Questions

Cosmology is the scientific study of the large scale properties of the universe as a whole. It endeavors to use the scientific method to understand the origin, evolution and ultimate fate of the entire Universe.

Depending on the outcome of the observations, the theories will need to be abandoned, revised or extended to accommodate the data. The prevailing theory about the origin and evolution of our Universe is the so-called Big Bang theory.

The United Nations Public Service Day is observed every year on June 23 to recognize the work of public servants and to encourage young people to pursue careers in the public sector. The day is also observed to celebrate value and virtue of public service to the community and to raise awareness regarding the contribution of public service in the development of society and honouring the work of public servants.

The Doppler effect or Doppler shift is the change in frequency or wavelength of a wave in relation to an observer who is moving relative to the wave source. 

Hydrogen is the common element to all Acids. But every element which contains Hydrogen is not an Acid. Most of the acids also contain Oxygen.