Scientists can levitate stuff and make it fly around using sound

Japanese scientists have made hundreds of tiny plastic balls float around like miniature spaceships.

Today’s news from the world of Awesome Science comes from the University of Tokyo, where a team has been levitating and controlling objects using sound. Here’s the video:

As the video points out at the beginning, levitation of objects using sound has been around for a few years. If you’ve ever stood in front of a large speaker you’ll know that they can pump out what feels like quite a forceful blast of air as they vibrate - but, somewhat deceptively, that’s not quite the whole story.

Rather than physically push air out from the speaker, what you’re experiencing is a wave of compression moving through the air. The speaker compresses a packet of air, which then “rolls” through the room, with the size of the compressed air corresponding the wavelength of the sound wave. And, just like sound waves, waves that overlap each other create new waves.

To levitate something just requires creating a standing wave. Think of it like this - if you’re watching a sound wave plotted out on a graph, it’ll be rolling along, going up and down as it oscillates. A standing wave occurs when two or more waves combine to create a new wave where, as the wave oscillates, there are points where there’s no movement. They’re called nodes.

Here’s a gif to illustrate how that works. The blue and green waves are combining to create the red wave, which has those points on the central axis that aren’t moving:

(Image: Wikimedia Commons)

If a speaker outputs a standing wave, in the most basic sense it means that it won’t feel like the areas of compression - those blasts of air - are moving. The gaps between those blasts of air will be positions of neutral force, with air pressure pushing in on it from both directions. If you stick an object in there that’s light enough, and smaller that the size the gap (which will be the sound’s wavelength), the force of the air should keep it floating in a stable position.

What the Tokyo University team has done is build upon that idea, by combining sound waves in three dimensions. The video shows not just tiny little plastic balls being levitated and controlled, but also resistors, LEDs, screws, bolts, and other small items. Rhett Allain at Wired worked out that you could levitate anything both smaller than 8mm and less dense than 1,000kg/m3, which is tiny - but it does have practical applications, particularly when people are working with sterile things they want to move but can't touch, like spaceship parts or medicines.

Ian Steadman is a staff science and technology writer at the New Statesman. He is on Twitter as @iansteadman.

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Why are online jokes funnier without punctuation and capital letters?

Academics and social media users weigh in on Twitter’s most unexplained phenomenon. 

The first person to notice it did so in 2010. “Sometimes I think a twitter joke is funnier if you omit punctuation,” tweeted @zacharylittle on 2 April. He was a pioneer. It took two years for anyone else to express the same thought, but they did so in droves. “I like not using punctuation like commas on twitter because its somehow funnier lol,” said @chxrliesheen, sans apostrophe. “I never use punctuation on twitter and tumblr I just think its funnier ok,” exclaimed @julieamarch. From then until now, people have been constantly questioning the phenomenon, but there are still no answers.

Why exactly are Twitter jokes funnier when they have grammatical errors, discard punctuation, lack capital letters, or are misspelled?

“There is a frisson, or sense of pleasure, from playfulness in language,” Dr Deborah Tannen, a professor of linguistics at Georgetown University, tells me over email – in which she demonstrates some of this playfulness herself. “writing wihtout caps, proper punctation, and leaving misspellings uncorrected also feels like private communication, like whispered kjokes, and therefore has the same potential thrill.”

Dr Hugh Rabagliati, a Chancellor's Fellow at the School of Philosophy, Psychology, and Language Sciences at the University of Edinburgh, warns me that most of his knowledge on the subject comes from “spending too much time on Twitter, rather than any obvious academic work”. It is true that research into the area is lacking – books about “internet language” get outdated quickly, and seem to focus on email and chatrooms, rather than more modern social media. “The misspellings [on Twitter] are often beautifully calibrated, like a very subtle malapropism, and the grammar errors are designed to make familiar material feel out of kilter,” he says.

Sometimes humour is found when grandiose sentiments are contrasted with train-wreck grammar, he argues, whereas other times the language can be exclusionary and people share it to prove they “get” the joke.

Perhaps the most famous Twitter user who has mastered the technique of the misspelled tweet is Jonathan Sun. Sun has gained 168,000 followers posing as an “aliebn confuesed abot humamn lamgauge”, and is part of what is known as “weird Twitter”, a subset of the site where humour is surreal and often bolstered by misspellings, a lack of punctuation, and grammatical errors. But while “weird Twitter” takes it to the extreme, many other arguably “normal” Twitter users will uncap the start of their Tweets or the word “I”.

“i’m not really sure why but i’ve been going out of my way to un-cap for ages,” one anonymous Twitter user told me via a direct message on the site. “i recognise that it is a stupid waste of time, ive had partners mock me for it.” Possibly, they theorise, they do this because they used to edit copy as part of their job. “it could be a reaction to that, to be completely armchair psychology about it.”

Naomi Baron, a professor of linguistics at American University and author of Words Onscreen: The Fate of Reading in a Digital World reinforces this point. She argues that language users are always looking for ways to distinguish their voices and express emotion. “A bevy of authors – from the poet e.e. cummings to social media scholar danah boyd – have further personalised their identity by eschewing the normal capitalisations in their names,” she says. “When it comes to social networking sites such as Twitter, lack of capital letters lends a tone of informality that makes the messages feel more speech-like.”

It’s hard to admit that you’re deliberately making mistakes in order to look offhand, as you are essentially revealing you try-very-hard-to-look-like-you’re-not-trying-at-all. But Rebecca Reid, a 25-year-old journalist, admits this is why she used to uncap her tweets. “Honestly I literally thought it made me look cooler,” she says. “I saw my sister doing it, and she's a couple of years younger and very trendy, so I thought it was just what we were doing. So I copied her. This is so tragic from me. And after a while I realised that it wasn't making me seem edgy, it was making it seem like the shift button on my key board was broken.”

It is true that informality is important in written messages, as a 2015 study revealed that ending text messages with a full stop was perceived to be insincere, most likely because it is seen as a sign of aggression. Twitter jokes that are written similarly formally – with full stops and capital letters – might also seem insincere, or be less inviting or inclusive than those with deliberate mistakes, run-on sentences, or five-too-many exclamation marks.

“There's also a phenomenon that linguists have only started discussing in the last decade, called ‘Eggcorns’,” says Rabagliati. “Here the speaker has learned a misanalysed locution. The phenomenon is named from the case of a woman who had, all her life, misheard the word acorn as ‘eggcorn’. ‘To all intensive purposes’ is a similar error. These mistakes play on our fear that our knowledge of language might not be as robust as we want to believe – think about all those words that you've read, but never heard aloud. Plus, the errors are fun because they demand some backwards reasoning to reconstruct.” 

More academic research is needed for a final answer on the phenomenon, but one thing is certain. If uncapitalising things on Twitter is cool, writing an 800-word article about it certainly isn't. 

Amelia Tait is a technology and digital culture writer at the New Statesman.