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.
Five poems about the mind
Work reinvented: Tech will drive the office evolution
As organizations navigate a new world of hybrid work, tech innovation will be crucial for employee connection and collaboration.
I taught myself to lucid dream. You can too.
We still don’t know much about the experience of being aware that you’re dreaming—but a few researchers think it could help us find out more about how the brain works.
Is everything in the world a little bit conscious?
The idea that consciousness is widespread is attractive to many for intellectual and, perhaps, also emotional
reasons. But can it be tested? Surprisingly, perhaps it can.
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