No one can really tell exactly how old the universe is. However, scientists have attempted to estimate the time by using the concept of Doppler effect which depends on the frequency of the stars and their relative velocities. From literature, the universe is about 13.82 billion years old. Thus, the age of the universe is 13.82×10⁹ times longer than a year.
Answer:
In an earthquake prone area, the things that are needed to be considered for the buildings to stand constant and no cause of damages are as follows-
- The foundation of the building must be made strong, using large amount of concretes so that it can hold the entire load of the building.
- The pillars of the buildings are also should be firmed, rigid, strong and thick.
- The buildings are needed to be construct in such a way that during any seismic event, the forces can be redistributed easily through the body of the building without causing any damage.
- The buildings must be overall comprised of holding high strength and stiffness.
Since the outer plumage of the penguin can resist the flow of heat in the cold antarctic air they might gain a little of this heat to keep them warm by thermal convection.
<u>Explanation:</u>
- Convection is the circular movement that happens when hot air/liquid moves with molecules that were fast, making it less dense rises while the cold air/liquid drops down.
- Also, they follow the technique of standing together always in a group which further helps them to decrease the loss of heat between them.
- The plumage of penguin provides 80 percent of total insulation and is highly resistant to wind penetration.
Answer:
Spontaneous emission is a quantum effect, which in a semiclassical picture can be described as an emission which is stimulated by vacuum noise.
