Non-equilibrium is the new challenge !

Athokpam Langlen Chanu *

A cold rain was drizzling, and I was enjoying a hot 'chai' at the SSS-I canteen. The mulberry tree just outside the window made me wonder, "How beautiful it is that we can learn Nature through Mathematics !" "Hey, Langlen! How's your day going on?" came a familiar voice that drew me back to reality.

"Hi, Laija! It's fine, thank you."
"Laija told me your Complex Dynamics Lab team is working on some interesting problems ," said Mitsna.

"Langlen! Tell us about your research," Laija said, "Let's see if we humanities researchers can understand a bit of it."
"You guys can surely understand. The crux is the science, not the technical details."
"Very true! C'mon! Your research!"

"Ever heard about 'Non-equilibrium systems' or 'Fluctuations'?" I asked. Both Laija and Mitsna shook their heads. I was silent for a moment. "Do you guys ever wonder what makes us alive?"
"Because... because we are breathing?" said Mitsna.
"Since we eat food?" added Laija.

"Yes, these activities produce the very act of living," I continued. "When we breathe, the cells inside our body absorb oxygen from the blood and release carbon dioxide into the same. When the foods we eat or drink are digested, our cells absorb the nutrients. When there is such a kind of exchange of energy or matter with the surrounding, the system is in non-equilibrium.

In the book What is Life ? : The Physical Aspect of the Living Cell (1944), the physicist Erwin Schrödinger said living systems stay alive by avoiding equilibrium.

Most systems, at the microscopic to macroscopic scales, are actually non-equilibrium, for example, enzymatic cycles in living cells, swarming schools of fish, flocking birds, swirling storms, etc. At equilibrium, system-properties don't change with time. Equilibrium is kind of boring, but non-equilibrium corresponding to 'activeness' is interesting!"

"So… we are basically alive because the cells inside us are continuously functioning in non-equilibrium conditions. Langlen, you also mentioned 'Fluctuations'. What are they?"

"Fluctuations are what we commonly know as noise. However, physicists prefer the term 'fluctuations'. Laija, do you think noise is bad?"
"I guess so. We normally don't want noise."

"Noise is unwanted. However, many researchers have found that noise or fluctuation is an interesting entity. Sometimes, noise is good. Cells inside us communicate by signalling process. In such small systems, stochastic or random noise can amplify weak signals and help in signalling, a phenomenon called stochastic resonance. The physics of fluctuations in equilibrium systems is well-established. However, the search for a general theory of non-equilibrium fluctuations is still going on."

"Wow! Noise is interesting!" Mitsna was stunned. "What's your research in this connection ?"

"Our recent work concerns a theoretical and computational study to find the role of stochastic fluctuations in a non-equilibrium model system. We have found that these fluctuations drive the system to non-equilibrium behaviour."

"What's your non-equilibrium model?" asked Laija.

"Think of a toy box consisting of three molecular species A, B and X. The molecules inside are now well-stirred, resulting in three possible chemical reactions due to random collisions among them. This means the system shows stochastic reaction dynamics. Considering the populations or numbers of A and B are quite large as compared to that of X, we now call it an open system. Assume the reactions occur at different rates. It is thus a non- equilibrium system where X constantly reacts with both A and B."

"Is this a realistic model? " asked Laija.
"Yes. This toy box can represent a cell. A, B and X can be the molecules inside, undergoing the three reaction channels, thereby exhibiting non-equilibrium behaviour. "
"How'd your team study stochastic fluctuations in this model ?" asked Mitsna.

"We studied stochastic fluctuations using two different approaches. Firstly, we adopted an approach called stochastic formalism from Physics and Mathematics and secondly, we used computers. In brief, the reactions are converted to a Mathematical equation popularly known as Master Equation (ME)," I said, "Mitsna, what do you think we do with an equation?"

"I think you try to solve it."

"YES! The solution of ME tells us the distributions of the variables A, B, X at any instant of time. This time-evolution of any system is called system-dynamics. Now, to measure fluctuations in the system, we used a quantifier called Fano factor (F). Depending on the value of F, one can study the behaviour of system-dynamics. So, we calculated the F value for our model and found F. This theoretically predicts a noise-enhancement process for our system where increased fluctuations are present. This indicates stochastic fluctuations drive the system to non-equilibrium."

"In science, predictions are not valid until they are proven experimentally," Laija said, "Is that right ?"

"To validate our Mathematical calculations, we performed what is known as numerical experiment or computer simulation," I replied.
"What's a numerical experiment or computer simulation?"

"There exist various natural processes difficult to experiment in real physical conditions, for instance, cascades of chemical reactions happening inside the microscopic cells (called metabolic pathways) or in the outer space (like interstellar or intergalactic). Nonetheless, we need to study their system-dynamics.

"This is when we create mini-labs on our computers, known as computer simulations or numerical experiments. We write algorithms or numerical codes to solve the equations governing these processes in cells to galaxies and give them to computers as inputs. Computers then execute the codes and show us how the system behaves."

"How'd you perform this simulation?"
"The ME is hard to manually solve for systems with multiple variables, but computers can easily solve it," I said, "Physicist Daniel Thomas Gillespie gave the Stochastic Simulation Algorithm (SSA) to numerically solve the ME."

"What's special about SSA?" asked Mitsna.
"In the well-stirred chemical system, two independent stochastic or random processes occur, namely, which reaction and at what time. These ideas are encoded in the SSA. SSA shows the time-evolution of the populations in the system. The SSA simulation of our model showed that X fluctuates about a steady-state value (~7777.78), driving the dynamics to non-equilibrium."

"Computer simulations are cool!"
"Indeed advanced and powerful techniques!" I continued, "Do you guys believe every natural process has some kind of inbuilt memory?"

"Memory as in how we remember things?" asked Laija.

"Memory is nothing but history. Processes with memory are called non-Markov processes, and those memoryless processes are Markov processes. Physicist van Kampen says "Non-Markov is the rule, Markov is an exception."

Practically, the three chemical reactions may not finish instantly once started; say A+X takes 14 seconds, B+X takes 4 seconds, and B+B takes 8 seconds. The reactions thus have inherent delays in time. SSA doesn't consider this time-delay. So, we performed simulations using Delay SSA (DSSA) given by Bratsun et al. Our mathematical analysis of fluctuations predicted that fluctuations vary with time-delay (T).

The DSSA simulation of our model verified this prediction (Fig3). As before, our calculation from DSSA simulation result data shows time-delay produces noise enhancement driving the system to non-equilibrium.

"What's the significance of this work? Does it have any real-life applications?" asked Laija. "Living cells work at non-equilibrium steady-state. Our theoretical and computational study can provide valuable insights into understanding how such systems work.

It also highlights time-delay affects system-dynamics and produces non- equilibrium. Studying non-equilibrium fluctuations is all about understanding life; how life emerges and continues. If we understand the role of these fluctuations, we can manipulate them in useful ways, for example, in the detection of the growth of cancerous cells.

"Research in non- equilibrium science, both theoretically and experimentally, is still in its infancy. Besides non-equilibrium biological systems, we also need to look at other non-equilibrium systems to solve varied issues such as energy crisis, financial crisis or climate control. Understanding non-equilibrium is the biggest challenge for the future."

"Your research on non-equilibrium fluctuations," Laija smiled, "has lots of prospects across many disciplines."
"Very interesting indeed!" Mitsna said in excitement, "Let's catch up again soon for more discussion."
"Sure! See you guys soon. Bye!"
And with that, I smiled back at the mulberry tree.

* Athokpam Langlen Chanu wrote this article for The Sangai Express
This article was webcasted on August 07 2021.

* Comments posted by users in this discussion thread and other parts of this site are opinions of the individuals posting them (whose user ID is displayed alongside) and not the views of We strongly recommend that users exercise responsibility, sensitivity and caution over language while writing your opinions which will be seen and read by other users. Please read a complete Guideline on using comments on this website.

  • Descent of Radha-Krishna #35: Download
  • Violence in Manipur 2023-2024 : Timeline
  • Gastronomy tourism in Manipur : Gallery
  • Triathlon : Manipur bag 6 medals (3 gold)
  • Illegal immigrants/fugitives from Myanmar
  • Eid-ul-Adha: Embracing sacrifice
  • A solution to Meitei-Kuki-Zo conflict
  • The Power of Poppy - 35 :: Poem
  • Scientist of Manipur: R K Brojen Singh
  • Brief sketch on General Balaram Sougaijamba
  • Non-violent for peaceful, mutual co-existence
  • Homeless person ..alcoholism & defeated TB
  • Cancer on rise among young adults
  • Defending, fighting for Idea of Manipur
  • From partiality to complicity
  • Bike Rally - Sekmai to Kangla : Gallery
  • 'Modi must announce finality of Naga pacts'
  • Gliding over Brahmaputra
  • Question leaks cause stress among student
  • Home remedies for prickly heat
  • After IIT, AIIMS it is now IIM
  • Stealing spotlight from Manipur crisis
  • Tarpon chaklen katpa @ Andro #2 : Gallery
  • Strongly condemns violence in Jiribam
  • Lessons from outcome of LS election
  • Tumcho releases "Goodness of God"
  • Right diagnostic for antimicrobial resistance
  • 12th June is World Day against Child Labour
  • Hands of geo-politics ?
  • The row over NEET-2014
  • 2nd Annual Art Exhibition #1 : Gallery
  • Chilli Chicken: Film Spotlighting NE in B'lore
  • Committee of Narcotics Anonymous - Imphal
  • The Power of Meditation
  • Oceans as a career choice
  • Getting more and more audacious
  • A test of leadership
  • Education Fair @Imphal #2 : Gallery
  • Gifting two seats to Cong
  • Voters empowered democracy
  • Postcards from Meghalaya premieres
  • Milk : Essential nutrient for a healthy body
  • Failing in competitive exam not end of world
  • Delhi : A mere spectator
  • Abandoning Jiribam
  • Birth Centenary of Jananeta Irabat, 1996 : #5
  • Ima Keithel flood- May 30 #2 : Gallery
  • Mainstream in Shoes of Alternative
  • Protect the medicines that protect us
  • Lets take action for our land & our future
  • Democracy and independent media
  • Agenda at work to shut Western Gate
  • Keeping Manipur on the boil
  • Descent of Radha-Krishna #34: Download
  • The Enigmatic Journey of 'Laikhutshangbi'
  • Individual and the Social
  • An Ardent Appeal to All Concerns
  • Condemnation of Attack & Govt Inaction
  • The Power of Poppy - 34 :: Poem
  • Scientist of Manipur: Laishram Shanta
  • Alien fishes spotted in Manipur's rivers
  • Training on mushroom at Langthabal
  • Digital avatars or deepfakes ?
  • 7th June is the World Food Safety Day
  • How to prepare for UPSC after 10th ?
  • The Jiri violence
  • Beginning of a new vote culture ?
  • Bimol Akoijam (Cong) wins Inner PC : Gallery
  • BJP, NPF & other NDA pay heavy price
  • Nature is one of greatest blessings of God
  • Plantation drive in Tripura, Assam & Manipur
  • Summer beauty
  • Environment conservation & over-exploitation
  • Is Modi cut out for leading a coalition ?
  • 'Ishanou' Selection @ Cannes #2: Gallery
  • Scholarship for Johnstone Hr Sec students
  • 1st foundation day of Interfaith Forum
  • World Environment Day: Our land, our future
  • Indonesia stronger anti-tobacco measures
  • Navigating a fragile Myanmar: India's policy
  • New breed entering electoral politics
  • The road to formation of new govt
  • International Dance Day #1 : Gallery
  • Matchbox marketing mantra
  • Stop harming nature :: Poem
  • Saving for oneself & the Nation
  • Model United Nations (MUN) conducted
  • Tobacco: Threat to health & environment
  • Candidate from ruling party biting the dust
  • The verdict
  • Birth Centenary of Jananeta Irabat, 1996 : #4
  • Imphal valley districts flooded #3 : Gallery
  • Navigating Remal amidst Manipur conflict
  • We are #GenerationRestoration
  • Intl Day of Innocent Children Victims
  • Apparel Industry Skills & Innovation CoE
  • What's in a cyclone's name ?
  • Ongoing clash, the floods, the losses
  • Exit poll predictions
  • Descent of Radha-Krishna #33: Download
  • Evading flood & rethinking urbanization
  • Manipur Flood: Health Advisory
  • Onus on civil bodies to ensure NNPG unity
  • Rats also cause flood
  • Benefits of JEE Main mock tests
  • People have spoken, now the results
  • The fury of Remal
  • Ima Keithel flood- May 30 #1 : Gallery
  • The flood in our Stars
  • The Power of Poppy - 33 :: Poem
  • 'Group of people misrepresented themselves'
  • EV industry and career options
  • Scientist of Manipur: Chandrakant Aribam
  • Candy flavoured traps to hook next Gen
  • Commemorate Naga Plesbicite Day 1951 #2
  • Tobacco affects health & environment too
  • Jio extend validity for Customer in Manipur
  • Students must learn about AI irrespective
  • As vote count day approaches : Floods
  • Imphal valley districts flooded #2 : Gallery
  • Flooded : Sacrifice of Yairipok's Maiden
  • World No Tobacco Day 2024
  • Chandam Rishikanta wins NPC Nat'l C'ship
  • Flood: Helpline numbers for emergency
  • Battling body odour ?
  • Floods : Not entirely natural phenomena
  • PM Modi's purpose
  • Imphal valley districts flooded #1 : Gallery
  • June Calendar for Year 2024 : Tools
  • Flood: Control Rooms & Helpline numbers
  • Economic impact of ongoing conflict
  • Army Recruitment Rally for Manipur
  • Cut deficit, boom likely
  • Are Gods angry ? Wake up call for Manipur
  • Beating of the Retreat #2 : Gallery
  • We did Overcome: Mayhem of Month of May
  • Training on mushroom at Potshagbam
  • Famous female Mathematicians in India
  • Disinformation campaign thengnare
  • Human trafficking puts humanity to shame
  • Sky opens up in all its fury
  • Licypriya meets Italy PM & Pope Francis
  • HSLC (Class X) 2024 : Full Result
  • HSLC 2024 : Important Info & Grading System
  • HSLC 2024 : Pass % : Private Schools
  • HSLC 2024 : Pass % : Aided Schools
  • HSLC 2024 : Pass % : Govt Schools
  • HSLC 2024 : Statistical Abstract
  • HSLC 2024 : Comparative Statement
  • Combined Defence Services Exam 2024
  • Good show in Class X exams
  • Downplaying the crisis
  • Birth Centenary of Jananeta Irabat, 1996 : #3
  • Reviving Lamphelpat : Conservation : Gallery
  • Commemorate Naga Plesbicite Day 1951 #1
  • "ST status for Meetei" at Hojai
  • The Power of Poppy - 32 :: Poem
  • Insights from CUET-UG Counselling
  • International Day for Biological Diversity
  • Unseen force at work: Time to unravel it
  • Sheikh Hasina's revelation
  • The Vanishing Meitei Tribe
  • Building career in defence & strategic study
  • Why example of model code of conduct ?
  • Ownership of responsibility
  • Will pressure mount on key players in NE
  • How to save your foot after an accident
  • Children Camp @JNMDA Imphal #3 : Gallery
  • Education Fair @Imphal #1 : Gallery
  • Project Associate @ CSE, Assam Univ
  • Understanding schizophrenia
  • Advancement in Multi Objective Optimization
  • When will women in voter list increase ?
  • Making 2 plus 2 is equal to 5
  • Changing face of drug menace
  • Scientist of Manipur: Jayanta Manoharmayum
  • 25 yrs since Atal Vajpayee visit to RIMS
  • 4 Lakhs donated to support (L) Maipak Family
  • Clarification: Guwahati Meet on Humanitarian
  • Start UPSC prep after 12th for success
  • Tips to avoid melting makeup in summer
  • Giving a big solid push to ST demand
  • Time to come clean
  • Sajibu Cheiraoba: 1 occasion, 2 narratives #3
  • Khongjom Day @Khebaching #2 : Gallery
  • A year of hostilities
  • Licypriya Kangujam to travel to Italy
  • Declining moral standards in public life
  • Healthy democracy with independent media
  • Why endangered species matter to us
  • Significant Guwahati meeting : 1st visible step
  • The Pallel story
  • Aftermath of ferocious hailstorm #2 : Gallery
  • Ukhrul: Climate change grip on water supply
  • Commemoration of World Eld's Deer Day
  • Indo-Naga Talks (From 2012) :: Timeline
  • "ST status for Meetei" at Hiyanglam
  • Dance of democracy, a miracle in making !
  • Learn to look 10/20/30 years hence
  • The zero FIR, zero lesson
  • 'Ishanou' Selection @ Cannes #1: Gallery
  • MOU signed: MTI-HUB & KIIT-TBI & SAbF
  • Lament of the Mourning Choir :: Poem
  • "ST status for Meetei" at Wabagai
  • RSS-BJP fracas
  • Trials for Canoe Slalom World Cup
  • Poser from a villager says it all Kamjong
  • The cover-up effort
  • Birth Centenary of Jananeta Irabat, 1996 : #2
  • Manipuri women in the arena of politics
  • "ST status for Meetei" at Assam
  • Aimee Baruah at red carpet of Cannes
  • National Defence Academy Exam 2024
  • How digital media changed communications
  • Manipur stands scandalised
  • All eyes on UP battle
  • Descent of Radha-Krishna #32: Download
  • Riots to a shrine- Ram Mandir of Ayodhya
  • Handle with care. F.R.I.E.N.D.S inside!
  • The Power of Poppy - 31 :: Poem
  • Celebrate the journey !
  • Career counselling : A life guidance tool
  • Scientist of Manipur: Amom Ruhikanta
  • Preserving Thang-Ta :: Rare Photos
  • Regarding Human Rights Situation in Manipur
  • Malemnganbi Laishram : Science Topper
  • Featured Front Page Photo 2024 #2: Gallery
  • Thokchom Sheityajit : Arts Topper
  • Aiena Naorem : Commerce Topper
  • AISSE 2024 Exam Result- RKM Imphal
  • Gold, new world currency !
  • Milk for hair and skin
  • Of illegal immigrants & the larger picture
  • The missive from Kamjong
  • Hr Secondary Exam 2024 : Science Topper
  • HSE 2024 : Subject Pass Percentage
  • HSE 2024 : District Pass Percentage
  • HSE 2024 : Candidates with Highest Marks
  • Hr Secondary Exam 2024: Science Full Result
  • Hr Secondary Exam 2024: Arts Full Result
  • Hr Secondary Exam 2024: Commerce Result
  • Hr Secondary Exam 2024 : Arts Topper
  • Hr Secondary Exam 2024 : Commerce Topper
  • World Bamboo Congress @Taiwan : Gallery
  • Aftermath of ferocious hailstorm #1 : Gallery
  • Radio E-pao: Manipuri Film OST (130+ song)
  • Cheirao-chingkaba @ Chinga : Gallery
  • Nupi Landa Thaunaphabishing : Full Book
  • A ferocious hailstorm @Imphal : Gallery
  • '365 Days of Chin-Kuki Aggression' : Gallery
  • Athoubasingi Numit #2 : Gallery
  • National Science Teacher workshop
  • Sajibu Cheiraoba Chak Katpa #2 : Gallery
  • Scientists of Manipur : Ngangkham Nimai
  • Kenedy Khuman (Singer) : Gallery
  • GHOST of PEACE :: Download Booklet
  • List of Kings of Manipur: 33 - 1984 AD