Time reversal technology probes blue cheese and red planet alike

This post is written in response to the contest I posted on my Twitter feed earlier today:

SciencePunk challenge: give me two unrelated topics and I will attempt to write a blog post combining them. Your time starts now.

Of several excellent and perplexing replies, I decided to seize the gauntlet thrown down by Martin of The Lay Scientist blog:

@SciencePunk Pigs, and the flu. No? Oh alright... erm... Mars and cheese.

So here it is Martin!

* * *

If you heard the words "time reversal technology" you'd be forgiven for thinking it was a plot point from the new Star Trek movie. Yet across the world, physicists and engineers are using it to explore the world around them, from astronomy to cheese-making.

Whenever waves pass through a medium, they respond to changes in the properties of that material. Sound waves passing through the ocean, for example, are warped and garbled by differences in the density of the water, making acoustic communication with submarines troublesome. Similarly, astronomers are vexed by atmospheric blurring, where the turbulent gasses that cocoon our planet can distort an otherwise BAT-worthy image of Mars.

However, help is at hand. Time reversal technology replays the signal in reverse, and subtracts this from the original. Because the distortions cancel out one another, the result is a much cleaner image or sound. You can read an incredibly complex article about it here.

So what does this have to do with cheese? Later this month, a group of French and Uruguayan scientists will attend a conference in Portland, Oregon, to discuss their work using the same technology to probe "soft solids". Directing acoustic waves through a material, they are using time reversal to analyse the distortions and draw conclusions about the properties of that object. This low-cost technology has various applications in the food industry, e.g. allowing cheese makers to test the ripeness of their Brie stock.

And that is how you combine Mars and cheese in a blog post.
Image is a composite, CC two Flickr members: Jason Burmeister and psd.

More like this

Talking to submarines is a very a tricky business - most communication systems are based on radio or acoustic signals, but neither travel very far in water. This means that to pick up radio signals, submarines must surface or raise communication buoys very close to the surface, neither of which…
Today, NASA announced three future key missions preselected as part of the Discovery program named GEMS, TiME and Comet Hopper. This is an important announcement, which was eagerly expected by our community. The NASA Discovery program is a low-cost mission ($425 million FY2010) program aimed at…
From the great Harold McGee comes an investigation into raw milk, bacteria and cultural evolution: On our journey up to the Stichelton Dairy last September, Mr. Hodgson [a cheesemaker] explained how cheese quality progressed for centuries, then declined in the age of mass production and…
"I have never gone out of fashion. And do you know why? Because I never sought it. When you don't seek it, it's always with you." -Bonnie Tyler Well folks, it's summer, and that means a lot of things for a lot of people, including for me! So, some fun announcements: I have an official pre-release…