On Jan. 7, 1610, Galileo Galilei's improvements to the telescope enabled humanity to see Jupiter's four largest moons for the first time. Io, Europa, Ganymede and Callisto-the so-called Galilean satellites-were seen by the Long Range Reconnaissance Imager on the New Horizons spacecraft during its flyby of Jupiter in late February 2007. The images have been scaled to represent the true relative sizes of the four moons and are arranged in their order from Jupiter.

Io is notable for its active volcanism, which New Horizons studied extensively. On the other hand, Europa's smooth, icy surface likely conceals an ocean of liquid water. New Horizons obtained data on Europa's surface composition and imaged subtle surface features, and analysis of these data may provide new information about the ocean and the icy shell that covers it.

New Horizons spied Ganymede from 2.2 million miles away. Ganymede, the largest moon in the solar system, has a dirty ice surface cut by fractures and peppered by impact craters. New Horizons' infrared observations may provide insight into the composition of the moon's surface and interior.

Scientists are using the infrared spectra New Horizons gathered of Callisto's ancient, cratered surface to calibrate spectral analysis techniques that will help them to understand the surfaces of Pluto and its moon Charon when New Horizons passes them in 2015.

Image Credit: NASA/JHU-APL/Southwest Research Institute

During World War II, Japanese soldiers stationed in Singapore glimpsed a strange version of Bigfoot there. Many reported seeing a primate-like creature covered in gray hair and standing up to 2 meters (6’6″) tall in the Bukit Timah rain forest.

Sightings peaked during the war, but there are also a few present-day sightings reported every now and then. The Bukit Timah area is now a biodiverse nature reserve that housed several creatures, including tigers, not too long ago.

Although it is still a mystery as to what the soldiers and others were actually seeing in this area, some people believe they might have confused macaques for primates. However, according to most experts, this would be unlikely as the macaques in Singapore resemble the ones in Japan and the soldiers at least would know what they were looking at. The last sightings took place in 2007 when visitors told stories of seeing an ape-creature being run over by a taxi and another scratching around in trash cans.

Time travel is one of my favorite topics! I wrote some time travel stories in junior high school that used a machine of my own invention to travel backwards in time, and I have continued to study this fascinating concept as the years have gone by.

We all travel in time. During the last year, I've moved forward one year and so have you. Another way to say that is that we travel in time at the rate of 1 hour per hour.

But the question is, can we travel in time faster or slower than "1 hour per hour"? Or can we actually travel backward in time, going back, say 2 hours per hour, or 10 or 100 years per hour?

It is mind-boggling to think about time travel. What if you went back in time and prevented your father and mother from meeting? You would prevent yourself from ever having been born! But then if you hadn't been born, you could not have gone back in time to prevent them from meeting.

The great 20th century scientist Albert Einstein developed a theory called Special Relativity. The ideas of Special Relativity are very hard to imagine because they aren't about what we experience in everyday life, but scientists have confirmed them. This theory says that space and time are really aspects of the same thing—space-time. There's a speed limit of 300,000 kilometers per second (or 186,000 miles per second) for anything that travels through space-time, and light always travels the speed limit through empty space.

Special Relativity also says that a surprising thing happens when you move through space-time, especially when your speed relative to other objects is close to the speed of light. Time goes slower for you than for the people you left behind. You won't notice this effect until you return to those stationary people.

Say you were 15 years old when you left Earth in a spacecraft traveling at about 99.5% of the speed of light (which is much faster than we can achieve now), and celebrated only five birthdays during your space voyage. When you get home at the age of 20, you would find that all your classmates were 65 years old, retired, and enjoying their grandchildren! Because time passed more slowly for you, you will have experienced only five years of life, while your classmates will have experienced a full 50 years.

So, if your journey began in 2003, it would have taken you only 5 years to travel to the year 2053, whereas it would have taken all of your friends 50 years. In a sense, this means you have been time traveling. This is a way of going to the future at a rate faster than 1 hour per hour.

Time travel of a sort also occurs for objects in gravitational fields. Einstein had another remarkable theory called General Relativity, which predicts that time passes more slowly for objects in gravitational fields (like here on Earth) than for objects far from such fields. So there are all kinds of space and time distortions near black holes, where the gravity can be very intense.

In the past few years, some scientists have used those distortions in space-time to think of possible ways time machines could work. Some like the idea of "worm holes," which may be shortcuts through space-time. This and other ideas are wonderfully interesting, but we don't know at this point whether they are possible for real objects. Still the ideas are based on good, solid science. In all time travel theories allowed by real science, there is no way a traveler can go back in time to before the time machine was built.

I am confident time travel into the future is possible, but we would need to develop some very advanced technology to do it. We could travel 10,000 years into the future and age only 1 year during that journey. However, such a trip would consume an extraordinary amount of energy. Time travel to the past is more difficult. We do not understand the science as well.

Actually, scientists and engineers who plan and operate some space missions must account for the time distortions that occur because of both General and Special Relativity. These effects are far too small to matter in most human terms or even over a human lifetime. However, very tiny fractions of a second do matter for the precise work necessary to fly spacecraft throughout the solar system.Time travel is one of my favorite topics! I wrote some time travel stories in junior high school that used a machine of my own invention to travel backwards in time, and I have continued to study this fascinating concept as the years have gone by.

We all travel in time. During the last year, I've moved forward one year and so have you. Another way to say that is that we travel in time at the rate of 1 hour per hour.

But the question is, can we travel in time faster or slower than "1 hour per hour"? Or can we actually travel backward in time, going back, say 2 hours per hour, or 10 or 100 years per hour?

It is mind-boggling to think about time travel. What if you went back in time and prevented your father and mother from meeting? You would prevent yourself from ever having been born! But then if you hadn't been born, you could not have gone back in time to prevent them from meeting.

The great 20th century scientist Albert Einstein developed a theory called Special Relativity. The ideas of Special Relativity are very hard to imagine because they aren't about what we experience in everyday life, but scientists have confirmed them. This theory says that space and time are really aspects of the same thing—space-time. There's a speed limit of 300,000 kilometers per second (or 186,000 miles per second) for anything that travels through space-time, and light always travels the speed limit through empty space.

Special Relativity also says that a surprising thing happens when you move through space-time, especially when your speed relative to other objects is close to the speed of light. Time goes slower for you than for the people you left behind. You won't notice this effect until you return to those stationary people.

Say you were 15 years old when you left Earth in a spacecraft traveling at about 99.5% of the speed of light (which is much faster than we can achieve now), and celebrated only five birthdays during your space voyage. When you get home at the age of 20, you would find that all your classmates were 65 years old, retired, and enjoying their grandchildren! Because time passed more slowly for you, you will have experienced only five years of life, while your classmates will have experienced a full 50 years.

So, if your journey began in 2003, it would have taken you only 5 years to travel to the year 2053, whereas it would have taken all of your friends 50 years. In a sense, this means you have been time traveling. This is a way of going to the future at a rate faster than 1 hour per hour.

Time travel of a sort also occurs for objects in gravitational fields. Einstein had another remarkable theory called General Relativity, which predicts that time passes more slowly for objects in gravitational fields (like here on Earth) than for objects far from such fields. So there are all kinds of space and time distortions near black holes, where the gravity can be very intense.

In the past few years, some scientists have used those distortions in space-time to think of possible ways time machines could work. Some like the idea of "worm holes," which may be shortcuts through space-time. This and other ideas are wonderfully interesting, but we don't know at this point whether they are possible for real objects. Still the ideas are based on good, solid science. In all time travel theories allowed by real science, there is no way a traveler can go back in time to before the time machine was built.

I am confident time travel into the future is possible, but we would need to develop some very advanced technology to do it. We could travel 10,000 years into the future and age only 1 year during that journey. However, such a trip would consume an extraordinary amount of energy. Time travel to the past is more difficult. We do not understand the science as well.

Actually, scientists and engineers who plan and operate some space missions must account for the time distortions that occur because of both General and Special Relativity. These effects are far too small to matter in most human terms or even over a human lifetime. However, very tiny fractions of a second do matter for the precise work necessary to fly spacecraft throughout the solar system.

Any shopper walking down the aisles of a modern grocery is spoiled for choice when it comes to food options. As of 2008, the number of products carried by the average supermarket stood around 47,000, according to Consumer Reports.

There is one particular item, however, that shouldn't ever appear in anyone's shopping cart, despite its place as a historical foodstuff, particularly during desperate times: human meat.

Cannibalism strikes the human conscience like few other taboo acts, eliciting a mix of dread, disdain and plain old nausea. But as seen in this slideshow, humans eating other humans has been an inseparable part of our history.

I grew up in a Kodak family. My grandfather worked in the photography dark rooms of a Kodak production facility in Rochester, New York for better than 30 years.  My father was a supervisor at Kodak headquarters in downtown Rochester, and later became a liaison between Kodak and Disney in Orlando, for 25 years. Other members of my family worked for the company in various roles, some until retirement.

As a kid, the Eastman Kodak brand was the undisputed king in a city known for its industry giants, including Bausch and Lomb, Xerox, Gannett, and Western Union. If you lived in Rochester and worked for Kodak, the expectation was that you would stay there until retirement, and receive a handsome pension thereafter. Every Kodak employee looked forward to a generous bonus–an annual event that juiced the local economy unlike any other.

By the mid1980s—just about 100 years after George Eastman invented paper-based film—my father was already voicing concerns about Kodak’s future. The digital revolution was sparking, and he wasn’t seeing signs that Kodak knew exactly what to do about it. Instead of focusing its strategic attention on the emerging digital technologies, Kodak was making odd maneuvers, like acquiring pharmaceutical giant Sterling Drugs for $5.1 billion and trying to establish a brand in the battery business.

The connection with Sterling—really the only linkage that made sense for Kodak—was Sterling’s diagnostic imaging business that Kodak rightly forecasted would become gigantic in the years ahead. But acquiring the entirety of Sterling proved a disastrous decision, resulting in massive losses and the eventual selling off of all Sterling’s divisions within six years. Likewise, Kodak took a costly black eye in the battery business from industry leaders Duracell and Eveready, and divested from its battery spin-off, Ultra Technologies, with another painful loss.

While embroiled in the Sterling and battery debacles, the digital revolution was already passing Kodak by, and the corporation’s infrastructure was steadily cracking. My father, along with tens of thousands of others, was among the first to receive an offer of early retirement. Each year after brought more forced retirements, more layoffs, and more downsizing.

Even in the film business, which Kodak comfortably owned for nearly a century, the losses were  mounting. Fujifilm had strategized around its titanic American opponent and was outselling Kodak in key markets. Brand partnerships that Kodak had invested in, nurtured and grown—like that with Disney—were no longer secure.  It seemed to me at the time that Kodak was fighting a war on multiple fronts and losing across the board. When Kodak finally shutdown its largest research and production facility in Rochester, known as Kodak Park, it appeared certain that the Kodak brand I grew up with was gone.

Popular perception is that Kodak didn’t even enter the consumer digital tech business until the mid 1990s (with the release of the Kodak DC-25 compact digital), but that’s incorrect. In 1990, the company pushed out the “Photo CD” as the industry defining digital image medium. That was a bold move and the company invested millions to make it work, but it turned out to be a myopic decision. Kodak was trying to benchmark the quintessential photo storage medium, evidently not realizing that the digital revolution was obliterating artificial boundaries between “photo storage” and other sorts of data storage. Kodak, by sticking to its old school philosophy that the photo is king, failed to see that there would never be a sustainable market for what it wanted to sell.

The company also courted the professional photojournalism market with a $13,000 digital retrofit camera that used a Nikon film body–the Kodak DCS-100–but it was slow to transition into the consumer market and fell behind competitors (including Nikon) that were closer to making the technology affordable to nonprofessionals.

Kodak did eventually make more aggressive moves into the digital tech business. By this time, most of the old guard of the corporation was gone and Kodak was recruiting from companies like Lexmark to re-create its brand image as a digital leader. Kodak sought to become the master of digital printing and was forging headlong into the self-service digital printing kiosk business, among others.

The problem Kodak would face in all of these new ventures is that it was too late to own any facet of the market. Whether fighting for territory in the printer or digital camera markets, it was always perilously behind well established players. The investment required to ramp up in those markets generated a debt load that outpaced the company’s ability to generate revenue, and that cycle can continue for only so long.

Which brings us to the present, with fears of impending bankruptcy sending Kodak stock plummeting from $2.38 a share to 78 cents within a week. For me, it’s sad to see one of the country’s greatest homegrown brands fall, especially since Kodak was such a dominant force for much of my life.  It has also been sad to watch the decline of Kodak’s (and my) hometown, Rochester, which has taken the brunt of the company’s decline.

The fall of the company that George Eastman built is perhaps the most salient commentary on the new economy in recent memory, and tells an unfortunate story about much of America’s industrial base. Monolithic, inflexible and unable to keep up with the shifts and turns of disruptive technology, once great companies like Kodak can’t survive without exhaustive restructuring. Hopefully, other U.S. companies have been watching and learning.

Days at Four Seasons Bora Bora slip by in a haze. Usually they include a spot of sunbathing on the terraces of guests’ over-water villas, but they could also include learning to paddle surf, snacking on seafood salads at the Faré Hoa beach bar, soaking in tubs with mountain views and snorkelling in the resort's fabulous Ruahatu Lagoon Sanctuary, where you can spot more than 100 species from octopus to eagle rays. The entrance of the dramatic cathedral-like spa looks like a temple and, melting to putty during a hot stone massage in the Kahaia couples suite as fish shimmer under the glass floor beneath you, it’s hard not to feel a little closer to heaven.

Travel to the past is probably impossible. But to the future? That’s a different story. Cathal O'Connell considers the feasibility of physics.

In 2009 the British physicist Stephen Hawking held a party for time travellers – the twist was he sent out the invites a year later. (No guests showed up.)
Travel into the past is probably impossible. Even if it were possible, Hawking and others have argued that you could never travel back before the moment your time machine was built.
But travel to the future? That’s a different story.
Of course, we are all time travellers as we are swept along in the current of time, from past to future, at a rate of one hour per hour.
But, as with a river, the current flows at different speeds in different places. Science as we know it allows for several methods to take the fast-track into the future. Here’s a rundown.
This is the easiest and most practical way to get to the far future – go really fast.
According to Einstein’s theory of special relativity, when you travel at speeds approaching the speed of light, time slows down for you relative to the outside world.
This is not a just a conjecture or thought experiment – it’s been measured. Using twin atomic clocks (one flown in a jet aircraft, the other stationary on Earth) physicists have shown that a flying clock ticks slower, because of its speed.
In the case of the aircraft, the effect is minuscule. But If you were in a spaceship travelling at 90% of the speed of light, you’d experience time passing about 2.6 times slower than it was back on Earth.
And the closer you get to the speed of light, the more extreme the time-travel.
The highest speeds achieved through any human technology are probably the protons whizzing around the Large Hadron Collider at 99.9999991% of the speed of light. Using special relativity we can calculate one second for the proton is equivalent to 27,777,778 seconds, or about 11 months, for us.
Amazingly, particle physicists have to take this time dilation into account when they are dealing with particles that decay. In the lab, muon particles typically decay in 2.2 microseconds. But fast moving muons, such as those created when cosmic rays strike the upper atmosphere, take 10 times longer to disintegrate. Gravity can slow down time.CREDIT: WIKIMEDIA COMMONSThe next method is also inspired by Einstein. According to his theory of general relativity, the stronger the gravity you feel, the slower time moves.
As you get closer to the centre of the Earth, for example, the strength of gravity increases. Time runs slower for your feet than your head.
Again, this effect has been measured. In 2010, physicists at the US National Institute of Standards and Technology (NIST) placed two atomic clocks on shelves, one 33 centimetres above the other, and measured the difference in their rate of ticking. The lower one ticked slower because it feels a slightly stronger gravity.
To travel to the far future, all we need is a region of extremely strong gravity, such as a black hole. The closer you get to the event horizon, the slower time moves – but it’s risky business, cross the boundary and you can never escape.
And anyway, the effect is not that strong so it’s probably not worth the trip.
Assuming you had the technology to travel the vast distances to reach a black hole (the nearest is about 3,000 light years away), the time dilation through travelling would be far greater than any time dilation through orbiting the black hole itself.
(The situation described in the movie Interstellar, where one hour on a planet near a black hole is the equivalent of seven years back on Earth, is so extreme as to be impossible in our Universe, according to Kip Thorne, the movie’s scientific advisor.)
The most mindblowing thing, perhaps, is that GPS systems have to account for time dilation effects (due to both the speed of the satellites and gravity they feel) in order to work. Without these corrections, your phones GPS capability wouldn’t be able to pinpoint your location on Earth to within even a few kilometres.How the television show Lost in Space envisioned the future.CREDIT: WIKIMEDIA COMMONS.Another way to travel to the future may be to slow your perception of time by slowing down, or stopping, your bodily processes and then restarting them later.
Bacterial spores can live for millions of years in a state of suspended animation, until the right conditions of temperature, moisture, food kick start their metabolisms again. Some mammals, such as bears and squirrels, can slow down their metabolism during hibernation, dramatically reducing their cells’ requirement for food and oxygen.
Could humans ever do the same?
Though completely stopping your metabolism is probably far beyond our current technology, some scientists are working towards achieving inducing a short-term hibernation state lasting at least a few hours. This might be just enough time to get a person through a medical emergency, such as a cardiac arrest, before they can reach the hospital.
In 2005, American scientists demonstrated a way to slow the metabolism of mice (which do not hibernate) by exposing them to minute doses of hydrogen sulphide, which binds to the same cell receptors as oxygen. The core body temperature of the mice dropped to 13 °C and metabolism decreased 10-fold. After six hours the mice could be reanimated without ill effects.
Unfortunately, similar experiments on sheep and pigs were not successful, suggesting the method might not work for larger animals.
Another method, which induces a hypothermic hibernation by replacing the blood with a cold saline solution, has worked on pigs and is currently undergoing human clinical trials in Pittsburgh.The artist Kjordand's impression of a wormhole.CREDIT: WIKIMEDIA COMMONSGeneral relativity also allows for the possibility for shortcuts through spacetime, known as wormholes, which might be able to bridge distances of a billion light years or more, or different points in time.
Many physicists, including Stephen Hawking, believe wormholes are constantly popping in and out of existence at the quantum scale, far smaller than atoms. The trick would be to capture one, and inflate it to human scales - a feat that would require a huge amount of energy, but which might just be possible, in theory.
Attempts to prove this either way have failed, ultimately because of the incompatibility between general relativity and quantum mechanics.
Another idea, put forward by the American physicist Ron Mallet, is to use a rotating cylinder of light to twist spacetime. Anything dropped inside the swirling cylinder could theoretically be dragged around in space and in time, in a similar way to how a bubble runs around on top your coffee after you swirl it with a spoon.
According to Mallet, the right geometry could lead to time travel into either the past and the future.
Since publishing his theory in 2000, Mallet has been trying to raise the funds to pay for a proof of concept experiment, which involves dropping neutrons through a circular arrangement of spinning lasers.
His ideas have not grabbed the rest of the physics community however, with others arguing that one of the assumptions of his basic model is plagued by a singularity, which is physics-speak for “it's impossible”.
1. Speed
2. Gravity
3. Suspended animation
4. Wormholes
5. Using light