Scientific Sunday #1: Acoustic Levitation
Levitation: Something only mastered by very good magicians and movies. No one would think that levitation would be possible in the near future, as we just don’t have the technology to make levitation a reality. Science fiction of the past predicted humans of our time to have invented so much more than we actually have done. There was a group of science fiction writers who predicted that by 2012, we would have had a base on the moon and a human expedition to Mars and possibly evidence of intelligent life elsewhere. Have we come anywhere near to any of the more realistic of those three predictions? No. In fact we’re probably in the same position as in 1987, no closer than before. But what if I told you levitation is possible?A group of scientists have managed to levitate small drops of pharmaceutical solution, but other small objects are possible as well. At the U.S. Department of Energy’s Argonne National Laboratory, using two speakers, managed to place these small drops of solution onto sound waves. As crazy as that sounds (no pun intended), the relation between drug development and technology only dreamt about is there, as these solutions can change state when in contact with any type of solid. Contact means that the drugs will become crystalline, and the drug in this state cannot be absorbed by the body as effectively, which means that you would have to take more of the drug to have the desired effect. The ideal state for the drugs is in a pristine form, so it is more efficient, therefore saving money.
Now to the actual science of acoustic levitation, as it is called. Two small speakers facing each other vertically generate sound waves of frequency 22 kilohertz. When the speakers are correctly aligned, a standing wave is formed, where the sound waves interrupt each other perfectly, almost like two curved lines crossing each other. The acoustic pressure has to be exact so it can cancel the effects of gravity, and there must be no energy transfer. This happens at points called nodes (the two waves ‘crossing’ each other). This means that objects of little mass can ‘balance’ at these points, and effectively levitate.
This is a breakthrough in itself, but what is even more exciting is the new possibilities it opens up. Many of you must have seen the Back to the Future trilogy, or at least heard about it. In the second movie, Marty McFly travels to 2015 to save his children, and encounters many technologies that people during the 1980s thought would have existed by now. One of the more famous gadgets was the hover board. This is quite self-explanatory; it’s a levitating skateboard. Could this recent scientific breakthrough mean that this could be possible by 2015? I know this may be a more of a long shot, as it is acoustic levitation, and you can’t make the ground a speaker, but what if you could? There could be speakers underneath the board or something, I’m not a genius, but I can’t stay calm with the idea that this is our future.
For all you sci-fi fans out there who would love a 1980s 2015, we’re on our way, and don’t worry, science has got this.
How do you feel about science fiction technology becoming a reality? Tell us in the comments below.
Posted on October 7, 2012, in Scientific Sundays and tagged Acoustic levitation, Argonne National Laboratory, Back to the Future, Back to the Future trilogy, Mars, Marty McFly, McFly, NASA, Science fiction, Sound, Sound pressure, Standing wave, United States Department of Energy. Bookmark the permalink. 3 Comments.