Hundreds of new 'smart genes' discovered by scientists

Hundreds of new genes associated with intelligence have been discovered by brain scientists, says a new study published in the journal Nature Genetics. Hundreds of new genes associated with intelligence have been discovered .

Hundreds of new genes associated with intelligence have been discovered Sydney: Scientists have identified hundreds of new genes associated with intelligence. In a joint research project from the University of Queensland's Brain Institute and its partners in the Netherlands, the scientists identified 939 new "smart genes," and over 500 genes associated with neuroticism -- an important risk factor for depression and schizophrenia, Xinhua news agency reported. The findings suggest that our brains have distinct genetic gene clusters responsible for the effects of depression and worry. "These results are a major step forward in understanding the neurobiology of cognitive function as well as genetically related neurological and psychiatric disorders," the researchers said.

More than 250,000 individuals were tested for their genetic data and measurements of intelligence while the study into neuroticism took data from almost half a million respondents. You May Like Why this IIM Program is a must have for future entrepreneurs Talentedge Sponsored Links Together these studies provide new insights into the neurobiology and genetics of cognition. Scientists also believe the newly-found "smart genes" may help protect against Alzheimer's disease and conditions like Attention Deficit Hyperactivity Disorder (ADHD), the report said.

In a previous study, reported in the journal Nature Genetics, scientists announced the discovery of 52 genes linked to human intelligence. These "smart genes" accounted for 20 per cent of the discrepancies in IQ test results among tens of thousands of people examined, the researchers said.

What Is The Highest IQ In The World Ever Recorded?

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The highest IQ ever recorded is of William James Sidis with an IQ score between 250-300. At the age of 5, he could use a typewriter and had learnt to speak Latin, Greek, Russian, French, German and Hebrew. He was denied admission to Harvard at the age of 6 because he was called too emotionally immature. Later, at age 11, they were forced to admit him, after which he gave his well-received first lecture on 4-dimensional physics!

The Intelligence Quotient or “IQ” has become the go-to term during discussions of a person’s mental abilities. By trying to measure someone’s intelligence, a debate has been fueled about whether that person has any control over his IQ whatsoever. Some believe that it might simply be affected by the genes they inherit, while others believe that it is nourished through hard work as they grow older. Whatever may be the case, one thing is for sure. IQ is the best measure of intelligence, as of now.

What is IQ?

Although we might have come across this term plenty of times during our lives, we still need to set some standards so that we can distinguish a great score from an average one.

IQ is nothing but the number that a person scores after taking one of the many standardized tests to measure the intelligence level of individuals. Originally, the intelligence quotient was calculated as the ratio of mental age and chronological age (IQ= MA/CA x 100, where MA is mental age, CA is chronological age). However, today, intelligence scores are calibrated against values of actual population scores. Here is a graph that shows how people fare when they take an IQ test:

This is, as you can see, a bell-shaped curve. It depicts that most measurements fall in the middle, and fewer fall at points farther away from the middle. What this means in our case is that most people’s IQ scores fall in and around the average range, while much less people score very low or very high.

The general score of 95% of the population from these tests ranges between 70 and 130. Since there are quite a few different classifications, the Stanford-Binet Scale of Human Intelligence is the most commonly used one and we shall use that as a reference. According to this scale, people who have a score higher than 145 are considered geniuses.

List of people with the highest IQ score ever recorded (in ascending order)

1. Stephen Hawking (IQ score – 160)
2. Albert Einstein (IQ score – 160 – 190)
3. Judit Polgar (IQ score – 170)
4. Philip Emeagwali (IQ score – 190)
5. Garry Kasparov (IQ score – 194)
6. Christopher Michael Langan (IQ score – 190 – 210)
7. Edith Stern (IQ score – 200+)
8. Kim Ung-Yong (IQ score – 210)
9. Christopher Hirata (IQ score – 225)
10. Marilyn Vos Savant (IQ score – 228)
11. Terence Tao (IQ score – 225 – 230)
12. William James Sidis (IQ score – 250-300)

Now, let’s meet these geniuses, but please remember that IQ tests are not necessarily all that accurate in estimating someone’s overall intelligence, even if they are good markers for specific cognitive skills, such as mathematical ability and logical reasoning. Also, note that this list is NOT an exhaustive one, and therefore may not feature the name of every high-IQ individual.

Stephen Hawking (IQ-160)

Stephen Hawking

This man needs no introduction. Considered one of the greatest minds of our time, he was a professor, author and world-renowned theoretical physicist. His book “A Brief History of Time” has sold more than 10 million copies worldwide. Moreover, he was the undisputed champion when it comes to the study of black holes, which was also his particular field of study at the time of his death in March 2018. Due to his inspiring battle with Amyotrophic Lateral Sclerosis (ALS) and his undying love for physics, Hawking was viewed as a symbol of knowledge and intelligence in pop culture, an honor he definitely deserved!

Albert Einstein (IQ- 160-190)

Albert Einstein

Speaking of ‘symbols of knowledge’, the name of this scientist is actually synonymous with genius. It cannot be denied that he shaped the future of science. He received a Nobel Prize for the discovery of the law of photoelectric effect. The theory of relativity was also his brainchild. Although there is no scientific method of calculating his IQ posthumously, researchers have had to resort to estimating his score through careful analysis of his papers.

Judit Polgar (IQ-170)

Judit Polgar

Chess Grandmasters rarely aren’tgeniuses, and by rarely, I mean never. Judit Polgar became the youngest one at the age of 15 and still proudly holds that record. She is not only viewed as a pioneer for women in chess, but also as one of the greatest chess players to ever live. She defeated Garry Kasparov, the reigning world champion, in 2002 and went on to conquer 10 other world championships.

Philip Emeagwali (IQ-190)

Philip Emeagwali

Philip Emeagwali is a Nigerian-born engineer, mathematician, computer scientist and geologist. He left school at an early age of 13 due to the Nigerian-Biafran War. Through hard work and self-study, he earned a degree in Mathematics.  He went on to win the 1989 Gordon Bell Prize, a prize from the IEEE, for his use of a Connection Machine supercomputer to help detect petroleum fields. Even after facing rejection due to racial discrimination, he didn’t give up and continued to inspire people worldwide by earning three Master’s degree in Mathematics, Environmental and Marine Engineering from various universities.

Garry Kasparov (IQ-194)

Garry Kasparov

Being ranked world No.1 225 times over the course of 228 months is no small achievement. Russian by birth, Kasparov is considered by some to be the greatest chess player of all time.  As a testament to his brilliance, he once tied a match with IBM’s Deep Blue, a chess computer that could calculate 3 million moves per second! He is also the proud record holder of the highest number of consecutive wins.

Christopher Michael Langan (IQ – 190 – 210)

Christopher Michael Langan (Photo Credit: By TeaFoam / Flickr.com)

Born in San Francisco, California, Christopher Langan began speaking at the age of 6 months, and taught himself to read when he was just 3 years old. It is said about Langan that he managed to hit the perfect score in SAT despite falling asleep during the exam! He is frequently hailed as the ‘smartest man in America’. He has also developed a theory called “Cognitive-Theoretic Model of the Universe” (CTMU) which basically deals with “the relationship between mind and reality”.

Edith Stern (IQ – 200+)

A 16-year-old Edith Stern teaching college trigonometry

Born in 1952 to Aaron Stern (a concentration camp survivor whose cancer treatment was paid for by Albert Einstein), Edith Stern could communicate with cards when she was no older than 11 months. At 1, she could identify letters and by 2 she could speak the entire alphabet. At 12, she had already entered college and 4 years later, she was teaching trigonometry there. Her IQ score is reported to be more than 200. Currently, she holds a PhD in Mathematics, and is a distinguished engineer and inventor at IBM.

Kim Ung-Yong (IQ – 210)

Kim Ung-Yong

Born in 1963 in Korea, Kim Ung-Yong started speaking when he was just 6 months old. By his third birthday, Kim Ung-Yong could already read English, Korean, Japanese, and German. As if this wasn’t mind-boggling enough, he was writing poetry and had completed two short stories by the time he was four years old! His drive and thirst for knowledge made him decline enrollment in Korea’s most prestigious university at the age of 16 and he instead started to pursue a PhD in Civil Engineering. Presently, he spends his time doing invaluable research and teaching students at Chungbuk National University in South Korea.

Christopher Hirata (IQ – 225)

Christopher Hirata (Photo Credit: The Ohio State University)

A former child prodigy, Hirata became the youngest American to clinch a gold medal at the International Physics Olympiad in 1996, and e accomplished the incredible feat when he was just 13! He was involved in a project at NASA when he was 16, and obtained his PhD from the prestigious Princeton University at a young age of 22. Presently, he is a visiting professor of astronomy and physics at Ohio State University.

Marilyn Vos Savant (IQ – 228)

Marilyn vos Savant (Photo Credit: Shelly Pippin / quotesgram.com)

Marilyn was born in Missouri, US in 1946. She believes that one should keep their premarital surnames, and hence she kept the surname of her mother, Marina vos Savant. As a teenager, she worked at her father’s general store and wrote articles for local newspapers under different names. She rose to fame when she first topped the Guinness Book of World Records list of the “highest iq” category in 1986 and stayed there until 1989. She was reported to have an IQ score of 228.

However, a psychology professor and author of IQ tests named Alan Kaufman challenged this and claimed that…

Miss Savant was given an old version of the Stanford-Binet (Terman & Merrill 1937), which did, indeed, use the antiquated formula of MA/CA × 100. But in the test manual’s norms, the Binet does not permit IQs to rise above 170 at any age. So, the psychologist who came up with an IQ of 228 committed an extrapolation of a misconception, thereby violating almost every rule imaginable concerning the meaning of IQs.

Terence Tao (IQ – 225 – 230)

Terence Tao (Photo Credit: UCLA Department of Mathematics)

Born in 1975 to a Chinese family, Terence displayed exceptional aptitude towards Mathematics from a very early age. The fact that he had started attending university-level Math courses should be proof enough of that. He had acquired his PhD when he was just 20, and perhaps more importantly, he was the co-recipient of the Fields Medal in 2006. For the uninitiated, the Fields Medal can be thought of as the Nobel-equivalent awarded in the field of Mathematics, only they give out that award once every 4 years. Presently, Tao resides in Los Angeles with his wife and kids and focuses on theories regarding partial differential equations, algebraic combinatorics, harmonic analysis and analytic number theory.

William James Sidis (IQ ~ 250-300… probably)

William James Sidis

This man simply plays in an altogether different league. Born in 1898 in New York City,  and raised in a family of intellectuals, he was gifted from the very beginning. At the age of 5, he could use a typewriter and had learnt to speak Latin, Greek, Russian, French, German and Hebrew. He was denied admission to Harvard at the age of 6 because he was called too emotionally immature.

Later, at age 11, they were forced to admit him, after which he gave his well-received first lecture on 4-dimensional physics! He was threatened by some fellow students at Harvard, so his parents assigned him to a teaching job in Texas. Due to this he could not pursue academics and instead decided to focus on his political career. He died of a stroke at the age of 46 as a reclusive, penniless clerk.

It should be noted that the fact that he was the smartest man ever is often challenged, because William’s sister and mother had developed a reputation of making exaggerated claims about the Sidis family, (source) and it was his sister who told a famous psychologist and author Abraham Sperling that his brother had an IQ score of 250+.

To quote Sperling, author of the 1946 book Psychology for the Millions:

Helena Sidis (William’s sister) told me that a few years before his death, her brother Bill took an intelligence test with a psychologist. His score was the very highest that had ever been obtained. In terms of IQ, the psychologist related that the figure would be between 250 and 300. Late in life William Sidis took general intelligence tests for Civil Service positions in New York and Boston. His phenomenal ratings are matter of record.

However, it seems that Sperling never actually gave Sidis an IQ test himself in order to test his IQ. Because if he did, then why didn’t he talk about it in A Story of Genius, which is basically Sterling’s account of Sidis’ intellectual prowess?

The controversy pertaining to Sidis’ realIQ score aside, he undoubtedly was an extraordinarily intelligent individual (a fact that is evidenced by the outstanding feats he accomplished so early in his life), and there is no telling what Sidis might have accomplished in the fields of mathematics and science if his talents had not been squandered.

A high IQ doesn’t necessarily indicate ‘smartness’

Having a high IQ does not necessarily mean that the person is intelligent or very ‘smart’. The problem with IQ tests is that although they’re pretty good at assessing our deliberative skills (which involve how we use our working memory and reason), but they are not able to asses our inclination to use them when the situation demands. This is a very important difference. According to as Daniel Kahneman, a professor at Princeton University, intelligence is about brain power whereas rational thinking is about control.

“Some people who are intellectually able do not bother to engage very much in analytical thinking and are inclined to rely on their intuitions,” says Jonathan Evans, a cognitive psychologist at the University of Plymouth, UK. “Other people will check out their gut feeling and reason it through and make sure they have a justification for what they’re doing.

A high IQ is like height in a basketball player. It is certainly a crucial trait, provided all other ‘things’ are equal. But if all other things aren’t equal, then the player needs a lot of more than just height in order to be a good basketball player. Similarly, there is a lot more to being a good thinker than having a high IQ.

10 Amazing Facts About Earthquakes!!!!

1. The largest earthquake ever recorded was a magnitude 9.5 in Chile back in 1960.           

 2. The 2011 earthquake near Japan increased the Earth’‘s rotation speed, shortening the day by 1.8 microseconds. 

3. There are about 500,000 detectable earthquakes in the world each year. 100,000 of those can be felt, and 100 of them cause damage. 

4. About 90% of the world’‘s earthquakes occur along the Ring of Fire, an area in the basin of the Pacific Ocean. 

5. The 1911 Sarez Earthquake triggered a massive landslide that formed The Usoi Dam, the tallest dam in the world. It had an estimated magnitude of 7.4 and lasted for 2 days.

6. Inca architecture was built to be earthquake resistant. Inca masonry is effective in withstanding even major tremors. 

7. An earthquake on Dec. 16, 1811 caused parts of the Mississippi River to flow backwards. 

8. Mount Everest shrank one inch (2.5 cm) due to the 2015 earthquake in Nepal. 

9. In 132 AD, a Chinese inventor built a seismograph which, at the moment of an earthquake, expelled a copper ball out of the mouth of a dragon and into the mouth of a frog. 

10. Japan suffers 1,500 earthquakes every year. 

Organic molecules found in ancient Martian rocks

Organic molecules have been found in ancient rocks under the surface of Mars. The discovery was made by NASA’s Curiosity Rover by drilling into mudstone that was laid down 3.5 bn years ago at the bottom of a Martian lake. The molecules found include sulphur-rich thiophenes, aromatic hydrocarbons, such as benzene, and aliphatic hydrocarbons such as propane.

While the presence of these molecules does not prove that life once existed on the red planet, the discovery suggests that conditions on Mars could have been like those here on Earth when life first emerged more than 3 bn years ago.

The discovery is reported in the journal Science by NASA’s Jennifer Eigenbrode and an international team of scientists. They used Discovery’s Sample Analysis at Mars (SAM) instrument to examine samples that had been gathered from Mars’ Gale crater using a drill that can probe 5 cm below the surface.

SAM works by heating rock samples to release any organic compounds that may be present. The emitted gases are then analysed using a gas chromatograph mass spectrometer and a laser spectrometer.

This is not the first time that Curiosity has detected organic molecules, but previous measurements were considered unreliable because of possible sample contamination and unwanted chemical reactions.

Curioser and curioser

While such organic compounds could have been produced by ancient life – or could have provided a food source for ancient organisms – it is also possible that the molecules were created in the complete absence of life. “Curiosity has not determined the source of the organic molecules,” explains Eigenbrode.

Apparently barren and devoid of life today, scientists believe that Mars may have once been a more hospitable environment. Data gathered by Curiosity in 2015 suggests that the Gale Crater was once home to streams and lakes of liquid water. Now, scientists know that some of this water contained molecules that could be associated with life.

NASA associate administrator Thomas Zurbuchen says the agency wants to keep searching for signs of life on Mars. “With these new findings, Mars is telling us to stay the course and keep searching for evidence of life”.

In a second paper in Science, NASA’s Christopher Webster and an international team describe how they have used instruments on-board Curiosity to measure a seasonal variation in methane levels in the Martian atmosphere. The study, which ran for three Martian years (about five Earth years), found that methane concentration in the summer was nearly three times higher than in the winter.  Webster and colleagues say that the variation cannot currently be explained by processes known to occur on Mars.

10 Amazing Facts About Nuclear Energy!!

1. Nuclear energy is energy that is released either by splitting atomic nuclei or by forcing the nuclei of atoms together. Nuclear energy comes from mass-to-energy conversions that occur in the splitting of atoms. Albert Einstein’‘s famous mathematical formula E = mc2 explains this. The equation says: E [energy] equals m [mass] times c2 [c stands for the speed of light]. This means that it is mass multiplied by the square of the velocity of light. Nuclear energy is produced by a controlled nuclear chain reaction and creates heat—which is used to boil water, produce steam, and drive a steam turbine.

 2. Nuclear power can come from the fission of uranium, plutonium or thorium or the fusion of hydrogen into helium. Today it is almost all uranium. The basic energy fact is that the fission of an atom of uranium produces 10 million times the energy produced by the combustion of an atom of carbon from coal. Nuclear power plants need less fuel than ones which burn fossil fuels. One ton of uranium produces more energy than is produced by several million tons of coal or several million barrels of oil. 

3.In France, nuclear power is the most widespread, supplying 80 percent of the country’‘s electricity. A protest movement exists, called Sortir du Nucléaire, or “Get Out of Nuclear,” but it appears to have made little headway. Nuclear energy is released by three exothermic processes: a. Radioactive decay, where a proton or neutron in the radioactive nucleus decays spontaneously by emitting a particle b. Fusion, two atomic nuclei fuse together to form a heavier nucleus c. Fission, the breaking of heavy nucleus into two nuclei The sun uses nuclear fusion of hydrogen atoms into helium atoms. This gives off heat and light and other radiation. 

4. Nuclear energy was first discovered accidentally by French physicist Henri Becquerel in 1896, when he found that photographic plates stored in the dark near uranium were blackened like X-ray plates, which had been just recently discovered at the time. 

5. As of 2004, nuclear power provided 6.5% (in 2015 10.6%)of the world’‘s energy and 15.7% of the world’‘s electricity, with the U.S., France, and Japan together accounting for 57% of nuclear generated electricity. 

6. There are 104 commercial nuclear generating units that are fully licensed by the U.S. Nuclear Regulatory Commission (NRC) to operate in the United States. Of these 104 reactors, 69 are categorized a pressurized water reactors (PWRs) totaling 65,100 net megawatts (electric) and 35 units are boiling water reactors (BWR) totaling 32,300 net megawatts (electric) compared to India’‘s 21 reactors. 

7. On June 27, 1954, the USSRs Obninsk Nuclear Power Plant became the world’‘s first nuclear power plant to generate electricity for a power grid, and produced around 5 megawatts electric power. 

8. The International Nuclear Event Scale (INES), developed by the International Atomic Energy Agency (IAEA), is used to communicate the severity of nuclear accidents on a scale of 0 to 7. The Chernobyl disaster in 1986 at the Chernobyl Nuclear Power Plant in the Ukrainian Soviet Socialist Republic (now Ukraine) was the worst nuclear accident in history and is the only event to receive an INES score of 7. 

9. Compared to other non-carbon-based and carbon-neutral energy options, nuclear power plants require far less land area. For a 1,000 MW plant, site requirements are estimated as follows: nuclear, 1-4 km2; solar or photovoltaic park, 20-50 km2; a wind field, 50-150 km2; and biomass, 4,000-6,000 km2. 

10. Nuclear energy can be very destroying. Hiroshima and Nagasaki are to date the only attacks with nuclear weapons in the history of warfare. The bombs killed as many as 140,000 people in Hiroshima and 80,000 in Nagasaki by the end of 1945, roughly half on the days of the bombings.

10 Amazing Facts About Phobias!!

1. There are more than 400 distinct phobias well recognized by psychologists.

2. Phobophobia is the fear of having a phobia.

3. Papaphobia is the fear of the Pope.

4. Hexakosioihexekontahexaphobia is the fear of the number 666.

5. Nomophobia is the fear of being without your mobile phone or losing your signal.

6. Anatidaephobia is the weird fear that somewhere, somehow, a duck is watching you. 

7. Phobias may be memories passed down through generations in DNA, according to a new research. 

8. Alexander the Great, Napoleon, Mussolini and Hitler, all suffered from ailurophobia, the fear of cats. 

9. Didaskaleinophobia is the fear of going to school. 

10. Hippopotomonstrosesquippedaliophobia is the fear of long words. 

Kaon // What is it? // Elementary Particle // All about Kaon//

In particle physics, a kaon, also called a K meson and denoted 
K
, is any of a group of four mesons distinguished by a quantum number called strangeness. In the quark model they are understood to be bound states of a strange quark (or antiquark) and an up or down antiquark (or quark). 

Quick Fact About Kaon:-

Kaon

Composition	K+ :  u s K0 :  d s  /  s d K− :  s u
Statistics	Bosonic
Interactions	Strong, weak, electromagnetic, gravitational
Symbol	K+ ,  K0 ,  K−
Discovered	1947
Types	4
Mass	K± : 493.677±0.013 MeV/c2 K0 : 497.648±0.022 MeV/c2
Electric charge	K± : ±1 e K0 : 0 e
Spin	0
Strangeness	1

Kaons have proved to be a copious source of information on the nature of fundamental interactions since their discovery in cosmic rays in 1947. They were essential in establishing the foundations of the Standard Model of particle physics, such as the quark model of hadrons and the theory of quark mixing (the latter was acknowledged by a Nobel Prize in Physics in 2008). Kaons have played a distinguished role in our understanding of fundamental conservation laws: CP violation, a phenomenon generating the observed matter–antimatter asymmetry of the universe, was discovered in the kaon system in 1964 (which was acknowledged by a Nobel Prize in 1980). Moreover, direct CP violation was discovered in the kaon decays in the early 2000s by the NA48 experiment at CERN and the KTeV experiment at Fermilab.

Basic properties

The decay of a kaon (
K+
) into three pions (2 
π+
, 1 
π−
) is a process that involves both weak and strong interactions.

Weak interactions : The strange antiquark (
s
) of the kaon transmutes into an up antiquark (
u
) by the emission of a 
W+
 boson; the 
W+
 boson subsequently decays into a down antiquark (
d
) and an up quark (
u
).

Strong interactions : An up quark (
u
) emits a gluon (
g
) which decays into a down quark (
d
) and a down antiquark (
d
).

The four kaons are :

1. 
   K−
   , negatively charged (containing a strange quark and an up antiquark) has mass 493.677±0.013 MeV and mean lifetime(1.2380±0.0020)×10⁻⁸ s.
2. 
   K+
    (antiparticle of above) positively charged (containing an up quark and a strange antiquark) must (by CPT invariance) have mass and lifetime equal to that of 
   K−
   . Experimentally, the mass difference is 0.032±0.090 MeV, consistent with zero; the difference in lifetimes is (0.11±0.09)×10⁻⁸ s, also consistent with zero.
3. 
   K0
   , neutrally charged (containing a down quark and a strange antiquark) has mass 497.648±0.022 MeV. It has mean squared charge radius of −0.076±0.01 fm².
4. 
   K0
   , neutrally charged (antiparticle of above) (containing a strange quark and a down antiquark) has the same mass.

It is clear from the quark model assignments that the kaons form two doublets of isospin; that is, they belong to the fundamental representation of SU(2) called the 2. One doublet of strangeness +1 contains the 
K+
and the 
K0
. The antiparticles form the other doublet (of strangeness −1).

More information :-

Properties of kaons

Particle name	Particle  symbol	Antiparticle  symbol	Quark  content	Rest mass(MeV/c2)	IG	JPC	S	C	B'	Mean lifetime (s)	Commonly decays to  (>5% of decays)
Kaon	K+	K−	u s	493.677±0.016	​1⁄2	0−	1	0	0	(1.2380±0.0021)×10−8	μ+  +  ν μ or π+  +  π0  or π+  +  π+  +  π−  or π0  +  e+  +  ν e
Kaon	K0	K0	d s	497.611±0.013	​1⁄2	0−	1	0	0	[a]	[a]
K-Short	K0 S	Self	${\displaystyle \mathrm {\tfrac {d{\bar {s}}+s{\bar {d}}}{\sqrt {2}}} \,}$[b]	497.611±0.013[c]	​1⁄2	0−	(*)	0	0	(8.954±0.004)×10−11	π+  +  π−  or π0  +  π0
K-Long	K0 L	Self	${\displaystyle \mathrm {\tfrac {d{\bar {s}}-s{\bar {d}}}{\sqrt {2}}} \,}$[b]	497.611±0.013[c]	​1⁄2	0−	(*)	0	0	(5.116±0.021)×10−8	π±  +  e∓  +  ν e or π±  +  μ∓  +  ν μ or π0  +  π0  +  π0  or π+  +  π0  +  π−

^[a] ^ Strong eigenstate. No definite lifetime 
^[b] ^ Weak eigenstate. Makeup is missing small CP–Violation. 
^[c] ^ The mass of the 
K0
L and 
K0
S are given as that of the 
K0
. However, it is known that a difference between the masses of the 
K0
L and 
K0
S on the order of 3.5×10⁻¹² MeV/c² exists.

Although the 
K0
 and its antiparticle 
K0
 are usually produced via the strong force, they decay weakly. Thus, once created the two are better thought of as superpositions of two weak eigenstates which have vastly different lifetimes:

1. The long-lived neutral kaon is called the 
   K
   L("K-long"), decays primarily into three pions, and has a mean lifetime of 5.18×10⁻⁸ s.
2. The short-lived neutral kaon is called the 
   K
   S("K-short"), decays primarily into two pions, and has a mean lifetime 8.958×10⁻¹¹ s.

An experimental observation made in 1964 that K-longs rarely decay into two pions was the discovery of CP violation (see below).

Main decay modes for 
K+
:

More information:-

Results	Mode	Branching ratio
μ+   ν μ	leptonic	63.55±0.11%
π+   π0	hadronic	20.66±0.08%
π+   π+   π−	hadronic	5.59±0.04%
π+   π0   π0	hadronic	1.761±0.022%
π0   e+   ν e	semileptonic	5.07±0.04%
π0   μ+   ν μ	semileptonic	3.353±0.034%

Decay modes for the 
K−
 are charge conjugates of the ones above.

Strangeness

The discovery of hadrons with the internal quantum number "strangeness" marks the beginning of a most exciting epoch in particle physics that even now, fifty years later, has not yet found its conclusion ... by and large experiments have driven the development, and that major discoveries came unexpectedly or even against expectations expressed by theorists.  — I.I. Bigi and A.I. Sanda, CP violation, (ISBN 0-521-44349-0)

In 1947, G. D. Rochester and Clifford Charles Butler of the University of Manchesterpublished two cloud chamber photographs of cosmic ray-induced events, one showing what appeared to be a neutral particle decaying into two charged pions, and one which appeared to be a charged particle decaying into a charged pion and something neutral. The estimated mass of the new particles was very rough, about half a proton's mass. More examples of these "V-particles" were slow in coming.

The first breakthrough was obtained at Caltech, where a cloud chamber was taken up Mount Wilson, for greater cosmic ray exposure. In 1950, 30 charged and 4 neutral V-particles were reported. Inspired by this, numerous mountaintop observations were made over the next several years, and by 1953, the following terminology was adopted: "L-meson" meant muon or pion. "K meson" meant a particle intermediate in mass between the pion and nucleon. "Hyperon" meant any particle heavier than a nucleon.

The decays were extremely slow; typical lifetimes are of the order of 10⁻¹⁰ s. However, production in pion-proton reactions proceeds much faster, with a time scale of 10⁻²³ s. The problem of this mismatch was solved by Abraham Pais who postulated the new quantum number called "strangeness" which is conserved in strong interactions but violated by the weak interactions. Strange particles appear copiously due to "associated production" of a strange and an antistrange particle together. It was soon shown that this could not be a multiplicative quantum number, because that would allow reactions which were never seen in the new synchrotrons which were commissioned in Brookhaven National Laboratory in 1953 and in the Lawrence Berkeley Laboratory in 1955.

Parity violation

Two different decays were found for charged strange mesons:

Θ+	→	π+  +  π0
τ+	→	π+  +  π+  +  π−

The intrinsic parity of a pion is P = −1, and parity is a multiplicative quantum number. Therefore, the two final states have different parity (P = +1 and P = −1, respectively). It was thought that the initial states should also have different parities, and hence be two distinct particles. However, with increasingly precise measurements, no difference was found between the masses and lifetimes of each, respectively, indicating that they are the same particle. This was known as the τ–θ puzzle. It was resolved only by the discovery of parity violation in weak interactions. Since the mesons decay through weak interactions, parity is not conserved, and the two decays are actually decays of the same particle,now called the 
K+
.

CP violation in neutral meson oscillations

Initially it was thought that although paritywas violated, CP (charge parity) symmetrywas conserved. In order to understand the discovery of CP violation, it is necessary to understand the mixing of neutral kaons; this phenomenon does not require CP violation, but it is the context in which CP violation was first observed.

Neutral kaon mixing

Two different neutral K mesons, carrying different strangeness, can turn from one into another through the weak interactions, since these interactions do not conserve strangeness. The strange quark in the anti-
K0
turns into a down quark by successively absorbing two W-bosons of opposite charge. The down antiquark in the anti-
K0
 turns into a strange antiquark by emitting them.

Since neutral kaons carry strangeness, they cannot be their own antiparticles. There must be then two different neutral kaons, differing by two units of strangeness. The question was then how to establish the presence of these two mesons. The solution used a phenomenon called neutral particle oscillations, by which these two kinds of mesons can turn from one into another through the weak interactions, which cause them to decay into pions (see the adjacent figure).

These oscillations were first investigated by Murray Gell-Mann and Abraham Pais together. They considered the CP-invariant time evolution of states with opposite strangeness. In matrix notation one can write

${\displaystyle \psi (t)=U(t)\psi (0)={\rm {e}}^{iHt}{\begin{pmatrix}a\\b\end{pmatrix}},\qquad H={\begin{pmatrix}M&\Delta \\\Delta &M\end{pmatrix}},}$

where ψ is a quantum state of the system specified by the amplitudes of being in each of the two basis states (which are a and b at time t = 0). The diagonal elements (M) of the Hamiltonian are due to strong interactionphysics which conserves strangeness. The two diagonal elements must be equal, since the particle and antiparticle have equal masses in the absence of the weak interactions. The off-diagonal elements, which mix opposite strangeness particles, are due to weak interactions; CP symmetry requires them to be real.

The consequence of the matrix H being real is that the probabilities of the two states will forever oscillate back and forth. However, if any part of the matrix were imaginary, as is forbidden by CP symmetry, then part of the combination will diminish over time. The diminishing part can be either one component (a) or the other (b), or a mixture of the two.

Mixing

The eigenstates are obtained by diagonalizing this matrix. This gives new eigenvectors, which we can call K₁ which is the sum of the two states of opposite strangeness, and K₂, which is the difference. The two are eigenstates of CP with opposite eigenvalues; K₁ has CP = +1, and K₂ has CP = −1 Since the two-pion final state also has CP = +1, only the K₁ can decay this way. The K₂ must decay into three pions. Since the mass of K₂ is just a little larger than the sum of the masses of three pions, this decay proceeds very slowly, about 600 times slower than the decay of K₁ into two pions. These two different modes of decay were observed by Leon Lederman and his coworkers in 1956, establishing the existence of the two weakeigenstates (states with definite lifetimesunder decays via the weak force) of the neutral kaons.

These two weak eigenstates are called the 
K
L(K-long) and 
K
S (K-short). CP symmetry, which was assumed at the time, implies that 
K
S = K₁and 
K
L = K₂.

Oscillation

An initially pbeam of 
K0
 will turn into its antiparticle while propagating, which will turn back into the original particle, and so on. This is called particle oscillation. On observing the weak decay into leptons, it was found that a 
K0
 always decayed into an electron, whereas the antiparticle 
K0
 decayed into the positron. The earlier analysis yielded a relation between the rate of electron and positron production from sources of pure 
K0
 and its antiparticle 
K0
. Analysis of the time dependence of this semileptonic decay showed the phenomenon of oscillation, and allowed the extraction of the mass splitting between the 
K
S and 
K
L. Since this is due to weak interactions it is very small, 10⁻¹⁵ times the mass of each state.

Regeneration

A beam of neutral kaons decays in flight so that the short-lived 
K
S disappears, leaving a beam of pure long-lived 
K
L. If this beam is shot into matter, then the 
K0
 and its antiparticle 
K0
 interact differently with the nuclei. The 
K0
 undergoes quasi-elastic scattering with nucleons, whereas its antiparticle can create hyperons. Due to the different interactions of the two components, quantum coherence between the two particles is lost. The emerging beam then contains different linear superpositions of the 
K0
 and 
K0
. Such a superposition is a mixture of 
K
L and 
K
S; the 
K
S is regenerated by passing a neutral kaon beam through matter. Regeneration was observed by Oreste Piccioni and his collaborators at Lawrence Berkeley National Laboratory. Soon thereafter, Robert Adair and his coworkers reported excess 
K
S regeneration, thus opening a new chapter in this history.

CP violation

While trying to verify Adair's results, J. Christenson, James Cronin, Val Fitch and Rene Turlay of Princeton University found decays of 
K
L into two pions (CP = +1) in an experiment performed in 1964 at the Alternating Gradient Synchrotron at the Brookhaven laboratory. As explained in an earlier section, this required the assumed initial and final states to have different values of CP, and hence immediately suggested CP violation. Alternative explanations such as nonlinear quantum mechanics and a new unobserved particle were soon ruled out, leaving CP violation as the only possibility. Cronin and Fitch received the Nobel Prize in Physics for this discovery in 1980.

It turns out that although the 
K
L and 
K
S are weak eigenstates (because they have definite lifetimes for decay by way of the weak force), they are not quite CP eigenstates. Instead, for small ε (and up to normalization),

K
L = K₂ + εK₁

and similarly for 
K
S. Thus occasionally the 
K
Ldecays as a K₁ with CP = +1, and likewise the 
K
S can decay with CP = −1. This is known as indirect CP violation, CP violation due to mixing of 
K0
 and its antiparticle. There is also a direct CP violation effect, in which the CP violation occurs during the decay itself. Both are present, because both mixing and decay arise from the same interaction with the W boson and thus have CP violation predicted by the CKM matrix. Direct CP violation was discovered in the kaon decays in the early 2000s by the NA48 and KTeV experiments at CERN and Fermilab.