This is a blog where science discussion is encouraged. The discussions I post will cover topics on anything science related. Questions about seemingly simple subjects will be broken down to science to the best of my ability. I am a sophomore in college studying physics. I post doodles and science sketches also...anything science related really. Articles

 

Graphene: Supermaterial Goes Superpermeable

Discovery

  • Wonder material graphene has revealed another of its extraordinary properties — University of Manchester researchers have found that it is superpermeable with respect to water.

Graphene’s Properties

  •  It is the thinnest known material in the universe and the strongest ever measured.
  • It conducts electricity and heat better than any other material.
  • It is the stiffest one too and, at the same time, it is the most ductile. 

Graphene Oxide ( The Discovery)

  • Graphene oxide is the same graphene sheet but it is randomly covered with other molecules such as hydroxyl groups OH-.
  • Graphene oxide sheets stack on top of each other and form a laminate.
  • The researchers prepared such laminates that were hundreds times thinner than a human hair but remained strong, flexible and were easy to handle.

Graphene Oxide’s Amazing Properties

  • When a metal container was sealed with such a film(of graphene oxide), even the most sensitive equipment was unable to detect air or any other gas, including helium, to leak through.
  • It came as a complete surprise that, when the researchers tried the same with ordinary water, they found that it evaporates without noticing the graphene seal.
  • Water molecules diffused through the graphene-oxide membranes with such a great speed that the evaporation rate was the same independently whether the container was sealed or completely open.

Dr Rahul Nair, who was leading the experimental work, offers the following explanation

  • Graphene oxide sheets arrange in such a way that between them there is room for exactly one layer of water molecules.
  • They arrange themselves in one molecule thick sheets of ice which slide along the graphene surface with practically no friction.
  • If another atom or molecule tries the same trick, it finds that graphene capillaries either shrink in low humidity or get clogged with water molecules.

Uses (Obvious)

  • This unique property can be used in situations where one needs to remove water from a mixture or a container, while keeping in all the other ingredients
  • Just for a laugh, we sealed a bottle of vodka with our membranes and found that the distilled solution became stronger and stronger with time.

BUT…..

The Manchester researchers report this experiment in their Science paper, too, but they say they do not envisage use of graphene in distilleries, nor offer any immediate ideas for applications.

(Source: sciencedaily.com)

String theorists squeeze nine dimensions into three

Subject

  • A simulation of the early universe using string theory may explain why space has three observable spatial dimensions instead of nine.

What is String Theory?

  • The leading mathematical explanation of physics goes beyond modern particle theory by positing tiny bits of vibrating string as the fundamental basis of matter and forces.
  • String theory also requires that the universe have six or more spatial dimensions in addition to the ones observed in everyday life.

Explaining how those extra dimensions are hidden is a central challenge for string theorists.

“This new paper demonstrates, for the first time, that our 3-D space appears naturally … from the 9-D space that string theory originally has,”

About the Simulation

  • In the simulation, the universe starts off as a tiny blob of strings that is symmetric in nine different dimensions.
  • As the strings interact, a random energy fluctuation — provided by the quantum laws that govern these small scales — breaks the symmetry.
  • Three dimensions balloon outward, leaving the other six stunted at a billionth of a trillionth of a trillionth of a centimeter, far too small to be detected.

Applying string theory to the beginning of the universe in this way has long proven difficult.

  •  the math included in traditional versions of the theory can be solved only when strings interact weakly at low temperatures, not in the seething maelstrom that existed moments after the Big Bang.

To tackle the extreme energies of the Big Bang…

  • Nishimura and his team had to recast one version of string theory, called IIB, as grids of equations that could be fed into a supercomputer.
  • Limited by the power of this computer, the researchers could track the interactions of no more than 32 strings for the first split second of history.

For some physicists, this way of approximating string theory is too oversimplified to be believable. “Frameworks like the one they’re using … lack a lot of other stuff that goes into trying to make a realistic model,” says Shamit Kachru, a theoretical physicist at Stanford University.

To prove the usefulness of the new approach, Nishimura’s team will need to study times much later in the universe’s history, comparing their results against real observations of how matter is distributed across the universe.




(Source: sciencenews.org)

Offsetting Global Warming: Molecule in Earth’s Atmosphere Could ‘Cool the Planet’

Discovery

  • Scientists have shown that a newly discovered molecule in Earth’s atmosphere has the potential to play a significant role in off-setting global warming by cooling the planet.
  • We have been able to quantify how fast Criegee radicals react for the first time.

About the newly discovered molecule - Criegee biradicals

  • invisible chemical intermediates are powerful oxidisers of pollutants such as nitrogen dioxide and sulfur dioxide, produced by combustion, and can naturally clean up the atmosphere.
  • chemical intermediates were hypothesised in the 1950s, it is only now that they have been detected.
  • Criegee biradicals react more rapidly than first thought and will accelerate the formation of sulphate and nitrate in the atmosphere. 
  • These compounds will lead to aerosol formation and ultimately to cloud formation with the potential to cool the planet.
  • "The main source of these Criegee biradicals does not depend on sunlight and so these processes take place throughout the day and night."
  •  ”A significant ingredient required for the production of these Criegee biradicals comes from chemicals released quite naturally by plants, so natural ecosystems could be playing a significant role in off-setting warming.”

HOW they discovered it (the boring science stuff)

  • The detection of the Criegee biradical and measurement of how fast it reacts was made possible by a unique apparatus, designed by Sandia researchers, that uses light from a third-generation synchrotron facility, at the Lawrence Berkeley National Laboratory’s Advanced Light Source.
  • The intense, tunable light from the synchrotron allowed researchers to discern the formation and removal of different isomeric species — molecules that contain the same atoms but arranged in different combinations.

BONUS FACTS

  • In the last 100 years, Earth’s average surface temperature increased by about 0.8 °C with about two thirds of the increase occurring over just the last three decades.
  • Most countries have agreed that drastic cuts in greenhouse gas emissions are required, and that future global warming should be limited to below 2.0 °C (3.6 °F)

(Source: sciencedaily.com)

VAISESIKA assigned the origin of the world to atoms, eternal in their nature, i.e., their ultimate peculiarities. These atoms were regarded as possessing an incessant vibratory motion… . The recent discovery that an atom is a miniature solar system would be no news to the old VAISESIKA philosophers, who also reduced time to its furthest mathematical concept by describing the smallest unit of time (KALA) as the period taken by an atom to traverse its own unit of space.

Autobiography of a Yogi

Vaisheshika - The Atomic Theory

  • Vaisheshika espouses a form of atomism and postulates that all objects in the physical universe are reducible to a finite number of atoms. 
  • Originally proposed by the sage Kaṇāda (or Kana-bhuk, literally, atom-eater) around the 2nd century BC.

THE ATOMIC THEORY

  • The early vaiśeṣika texts presented the following syllogism to prove that all objects i.e. the four bhūtas, pṛthvī (earth), ap (water), tejas (fire) and vāyu (air) are made of indivisible paramāṇus (atoms)

WHY THEY SAY?

  • Assume that the matter is not made of indivisible atoms, and that it is continuous. Take a stone. One can divide this up into infinitely many pieces (since matter is continuous).
  • Now, the Himalayan mountain range also has infinitely many pieces, so one may build another Himalayan mountain range with the infinite number of pieces that one has.
  • One begins with a stone and ends up with the Himalayas, which is a paradox - so the original assumption that matter is continuous must be wrong, and so all objects must be made up of a finite number of paramāṇus (atoms).

vaiśeṣika school

  •  The paramāṇus (atoms) are indivisible and eternal, they can neither be created nor destroyed.
  • Each paramāṇu (atom) possesses its own distinct viśeṣa (individuality).

(Source: Wikipedia)