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National Bird Day: Why Birds Matter to Us

National Bird Day is celebrated every year on 5 January . This day is observed to spread awareness about birds, their importance in nature, and the need to protect them. Birds are beautiful living beings and play a very important role in keeping our environment healthy. Origin of National Bird Day National Bird Day was first celebrated in the year 2002 . It was started by bird lovers and environmental groups to protect birds from dangers like deforestation, pollution, and illegal hunting. The main aim of this day is to teach people, especially students, why birds are important and how we can help save them. Why Is National Bird Day Celebrated Every Year? National Bird Day is celebrated every year because many bird species are disappearing due to human activities. Cutting trees, using plastic, pollution, and climate change are harming birds and their homes. This day reminds us that: Birds need protection Nature should be respected Everyone has a responsibil...
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Heisenberg’s uncertainty principle | Quantum mechanics | Physical basis of quantum mechanics

Heisenberg’s uncertainty principle

  • According to Heisenberg’s uncertainty principle it is impossible to determine precisely and simultaneously two canonically conjugate variables.
  • If we measure one physical quantity precisely then the other will have a great uncertainty.
  • This principle is observed only in microscopic particles, not in macroscopic bodies.
  • If Δp = uncertainty in momentum, and Δx = uncertainty in position, then according to Heisenberg's principle
                Δx ✕ Δp ≥ ħ / 2
  • Here ħ = h / 2 and it is known as reduced Planck's constant
  • If ΔE and Δt are the uncertainties in the energy and time then the uncertainty principle will be
                ΔE ✕ Δt ≥ ħ / 2
  • and if ΔJ and Δϕ are the uncertainties in the angular momentum and angular position then the uncertainty principle will be
                ΔJ ✕ Δϕ ≥ ħ / 2
  • In solving the problem related to Heisenberg uncertainty principle we use
                Δx ✕ Δp ≈ ħ

Physical significance of uncertainty principle

  • If the position of a particle is determined with great accuracy, Δx = 0, then Δp = ∞, the uncertainty in momentum become infinite.
  • If the momentum of a particle is determined with great accuracy, Δp = 0, then Δx = ∞, the uncertainty in position become infinite.
  • If a particle of mass m moves with velocity v, then uncertainty relation.
                Δx ✕ Δv ≈ ħ / m
  • Since for a very heavy particle m is very large, and therefore Δx ✕ Δv is very small.
  • Therefore for very heavy particle we can measure the values of position and velocity both with accuracy.
To know more about Heisenberg's uncertainty principle in English please click on the link  https://youtu.be/Mm3BqM1ZlWs  and for bilingual (Hindi/English) click on https://youtu.be/R0Z2k3vKL5Q
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