To burn anything we need oxygen but have you ever thought why our sun does not need any oxygen to burn and how does it burns without any oxygen?
The answer is sun never burns. Sun is not burning. What is burning ? Burning is combustion. Anything that burns needs oxygen, combustion is a chemical reaction which occurs between fuel and oxidizer to create a new substance called exhaust.
If sun was burning it would also create smoke, but we don’t see sun creating a smoke, infant there is no exhaust created by sun.
If sun does not burn then why sun looks like its burning?
There is a nuclear fusion going on at sun where one proton smashes another proton. This kind of fusion is called proton proton fusion.
These protons fuse together to create helium and this transformation creates a tremendous amount of energy that keeps the sun hot and it looks like it’s burning.
The Cryogenic Rocket Engine or the CE-20 is basically a subsidiary of ISRO or the Indian Space Research Organization. It was developed and designed by the Liquid Propulsion Systems Center (LPSC).
ISRO has been developing a Cryogenic Engine with a high thrust that can be utilized for the upper stage of the launch vehicle (heavy lift), i.e., GSLV Mk-III. This cryogenic engine with high thrust easily generates 196.5 kN of nominal thrust in a vacuum in addition to 434 seconds of specific impulse. The cryogenic engine works on the “Gas Generator Cycle.” This cycle has the flexibility for being developed independently prior to the integrated engine test of each sub-system. This goes a long way to reducing uncertainty when it comes to the final developmental phase as well as the development time.
The cryogenic engine is also responsible for producing almost 2 MW of power as opposed to the Cryogenic Upper Stage (CUS) engine that produces only 1 MW of power. Therefore, the cryogenic engine of high thrust can easily be regarded as one of the most powerful and robust engines that belong to the upper stages throughout the world.
ISRO also went on to conduct a ground test of the Indigenous Cryogenic Engine (High Thrust) on 28th April 2015 at the Propulsion Complex of ISRO at Mahendragiri. This ground test took place for 635 seconds at 1657 hours and is considered to be a major feat in the history of ISRO. It is also noteworthy that the entirety of the propulsion parameters was found satisfactory during the test and they also matched with the predictions closely. Prior to these ground test approximately a few weeks before, four other short duration tests lasted 5.5, 7.5, 20 as well as 30 seconds.
The Liquid Propulsion Systems Center (LPSC) situated at Valiamala have designed as well as realized this high thrust cryogenic engine with the active support of VSSC or Vikram Sarabhai Space Center at Thiruvananthapuram. The engine integration, testing as well as the assembly is carried out at Mahendragiri by the ISRO Propulsion Complex (IPRC). In addition to that, countless Indian industries have also gone out of their way to contribute significantly to the realization and success of the cryogenic engine.
Many ground tests have been conducted to date that validate the design, performance, and adequacy of the integrated engine. Several other demonstration tests have also been planned at the stage and engine level in order to characterize the distinct performance parameters that fall under a variety of operating conditions. It is planned that once these tests are completed, the indigenous cryogenic engine (high thrust), as well as the stage, will be flight tested in the mission of GSLV Mk – III – D1.
The Search For CE-20
ISRO started the GSLV program in response to the mounting communication requirements of India. The government approved the second-generation series of satellites of INSAT-2 in 1987 that weighed over 2 tons. ISRO also wanted to develop and design a class of satellites that weigh 2.5 tons and place them in the geostationary transfer orbit situated at a distance of 36,000 km from the Earth’s surface. In addition to that, ISRO also intended to create a lighter, bigger as well as more efficient vehicle than the Polar Satellite Launch Vehicle (PSLV) that is its workhorse. There was a total of three fuel options available namely cryogenic, semi-cryogenic and earth storable.
Cryogenic Engines use liquid oxygen and liquid hydrogen as a fuel in order to provide the maximum amount of thrust possible. They are, more often than not, ready for the “upper stages” as well as the last rocket stage as this is the stage that delivers 50% of the total 10.2 km/s velocity that is required at the time of satellite injection. ISRO scientists also started developing a cryogenic engine of 1 ton in 1986 at ₹12 crores. They wanted to understand exactly how to handle liquid oxygen as well as liquid nitrogen. At the same time, ISRO also formed a design team at Mahendragiri, Tamil Nadu at the Liquid Propulsion Center. They intended to design a turbo-fed engine of 7 tons. This development went a long way to boost the confidence of the engineers of ISRO, and the organization knew that they could not wait any longer to design and develop the indigenous engine.
Final Words
ISRO has managed to perform amazing feats when it comes to outer space. The cryogenic engine is one such achievement that helped scientists and researchers discover several things and get answers to many questions that had been plaguing them for a long time. The achievements of ISRO as an organization are because of its constant thirst of growth and finding answers to the unknown entities of the world. Their list of successes is only expected to increase in the future.
What we see as light is just a tiny portion of what is called electromagnetic spectrum.
The more apt answer would be ‘Light is elctromagnetic radiation’
You might have heard some fancy words like gamma-rays, X-rays, ultraviolet, optical, infrared, and radio and you would be surprised to know that they are all light.
The Electromagnetic Spectrum
The electromagnetic spectrum consists of many wave lengths of light. When you put prism in sun, you can see the rainbow of light, each wavelength is redirected at different angle and that’s what create the rainbow like structure.
Source Wikipedia
Electromagnet Spectrum can be broken down into following waves.
Radio Waves
The length of radio waves can be as large as a football field to the size of planet. Most of the stars emit radio waves in universe. Those Radio waves are the same waves that are transmitted by a radio station and are received by your radio device where you listen your favourite music.
Radio telescopes are used to study these radio waves emitted in our universe and solar system. Through radio telescope we can study the structure, composition and motion of heavenly bodies.
Do you know how data is sent using radio waves ?
Most of the time radio waves amplitude or frequency is same all the time and this is where we can manipulate things to send our data using radio waves.
Supppose if we had to send data such as 0 or 1
We can send this in two ways
By amplitude modulation
Frequency modulation
Microwave
You might have heard about microwave oven, where food is cooked quickly. Do you know how it happens?
Microwaves are actually high frequency radio waves that makes water and oil molecules to vibrate thus making the food hot and cook.
Microwaves are also emitted by mobile phones. Thus it can affect the part of your brain. If you are still young and your brain is still growing please avoid using cell phones.
Looking for long at microwave oven when food is being cooked may cause you cataract. Please avoid opening oven every time to check if food is ready.
Infrared
Infrared waves have a wavelength of 700 nm to 1 mm. We can’t see infrared waves but we can feel it as a form of heat.
Infrared is used in thermal imaging and for night vision. Since living organisms body has heat, which it emits , that can be caught by thermal imaging.
Using infrared waves we can see many things in our universe that is not visible through normal telescope. Many planets emit infrared which helps scientist study them with out the need for visible light.
Infrared light helps scientists study things that are covered by dense cloud of dust and gas, because infrared waves have longer wavelengths which can easily pass through gas and dust.
Visible Light
The visible light has wavelength that ranges from 400 nm to 700 nm. The visible light is the light that can be seen by our eyes.
The following table lists the different colors of visible light spectrum and their wavelengths.
Color
Wavelength (nm)
Red
625 – 740
Orange
590 – 625
Yellow
565 – 590
Green
520 – 565
Cyan
500 – 520
Blue
435 – 500
Violet
380 – 435
fire flies, light bulbs, stars they all emit visible light.
Ultraviolet Rays
Sun is the main source of ultraviolet rays, UV rays causes skin cancer if exposed for prolonged time.
There are three types of UV radiation that is radiated from the sun.
