15. What the definition of dark energy?
O Energy that humans cannot observe directly
O Energy that has a small effect on the universe O Energy characterized by black and dark gray colors
O Energy that is only emitted by glowing nebulae.
The correct definition of dark energy is:
O Energy that humans cannot observe directly.
The definition of dark energy is:
O Energy that humans cannot observe directly.
Dark energy is a hypothetical form of energy that is believed to make up a large portion of the universe's total energy content. It is called "dark" because it does not interact with light or other forms of electromagnetic radiation, making it impossible to observe directly. Its existence is inferred from its gravitational effects on other objects in the universe, such as galaxies and galaxy clusters.
The correct definition of dark energy is: energy that humans cannot observe directly.
Dark energy is a term used in cosmology to refer to a hypothetical form of energy that is believed to be responsible for the current accelerating expansion of the universe. It is called "dark" because it does not interact with light or other forms of electromagnetic radiation, which means it cannot be detected or observed directly using telescopes or other instruments that rely on light.
So, the correct answer to this question is option O: Energy that humans cannot observe directly.