Want to freeze an object using the power of your mind? Watch the spinning objects in this video and they will suddenly appear to stop moving. However, they never actually freeze and are constantly turning at a steady rate.
The illusion, created by researcher Max Dürsteler from University Hospital Zurich, uses a swaying background to trick our perception. When it rotates faster than the object in the foreground, and in the same direction, the object seems to slow down. But when the background moves in the opposite direction, the figure in the middle appears to speed up.
In the first two examples, the background is distinct from the image on top of it. But in a third clip, the rotating figure blends in with the background, making the illusion more pronounced. In a final example, where background and foreground are contrasting once again, the backdrop rotates at a constant rate while the central figure sways back and forth. With this role reversal, the illusion is lost.
While researchers are still investigating how this illusion works, Dürsteler suspects that our brain has a bias towards seeing objects as stationary. Motion is usually perceived in one of three states: either in or out of sync with its surroundings or stationary in relation to the observer
Think flies aren't acrobatic? In this video, a fly performing an aerial somersault has been filmed in nature for the first time. The move is seldom observed in real time due to its speed, but Joris Schaap and Emile van Wijk managed to capture the behaviour using a high-speed camera. The escape manoeuvre is performed when a fly is taken by surprise, allowing it to regain control during the tumble.
The same behaviour in fruit flies has been observed in the lab by biologists Michael Dickinson from the University of Washington and Gwyneth Card from the Howard Hughes Medical Institute. Dickinson and Card typically study fruit flies in flight, for example to find out more about wing dynamics and how the brain translates decisions into motion.
The short film is one of the winners in a competition organised by the Flight Artists group at Wageningen University in the Netherlands. The team taught amateur filmmakers how to use high-speed cameras to capture flying animals, or plant seeds, and selected the best results.
Ever wondered why some stones are round while others are flat? In our latest One-Minute Physics episode, producer Henry Reich teams up with illustrator Zach Weiner from SMBC Comics to explain how gravity is involved in stone formation.
Leys has appropriately nicknamed the space-filling curve a 'spaghetti factory'. Its noodle-like strands quickly envelop the screen and if it were allowed to continue growing, it would eventually fill the whole of 3D space.
The artificial tail can be actively controlled to swing up or down, counteracting the mass of the robot's main body. In this video, you can see how it helps the robot when it's dropped nose-first during a trial. With a quick swing of the tail, the robot rights itself and lands with its wheels on the ground. A second clip shows how the tail is also useful during ground-based manoeuvres. Rolling over bumps causes a tail-less version of the bot to lose control, landing helplessly on its side. But with the extra appendage, it gets a slight boost which keeps it horizontal, allowing it to hop over the obstacles and continue on its way.
Such biologically inspired engineering could be incorporated into robots operating in rough terrain to facilitate search-and-rescue operations.
Don't believe your eyes as you watch this video: although the rectangles moving in sync suddenly seem to shuffle, their motion hasn't actually changed. Keep watching when a backdrop of morphing stripes appears and a caterpillar-like motion can be seen.
Created by graduate student Sebastiaan Mathôt from VU University of Amsterdam, the brain trick occurs when the background is striped rather than solid, an illusion originally developed by researcher Stuart Anstis from University of California, San Diego. The effect is caused by the influence of contrast on motion. When there is a big difference in contrast between a moving object and its background, it appears to move faster than when brightness levels are similar.
Ever wish you could cover up an embarrassing event? By getting your hands on a time cloak, you could make it seem like it never happened.
Now, a new animation by Moti Fridman and his team at Cornell University, who have developed a technology that can hide superfast events, demonstrates how such a device would work. It shows how a stealthy ball can sneak by a laser beam thanks to a series of light tricks that mask an event over a specific period of time.
The demo shows how manipulating the laser beam creates an opportune time gap. Laser pulses, shown in red, break the signal beam, denoted in green, into a rainbow of different wavelengths that travel at different speeds. This change creates an opening in the beam where the ball can pass. The effect is then reversed with another pulse of light to make the change undetectable.
So far, the team has used the effect to edit out 15 picoseconds as a light beam passed through filters. However, the technique could be developed for a range of applications, for example to hide data moving through fibre optic cables to prevent eavesdropping.
At 5000 metres below the surface of the Caribbean Sea, this scorching black smoker vent is the deepest discovered to date. The minerals from the hydrothermal plume support a robust community of animals, including a previously unknown species of shrimp sporting a light-sensing organ.
Read our full article to find out more about this unusual deep sea habitat.
It may look like a prank but these mathematics students from St. Mark's School in Southborough, Massachusetts aren't toilet papering the famed infinite corridor at MIT. Using intricate choreography and brute force, they're breaking a paper-folding record by completing 13 folds, a challenge that students at the school have been tackling for seven years with the help of teacher James Tanton.
Based on the thickness of a sheet of paper, a formula can be used to calculate the minimum length needed to fold it a given number of times. Paper roughly doubles in size with each fold and the sides become more rounded, making it harder and harder to bend. Wrinkles also have a significant impact, making the formula difficult to follow in practice. In addition, no single roll is long enough to fold thirteen times, requiring the group to tape together numerous rolls of industrial toilet paper 1.2 kilometers long.
In this One-Minute physics episode, animator Henry Reich takes us on a field trip to show how the Italian researchers measured the groundbreaking neutrino speed.
