What is the postulate having to do with the speed of light on which the theory of special relativity is based?
A. The speed of light remains the same in all inertial frames of reference.
B. The speed of light depends on the speed of the source emitting the light.
C. The speed of light changes with change in medium through which it travels.
D. The speed of light does not change with change in medium through which it travels.
Scientists now believe that at one time, everything existed at one point, which then expanded rapidly outwards to form the Universe as it is today. What is this theory called?
A. Big Bang Theory
B. Steady State Theory
C. Big Crunch Theory
D. The Theory of Relativity
Answer (2)
The two questions you've asked are both quite significant in the realm of physics, relating to fundamental theories about the universe.
Special Relativity and the Speed of Light :
The correct answer to the first question is A. The speed of light remains the same in all inertial frames of reference . This is a cornerstone postulate of Albert Einstein's Theory of Special Relativity, which he proposed in 1905.
What : The speed of light in a vacuum is constant and approximately 299 , 792 , 458 meters per second (commonly rounded to 3.0 × 1 0 8 m/s ).
Why : This constancy means that all observers, regardless of their motion relative to the light source, will measure the speed of light to be the same.
How : This postulate leads to several revolutionary implications, such as time dilation and length contraction, which fundamentally changed our understanding of space and time.
The Origin of the Universe - The Big Bang Theory :
The correct answer to the second question is A. Big Bang Theory . This theory describes the beginning of our universe approximately 13.8 billion years ago.
What : The Big Bang Theory proposes that the universe started from a singular, extremely hot and dense point, which expanded rapidly.
Why : This expansion marks the beginning of time as we understand it, from which space has continuously expanded and cooled, leading to the formation of galaxies, stars, and planets.
Who and How : The foundational ideas of the Big Bang Theory were developed throughout the early 20th century, with notable contributions from scientists like Georges Lemaître, Albert Einstein, and Edwin Hubble, whose observations of galactic redshift gave significant support to the theory whether that galaxies are moving away from us due to expansion of universe.
Together, these theories form part of the modern understanding of physics and cosmology, describing both the fundamental behaviors of light and the vast timeline of our universe.
The correct answer to the first question is A, indicating that the speed of light is constant in all inertial frames. The answer to the second question is also A, referring to the Big Bang Theory as the origin of our universe. Both concepts are central to modern physics and cosmology.
;
