Showing posts with label Science. Show all posts
Showing posts with label Science. Show all posts

Wednesday 5 April 2017

From the Butterfly's Wing to the Tornado: Predicting Turbulence

Flap of Butterfly's Wing could Generate a Tornado

An old saying states that in Brazil, the flap of a butterfly’s wing could generate a tornado in Texas, weeks thereafter. However, chaos theory state that is essentially impossible in computing precisely how it could take place and Georgia Tech scientists are making headway in getting math around the swirly occurrence behind it and called it turbulence.

Latest development from the Georgia Institute of Technology by physicists could probably help improve weather forecasts extending their range by making improved use of masses of weather as well as climate data. Turbulence could bend like a puff of air, swirl past a river bend or even churn as a hurricane. Although its curlicues may seem accidental, turbulence leaves down signature patterns which the physicists have been investigating.

 It is said that they have established a simple mathematical model which has assisted them in showing how turbulent flows tend to evolve over internals. Moreover, in a novel experiment, they have verified their predictions substantially in a two dimensional turbulent flow produced in a lab. The new Georgia Tech research suits the origins of that proverb.MIT, meteorology professor Edward Lorenzhad invented more than 55 years back, while he had recognized that the tiny forces had influenced major weather adequate in throwing long-range forecasts for a loop.

Theory of Relativity

The name of his paper, `Predictability: Dose the Flap of a Butterfly’s Wing in Brazil Set Off a Tornado in Texas?’ got transformed into the well-known slogan. The professors in Georgia Tech’s School of Physics, Michael Schatz and Roman Grigoriev together with graduate researchers, Balachandra Sur and Jeffrey Tithof, had published their research result online in the journal Physical Review Letters on March 15, 2017 and the research was supported by the National Science Foundation.

While the scientists, for hundreds of years, had utilised math in order to get a hold on the falling apple of Newton, in verifying the Theory of Relativity and speculate the existence of the Higgs boson, turbulence was like wet soap in the understanding of math. However for all its elusiveness, turbulence tends to influence with visibly coherent, recognizable, recognizing shapes. Fluid swirl tend to rapidly form themselves and thereafter seem to shift or disappear though they tend to reappear obstinately at various areas, generating transient as well as varying and still repeat the patterns.

Exact coherent structures – ECS’s

According to Grigoriev, people have envisaged these patterns in turbulence flows for centuries though they are finding methods of relating the patterns to mathematical equations describing the flows of fluid. Some of the recurrent patterns had drawn the attention of Grigoriev and Schatz which are known as exact coherent structures – ECS’s.

The physicists were given convenient entry points in computing predictions regarding what turbulence would do afterward. Regarding exact coherent structures, visually in turbulence, they tend to show up as brief moments when patterns seem to stop changing and it could be like the flow is for the time being is slowing down.

An ECS to an unqualified eye does not seem much different from the rest of the swirls and curls though one could be trained to spot them. As per Schatz that is precisely how they go about locating them and they watch the turbulence, continually taking snapshots. The flow moves around, moving around and they look out for the moment when it tends to slow down the most and it is then that they pick out a snapshot.

Flow of turbulence reliable patterns reflect dynamics

He further informed that they feed that in the mathematical model which indicates that they are close showing what the math looks like at that point. The math solution defines a point in the turbulent flow which could be worked with to figure out a prediction of what the turbulence would be afterwards.

In order to comprehend what an exact coherent structure is dynamically we should step back from what turbulence seems like visually with bunches of curls and swirls and rather look at a turbulent flow as an individual physical entity by decoding it into a crude metaphor – a swinging pendulum with a few marked peculiarities.

Rather than picturing the bottom point of a normal swing of the pendulum, the equilibrium as a steady point in a firm swing now the equilibrium is at the top most point, with the upside-down pendulum and it is unstable. Moreover, it does not swing in just two directions but in all directions. The flow of the turbulence reliable patterns tends to reflect dynamics which are back-and-forth-to-and-fro though in all types of variations.

 As the symbolic pendulum seems to swing up towards its peak, it tends to come near but never a complete stop. Rather it seems to flop over some other side. This near-halt point is equivalent to an exact coherent structure though there are some more bends in the metaphor.

Harnessed to Define Dynamics

Grigoriev had informed that if initial dynamics were ever changed slightly, an inverted pendulum can swing past its unstable equilibrium at the peak or it could halt and then start moving in the opposite direction. Similarly, the turbulent flow can evolve in various different manners after passing by an ECS.Numerous exact coherent structures with various qualities tend to turn up in a turbulent flow. Schatz had mentioned that usually people prefer to lookat steady things which seem to be unchanging like the evensymmetric normal pendulum and turns out to be unstable patterns which form a rough core alphabet which is used in building a kind of predictive theory.Withthedynamics of loose inverted pendulum now image eachexact coherent structure as a town on a map. With paths it seems to guide the turbulent flow `traffic’ toward, from, as well as each town like roadways. Grigoriev had mentioned thatthe road around as well as between towns do not change with passage of time which allowsforecastthe evolution ofthe flow. ECSs seems to occur frequently just like clockwork withthe likelihood of opening of refining predictions at regular intervals. Exact coherent structures arealready known to be existent.Schatz has commented that no one has done demonstration before in a lab experiment on how they can be harnessed to define dynamics, the behaviour evolving in time is the same,is certainly what is needed for prediction.

Friday 24 July 2015

Earth Heading For ‘Mini Ice Age’ Within 15 Years

Prediction – Earth to Face a New `Mini Ice Age’

Scientist predict that the Earth would face a new `mini ice age’ in the next 15 years which would cause severe cold winters during which rivers like the Thames may tend to freeze. As Antarctic Vortex grips Australia, solar researchers from the University of Northumbria in UK state that solar activity is set to drop by 60 percent by 2030.

Professor Valentina Zharkova, research head, informed that the fluid movements in the Sun, which is believed to create 11 year cycles in the weather would cancel each other out causing a dramatic temperature drop which would lead to a weather phenomenon known as a `mini ice age which had earlier hit between 1645 and 1715. The discoveries are established on new model that the scientist believes produces `unprecedentedly accurate prediction of irregularities’, within the Sun’s 11-year heartbeat.

According to Professor Zharkova, he states that between the cycle 2030 and around 2040, two waves will mirror each other exactly, peaking at the same time though in opposite hemispheres of the sun. Their interaction would be disruptive or they will nearly cancel each other and predicts that this would lead to the properties of a `Maunder Minimum’.

Maunder Minimum – Europe/North America Experienced Cold Winters (1645-1715)

Maunder Minimum was the name that was given when Europe and North America had experienced very cold winters, during the period between 1645 and 1715 and during that time the Thames River in England was said to be frozen over. Research findings were presented at the National Astronomy Meeting in Llandudno, Wales and also published in the papers of the Royal Astronomical Society.

This surprising news has been given as the Antarctic Vortex whirled into eastern Australia bringing about a freak phenomenon known as thunder-snow. The tropical style thunderstorms, accompanied by heavy snowfalls thundered through the Blue Mountains, west of Sydney and town as far as Orange recently. Several areas of the country are expecting destructive winds, which could reach blizzard intensity of 90km/h while the snow tends to continue to fall and the big freeze begins to bite.

Snow that falls as the big freeze tend to start to affect the nation’s south east where sub-zero temperature are predicted in some places for much of the coming week. According to the Bureau Meteorology, in the coming days, it is said that strong cold front with low to the south would be moving through the state, bringing in cold vigorous, westerly winds.

Sun’s Activity Differs – Cycle of 10 to 12 Years

Scientists had first discovered that the sun’s activity differs over a cycle of 10 to 12 years in 1843. Variations within that cycle became difficult to predict though several solar physicists were aware that the fluctuation were due to a dynamo of moving fluid deep within the sun. Professor Zharkova’s team found that adding a second dynamo near the surface of the sun created a far more accurate model.

They found magnetic waves in two various layers of the sun’s interior that varied between the northern and the southern hemispheres of the sun.According to Professor Zharkova, on combining both waves together and comparing the real data for the current solar cycle, they observed that the predictions showed an accuracy of 97 percent. The magnetic wave patterns indicated that there would be few sunspots in the next two solar cycles. Cycle 25 that peaks in 2022 and Cycle 26, between 2030 and 2040 will be having both a significant reduction in solar activity.

Thursday 9 July 2015

Neutrinos Found To Switch To Elusive ‘Tau’ Flavour

First Direct Proof of Metamorphosis

Physicist have found the first direct proof of a metamorphosis between two of the known forms of neutrinos by utilising a beam shot through the Earth’s crust, which are known as `muon’ and `tau’ of basic particles.Oscillation Project with Emulsion tracking Apparatus – OPERA conducted an experiment, at the Gran Sasso underground lab in central Italy made headlines in the year 2011 after its announcement that it had identified neutrinos travelling faster than light, against Einstein’s special theory of relativity.

 However, the claim was later proved false when the researcher found various probable sources of error in the measurements. The OPERA association declared on June 15 that it had now achieved the original goal of observing the switch in neutrino flavours. According to a neutrino physicist at the University of Genoa, Marco Pallavicini, who is not a member of the OPERA collaboration, states that `it was an extremely difficult measurement that no one had done before.Three known forms of flavours, neutrino, electron, muon and tau and the particles name refer to the fact that on unusual occasion when neutrino tend to interact with protons or neutrons, they create electrons, muons or tau leptons.

T2K – First Direct Evidence of Appearance of Different Flavour

Scientists have been suspecting that neutrinos could transform from one flavour to another and various previous experiments conducted which had used known sources of certain type of neutrino have detected fewer neutrinos than what could be expected if particles had not changed flavour. The T2K experiment carried out in July 2013 envisaged the first direct evidence of the appearance of a different flavour rather than the disappearance of the original one and discovered electron neutrinos in a beam which was originally made of muon neutrinos. In the span of 2008 and 2012, a beam of muon neutrinos was shot from Europe’s particle physics lab – CERN, near Geneva, Switzerland, to the base of the Gran Sasso massif some 730 km towards the southeast where the Italian lab is carved in the rock. Some of the muon neutrinos had changed into tan neutrinos by the time the neutrinos had arrived at Gran Sasso and when these hit the lead targets in the OPERA detector, they created tau lepton according to the latest result.

Discovered 5th Tau Lepton – Experiment 

Giovanni De Lellis, a physicist at the University of Naples, also an OPERA spokesperson informed that the leptons tend to decay in just one-trillionth of a second. Although it tends to travel at almost the same speed of light, the tau lepton only runs for less than a millimetre. The short lived particles with an array of 150,000 bricks, each of which weighs around 8 kg containing 57 stacked emulsion plates, was detected by OPERA.

With the set-up having 110,000 square metres of surface area, researchers have set up an automated system in order to search the plates for microscopic streaks which could signal the fleeting presence of tau leptons. In the incomplete result which was announced last year, OPERA collaboration calculated four probable tau lepton findings not adequate in claiming a success as per the severe detection criteria of particle physics. However, the physicists have now discovered a fifth tau lepton adequate for the experiment to be considered as successful.