The Indian Express (Delhi Edition)
8 crossings, 192 atoms in tightest knot ever
BRITISH SCIENTISTS have tied the tightest knot ever tied and, as unlikely as it may seem, this is important.
Knots are useful in everyday life — and the same is true on the molecular level, where braided or knotted strings of atoms and molecules can be put together in different patterns with varying characteristics.
Until now, scientists have been able to create only simple molecular knots with 3 or 5 crossings of strands. Now, researchers have described a way to tie a much more complicated, and therefore much stronger, knot.
Everyone knows that Kevlar is very strong — impenetrable even to a bullet. But why? Its molecules connect to form long chains that run parallel to each other. Together these molecules form an extremely strong yet flexible material.
But the structure of Kevlar is relatively simple: identical molecules packed tightly next to each other like pencils in a pencil box. Knotted or woven strands of molecules, on the other hand, can potentially create an even more flexible, lighter and stronger material — a tightly knit sweater on the molecular level.
To create their stronger knot, the researchers mixed oxygen, nitrogen and carbon in a solution with metal ions. The organic molecules wrap themselves around sticky iron ions and chloride ions, crossing in just the right ways and at just the right points. The loose ends were then sealed together chemically, forming a completely tied knot with 8 crossings. The number of crossings made the knot much tighter than anything that had ever been achieved before at the molecular level. The entire loop is tiny, the length of 192 atoms.
Davidaleigh,aco-authorofthestudy,said that while the technique was still some time away from any practical application, the potentialisclear.“knottingandweavinghaveled tobreakthroughtechnologiessinceprehistoric times...,” he said. “Knots are just as important at the molecular level, but we can’t exploit them until we learn how to make them.”
THE NEW YORK TIMES
■ This was an explicit recognition of the fundamental tension between Britain’s basic ambitions: unencumbered trade with the European Union, but also control of its borders and laws — issues that the Prime Minister identified as the primary force behind the voters’ decision to leave the bloc. To that end, her priorities are twofold: controlling migration and exiting the jurisdiction of the European Court of Justice. Not accepting the court’s rulings means leaving the internal single market, which allows for the free movement of capital and services. Without this free movement, it is likely that Britain’s lauded financial services industry will lose some of the rights that give it unfettered access to Europe.
There are several options for a customs union
“I do want us to have a customs agreement with the EU. Whether that means we must reach a completely new customs agreement, become an associate member of the customs union in some way, or remain a signatory to some elements of it, I hold no preconceived position.”
■ May wants a new deal on customs. The current customs union eliminates tariffs between EU countries but limits their ability to strike individual free-trade deals with noneuropean nations. Throughout her speech, she repeatedly said that Britain wanted new trade deals with non-eu countries such as India and China. She wants a “truly global Britain” with the ability to negotiate its own trade agreements and also maintain tarifffree trade with Europe.
There is uncertainty on EU citizens’ rights in Britain
“We want to guarantee the rights of EU citizens who are already living in Britain, and the rights of British nationals in other member states, as early as we can. I have told other EU leaders that we could give people the certainty they want straight away, and reach such a deal now. Many of them favour such an agreement — one or two others do not — but I want everyone to know that it remains an important priority for Britain, and for many other member states, to resolve this challenge as soon as possible.”
■ The June 23 referendum caused much anxiety and uncertainty for the roughly 3.2 million EU citizens living in Britain and the 1.2 million Britons living in other member countries. May’s latest comments are the same as those she expressed in November, when she refused to guarantee the rights of European residents in Britain unless the rights of British people living in Europe were also protected. Amid the uncertainty, the Home Office has been overwhelmed by applications for permanent residence.
A warning: do not try to punish Britain
“I must be clear. Britain wants to remain a good friend and neighbour to Europe. Yet, I know there are some voices calling for a punitive deal that punishes Britain and discourages other countries from taking the same path. That would be an act of calamitous self-harm for the countries of Europe. And it would not be the act of a friend. Britain would not — indeed, we could not — accept such an approach.”
■ Since the referendum, Britain’s European partners have taken a hard line, warning that it cannot have an à la carte membership in which it cherry-picks the benefits it wants to retain. Some European leaders have also said that Britain should be punished in some way, to deter other countries from trying to leave the bloc.
In her speech, May emphasised Britain’s friendship with Europe and said that the nation did not seek to unravel the union. But those comments were quickly followed by the threat that punitive measures against Britain could easily backfire. Case in point: Earlier this week, Philip Hammond, the Chancellor of the Exchequer, suggested that Britain could transform itself into a corporate tax haven if the European Union failed to strike a trade agreement with Britain. KIMIKO DE FREYTAS TAMURA,
THE NEW YORK TIMES