NEUTRINO: The Ghost Particle

Neutrino’s, the ultimate global travellers are the biggest introverts full of secrets glimpse of the unknown knowledge.

They are an inscrutable ghost which enigmatically interacts with weak nuclear force. Almost 65 million neutrinos pass through you every second. In 1930, while dealing with radioactive decay scientists found something tizzy. They observed neutrons get converted to protons by knocking out electrons but the energy of electron as compared to energy electron before beta decay wasn’t equal. This flaw of missing energy and angular momentum was amended by wolf gang Pauli by predicting a hypothetical particle whose mass is lesser than any known fundamental particles and does not carry any charge. Enrico Fermi in 1934 coined the term neutrino.

26 years later, In 1956 Clyde Cowan and Fredrick Reines carried out an experiment in South Carolina. Two enormous tanks with scintillator and photomultiplier tubes were implanted near a nuclear reactor which emits about 10 trillion neutrinos every second.

Antineutrino + Proton -> Positron + Neutrinos.

Two distinct gamma rays of 0.5Mev get generated in different directions when a position is hit the electron. Cadmium chloride was dissolved to absorb the neutrons which produced one extra gamma ray after 5×10^-6 seconds later. Frederic Reine, Clyde Cowan, F.B Harrison, H.W Kruse and A.D McGuire were remunerated with Nobel prize in 1995.

Another experiment was conducted in 1964 by Raymond Davis. An underground vat of depth 1478 meters and 380 cubic meter tank filled with tetrachloroethylene was built. Neutrino striking on chlorine atom converts it into an isotope of argon atom but the madding solar problem occurred, the captured solar neutrinos were less than calculated. Scientists came up with an idea of neutrinos oscillations i.e changing their identities, from electron neutrino to tau neutrino to muon neutrino and so on.

The substantiation of neutrinos changing flavours was supported by Super- Kamiokande experiment in 1998.

The underground base zinc mine 3300 feet deep filled with 50,000 tons of water and 13000 photomultiplier tubes formulated on Cherenkov radiation i.e presence of highly energised particle travelling faster than the speed of light in an electrical polarizable medium gives a blink of light which is captured by photomultiplier tubes to reconstruct the trajectory of solar neutrinos. Takaaki Kajata and B McDonald was honoured with the noble prize in 2015 for solving solar neutrino problem

THE GRAVEYARD ORBIT: Space debris

Space is littered with stages of launch vehicles when separated out, dead satellites, waste from astronaut’s suit, waste from International space station, equipment slipped by astronauts, growing occupants- CubeSats, the residue of rockets etc.

In 1983, space shuttle Challenger’s windshield was cracked by a piece of space wreck. Moreover, more than 500,000 space debris dispersed pieces orbiting the earth at 17,500 miles per hour. A tiny screw travelling at a speed of 17,500 miles per hour can evoke a catastrophic failure of any active satellite or rocket i.e if velocity is doubled then kinetic energy increases four times. The dangerously congested population of space thrash varies in sizes from 1 mm to 1 cm diameter objects are 106 million, 1cm to 10 cm diameter objects are 750,000, more than 10 cm diameter objects are 29000. The average distance between two wreckage is 190 km.

In 1978, Donal J. Kessler proposed ‘The Kessler syndrome’. The sprouting amount of space junk has an impact potential of rising higher risk of collisions in lower earth orbit. It is absurd to get telecommunication and metrological satellites orbiting geosynchronous path back on earth. Therefore, full stop on space explorations. No manned missions, no weather forecasting, no communication systems, no internet services, no global positioning system, no more research probe etc.

Accidental collisions occurred:-

  • July 24, 1996, French microsatellite CERISE hit ORIANE rocket.
  • February 10, 2009, Russia’s dead military communication satellite COSMOS 2251 collided with IRIDIUM 33.
  • January 11, 2007, the Chinese military launched an anti-satellite missile which completely demolished FENG YUN 1C, old weather satellite into more than 4000 remnants.
  • In 2014, International Space Station was relocated thrice due to the threat of contingent smashing with space debris.

Interagency Space Debris coordination committee, working on multiple projects

  • Remote control robot Justin for spacewalk and exoskeleton suit.
  • Space fence with optical sensors to keep an eye on 10 cm diameter objects.
  • Electromagnetic net capturing debris, dragging them back to earth’s atmosphere and gradually obliterates due to friction.
  • Ejecting laser beams to targeted debris.

STELLAR TIME BOMBS

Every spectacular shining star as a hub of nuclear reactors has a specific lifespan, forming helium from hydrogen and then to heavier elements carbon, silicon, oxygen, nitrogen and iron. Core temperature gradually increases transforming star into red giant. Rising amount of iron eventually stops the nuclear fusion resulting in the rapid collapse of the core under its own gravitational pull producing shock waves with a massive explosion called supernova, creating nebula which contains heavier elements, ions and stardust clouds. Within every 50 years, a supernova explosion occurs in milky way galaxy.

Cosmologist hunt for supernova by clues left behind through X-rays, gamma rays, radio waves for analysing its chemical composition, temperature, pressure, density and expansion rate. Chinese ancient text first catalogued supernova RCW86 in AD185 as a guest star for eight months and was visible during daytime. Cassiopeia 11,000 light years away, Crab Nebula 6,100 light years away are supernova explosions but farthest explosion observed was SN1987A 160,000 light years away whereas nearest red giant Betelgeuse 640 light years away has chances of being a supernova explosion anytime. There are two types of supernova. Type 1 supernova, have uniform size and releases no hydrogen. Type 2 supernova, releases a large amount of hydrogen and has gigantic size.

According to Chandrashekar limit, after the explosion star with mass 1.3 times mass of sun turns out to be white dwarfs. Star between 1.3-3 times mass of sun ends up as neutron star. Star more than 3 times mass of sun emanate into black holes.

Dense neutron star was first discovered by James Chadwick, ranging from 20-25 km in diameter. Immense gravity combines electron and protons together leaving neutrons behind.

1 teaspoon of neutron star= 100 million tons.

A neutron star is classified into pulsars and magnetars.

Pulsars, rotating neutron stars ejecting beams of electromagnetic radiation from its poles whereas magnetars are rotating neutron stars with extremely influential magnetic field 100 million to 1 quadrillion times stronger than earth. Fritz Zwicky and Walter Baadle were the first to prose this idea. PSRJ1748-2446ad, swiftly spinning pulsar 716 times per second.

REVOLUTIONARY IDEA: gravitational waves

The groundbreaking discovery of gravitational waves can open the whole new domain of cosmology

In 1915 Abert Einstein published a paper on the general theory of relativity, describes gravity as curves in the fabric of space-time by massive bodies rather than a force. The mathematical equations of the general theory of relativity predicted the existence of gravitational waves i.e formation of ripples due to distortion in the space-time fabric by the most violent astronomical phenomena such as the collision of two neutron stars, merging of two black holes, the explosion of a supernova etc.

In 1974, two astronomers from Arecibo Radio Observatory in Puerto Rico observed binary pulsars orbiting each other and getting closer. Scientists were unable to examine it practically until 2015. In morning 3:50 am on September 14, 2015 LASER INTERFEROMETER GRAVITATIONAL WAVE OBSERVATORY LIGO identified waves whose characteristics were similar to gravitation waves i.e produced by accelerating the mass, travel with the speed of light, having weak interaction and cannot be absorbed. It was produced by the collision of two black holes 1.3 million light-years away.

After 100 years of Einstein’s prediction, the significance of gravitational waves was again alive unlocking deep secrets. Annihilation after big bang would have created ripples of gravitational waves carrying information.

LIGO LASER INTERFEROMETER GRAVITATIONAL WAVE OBSERVATORY:- central building shoots a laser beam and split it perpendicularly by beam splitter in L shaped tubes 4 km long and has mirrors on both the ends. The beam of light then strikes both the mirrors resulting in destructive interference due to the cancellation of their peak alignment but distortion in space-time leads to stretching and squeezing of arms until gravitational waves fully pass the earth. This sensitive equipment can detect a gravitational wave of 1/1000 width of a proton.

In 2017, three physics Rainer Weiss, Barry C.Barish and Kip throne were honoured with Nobel prize for their contribution in LIGO project. LIGO is located in Hanford and Livingston at the distance of 3,002 km to avoid abstraction of local noise.

EXTRAORDINARY PREDICTION: Antimatter

“Some extraordinary predictions radically alter our perspective of analysing things in a better way.”

Paul Dirac predicted the existence of antimatter with his theory of relativistic quantum mechanics combining equation of motion of electrons and wave function in 1928. Just like x^2= 9 having two solutions 3,-3. Surprisingly, normal matter’s birth twin antimatter look, feel similar to it, having same properties and behaviour towards gravity but with opposite charge.

During big bang equal amount of matter and antimatter would have been formed but their collision leads to annihilation. However, matter somehow managed to survive. In 1932, Carl Anderson confirmed the existence of antimatter with his experiment of passing cosmic particles through a cloud chamber filled with water vapours surrounded by an electromagnet resulting in ionising particles moving in circular trajectories and took a photograph.

The photograph showed a particle with the same mass as an electron moving in the wrong direction and termed it position. Anderson’s evidence of positron indicated antimatter to be taken seriously in the matter dominated universe. Many antimatter particles such as Antiquark, Antineutrino, Antileptons, Antihydrogen atoms have already been discovered.

In 2011, CERN launched Alpha Magnetic Spectrometer aiming to detect antimatter in cosmic rays. It spotted a boom of antimatter near the centre of our galaxy. In 2016, it created 309 antihydrogen atoms which were held for 17 minutes. Moreover, CERN has successfully made 10 nanograms of antimatter which could glow a light bulb for 4 hours.

90 trillion joule energy is required to create 1 gram of antimatter costing around 62.5 billion dollar. 1 gram of antimatter has potential to blast equal to 100 nuclear booms exploded together. It is used in Positron Emission Tomography or PET scan and can also be incredibly used as 100% efficient fuel in interstellar space missions.

FROM EARTH TO OBSERVABLE UNIVERSE

Is universe infinite?

Or

Does it have an end?

Then

What lies beyond it?

Exploring universe……..

From our home planet earth to moon at a distance to 3,84,400 km. Next, to mars distance 22.5 crore km then crossing our solar system having a diameter of 9.09 billion km. Moving ahead to NASA’s satellite Voyager 1 beyond our solar system at 18.8 billion km. Next, stepping out of our milky way galaxy which is 1,00,000 light years wider moving with the speed of 828,000 km/hr. Lightyear refers to the distance travelled by light in one year.

1 light year= 9460730472580.8 km speed of light= 299,792,458 m/s

Distance sucks!

I know ………..

Our galactic neighbour, Triangulum, Andromeda and various dwarf galaxies NGC 6822, LEO 1, LMC etc forms a local group of galaxy inside a diameter of 10 million light years. These local group of galaxies collectively known as Virgo supercluster spread across the region of 100 million light years includes laniakea supercluster where our home galaxy is located, MOF301 supercluster etc.

Precisely, the age of universe is 13.82 billion light years but actual observed universe is 93 billion light-years wider. Space is stretching itself faster than the speed of light.

Alan Guth proposed an idea of inflation i.e energy in vacuum forms virtual particles, suddenly jump to higher energy level resulting in space-time expansion. By the time photons from distant galaxy would reach us, space-time would have been expanded. Therefore, no laws of physics are violated, no speed limit is disturbed and no paradoxes are created. All matter and space inside the region of 93 billion light years diameter is known as observable universe

Our complete address

Laniakea supercluster Milkyway galaxy Orion arm Earth

THE BEGINNING: The big bang theory

The Big bang theory itself is the outcome of thousands of brilliant minds put all together in astronomy and cosmology cautiously for

exploring the origin of our universe.

Let’s move back in time.

13.82 billion years ago, what was there?

A point of singularity, extraordinary small and hot where no laws of physics were applied, the time has no existence, all four fundamental forces exist forming a unified force called super force suddenly exploded because of no reason.

”something came from nothing”

In less than one second, gravity split off from the super force. Three minutes later, the temperature dropped to 10 billion degrees of Fahrenheit, an appropriate temperature for the formation of atoms to take place. Lighter element, hydrogen came into existence.

After 380,000 years, light travelled through the darkness. 4 billion years later, stars started shaping due to the presence of heavier elements such as nitrogen, oxygen, carbon etc. At the age of 13.7 billion years, the sky filled with stars and galaxies.

Herman Bondi, Thomas Gold, Fred Hoyle including Einstein proposed a steady-state model of universe i.e universe is static, having no beginning and no end. This process of creation and destruction is infinite. this idea challenged big bang theory but was prohibited when Edwin Hubble in 1920’s concluded that most of the galaxies are redshifted i.e moving away from us.

In 1965, Arno Penzias and Robert Wilson build a radio receiver which accidentally recorded echo or aftershock noise of big bang docking from everywhere and every corner of the universe. This was experimentally proved by NASA’S Wilkison microwave Anisotropy probe on 3 June 2001.

In February 2003, Cosmic microwave background provided a baby picture of our universe

Some of the major anomalies with the big bang theory were the unanswerable questions

Is there something out of our universe?

What happened at the point of singularity?

What’s the exact shape of our universe?

How is space stretching itself faster than the speed of light?

What was the reason behind big bang explosion?

Many alternate theories exist claming answer to these questions but none of them is experimentally verified. In 1980’s Alan Guth came up with the hypothesis of cosmic inflation i.e expanding universe which is now accepted as part of big bang theory.

Story of our observable universe