Correct
Ans: C
Exp:
The discovery, honoured with the Nobel Prize in Physics (for Saul Perlmutter, Brian P Schmidt, and Adam G Riess) in 2011, forced scientists to hypothesise ‘dark’ energy.
Statement 1 is correct: Dark matter and dark energy together make up 95% of the universe. Around 68% of the Universe is made of dark energy while dark matter makes up 27%. It is responsible for the accelerated expansion of the universe.
Statement 2 is correct: Dark energy is a property of space, so it does not get diluted as space expands. Normally, as the universe expands the density of mass and radiation in it decreases. However, the density of dark energy remains constant throughout. This means the dark energy in the universe is ever increasing, in order to keep the energy-density constant.
Statement 3 is incorrect: Dark energy has been hypothesised as a repulsive force or anti-gravity, i.e. while gravity tends to make objects attract, dark energy would pull them apart by increasing the space between them. Thus, dark energy has an expansionary effect. As our universe is expanding, it indicates that dark energy has a greater abundance than dark matter.
Statement 4 is correct: DESI has produced the largest ever 3D map of the universe to study dark energy’s effects over the past 11 billion years, achieving a precision better than 1% for the first time. The leading model, Lambda CDM, incorporates both cold dark matter (CDM) and dark energy (Lambda), where matter and dark matter slow down expansion, whereas dark energy accelerates it.
Incorrect
Ans: C
Exp:
The discovery, honoured with the Nobel Prize in Physics (for Saul Perlmutter, Brian P Schmidt, and Adam G Riess) in 2011, forced scientists to hypothesise ‘dark’ energy.
Statement 1 is correct: Dark matter and dark energy together make up 95% of the universe. Around 68% of the Universe is made of dark energy while dark matter makes up 27%. It is responsible for the accelerated expansion of the universe.
Statement 2 is correct: Dark energy is a property of space, so it does not get diluted as space expands. Normally, as the universe expands the density of mass and radiation in it decreases. However, the density of dark energy remains constant throughout. This means the dark energy in the universe is ever increasing, in order to keep the energy-density constant.
Statement 3 is incorrect: Dark energy has been hypothesised as a repulsive force or anti-gravity, i.e. while gravity tends to make objects attract, dark energy would pull them apart by increasing the space between them. Thus, dark energy has an expansionary effect. As our universe is expanding, it indicates that dark energy has a greater abundance than dark matter.
Statement 4 is correct: DESI has produced the largest ever 3D map of the universe to study dark energy’s effects over the past 11 billion years, achieving a precision better than 1% for the first time. The leading model, Lambda CDM, incorporates both cold dark matter (CDM) and dark energy (Lambda), where matter and dark matter slow down expansion, whereas dark energy accelerates it.
April 11, 2024