EVOLVE
How animals have helped us to advance our technology
ECHOLOCATION
EVOLVE
HOW CAN ECHOLOCATION CAN HELP VISUAL IMPAIRMENT? “Bats are not blind” In fact they can see almost as well as humans. But to fly around and hunt for insects in the dark, they use a remarkable high frequency system called echolocation.
Echolocation works in a similar way to sonar. Bats make calls as they fly and listen to the returning echoes to build up a sonic map of their surroundings. The bat can tell how far away something is by how long it takes the sounds to return to them. These calls are usually pitched at a frequency too high for adult humans to hear naturally. Human hearing ranges from approximately 20Hz (cycles per second) to 15 to 20 kHz
(1000Hz) depending on age. In comparison, some bats can hear sounds up to 110 kHz in frequency. By emitting a series of often quite loud ultrasounds that either sweep from a high to low frequency or vary around a frequency, bats can distinguish objects and their insect prey and therefore avoid the object or catch the insect. Individual bat species echolocate within specific frequency ranges that suit their environment and prey types. This means that we can identify many bats simply by listening to their calls with bat detectors.
Echolocation sound wave
2
“ Advantages of Echolocation for Blind Mobility over the White Cane” We all recognise the white cane and understand how it helps blind people with their mobility. This object has been around for nearly 100 years and has become an accepted outward sign of visual impairment. People still find it useful and are reluctant to try out the new echolocation system. They’ve got used to using the cane and can’t understand the additional benefits that the new system has to offer. Perhaps they can successfully find their way around known routes and would rather not use something that makes a clicking noise. Looking at the differences between the two systems there is a clear advantage to the new technology. If a visually impaired person comes
3
across an obstacle, when using a cane, it takes quite a time to work out its size and shape as well as its position. You have to collect information by moving and touching different parts of the object before knowing what it is. However, with Echolocation all it takes is one click to give you a full picture of what is around you, instantly. Another important advantage is that with the new device you can locate objects all around you, whether they are on the ground or at head level, in front of you or behind. This makes the process of swinging the cane across the ground in front of you in a semi circle seem very primitive in comparison.
EVOLVE Miracles of Nature As part of the television series, ‘Miracles of Nature’ Richard Hammond will be reporting on the new ‘Bat echolocation’ technology. This week’s programme will show Dan Smith, a blind student from Bristol, facing up to a new challenge, negotiating his way around a course on his mountain bike. This will be the first time that he has been able to ride his bike without a sighted guide, since he lost his sight a year ago. Cycle enthusiast Dan and his brother have the same condition, Leber’s Optic Neuropathy. This very rare form of sight loss is degenerative and leads to an almost complete loss of vision which is caused by damage to cells in the optic nerve. The result
of this is that visual information picked up by the eyes does not get transmitted to the brain. Dan and his brother Michael were asked to test this mobility aid after the makers of the show heard about their cycle ride for charity. Riding on a tandem, the brothers cycled all the way to Amsterdam from their home, with the help of sighted guides. This was such a great achievement. The Ultracane device was fitted to a standard mountain bike to be the riders ‘eyes’. Working in the same way as a bats navigation system, a picture is built up of their surroundings and warnings are given when there is an obstacle on the ground ahead or at head height. Dan talks about how the
handle bars of the bike vibrate on the right or left depending on the location of the object.Although he has an engineering background, the thought of relying on this gadget was a little daunting but he found it really exciting and enjoyed the feeling of independence. He soon got used to using bat technology and found it a really efficient guidance system. He considers it a real step forward in making the lives of visually impaired people easier.The series will continue with more stories of how innovations in science are inspired by the world of nature and the super senses of animals.
KINGFISHERS
Kingfishers hunt by hovering above the water where their prey lives. They wait until the target fish appears in the proper position, and then they drop like a stone to pick the fish out of the water. The hunt is relatively brief, but thoroughly exciting to witness. Visually, they accomplish tasks that are nothing short of astonishing. Each of their two eyes has two foveae. The fovea is the area of an eye with the best vision because of the concentration of visual cells called photoreceptors. You use your fovea for best vision—for example, you are reading this sentence with your foveae.
5
Kingfishers have two foveae in each eye, with one fovea near the beak, and having the best vision by virtue of the highest concentration of photoreceptors. This is the fovea a kingfisher will use to sight its prey during the period of hover. During the drop to the water’s surface, the kingfisher sights the fish with this nasal fovea with the sharpest vision. But, once the kingfisher’s beak hits the water, the fish senses the vibration and shock wave coming from that beak entrance. The fish, being alarmed, may respond by trying to escape in an unpredictable manner, and if the kingfisher can’t react to that movement and direction, the hunt will be unsuccessful.
By the time the kingfisher can determine the direction of the target fish, his eyes will be close to or in the water. This changes the angle of the incoming image because of the index of refraction of water. The kingfisher solves this problem with a second fovea in each eye. Once the eyes are immersed in water, the image of the fish is focused on the second fovea in each eye. That means that there is stereoscopic visualization of the prey as it tries to dart away, an action that is usually not successful.
EVOLVE
“Kingfishers have specialized eyes and excellent eyesight. The retina of each eye has two fovea. The cone cells have a high proportion of red droplets, which may act as chromatic filters, allowing sight through the surface of the water.� (Fowler and Miller 2003: 254)
“Already, the designers are lookingn into applying kingfisher tech to air-sea rescue. Last year, over 5,000 people were successfully rescued from British waters. But a further 300 lost their lives or were never recovered.”
Kingfisher Eye
7
Camera developed on kingfisher eye
EVOLVE
Air-sea rescue teams takes inspiration from the kingfisher... In this episode Richard Hammond looks at sight, and especially that of the kingfisher which has helped to develop a new system to find people lost at sea. This bird has complex vision with different lenses within its eye. It’s a bit like the different types of glasses that humans have when they get older; pairs of glasses to use in various situations such as when reading, driving or looking at the computer. Without getting too technical it’s like the kingfisher is wearing all of
those glasses at the same time. Each of the lenses, which are actually oil droplets, also filters out different light wavelengths. These can be seen clearly under high magnification and enable the kingfisher to see under water. This technology is now used in cameras fitted to the rescue service’s light aircraft and has already led to successful rescues. Yet again ideas from animals have inspired scientists and will benefit the human race.
8
INFRARED
INFRARED SNAKE SENSES CAN BE USED TO FIND SURVIVORS.
Infrared is used by snakes to locate their prey by using thermosensitive pits which are located on their heads. Snakes have evolved over many centuries but boas and pythons still have organs called biods and crotalines with similar structures and functions. These are located between the nostril and the eye of the snake enabling the snake to find its prey by detecting their body temperature and identifying it in terms of infrared wavelengths.
“If the radiation intensity hitting the membrane at some point is larger than the emitted thermal radiation of the membrane itself, the membrane heats up at that location,�
For example pit vipers appear to have a simple hole... at the front of each eye but these in fact contain 1,600 sensory cells. The snake also has a wide field of vision which, when on the lookout for small animals, can pick up on the parts of the body that give out the most heat, usually the eyes. Although their vision is very different to our own it is extremely effective is locating prey using their heat vision. Scientists have found a way to use this in developing technology which can find the survivors of earthquakes and landslides all over the world. These natural disasters can happen without warning and lead to great loss of life and people being trapped in collapsed
9
buildings or under rubble. Special teams need to move quickly to prevent more people dying following such an incident. By using thermal imaging, fibre optics and sound vibration victims can be found several days after the disaster or act of terrorism. This new equipment was used following the 2009 earthquake in Abruzzo, Italy when 300 people lost their lives. Many important buildings collapsed and even the smaller houses had to be checked to make sure that there were no signs of life. This system, based on the senses of the snake, enables emergency services to respond quickly and effectively in saving lives.
EVOLVE
10
POWER OF TIME Monarch butterflies find their way home using sight and time Professor Brian Cox, the famous scientist, explores the uniqueness of life on earth in a programme entitled ‘Wonders of Life.’ This BBC series shows him travelling the world to find examples of animal behaviour which have amazed and influenced scientists. This week he’s in a Mexican forest surrounded by Monarch butterflies whose migration involves them travelling 3,000 miles, the longest journey of any butterfly. Millions of them travel together to escape the cold weather, that would kill them. The butterflies are seen hanging from the pine and oyamel trees in this environment in a state of hibernation. It’s cold here, due to the high altitude, and so they huddle together for warmth. This forest, north-west of Mexico City, is one of the very few places where this phenomenon can be observed.
Inbuilt clocks and compasses Inbuilt clocks and compasses Brian Cox explains how the Monarch butterfly can tell which direction it should travel in to find its way. He demonstrates how to find your way to safety by using your wristwatch, which could help next time you are stranded somewhere inhospitable. We see a colony of Monarchs heading off from the forest but how do they which way is north or south? How does the butterfly manage this without a wristwatch? We all know that the sun rises in the east and goes down in the west but they can’t follow the sun as it moves across the sky during the day. To navigate the butterflies must use a combination of direction and time for navigation. Their eye sight isn’t very good but they can locate the sun, even through cloud. They use this information together with an integral timepiece to work out the direction. Nature holds the key to a lot of our problems and this small insect can help scientists to develop new mechanisms to utilise sunlight in a way which has little ecological impact on the planet.
Did You Know...? To get precise direction we can learn from the monarch butterflies and develop future compass that can solar light energy efficient access by the sun. This also can develop wellorganized accurate time with no matter whatever country we in. Nature holds the power of time and direction without mankind influences.
11
EVOLVE
12
ABNORMAL SURROUNDINGS
CAN CATS SEE GHOSTS, SPIRITS, DEAD PEOPLE? You would have thought with the five senses that we have we could detect everything around us, but that’s not true. Cats make a much better job of it than we do. These household pets have fantastic vision in low light so that they can see better at night. They only need a low level of light, equivalent to 20% of the amount that we need to see things. They can quickly pick up movement, which helps them when hunting their prey. A cat’s sense of smell is much better than humans, as they have 40 times the number of smell sensitive cells in their
noses compared to us. Have you ever noticed how your cat is aware of another cat in the garden a long time before you see them even when you are both in the house? But can they see ghosts, angels or aliens of the extra-terrestrial kind? Could they understand what these things are and how would they communicate this to us? Television programmes such as ‘Most Haunted’ show ghost hunters using the latest technology to recreate these feline super senses.
“They only need a low level of light, equivalent to 20% of the amount that we need to see things. They can quickly pick up movement, which helps them when hunting their prey.”
13
Expensive specialist cameras, microphones and chemicals are used in these ghost hunts to detect sounds, objects in low levels of light and certain smells. The programmes on the television don’t seem to show any successes in capturing ghosts or detecting anything that can be scientifically proved to be supernatural. Perhaps this is best left to our feline friends.
EVOLVE
SUPERNATURAL TRANSMITTER This is the future of tracking devices and is completely new to the market. It has been inuenced by cats and their ability at sensing and identifying supernatural phenomena. The device has builtin night vision, making it easy to detect the spirits in your location. It’s similar to a Global Positioning System (GPS) and will show your exact location on the map together with any spirits that may be nearby. To help you stay alert the device will bleep when it picks up any
supernatural energy from spirits such as ghosts. If you think your house is haunted then look no further. This device is right for you. You could use it to check out a house before you buy it or perhaps it would help you find a long dead relative who knows the hiding place of the long lost family jewels. If it is evil you could track them and get them exorcised. I wonder if it would work on aliens!
14