Science and Technolgy Current Affairs

Molten Jet Stream discovered deep inside Earth’s core  

Scientists for the first time have discovered the so-called molten jet stream within the Earth’s molten iron core using latest data obtained from three European satellites called Swarm.

The three satellites were launched in 2013 with the goal of studying Earth’s magnetic field.  The latest satellite data that helps create an sharpest ‘x-ray’ view of the planet.

Key Facts 
  • The molten jet stream is an accelerating band of molten iron circling the North Pole. It just like the jet stream in the atmosphere
  • It moves about 40 km per year, currently in a westward direction. This speed is three times faster than normal outer-core speeds and hundreds of thousands of times faster than rate at which Earth’s tectonic plates move.
  • It is located along a boundary between two different regions in the core. This movement is caused when liquid in core flows toward the boundary from both sides and then is squeezed out sideways.
  • Significance: The satellite data has helped clarify Earth’s inner workings and magnetic field. It showed that changes in the magnetic field are actually being caused by the molten jet stream.
  • The discovery can also add light in changing magnetic field of earth and may relate it with switch in direction of the jet stream.

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Israeli scientists create world’s first water-wave laser

Scientists from Israel have created the world’s first ‘water-wave laser’ that emits a beam through the interaction of light and water waves.

The study conducted by team of researchers from Technion-Israel Institute of Technology led by Professor Tal Carmon.

Significance of this research

A typical laser can be created when the electrons in atoms become “excited” by energy absorbed from an outside source causing them to emit radiation in the form of laser light. However, the water-wave laser for the first time showed that water wave oscillations within a liquid device can also generate laser radiation. It also successfully demonstrated nonlinear optics and water waves, two areas of research that were previously considered unrelated to one another.

How it works?
  • In this case, researchers had created a device in which an optical fibre delivers light into a tiny droplet of octane and water.
  • The energy is emitted by the droplet when light waves and water waves pass through each other many times (about one million times) inside the droplet
  • The interaction between the fibre optic light and the miniscule vibrations on surface of the droplet creates an echo i.e. interaction of sound waves causing it to emit radiation.
  • Event when minute pressure is applied by light it can cause droplet deformation that is a million times greater than in a typical optomechanical device. It may offer greater control of the laser’s emissions.
  • In order to increase this echo effect in the device, highly transparent, runny liquids was used to encourage light and droplet interactions.
Potential Applications

The ‘water-wave laser’ may be used in ‘lab-on-a-chip’ devices to study cell biology and test new drug therapies. It can be used in tiny sensors that combine light waves, sound and water waves. It also offers scientists a playground for studying the interaction of light and fluid at a scale smaller than the width of a human hair.

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