science and Technology blog: Doppler Effect

science and Technology blog: Doppler Effect: The change in the observed frequency of an acoustic or electromagnetic wave due to relative motion of source,observer or both is called Do...

Doppler Effect

The change in the observed frequency of an acoustic or electromagnetic wave due to relative motion of source,observer or both is called Doppler effect. As the source moves towards the observer the frequency increases or wavelength decrease and if the source is moving away then the frequency decrease or wavelength increase.

The movement of the source alters the wavelength and the received frequency of the waves ,even though the source frequency and wave velocity are unchanged. The Doppler effect can be observed for any type of waves like water waves, sound waves, light waves, etc.

There are many practical applications of Doppler effect ,let us look at few specific examples.

Astronomy

Astronomers have found that Universe is expanding by Doppler effect . When a star or a galaxy moves away from us the frequency decreases or wavelength increases.This change to longer wavelengths towards the red end of the visible spectrum for visible wavelengths is called a redshift. Conversely, if the source is moving towards the observer, there is a change to shorter wavelengths, i.e. a blueshift. Most of the galaxies appeared red shifted and hence moving away from us .This is the basis for the conclusion that the Universe is expanding and was one of the greatest intellectual revolutions of the twentieth century.

Radar Gun

Police use Radar gun to measure the speed of moving vehicles ,the radar gun function on the principle of Doppler effect .The radar gun includes a radio wave transmitter integrated with a radio wave receiver. The gun emits radio waves at a particular frequency so that the radio waves travel via the air and bounce off the moving vehicles. Some of these reflected waves will return back to the radar gun, and the waves that are reflected from the vehicles undergo a Doppler Shift.This Doppler shift in turn causes a change in the frequency of the radio waves. The radar gun makes use of this frequency change to measure the speed of the vehicle.

Ocean Depth 

The depth of a ocean can be determined by using Doppler effect ,the sound waves are transmitted from the ship towards the ocean floor using a sonar(sound navigation ranging) and they are reflected from the ocean floor back to the ship.The depth can be 

calulated using the formula

        v X t

   d= --------

            2

where v is the velocity of sound and t is time taken from the ship towards the ocean floor and back to the ship.

Future Trains

Future trains may travel in the air with no tracks hence no surface as well as air friction.Japan is using maglev(magnetic levitation) technology for fast speed trains, levitation means to rise or cause to rise into the air and float in apparent defiance of gravity. Maglev uses magnets to travel above the ground and hence can travel at high speeds.The magnetic field created by the electrified coils in the guideway walls and the track combine to propel the train. Maglev transport systems are in operation in just three countries Japan, South Korea and China.

 

A Japan Railway maglev train hit 603 kilometers per hour on an experimental track in Yamanashi setting a decisive new world record. The train is planned to begin service in 2027. Right now China operates the world's fastest commercial maglev, which has hit 431 kilometers per hour on a route through Shanghai.

Elon Musk new concept of Hyperloop transporation technolgy where a train can travel upto 700 mph .Hyperloop would work by propelling pods at high speeds through a vacuum tube with almost all air removed, capsules carrying passengers or cargo would be pushed along by a series of electromagnets. The almost complete lack of friction due to low air pressure means the train could travel at speeds of over 800mph, and 760mph with passengers on board.

China to take on Elon Musk hyperloop with supersonic flying train .China working on flying train which can travel at around 2500Mils/hour according to China Aerospace Science and Technology Corporation in short called CASC. Although the technology is still in its teething stages,the flying train is in essence a passenger pod that uses magnetic levitation and travels through a near-vacuum tube according to CASC  manager Liu Shiquan. The concept is similar to that of the Hyperloop.

 

 

 

science and Technology blog: Comets,Asteroids and Meteoroids

science and Technology blog: Comets,Asteroids and Meteoroids: Comets are snowballs composed of ice,rock and dust.Comets are formed farther from the Sun where ices would not melt. When a comet approach...

Comets,Asteroids and Meteoroids

Comets are snowballs composed of ice,rock and dust.Comets are formed farther from the Sun where ices would not melt. When a comet approaches the sun ,some of the ice in its nucleus (center) turns into gas .The gas shoots out of the sunlit side of the comet. The solar winds then carries the gas outward forming it into a long tail.

Astronomers divide comets into two main types ,long-period comets ,which take 200 years to orbit the sun ,short-period comets which complete their orbits fewer than 200 years. The two types come from two regions at the edges of the solar system. Long-period comets originate in the Oort cloud ,a cluster of comets far beyond the orbit of Pluto ,the short-period come from the Kuiper belt beyond the orbit of Neptune.

Our solar system most famous comet is probably the Halley's comet.Halley's comet has been spotted from earth every 75 years or so.

Asteroids are minor planets are basically broken pieces of unfinished planets and  leftover debris from the formation of our solar system about 4.6 billion years ago . Most of the asteroids circle around the sun in a region called asteroid belt between Mars and Jupiter .The belt contains more than 200 asteroids larger than 100 kilometers in diameter.

Scientists estimate the asteroid belt also contains between 1.1 million and 1.9 million asteroids larger than 1 km in diameter and millions of smaller ones. Astronomers have found several large asteroids with smaller asteroids orbiting them.The largest asteroid is Ceres, which is 933 kilometers (580 miles) across.

Meteoroids are broken chunks of asteroids that resulted from collisions in the asteroids belt. when meteoroids plunge into earth's atmosphere they form bright streaks of light called meteors as they disintegrate .Some meteoroids reach earth and they become known as meteorites. Some meteoroids are fragments from bodies such as Mars or our moon that have been thrown into space by an impact.

A meteor shower is the result of an interaction between a planet such as Earth and stream of debris from a comet or other source. 

 

Microchip Implants For Employees

We are in the beginning or midst of a new technology a microchip implantation for the employees or cyborg implants, which provide many benefits which outweigh the drawbacks.The microchip uses RFID technology (Radio-frequency identification) is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders.

These microchips helps the employee to open the doors, log on to computers , buy snacks, interact with their smartphones, computers, sharing business cards, and storing medical/health information.

Sweden company called Epicenter ,Wisconsin tech company called Three Square Market are already using this new technology for its employees. Don’t be a scaredy-cat ,data in the microchip is encrypted and does not use GPS, so it cannot be used to track employees or obtain private information.

Television and broadcasting company NBC have claimed that by 2017 all Americans will have been implanted with a microchip that will allow for immediate identification of a person’s identity. Of course some are concerned that this gives total control to the government and can track the whereabouts of a person and hence violation of privacy. We become a government controlled cyborg. According to Elon Musk humans must become cyborgs and develop a direct high-bandwidth connection with machines or risk irrelevance and obsolescence.

Cyborgs have been as big a part of sci-fi and many cyborg movies were made on these concepts such as Terminator, Robocop even Star Trek, etc. Of course moral questions are raised around the ethics of this particular technological advancement.

Finally It  may  not  be an overstatement that one day scientists will invent  a super pill which provides everything from Vitamins to minerals ,good fats to bad fats what all your body requires instead of having a cheese burger , a macaroni that regular stuff we eat .These must be considered as human enhancement/augmentation or become less human as some may argue.