Refining radio observations of the sun
While staring at the sun, a question that sometimes pops up is how do we know what the sun is made of, if the light from the sun is blindingly bright to our instruments? We study such objects by looking at them through forms of light other than visible light. This could include radio, infrared, X-rays and UV rays. Solar radio observations, especially, could reveal unique insights into the outer solar atmosphere. One challenge in studying the radio waves is distinguishing the intrinsic properties of the source of the radio waves from the effects of radio wave propagation.
In the new study, the scientists have been able to characterise the fine structures produced during a radio burst. Their observations have shown that the spatial characteristics are guided by the effects of radio wave propagation more than that of the intrinsic emission source of the waves. These observations could allow for better models of the solar surface, with a better accuracy of source brightness temperatures, giving us an accurate picture of the sun.
Charged with UV light
In a recent study published in the journal Energy Technology, researchers from Indian Institute of Science have designed a supercapacitor that can be charged using UV light. The researchers have used novel electrodes based on the integration of UV light sensitive zinc oxide nanorods and electrochemically active nickel cobalt oxide.
When light falls on zinc oxide, photo-charges are released and these add on to the number of charges present that builds up on the oppositely charged electrodes. More charge accumulates on the electrodes, thus resulting in larger capacitance. The use of these integrated nanostructures makes the device compact and can be used as a self-powered energy storage cell.
The formation of stars
The current cosmological model to explain our universe, the ‘Big Bang’ model, aims to describe all the phenomena we observe, which includes the galaxies and their evolution from earliest times to the present day.
One of the major problems faced by the standard form of this model is that it has predicted a star formation rate which is far too big. All the star forming material in galaxies should have been turned into stars when the universe had only a fraction of its present age, 13.8 billion years.
However, over half the galaxies we see, mainly the spirals, are very actively forming stars right now. This discrepancy between theoretical prediction and observation has forced to look much more closely at processes which can slow down the rate of star formation during the lifetimes of galaxies, collectively known as star formation quenching. Without quenching, the standard Big Bang model fails to predict the universe as we know it.
There have been a number of mechanisms proposed for quenching, for example ‘feedback’ from supernovae or active galactic nuclei which breaks up the star forming clouds and reduces the star formation rate. One of the mechanisms has been published in the journal Nature Astronomy.
The metal cores
Scientists have long pondered how rocky bodies in the solar system got their metal cores. According to research conducted by The University of Texas at Austin, USA, evidence points to the downward percolation of molten metal towards the centre of the planet through tiny channels between rocks. The finding calls into question the interpretation of prior experiments that sought to understand how metals behave when planets form.
The research suggests that once the isolated pores grow large enough to connect, the molten metal starts to flow, and most of it is able to percolate along grain boundaries. This process would let metal trickle down through the mantle and form a metal core. The study appears in the Proceedings of the National Academy of Sciences.
In the Womb: Identical Twins
In the Womb: Identical Twins, directed by Lorne Townend, examines the elusive mysteries of the human species from its earliest stages. Utilising highly advanced 4D ultrasound imagery and computerised graphics, it illustrates the processes that determine both the similarities and the differences between identical twins while they develop in the womb.
Born from the same fertilised egg, identical twins often share common physical attributes, social interests and personality traits. However, it’s the differences between these identical twins that provide the greatest potential for new discoveries to be made.
The documentary’s revelations deepen our understanding of the human species, and show us that there is much we have yet to learn. To watch the documentary, visit www.bit.ly/2BHkkO7.