Guide dogs are great, but vision-impaired people sometimes need to find their own way through complex environments. Instead of checking for obstacles with a trademark white stick, inventor Steve Hoefer has another idea: Use wrist-mounted sonar.
Cities can only do so much to improve bicyclists’ safety — bike lanes and automatic traffic light sensors are great, but motorists are really the ones who have to pay attention for bike riders to be safe. An intrepid mechanical engineer has one solution: Make bike lights as obvious as car lights.
Why can some animals regenerate limbs but humans cannot?
All organisms, including humans, have the ability to regenerate something in the body. But the process is much more developed in lower organisms such as plants, protists -- unicellular organisms such as bacteria, algae, and fungi and many invertebrate animals such as earthworms and starfish. These organisms can grow new heads, tails, and other body parts when injured.