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.

Getty
Show Hide image

“Stinking Googles should be killed”: why 4chan is using a search engine as a racist slur

Users of the anonymous forum are targeting Google after the company introduced a programme for censoring abusive language.

Contains examples of racist language and memes.

“You were born a Google, and you are going to die a Google.”

Despite the lack of obscenity and profanity in this sentence, you have probably realised it was intended to be offensive. It is just one of hundreds of similar messages posted by the users of 4chan’s Pol board – an anonymous forum where people go to be politically incorrect. But they haven’t suddenly seen the error of their ways about using the n-word to demean their fellow human beings – instead they are trying to make the word “Google” itself become a racist slur.

In an undertaking known as “Operation Google”, some 4chan users are resisting Google’s latest artificial intelligence program, Conversation AI, by swapping smears for the names of Google products. Conversation AI aims to spot and flag offensive language online, with the eventual possibility that it could automatically delete abusive comments. The famously outspoken forum 4chan, and the similar website 8chan, didn’t like this, and began their campaign which sees them refer to “Jews” as “Skypes”, Muslims as “Skittles”, and black people as “Googles”.

If it weren’t for the utterly abhorrent racism – which includes users conflating Google’s chat tool “Hangouts” with pictures of lynched African-Americans – it would be a genius idea. The group aims to force Google to censor its own name, making its AI redundant. Yet some have acknowledged this might not ultimately work – as the AI will be able to use contextual clues to filter out when “Google” is used positively or pejoratively – and their ultimate aim is now simply to make “Google” a racist slur as revenge.


Posters from 4chan

“If you're posting anything on social media, just casually replace n****rs/blacks with googles. Act as if it's already a thing,” wrote one anonymous user. “Ignore the company, just focus on the word. Casually is the important word here – don't force it. In a month or two, Google will find themselves running a company which is effectively called ‘n****r’. And their entire brand is built on that name, so they can't just change it.”

There is no doubt that Conversation AI is questionable to anyone who values free speech. Although most people desire a nicer internet, it is hard to agree that this should be achieved by blocking out large swathes of people, and putting the power to do so in the hands of one company. Additionally, algorithms can’t yet accurately detect sarcasm and humour, so false-positives are highly likely when a bot tries to identify whether something is offensive. Indeed, Wired journalist Andy Greenberg tested Conversation AI out and discovered it gave “I shit you not” 98 out of 100 on its personal attack scale.

Yet these 4chan users have made it impossible to agree with their fight against Google by combining it with their racism. Google scores the word “moron” 99 out of 100 on its offensiveness scale. Had protestors decided to replace this – or possibly even more offensive words like “bitch” or “motherfucker” – with “Google”, pretty much everyone would be on board.

Some 4chan users are aware of this – and indeed it is important not to consider the site a unanimous entity. “You're just making yourselves look like idiots and ruining any legitimate effort to actually do this properly,” wrote one user, while some discussed their concerns that “normies” – ie. normal people – would never join in. Other 4chan users are against Operation Google as they see it as self-censorship, or simply just stupid.


Memes from 4chan

But anyone who disregards these efforts as the work of morons (or should that be Bings?) clearly does not understand the power of 4chan. The site brought down Microsoft’s AI Tay in a single day, brought the Unicode swastika (卐) to the top of Google’s trends list in 2008, hacked Sarah Palin’s email account, and leaked a large number of celebrity nudes in 2014. If the Ten Commandments were rewritten for the modern age and Moses took to Mount Sinai to wave two 16GB Tablets in the air, then the number one rule would be short and sweet: Thou shalt not mess with 4chan.

It is unclear yet how Google will respond to the attack, and whether this will ultimately affect the AI. Yet despite what ten years of Disney conditioning taught us as children, the world isn’t split into goodies and baddies. While 4chan’s methods are deplorable, their aim of questioning whether one company should have the power to censor the internet is not.

Google also hit headlines this week for its new “YouTube Heroes” program, a system that sees YouTube users rewarded with points when they flag offensive videos. It’s not hard to see how this kind of crowdsourced censorship is undesirable, particularly again as the chance for things to be incorrectly flagged is huge. A few weeks ago, popular YouTubers also hit back at censorship that saw them lose their advertising money from the site, leading #YouTubeIsOverParty to trend on Twitter. Perhaps ultimately, 4chan didn't need to go on a campaign to damage Google's name. It might already have been doing a good enough job of that itself.

Google has been contacted for comment.

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