This is a series of articles intended to educate aspiring astronomers about observational and theoretical Astronomy. Our discussion will range from the basic unaided techniques to the frontiers of ongoing Astronomical research which will include fun Mathematics and Physics involved in Astronomy. Advanced technologies, and engineering methods prevalent in modern Astronomy will also be covered in the forthcoming articles of this series. A dedicated post shall also look into the various career options related to Astronomy. Have you ever wondered what the sky really is? Have you ever asked why the sky acts like the largest canvas you have ever seen, a canvas that stretches from the horizon to the zenith (the point directly overhead) which consistently carries varying pictures at various times? If you have evolved to have become a human being, you must have. We humans have always wondered at the enormity of the sky. Not just wondered, we have shed our sheer animal instincts and have evolved as humans by relentlessly trying to look at the sky and understand it. No other animal than Humans have acquired the physiological vantage point of the human head that is the best suited to watch the sky. Or should we say, the heavens, as commonly perceived.
So, what is the Sky and where does it those colours that it flaunts?
The evenings were the most crucial time for me since, they hosted clear night skies full of planets, stars, and cosmic bands of haze. Lying down on a cot in the courtyard, being caressed by the cool evening summer breeze, looking up at the sky that appeared as a perfectly crafted sheet of silk laden with gems of different colours and radiance, made me wonder about the true nature of Nature.
इनको पढ़ाना बहुत पसंद था । इनका मानना था कि यदि आपको किसी विषय पर महारथ हासिल करनी है तो आपको इसे पढ़ाना प्रारम्भ कर देना चाहिए। किसी भी कठिन से कठिन सिद्धांत को आसान शब्दों में व्याख्या(Explain) करने की क्षमता अद्वितीय थी इनमें। इनकी पुस्तक Feynman Lecture of Physics भी भौतिक विज्ञान की प्रारंभिक समझ विकसित करने के लिए अद्वितीय (Unique) पुस्तक है। Feynman एक अच्छे आर्टिस्ट भी थे। उन्होंने विद्यार्थियों के लिए किसी भी Concept को आसानी से समझने और याद रखने का एक अनोखा तरीका सुझाया जिसे Feynman Technique के नाम से जाना जाता है। इसमें रेखाचित्रों (sketch) के माध्यम से किसी भी विषयवस्तु को याद रखा जा सकता है। क्वांटम भौतिकी (Quantum Physics)और आण्विक भौतिकी(Particle Physics) में कणों के मध्य होने वाली अंतः क्रिया को समझाने के लिए Feynman Diagram दिए जो आज भी प्रासंगिक हैं। इस कार्य के लिए इन्हें 1965 में नोबल पुरस्कार मिला।
PSR or Preparation Status Report is a status reporting system designed for the preparation group (common for the paying and free) community members of ThePhysicist. The system generates the spreadsheet containing data on an individual member’s educational qualification, target competitive exam, current self-study topic as well as the topics already covered. This helps the students in the following ways:
Coronaviruses are a family of viruses. Coronaviruses are zoonotic (first develop in animals before developing in humans). virus transmission from animals to humans due to close contact with an animal that carries the infection. Coronaviruses can be spread from person to person through respiratory droplets( wet stuff that moves through the air when you cough or sneeze). The viral material hangs out in these droplets and can be breathed into the respiratory tract (your windpipe and lungs)leading to infection. Researchers believe that possibly the virus may have been transmitted to humans via bats to another animal — either snakes or pangolins. This transmission likely occurred in the open food market in Wuhan, China, or may have been engineered by a lab in Wuhan.
This problem is a typical JEE Main as well NEET level Physics question. However, in this post, the second question is added to ensure that the reader understands the basics very well and is comfortable with not only the Physics tricks but also the Mathematics involved. The detailed analysis of the background has been covered in the previous post. In this post we shall illustrate how and why the principle of conservation of energy should be used to save time, instead of taking the lengthier approach that has been already discussed.
This is a key problem for students preparing for JEE Advanced, JEE Main, and NEET (undergraduate). Many questions of varying standards and toughness can be formed on its basis, some of which have been put here in the question statement. For example, the magnetic field working perpendicular to the velocity vector all the time is not going to produce any work. Thus the question can be a little modified to be easily solved by using the Work-Energy principle so that the work done by the electric field can be equated to the kinetic energy of the particle. However, in this particular problem, that technique is useless. That’s why we must understand the Physics and Mathematics involved in this question. A short tutorial post explaining how a sample variant of this question can be asked is going to be published next.
This problem can be solved in at least 3 meaningful ways, (a) from the ground frame, (b) from the rotating frame and (c) with Lagrangian. Let us do it in all of them. But even before we begin to decide whether to use Lagrangian mechanics or not, we need to understand the motion from the ground frame. It is not always advisable to use the ground frame to solve problems in rotational motion. More often than not, the ground frame calls for more variables and thus more equations than the rotational frame. However, using the rotational frame calls for fictitious or pseudo forces and without a firm understanding of the motion through the real forces, there is a big possibility of making mistakes. Hence, ThePhysicist suggests that the students, while practicing, should always try to solve problems of rotational motion from the ground frame first and then from the rotational frame.
ThePhysicist was initially planned to be a Physics blog that aimed to provide everything in Physics to everyone in Physics. To achieve the vision, ThePhysicist has been expanded from the idea of being only a blog to a full fledged website with content and features for those who are interested in Physics, viz, enthusiasts, students and researchers. ThePhysicist aims to establish continuity among the levels of its audience through well crafted posts, materials, classes, news and research tools. The aspiration here is to provide a single platform to educators, learners and researchers in Science in general and Physics in specificity. Not only that the content on ThePhysicist shall be unique and empowering for the readers, subscribers and visitors, but also that if some new, interesting and useful content is available elsewhere on the internet, it finds a special mention on ThePhysicist.