After the sun rises, the earth heats unevenly. When a surface grows hot enough, a thermal column rises into the atmosphere. They are called Convection Currents. Eagles and Hawks can find such areas and fly into those thermals. Without flapping, the eagles will descend, but inside the thermal, hot air pushes them vertically. So they stop flapping but keep their wings extended. To remain inside a thermal column, eagles navigate in circular paths. The centripetal force is supplied by the horizontal component of vertical force by inclining to the centre of the circle.
You may have seen birds, like Eagles and Hawks are flying on a circular path, without flapping their wings.How are they flying like this, without falling down ?
Researchers have warned that by the end of the decade, global wildlife populations will fall by more than two thirds compared to 1970 levels. Assessment of species of mammals, birds, fish, amphibians and reptiles from around the world has revealed a 58% fall between 1970 and 2012. By 2020. It is predicted that the populations of vertebrate species will fall by 67% over a 50-year period unless action is taken to reverse the destructive human activities.
A new project in Iceland has started drilling down the world’s hottest hole into molten magma, flows through volcanoes. It hopes to establish a powerful new sustainable energy source by the end of this year.The hole which will be deep 5-km in the south-west corner of Iceland.It will enough to generate supercritical steam that experts estimate could generate up to 50 megawatts of electricity – making it 10 times more efficient than traditional geothermal wells.
The Drone which was developed as a result of development of technology is currently used for video shooting world wide. But what if they are used to deliver goods. Recently, Ruwanda made a emergency drone delivery service which they use drones to deliver blood for patients in rural and hill areas where it is difficult to reach by roads. When a patient is required blood, Healthcare workers send a text message to the emergency drone delivery service and then a drone is loaded with required blood and arrives to the destination within shorter period of time. Then it will release the parcel, with the help of a small parachute.
During daytime,sun’s radiation continuously warms the earth. As earth re-emits thermal radiation, the earth’s surface gradually cools down at night.Some gases in our atmosphere, such as water vapour and CO2 absorb thermal radiation, heat up and radiate heat in all directions (Including back to earth).So,less heat escapes earth. Water droplets in clouds are even better at this, making night life warmer on cloudy nights.
Why are nights with clear skies cooler than cloudy nights?
Have you heard of the “Great Green Wall”(Great Green Wall of Sahara and Sahel Initiative)? This is no ordinary wall. It has been formed by planting millions of trees across thousands of miles on the south border of the Sahara desert. Its goal is to reverse land degradation and desertification in the Sahel and Sahara, boost food security and support local communities to adapt to climate change.
Can you imagine machines which consist of only several molecules? Yes, they exist and three experts in this field have been rewarded with the Nobel Prize in Chemistry this year for showing promise in nanomachines.
Even though spiders don’t have ear drums, they can also hear, using special hairs on their legs. Previously scientists thought that these hairs can only feel vibrations coming through the ground from up to 1 metre away, but jumping spiders (Salticidae) have proven them wrong. In a study, jumping spiders have been able to hear even airborne sounds up to 3-5 metres.
The heat of the flame expands the surface of the balloon, creating a weak point in its surface. As the inside air pressure also increases, the balloon bursts instantly. In the balloon with water, water absorbs a lot of heat (because water has a high heat capacity), and keeps the balloon surface cooler for a longer time. So, the water balloon becomes pretty fire resistant.
If you hold an inflated balloon over a fire, the balloon will burst immediately (as expected). However, if you try it with a balloon filled with water it will take much longer to explode. Do you know why?
A new fabric uses sunlight and body movements to charge wearable devices such as watches and phones. The fabric is based on low-cost, lightweight polymer fibres coated with metals and semiconductors. Tiny solar cells and nanogenerators ( which harvest energy from body movements) are built into the fabric using these special fibres.
In an earlier message, we have told that yawning helps our brain to work efficiently by cooling it down. Now biologists have discovered that the average yawn duration of a mammal species predicts the complexity of the species’ brain. It turns out that humans are the “longest yawners” and that animals like elephants, gorillas, camels take longer than animals such as mice and rabbits.
Paralysis limits movement because the damaged brain parts block neural signals from reaching a desired body part. So, forming new neural paths to transmit signals could be the cure. To test this, patients were told to “think” about moving their fingers. After the“thought”was detected by a computer, the fingers were moved using a machine. When the fingers move, neural signals are sent from the hand to the brain. This strengthens new neural connections. In the study 70% have had improvement in finger mobility.
When the bucket is in water, water applies an upward force on the bucket, which is equal to the weight of the water displaced by the bucket. This force is known as upthrust. As the tension of the string attached to the bucket decreases, we feel that the water bucket is less heavy. But, once the bucket is pulled out of water, the upthrust ceases and gives the actual weight of the water bucket.
When pulling a bucket of water from a well, why does the bucket feel heavier once it comes out of the water surface?
As stainless steel medical needles(specially to inject insulin) are expensive to make, scientists looked into plastic, but found that plastic wasn’t rigid and thin at the same time to penetrate skin. When searching for inspiration from nature, they found that porcupine quills provide the answer. Taking ideas from the structure of porcupine quills, they were able come up with a usable plastic needle.
The ability to move objects without touching them sounds like science fiction, but scientists have found that “sound” can actually do that. By using high-amplitude sound waves, scientists have been able to create a force field which can lift and move small objects. Using the technique it will be possible to transport and assemble delicate objects without any physical contact.
Did you know that DNA can be used for storing digital data? As DNA has an unbelievable data storage capacity (one gram of DNA can store data of 100 billion DVDs!) and durability for hundreds of years, these studies offer ground-breaking potential for digital data storage.
Diamonds don’t have free electrons to conduct heat but its lattice structure allows quick vibrations between atoms to conduct heat. The high symmetry of the lattice and the strong bonding result in efficient vibrations, making diamonds even better than copper at conducting heat. As diamonds have neither free electrons nor mobile ions, it is a good electrical insulator.