also a possibility. The team calculated what signal a detector would register if a cosmic ray creates a miniature black hole that explodes nearby. The researchers' prediction is consistent with the observed Centauro events.
The Tomaras team hopes that computer simulations of mini-black holes exploding, and further observations, will solve the puzzle.
Solution to the Centauro puzzle
In 2003 an international team of researches from Russia
and Japan
found out that the mysterious observation from mountain-top
cosmic ray experiments can be explained with conventional
physics.
The new analysis of Centauro I reveals that there is a
difference in the arrival angle between the upper block and lower block events,
so the two are not products of the same interaction.
That leaves only the lower chamber data connected to the Centauro I event.
In other words, the man-horse analogy becomes redundant.
There is only an obvious "tail", and no "head".
The original detector setup had gaps between neighboring blocks
in the upper chamber.
Linear dimensions of gaps were comparable to the geometrical
size of the event.
The signal observed in the lower detector was similar to an
ordinary interaction occurred at low altitude above the chamber,
thus providing a natural solution:
passing of a cascade of particles through a gap
between the upper blocks.
In 2005 it was shown that "other Centauro events" can be explained by
peculiarities of the Chacaltaya detector.
So-called "exotic signal" observed so far in cosmic ray experiments
using a traditional X-ray emulsion chamber detector can
be consistently explained within the framework of standard physics
.
The authors of the new analysis firmly believe that the behavior of Nature
is
more complex than people imagined.
Nevertheless, in present case, mundane explanation without any exotic
guesswork provides an answer.
Centaur
In Greek mythology, a centaur or hippocentaur is a member of a composite race of creatures, part human and part horse...
: i.e., highly asymmetric
Asymmetric
Something which is asymmetric displays asymmetry. Specific uses of the term may include:*Asymmetric relation for information on such relations in mathematics and set theory*Asymmetric warfare for information and theories of modern war...
.
If some versions of string theory
String theory
String theory is an active research framework in particle physics that attempts to reconcile quantum mechanics and general relativity. It is a contender for a theory of everything , a manner of describing the known fundamental forces and matter in a mathematically complete system...
are correct, then high-energy cosmic ray
Cosmic ray
Cosmic rays are energetic charged subatomic particles, originating from outer space. They may produce secondary particles that penetrate the Earth's atmosphere and surface. The term ray is historical as cosmic rays were thought to be electromagnetic radiation...
s could create black holes when they collide with molecule
Molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...
s in the Earth's atmosphere
Earth's atmosphere
The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...
. These black holes would be tiny, with a mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
of around 10 microgram
Microgram
In the metric system, a microgram is a unit of mass equal to one millionth of a gram , or 1/1000 of a milligram. It is one of the smallest units of mass commonly used...
s. They would also be unstable enough to explode in a burst of particle
Particle
A particle is, generally, a small localized object to which can be ascribed physical properties. It may also refer to:In chemistry:* Colloidal particle, part of a one-phase system of two or more components where the particles aren't individually visible.In physics:* Subatomic particle, which may be...
s within around a billion-billion-billionth of a second
Second
The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock....
(10−27 of a second).
Theodore Tomaras, a physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
at the University of Crete
University of Crete
The University of Crete ' is the principal higher education institution on the island of Crete, Greece.The University of Crete, is a multi-disciplinary, research- oriented institution, located in the cities of Rethymno and Heraklion...
in Heraklion
Heraklion
Heraklion, or Heraclion is the largest city and the administrative capital of the island of Crete, Greece. It is the 4th largest city in Greece....
, Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....
, and his Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
n collaborators hypothesize that these miniature black holes could explain certain anomalous observations made by cosmic-ray detectors in the Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
n Andes
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
and on a mountain in Tajikistan
Tajikistan
Tajikistan , officially the Republic of Tajikistan , is a mountainous landlocked country in Central Asia. Afghanistan borders it to the south, Uzbekistan to the west, Kyrgyzstan to the north, and China to the east....
.
In 1972, the Andean detector registered a cascade that was strangely rich in charged, quark
Quark
A quark is an elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. Due to a phenomenon known as color confinement, quarks are never directly...
-based particles; far more particles were detected in the bottom portion of the detector than in the top portion. It was called a "Centauro" event, because it resembled the half-man half-horse
Horse
The horse is one of two extant subspecies of Equus ferus, or the wild horse. It is a single-hooved mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today...
beings of Greek mythology
Centaur
In Greek mythology, a centaur or hippocentaur is a member of a composite race of creatures, part human and part horse...
.
In years since, the detectors in Bolivia and Tajikistan
Tajikistan
Tajikistan , officially the Republic of Tajikistan , is a mountainous landlocked country in Central Asia. Afghanistan borders it to the south, Uzbekistan to the west, Kyrgyzstan to the north, and China to the east....
have detected more than 40 Centauro events. Various explanations have been suggested. One possible explanation might be if the strong force between particles behaves unusually when they have extremely high energies.
Exploding black holes are also a possibility. The team calculated what signal a detector would register if a cosmic ray creates a miniature black hole that explodes nearby. The researchers' prediction is consistent with the observed Centauro events.
The Tomaras team hopes that computer simulations of mini-black holes exploding, and further observations, will solve the puzzle.
Solution to the Centauro puzzle
In 2003 an international team of researches from Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
and Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
found out that the mysterious observation from mountain-top
cosmic ray experiments can be explained with conventional
physics.
The new analysis of Centauro I reveals that there is a
difference in the arrival angle between the upper block and lower block events,
so the two are not products of the same interaction.
That leaves only the lower chamber data connected to the Centauro I event.
In other words, the man-horse analogy becomes redundant.
There is only an obvious "tail", and no "head".
The original detector setup had gaps between neighboring blocks
in the upper chamber.
Linear dimensions of gaps were comparable to the geometrical
size of the event.
The signal observed in the lower detector was similar to an
ordinary interaction occurred at low altitude above the chamber,
thus providing a natural solution:
passing of a cascade of particles through a gap
between the upper blocks.
In 2005 it was shown that "other Centauro events" can be explained by
peculiarities of the Chacaltaya detector.
So-called "exotic signal" observed so far in cosmic ray experiments
using a traditional X-ray emulsion chamber detector can
be consistently explained within the framework of standard physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
.
The authors of the new analysis firmly believe that the behavior of Nature
Nature
Nature, in the broadest sense, is equivalent to the natural world, physical world, or material world. "Nature" refers to the phenomena of the physical world, and also to life in general...
is
more complex than people imagined.
Nevertheless, in present case, mundane explanation without any exotic
guesswork provides an answer.