# 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.

Photo: Getty
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# The science and technology committee debacle shows how we're failing women in tech

It would be funny if it wasn’t so depressing.

Five days after Theresa May announced, in her first Prime Minister’s Questions after the summer recess, that she was "particularly keen to address the stereotype about women in engineering", an all-male parliamentary science and technology committee was announced. You would laugh if it wasn’t all so depressing.

It was only later, after a fierce backlash against the selection, that Conservative MP Vicky Ford was also appointed to the committee. I don’t need to say that having only one female voice represents more than an oversight: it’s simply unacceptable. And as if to rub salt into the wound, at the time of writing, Ford has still not been added to the committee list on parliament's website.

To the credit of Norman Lamb, the Liberal Democrat MP who was elected chair of the committee in July, he said that he didn't "see how we can proceed without women". "It sends out a dreadful message at a time when we need to convince far more girls to pursue Stem [Science, Technology, Engineering and Mathematics] subjects," he added. But as many people have pointed out already, it’s the parties who nominate members, and that’s partly why this scenario is worrying. The nominations are a representation of those who represent us.

Government policy has so far completely failed to tap into the huge pool of talented women we have in this country – and there are still not enough women in parliament overall.

Women cannot be considered an afterthought, and in the case of the science and technology committee they have quite clearly been treated as such. While Ford will be a loud and clear voice on the committee, one person alone can’t address the major failings of government policy in improving conditions for women in science and technology.

Study after study has shown why it is essential for the UK economy that women participate in the labour force. And in Stem, where there is undeniably a strong anti-female bias and yet a high demand for people with specialist skills, it is even more pressing.

According to data from the Women’s Engineering Society, 16 per cent of UK Stem undergraduates are female. That statistic illustrates two things. First, that there is clearly a huge problem that begins early in the lives of British women, and that this leads to woefully low female representation on Stem university courses. Secondly, unless our society dramatically changes the way it thinks about women and Stem, and thereby encourages girls to pursue these subjects and careers, we have no hope of addressing the massive shortage in graduates with technical skills.

It’s quite ironic that the Commons science and technology committee recently published a report stating that the digital skills gap was costing the UK economy £63bn a year in lost GDP.

Female representation in Stem industries wasn’t addressed at all in the government’s Brexit position paper on science, nor was it dealt with in any real depth in the digital strategy paper released in April. In fact, in the 16-page Brexit position paper, the words "women", "female" and "diversity" did not appear once. And now, with the appointment of the nearly all-male committee, it isn't hard to see why.

Many social issues still affect women, not only in Stem industries but in the workplace more broadly. From the difficulties facing mothers returning to work after having children, to the systemic pay inequality that women face across most sectors, it is clear that there is still a vast amount of work to be done by this government.

The committee does not represent the scientific community in the UK, and is fundamentally lacking in the diversity of thought and experience necessary to effectively scrutinise government policy. It leads you to wonder which century we’re living in. Quite simply, this represents a total failure of democracy.

Pip Wilson is a tech entrepreneur, angel investor and CEO of amicable