Steel-Belted Silence
Automobiles leave mountains of used tires: Two billion tires have accumulated in piles across the United States alone. Researchers at the Instituto de Acstica in Madrid, Spain, are using this waste to ameliorate another environmental impact of the automobile by packing crumbs of rubber from discarded tires into highway sound barriers.
Rubber turns out to have a broad sound absorption spectrum well-suited to traffic noise, and the tire crumbs stand up better to rain and dust than the glass and rock wool used in traditional sound barriers. Reverberation room tests have shown that the smaller the rubber crumbs are, the better they absorb sound. In June, the Madrid researchers tested a full-scale prototype barrier made with the recycled rubber.
Keep Reading
Most Popular
Geoffrey Hinton tells us why he’s now scared of the tech he helped build
“I have suddenly switched my views on whether these things are going to be more intelligent than us.”
Meet the people who use Notion to plan their whole lives
The workplace tool’s appeal extends far beyond organizing work projects. Many users find it’s just as useful for managing their free time.
Learning to code isn’t enough
Historically, learn-to-code efforts have provided opportunities for the few, but new efforts are aiming to be inclusive.
Deep learning pioneer Geoffrey Hinton has quit Google
Hinton will be speaking at EmTech Digital on Wednesday.
Stay connected
Get the latest updates from
MIT Technology Review
Discover special offers, top stories, upcoming events, and more.