Time travel in the real world isn't yet possible. But thanks to new physics flicks, you can now experience an alternate universe to see what it might look like.
Developed by Wolfgang Schleich and colleagues at the University of Ulm in Germany, these first time-travel videos mathematically recreate the weird world of Gödel's universe. In the first clip, a camera is placed at the centre of this cylindrical universe, simulating what an Earth-like object would look like. Because light behaves differently in this space, as the sphere moves away from you, you see an image of both the front and the back. If it moves above you, it appears as a collection of slices. During its orbit, you see many versions from different time periods all at once.
If your friend has a more efficient way of getting food, it makes sense to copy them. Now an experiment is showing for the first time that chimps also come to the same conclusion.
Captured by Shinya Yamamoto from Kyoto University in Japan and colleagues, this video shows how a chimp improves its use of a straw after observing a more proficient companion. At first, it uses the tool almost like an eye-dropper, dipping it in a box to sop up juice. But after it watches its friend drink faster by sucking on the straw, it learns to adopt this new approach. According to the team, which studied nine chimps, once an ape switched to straw-sucking, it never went back to the less efficient dipping technique.
A working tractor beam has now been caught on video, showing how light can pull objects - on a microscopic scale.
While it's well known that light can push objects as they follow the flow of photons, attracting them isn't as simple. By shining a laser through a lens and mirror set-up, Tomas Cizmar from the University of St Andrews in the UK and colleagues were able to reverse the effect, thanks to the interference pattern of reflected beams. Their technique works both in liquids and in a vacuum.
In this video, the first clip shows how the system can be used to separate objects of different sizes. When a tractor beam in the centre of a mixture of particles is turned on, large spheres move left towards the light, while smaller ones are pushed to the right.
A second clip shows how the beam can pull a collection of particles. "When the right configuration of particles occurs the tractor beam makes it stable and the whole structure moves against the tractor beam," says Cizmar.
We recently showed you a speedy cardboard cockroach, ranked as one of the fastest robots in the world. But its tailed relative is equally impressive: it can turn precisely without slowing down, allowing it to corner more rapidly than any other legged robot to date.
We interact with the concept of mass every day. Without it, gravity wouldn't keep us firmly planted on Earth. But mass is also a component of inertia, making it hard, for example, to push a stalled car.
Even after death, this parrot retains its striking plumage. But its feathers and tissue disappear when subjected to flesh-eating beetles for about three weeks, leaving behind a grisly skeleton.
The video, captured by Brian McClave from Site-Eye Films in collaboration with Joanne Cooper from the Natural History Museum at Tring, UK, shows the process often used by museums to prepare a skeleton for their collections. Beetles are best for stripping a bird's flesh since chemical alternatives can eat into bone and change its structure. To speed up decomposition, specimens are usually defeathered before beetles are left to do their work.
Think fleas aren't capable of circus tricks? In Victorian London, they were the stars of a popular sideshow that could soon be resurrected in the UK.
Tim Cockerill from the University of Cambridge, who made this video, hopes to revive the act that declined with the advent of the vacuum cleaner - which decimated the flea supply. Now he typically gets hold of the insects from a hedgehog sanctuary. "Hedgehogs are famously infested, so the fleas are easy to get hold of, and they're quite strong," he says.
Does objective reality exist? Is there an underlying truth that doesn't depend on the observer?
According to quantum physics, there may be no consistent reality. Not only do we change the outcome of experiments by what we choose to measure, but we can alter those results after they've already happened.
In this animation, find out how our choices of what to observe can change what actually happens, and what that means for our understanding of reality. A classic experiment illustrates the conundrum by attempting to measure whether a photon behaves as a particle or a wave. It turns out that it can be either, or a mixture of both, depending on how the experiment is set up.
It may be considered poor form in the human dating game, but cannibalistic sex is common practice among hump-winged grigs. This video shows a female insect feasting on her partner's hind wings then drinking the blood from his wound, apparently with little interest in procreation. The male isn't completely passive though: he uses a hook on his abdomen to catch the female, linking their genitals together.