Wrapping a Cube

This puzzle comes from a wonderful Russian site, where its solution is presented as a sequence of animations. (A later remark: through the efforts of Colm Mulcahy who approached David Singmaster an earlier reference has been found: Martin Gardner describes the puzzle at the end of Chapter 5 of his New Mathematical Diversions – a book from 1995. Colm Mulcahy later reported that the article was included into Gardner’s 1966 Third book of Mathematical Diversions from Scientific American and later added that the original column appeared in 1960.))


Is it possible to wrap the cube with a 3×3 piece of paper below it?

Handling of the paper is subject to two conditions:

  1. The paper may be only cut or folded along the crease lines.
  2. The cutting should not cause pieces to separate.

Would you like to check? Here is the answer



Star Wars land

Disney is planning something big to mark the conclusion of the current Star Wars trilogy. How big? The size of a theme park.

On a call with investors, Disney CEO Bob Iger on Tuesday revealed that the 14-acre Star Wars Land attraction at Walt Disney World in Orlando will open in 2019, the same year as Star Wars Episode IX, the final chapter in the current “Skywalker Saga” arc of the beloved space opera.

Construction started on the Hollywood Studios attraction last April, following its August 2015 announcement. Until Iger’s statement on Tuesday, Disney had remained quiet about the attraction — which will be paired with a similar one in Disneyland Anaheim — beyond the release of concept artwork last summer. While it’s still unconfirmed just what the attraction will include, a Disney Parks blog post promised “guests will get the opportunity to pilot the fastest hunk of junk in the galaxy” after climbing on board a full-size replica of the Millennium Falcon.

That wasn’t the only Star Wars information Iger dropped during Tuesday’s call; the exec also revealed that he’s already seen Star Wars: The Last Jedi ahead of its December release, telling investors that Rian Johnson’s follow-up to 2015’s Star Wars: The Force Awakens will be a great next installment to the Skywalker story.

Iger also teased the upcoming Avatar attraction, saying, “This is a very big land with unique design and architecture that really does make you feel like you’re in Pandora.”


Hack that android phone

Your Android device’s Pattern Lock can be cracked within five attempts

The popular Pattern Lock system used to secure millions of Android phones can be cracked within just five attempts – and more complicated patterns are the easiest to crack, security experts reveal.

Pattern Lock is a security measure that protects devices, such as mobile phones or tablets, and which is preferred by many to PIN codes or text passwords. It is used by around 40 per cent of Android device owners.

In order to access a device’s functions and content, users must first draw a pattern on an on-screen grid of dots. If this matches the pattern set by the owner then the device can be used. However, users only have five attempts to get the pattern right before the device becomes locked.

New research from Lancaster University, Northwest University in China, and the University of Bath, which benefitted from funding from the Engineering and Physical Sciences Research Council (EPSRC), shows for the first time that attackers can crack Pattern Lock reliably within five attempts by using video and computer vision algorithm software.

By covertly videoing the owner drawing their Pattern Lock shape to unlock their device, while enjoying a coffee in a busy café for example, the attacker, who is pretending to play with their phone, can then use software to quickly track the owner’s fingertip movements relative to the position of the device. Within seconds the algorithm produces a small number of candidate patterns to access the Android phone or tablet.

The attack works even without the video footage being able to see any of the on-screen content, and regardless of the size of the screen. Results are accurate on video recorded on a mobile phone from up to two and a half metres away – and so attacks are more covert than shoulder-surfing. It also works reliably with footage recorded on a digital SLR camera at distances up to nine metres away.

Researchers evaluated the attack using 120 unique patterns collected from independent users. They were able to crack more than 95 per cent of patterns within five attempts.

Complex patterns, which use more lines between dots, are used by many to make it harder for observers to replicate. However, researchers found that these complex shapes were easier to crack because they help the fingertip algorithm to narrow down the possible options.

During tests, researchers were able to crack all but one of the patterns categorised as complex within the first attempt. They were able to successfully crack 87.5 per cent of median complex patterns and 60 per cent of simple patterns with the first attempt.

Researchers believe this form of attack would enable thieves to access phones after pinching them to obtain , or would allow malware to be quickly installed on devices while their owners were distracted.

In addition, given people often use the same pattern across multiple devices a pattern obtained from one device could be used to access a second device.

Dr Zheng Wang, principle investigator and co-author of the paper, and Lecturer at Lancaster University, said: “Pattern Lock is a very popular protection method for Android Devices. As well as for locking their devices, people tend to use complex patterns for important financial transactions such as online banking and shopping because they believe it is a secure system. However, our findings suggest that using Pattern Lock to protect sensitive information could actually be very risky.”

“Contrary to many people’s perception that more complex patterns give better protection, this attack actually makes more  easier to crack and so they may be more secure using shorter, simpler patterns,” Guixin Ye, the leading student author from Northwest University, added.

The researchers have proposed suggested countermeasures to prevent this attack. They include device users fully covering fingers when drawing the pattern; or pattern lock designers mixing pattern locking with other activities such as entering a sentence using Swype-like methods; in addition having the screen colour and brightness change dynamically could confuse the recording camera.


Where cabin crew sleep

Long-haul journeys can be exhausting for hardworking flight attendants as well as passengers, but where do crew go to unwind and escape demanding flyers?

Many Boeing 777 and 787 planes feature a secret staircase that leads to a tiny set of windowless bedrooms known as Crew Rest Compartments (CRCs).

Fascinating images provide a rare glimpse inside these confined areas, which few people have a chance to witness for themselves.

This image of a Boeing plane shows flight attendants stretched out in the hidden bedroom area, which many passengers don’t get to see

A small staircase can be seen leading to a compartment of sleeping spaces for long-haul crew members. These bedrooms are located in the rear of this Boeing 787 Dreamliner, and there are another two further sections at the front of the plane too

Sleep tight: The cosy  sleeping quarters on the Boeing 787 Dreamliner  feature cushions, pillows and curtains to offer a touch of privacy

Sleep tight: The cosy sleeping quarters on the Boeing 787 Dreamliner  feature cushions, pillows and curtains to offer a touch of privacy

Enter the cabins where aircraft crew sleep during long journeys

Most flyers are unlikely to have spotted the area before, as its narrow stairs are concealed behind a door, which usually requires a code or key to access it, and sleeping areas for crew are discreetly hidden above their heads.

The size and position of these spaces varies depending on each aircraft model, but they are typically nestled away behind the cockpit area, located above first class.

One image of an American Airline’s Boeing 777 300 even shows staff members entering the relaxation areas through a hatch disguised as an overhead bin.

The accommodation is cramped and features an average of eight beds, depending on the airline.

On Boeing 777s, there are between six to ten beds, each containing storage space for flight attendants’ belongings during the journey.

This model of plane also includes a separate area for pilots, with two beds, two business-class seats and, in some airlines, a bathroom area with a sink or lavatory.


A British Airways flight attendant revealed to MailOnline Travel: ‘On the Boeing 747s it is all bunk beds and on the 777 it feels like you are in a coffin.

‘They are cramped but you can make it comfortable as you get a blanket and a pillow.

‘I always take my own pyjamas and I make a little bed up. I sometimes try to take pillows and blankets from business class if they aren’t in use.

‘It’s very basic, some have TVs but they are tiny, smaller than iPad minis.’

On the Boeing 777, there is a separate area for pilots, with two beds, two business-class seats and, on some airlines, a bathroom area with a sink or lavatory

As this graphic shows, some of the sleeping compartments are situated at the front of the plane above the first class section

As this graphic shows, some of the sleeping compartments are situated at the front of the plane above the first class section

Staff are pictured chatting and relaxing with magazines and refreshments inside the Crew Rest Compartments on a Boeing 777

Some bays come with entertainment systems, a blanket, pillows and on occasion, pyjamas, with each bed separated by draped heavy curtains which muffle out the sounds of other crew.

Different airlines have opted for varying bed layouts, ranging from Malaysian Air A380s, which has beds stacked on top of each other, to American Airlines Boeing 773s, which has beds sectioned-off from a central aisle.

A British Airways flight attendant revealed to MailOnline Travel: ‘On the Boeing 747s it is all bunk beds and on the 777 it feels like you are in a coffin.

‘They are cramped but you can make it comfortable as you get a blanket and a pillow.

‘I always take my own pyjamas and I make a little bed up. I sometimes try to take pillows and blankets from business class if they aren’t in use.

‘It’s very basic, some have TVs but they are tiny, smaller than iPad minis.’

The crew accommodation is cramped and features an average of eight beds, depending on the airline.This image shows the layout inside a Boeing 787 Dreamliner

The crew accommodation is cramped and features an average of eight beds, depending on the airline.This image shows the layout inside a Boeing 787 Dreamliner

Tight surroundings: Layouts vary depending on each model, but the sleeping areas are typically nestled away behind the cockpit area

Tight surroundings: Layouts vary depending on each model, but the sleeping areas are typically nestled away behind the cockpit area

There is a strict policy of one staff member to each bunk, which usually stretches 6ft long by 2.5ft wide.

Dan Air, the flight attendant behind Confessions of a Trolley Dolley, which has thousands of fans on Facebook and Twitter, told MailOnline Travel: ‘Crew rest areas on certain aircraft are a lot better than they used to be.

‘They are very small and very cramped and yes can be very claustrophobic. It’s not nice being in the tiny, confined space during severe turbulence, it can get very unnerving.

‘In terms of what staff do there, well that would be telling, but I’m sure you can imagine that a lot more than sleeping often goes on here.

‘We try to make them as comfortable as possible for us, bringing our own pyjamas, blankets and teddies to try and help us get some sleep, but to be honest it’s often very difficult to sleep.’

Cathay Pacific ‘A Day in The Life of a Flight Attendant’

Why is Dubai so wealthy?

Dubai as a city is not as wealthy as, let’s say New York or London. It seems very wealthy, because the city’s PR agency does a great job in marketing it as the wealthiest place. Abu Dhabi is actually the richest city in the world. Dubai has no oil left, only 2% of its GDP is based on oil. Everything else is trade, tourism, finance, entertainment and nowadays real estate and health care.

The native population of Dubai is so low in number that if the government distributed the wealth of the city, it would be enough to make everyone very rich. Despite being a wealthy city, Dubai is also in debt because during a real estate boom, the city borrowed loads of cash from banks and private funds.

Dubai is a perfect example of a well curated capitalism. Yes, there are many wealthy families, but their wealth is far less compared to those families in Abu Dhabi let’s say.

Since the local population of Dubai lives a good life, mostly because they are either supported by their rich relatives or government, the general scene of Dubai is wealthy.

The Ruler of Dubai is an amazing person and he is very progressive. He is not afraid to do things others would not even dare, hence his actions draw interest from foreign investors. When money pours business grows. Also, due to Dubai’s lenient financial regulations many foreign wealthy people prefer to invest here or simply park their money, similar to Switzerland.

Dubai has a potential to be a very rich city on a global scale, and I hope this happens in near future because it deserves it.

Real or plastic Christmas tree?

The Christmas tree: it’s a quintessential part of the holiday season. But it turns out not all festive trees are made equal — at least not when it comes to environmental friendliness.

So, which is better for the planet — a freshly cut tree or a fake one?

The short answer, which may come as a surprise to some, is a real tree. But it’s actually more complicated than that.

It ultimately depends on a variety of factors, including how far you drive to get your evergreen and how you dispose of it at the end of the holidays ― and, if you choose an artificial tree, how long you end up using it.

Here’s an explainer on how to make the more Earth-friendly choice this Christmas season:

1 If you choose an artificial tree, you need to use it for a very long time

An artificial tree needs to be reused for many years to make it more environmentally friendly than buying a fresh-cut tree annually. According to forester Bill Cook, a fake tree would have to be used for more than eight to nine years. A 2009 study out of Montreal, however, concluded it would take more than 20 years of use to make it a more eco-friendly choice.

Artificial trees have “three times more impact on climate change and resource depletion than natural trees,” said the study, conducted by the consulting firm Ellipsos.

2 Most fake trees are made from toxic, non-recyclable materials

Artificial Christmas trees are made of polyvinyl chloride, or PVC, a non-recyclable plastic. PVC has been linked to adverse health and environmental impacts. Fake trees may also be manufactured with lead and other toxic additives.

There are artificial trees on the market that are not made from PVC. Polyethylene plastic (or PE) trees are said to be a less toxic option.

3 If you’re going to buy artificial, choose domestic

More than 85 percent of artificial Christmas trees in the U.S. are imported from China, significantly enlarging their carbon footprint.

If you’re opting for a fake tree, aim to buy one with a “Made In USA” label.

4 Similarly, if you’re buying a real tree, go local

Minimize the number of miles driven to get your Christmas tree. Research shows that driving to get your tree often has more environmental impact than the tree itself.

“If you pick up a real tree close to your home or pick it up on a trip you were going to make anyway, the impact of the real tree is almost nil,” Bert Cregg, a horticulture expert at Michigan State University, told HuffPost.

Buying local also means supporting your community’s growers and businesses, as well as preserving local farmland.

The Christmas Tree Farm Network maintains a comprehensive list of farms in the U.S., organized by state.

5 Real Christmas trees are grown specifically for that purpose

“You’re not doing any harm by cutting down a Christmas tree,” Clint Springer, a botanist and professor of biology at Philadelphia’s Saint Joseph’s University, told The New York Times in an earlier interview. “A lot of people think artificial is better because you’re preserving the life of a tree. But in this case, you’ve got a crop that’s being raised for that purpose.”

6 Christmas tree farms can serve as a habitat for local wildlife

About 350 million trees grow on Christmas tree farms in the United States, according to the National Christmas Tree Association. About 30 million of these trees are harvested annually.

These farms have environmental costs of their own, noted Thomas Harman, who sells artificial Christmas trees. “If you use an artificial tree for 10 years, you need 10 trees, and that is 70 years’ worth of growing trees,” he told Weather.com in 2013. “You have 70 years of water and pesticide consumption.”

Researchers say, however, that pesticides aren’t actually too much of an issue on Christmas tree farms.

“If you look at the continuum of chemical use in U.S. agriculture, Christmas trees production certainly ranks on the low end,” Cregg told Mother Jones in an earlier interview.

Christmas tree farms can also serve as important habitats for local birds, insects and other wildlife.

7 Real trees can be composted or recycled

Don’t just chuck your used Christmas tree in the trash after the holidays. Repurpose or recycle it!

Many towns and cities have curbside pick-up options for recycling Christmas trees, or recycling drop-off centers. Some also offer tree mulching and chipping programs, allowing residents to recycle their trees and take home a free bag of mulch for their garden.

Feeling handy? You can also turn your tree into a DIY project. Create coasters and decorations with the branches and trunk of your tree. Or make some Christmas-scented potpourri.

The bottom line

All things being equal, it seems real Christmas trees are better for the health of the Earth ― and of your family. But depending on a variety of factors, either option can be a good choice.

If you have an artificial tree, reuse it for at least a decade and consider choosing a domestically manufactured, non-PVC option. If you want a real tree, get one close to where you live, and recycle or compost it when the season is over.


Russia aims to develop teleportation in 20 years

It’s a question that physicists, philosophers, and science fiction writers have pondered for decades: how to travel from one place to another without travelling through the space in between.

Now a Kremlin-backed research program is seeking to make the teleportation technology behind Captain Kirk’s transporter a reality.

A proposed multi-trillion pound strategic development program drawn up forVladimir Putin would seek to develop teleportation by 2035.

“It sounds fantastical today, but there have been successful experiments at Stanford at the molecular level,” Alexander Galitsky, a prominent investor in the country’s technology sector, told Russia’s Kommersant daily on Wednesday. “Much of the tech we have today was drawn from science fiction films 20 years ago.”

The Star-Trek style target is listed in the National Technological Initiative, a state-sponsored strategic development plan designed pour investment into research and development sector in a number of key sectors.

The $2.1 trillion (£1.4 trillion) “road map” for development of the cybernetics market to 2035 also includes developing a Russian computer programming language, secure cybernetic communications, quantum computing, and neural interfaces (direct connections between computers and human brains), Kommersant reported.

The goal is not as outlandish as it might seem.

In 2014, scientists at Delft University of Technology in the Netherlands showed for the first time that it was possible to teleport information encoded into sub-atomic particles between two points three metres apart with 100% reliability.

While teleportation remains a remote prospect, experts believe significant progress in quantum computing and neural interfaces is likely in the next few decades.

The program appears to be part of a new Kremlin drive to boost Russia’s IT sector and high-tech economy.

Mr Putin heaped praise on Russia’s IT sector earlier this week when he met a team of programmers from St Petersburg state university who won the 2016 international “programming olympiad.”

Russia has a talented programming community and a small but vibrant software sector that has produced several successful IT companies, including Yandex and Kaspersky Labs.

Western governments also believe Russia has leveraged its computing talent to put together one of the most fearsome state-sponsored hacking and cyber-warfare programs on the planet.


The tallest building ever

The X-Seed 4000 is the tallest buildingever fully envisioned, meaning that the designs for the building have been completed. The idea was initially created and developed by Peter Neville. Its proposed 4-kilometre (2.5 mi) height, 6-kilometre (3.7 mi) wide sea-base, and 800-floor capacity could accommodate 500,000 to 1,000,000 inhabitants. This structure would be composed of over 3,000,000 tons of reinforced steel.

It was designed for TokyoJapan by the Taisei Corporation in 1995 as a futuristic environment combining ultra-modern living and interaction with nature. Methods of transportation within the X-seed would most likely include MagLev trains.

The X-Seed 4000 “is never meant to be built,” says Georges Binder, managing director of Buildings & Data, a firm which compiles data banks on buildings worldwide. “The purpose of the plan was to earn some recognition for the firm, and it worked.”

Unlike conventional skyscrapers, the X-Seed 4000 would be required to actively protect its occupants from considerable air pressure gradations and weather fluctuations along its massive elevation. Its design calls for the use of solar power to maintain internal environmental conditions. Also, the proposed area is situated on the Pacific Ring of Fire, which is the most active volcano range in the world, so the X-Seed 4000 would be subject to tsunamis and earthquakes. The Shimizu Mega-City Pyramid (proposed in 2007, also planned for TokyoJapan) faces most of the same problems.

A sea-based location and a Mount Fuji shape are some of this building’s other major design features — the real Mount Fuji is land-based and is 3,776 m (2.35 miles) high, 224 m shorter than the X-Seed 4000. The X-Seed 4000 is projected to be twice the height of the Shimizu Mega-City Pyramid at 2,004 m. Other projects that may be in the top five man made structures are the Ultima Tower (3,218 m), Dubai City Tower(2,400 m) and the Bionic Tower (1,228 m) in either Hong Kong or Shanghai.

Some estimate that the cost to construct the X-Seed 4000 may be somewhere between US$300–900 billion, in 2006 dollars ($353.00–$1.06 thousand billion in 2016).