Jewelry robbers, magicians, exam cheats and practical jokers everywhere will have an interest in an offbeat idea launched by physicists yesterday: to make the passage of time invisible.
The scientists have conceived of a “spacetime cloak” which manipulates light and, in essence, conceals whole events from a viewer.
The theory is based on censoring the flow of events, which we perceive as a stream of light particles, also called photons, that strike the retina.
By exploiting a characteristic of fiber optics, the flow of photons can be slowed, events edited out and stitched back together, say the team from Imperial College London and Salford University, northwestern England.
“A safecracker would be able, for a brief time, to enter a scene, open the safe, remove its contents, close the door and exit the scene, whilst the record of a surveillance camera apparently showed that the safe door was closed all the time,” their paper said.
The theory is expounded in a daunting series of equations and diagrams in the Journal of Optics, published by the Institute of Physics.
It would work thanks to different light intensities that affect the refractory index in optical fiber, the cable widely used in telecoms today.
The refractory index is a determinant of the speed with which the light is transported in the cable.
In the example of the safe cracker, the “leading” segment (the image of the unmolested safe) would be slowed down. The middle segment, of the robber opening the safe and making off with the contents would be edited out, disappearing into a “spatio-temporal void.”
The final segment — of the safe room apparently untouched — would be accelerated so that it catches up with the leading segment and dovetails seamlessly with it.
“By manipulating the way the light illuminating an event reaches the viewer, it is possible to hide the passage of time,” said Martin McCall, an Imperial College professor who headed the work. “Not only can specific events be obscured, but it is possible for me to be watching you, and for you to suddenly disappear and reappear in a different location.”
The theory has yet to be tested or confirmed in a lab, but the authors are confident that this will not be too far ahead.
The physicists are keen to point out that their notion of “invisible events” differs from the fast advancing realm of “invisible materials.”
These are so-called metamaterials, whose nano-metric surface interferes with light at specific wavelengths. As a result, light deviates around an object, making it invisible — or, more accurately, invisible in specific colors of the light spectrum.
“It is unlike ordinary cloaking devices because it does not attempt to divert light around an object,” co-author Alberto Favaro said. “Instead, it pulls apart the light rays in time, as if opening a theatre curtain — creating a temporary corridor through which energy, information and matter can be manipulated or transported undetected.”
Beyond its sci-fi potential, the “spacetime cloak” could have benefits for quantum computing, which depends on the manipulation of light to transport huge amounts of data.
Thousands gathered across New Zealand yesterday to celebrate the signing of the country’s founding document and some called for an end to government policies that critics say erode the rights promised to the indigenous Maori population. As the sun rose on the dawn service at Waitangi where the Treaty of Waitangi was first signed between the British Crown and Maori chiefs in 1840, some community leaders called on the government to honor promises made 185 years ago. The call was repeated at peaceful rallies that drew several hundred people later in the day. “This government is attacking tangata whenua [indigenous people] on all
The administration of US President Donald Trump has appointed to serve as the top public diplomacy official a former speech writer for Trump with a history of doubts over US foreign policy toward Taiwan and inflammatory comments on women and minorities, at one point saying that "competent white men must be in charge." Darren Beattie has been named the acting undersecretary for public diplomacy and public affairs, a senior US Department of State official said, a role that determines the tone of the US' public messaging in the world. Beattie requires US Senate confirmation to serve on a permanent basis. "Thanks to
RIGHTS FEARS: A protester said Beijing would use the embassy to catch and send Hong Kongers to China, while a lawmaker said Chinese agents had threatened Britons Hundreds of demonstrators on Saturday protested at a site earmarked for Beijing’s controversial new embassy in London over human rights and security concerns. The new embassy — if approved by the British government — would be the “biggest Chinese embassy in Europe,” one lawmaker said earlier. Protester Iona Boswell, a 40-year-old social worker, said there was “no need for a mega embassy here” and that she believed it would be used to facilitate the “harassment of dissidents.” China has for several years been trying to relocate its embassy, currently in the British capital’s upmarket Marylebone district, to the sprawling historic site in the
UNDAUNTED: Panama would not renew an agreement to participate in Beijing’s Belt and Road project, its president said, proposing technical-level talks with the US US Secretary of State Marco Rubio on Sunday threatened action against Panama without immediate changes to reduce Chinese influence on the canal, but the country’s leader insisted he was not afraid of a US invasion and offered talks. On his first trip overseas as the top US diplomat, Rubio took a guided tour of the canal, accompanied by its Panamanian administrator as a South Korean-affiliated oil tanker and Marshall Islands-flagged cargo ship passed through the vital link between the Atlantic and Pacific oceans. However, Rubio was said to have had a firmer message in private, telling Panama that US President Donald Trump