Why it matters: Stretchable gold wires & others

Highlighting science news you may have missed, and telling you why it matters in about a minute.

July 22, 2013 01:22 pm | Updated November 16, 2021 08:50 pm IST

> Stretchable gold conductor grows its own wires

What it is : Extremely small spherical particles of gold embedded in an elastic substance rearrange themselves to form a chain when the substance is stretched.

Copper and silver are widely used metallic electrical conductors in commercial and industrial applications, with gold also used to some extent. In order to conduct electricity, they must be of a particular design – they can’t be stretched too much or the metal will break.

On a quest to find an alternative, on July 18, University of Michigan researchers found that when nanometer-wide particles of gold, called nanoparticles, are embedded in an elastic substance like polyurethane, they display strange behaviour. When the polyurethane is relaxed, the nanoparticles were distributed over a wide area. When the polyurethane is stretched, the nanoparticles line up like a chain.

When stretched, the elastic substance does not easily break, and the gold nanoparticles continue to conduct electrons inside the material. In fact, the researchers found that this stretchable conductor was not in its “early stages” or anything. It conducted just as well as mercury when relaxed, and just as well as certain plastics when stretched to a ridiculous 5.8 times its original length.

Why it matters : This is a breakthrough for materials science as well as the many fields that could immediately use this idea – like flexible electronic prosthetics for missing limbs and flexible electrical “patches” to be applied on the head to study brain signals.

> Even bacteria use social networks

What it is : A single-celled soil bacterium was found to be physically interconnected with neighbour cells, probably as a mode of nutrition and defense.

Myxococcus xanthus is a common predatory bacteria which exists as swarms in soil. The species was already known for its ability to self-organise. For example, when swarms of M. xanthus have been observed moving as a group and surrounding a prey like E. coli .

This self-organising mechanism was credited to floating spheres called vesicles found surrounding individual cells. These vesicles were thought to be helping the cells communicate with each other.

However, scientists have now found out that the mode of communication is much more targeted. A single M. xanthus produces chains of vesicles which physically connect it to several other M. xanthus cells, “like a microscopic intranet.”

The scientists think that these connections carry proteins and other molecules from cell to cell in a targeted manner. They also think that this would enable the M. xanthus to evade enemies and capture prey without revealing its location.

Why it matters : Figuring out how this mechanism works will enhance our understanding of how other self-organising bacteria work together to pull off processes like biofuel production. It could also help design new strategies to knock out communication systems of harmful bacteria.

> ICANN approves first set of new generic top-level domains

What it is : Internet users will soon start being able to access websites ending with new domain extensions.

‘Top level domains’ first came into existence as a means of navigating the World Wide Web. The top three such domains, which are the most popular, are .com (commercial), .net(network) and .org(organization).

With the growth of the Internet and the World Wide Web to countries across the world, however, the Internet Corporation for Assigned Names and Numbers (ICANN) decided to expand the scope of generic top-level domains (gTLDs) to include non-English words.

In its first such decision, the corporation has approved four new top level domains: .شبكة(“Web” in Arabic), .游戏 (“Game” in Chinese), онлайн (“Online” in Russian) and сайт (“Web site” in Russian).

Users in these countries will be able to access and type in a website address for generic top-level domains in their native language! ICANN is yet to approve whether corporates such as Reliance and Airtel will be able to apply for their own gTLDs such as .airtel or .reliance.

Why it matters : With the floodgates open, this move has huge significance for web browsing speeds, marketing, advertising, etc. Regional content can also be expected to finally kick-off, with the new gTLDs proving to be the spark.

> Neutrino shape-shift points to new physics

What it is : “Ghost-like” particles called neutrinos have been caught doing something that could explain a decades-old problem about the universe.

When the universe was created 13.82 billion years ago, equal amounts of matter and antimatter were created. These are two materials that, when they meet, destroy each other in a flash of energy. What’s puzzling is that if they were created in equal amounts, why didn’t they wipe themselves out?

How did matter win out? Obviously, there was something that helped it.

That “something” has been discovered at the T2K particle experiment in Japan. Scientists there have observed particles called muon neutrinos transform into electron neutrinos without warning.

Neutrinos are shifty beings and very hard to detect. Physicists measure their ‘shape-shifting’, a.k.a. oscillation, by producing neutrinos of a particular type (like ‘muon’) and then seeing how many disappear.

T2K, however, has for the first time been able to measure their type when they arrive at the detector (like ‘electron’), too. The readings, which are accurate to 99.999999999999 per cent, show that when they started the experiment with less than 5 electron neutrinos, they ended up with 28.

Now that we know muon neutrinos shift to electron neutrinos, physicists think that muon antineutrinos – the antimatter version – will not shift to electron antineutrinos at the same rate.

Why it matters : This will mean that there will be a dominance of electron neutrinos over muon antineutrinos, the latter becoming destroyed by some other process.

> Giant viruses open Pandora's box

What it is : Researchers have discovered two viruses that are twice as large as the previous record holders and are more genetically complex, too.

This new group of giant viruses is being called ‘Pandoraviruses’. One of them, Pandoravirus salinus was found in sediment off the coast of Chile, while the other, Pandoravirus dulcis was found in a muck pond in Australia.

Viruses are usually barely considered living organisms because of their highly simplistic genomes (hereditary information stored in DNA) and their reliance on the host for survival.

But scientists argue that these two viruses, which can measure up to a 1 micrometre (that’s a minuscule one-thousandth of a millimetre!) and contain more genes (more than 2,500 compared to the flu virus’s 13 genes) than some bacteria and even some eukaryotes (higher life forms), could constitute a ‘fourth domain of life’ (besides the three we know of today: bacteria, archaea and eukaryotes).

Why it matters : Studying giant viruses will in the long run help shed more light on the difference between viruses and other life forms. For now, what matters is what effect these giant virus have on our ecosystem and on our body, where some of them have been found to lurk.

(Compiled by Vasudevan Mukunth, Anuj Srivas, Nandita Jayaraj)

vasudevan.m@thehindu.co.in, nandita.j@thehindu.co.in, anuj.s@thehindu.co.in

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