Which of the following is/are cited by the scientists as evidence/evidences for the continued expansion of universe ? 1. Detection of microwaves in space 2. Observation of red shift phenomenon in space 3. Movement of asteroids in space 4. Occurrence of supernova explosions in space Select the correct answer using the codes given below :

Scientists cite several key observational phenomena as evidence for the continued expansion of the universe. The detection of Cosmic Microwave Background (CMB) radiation, which is relic thermal radiation from the Big Bang, is a landmark proof of an expanding universe [2]. This radiation, now detected in the microwave domain due to cooling and stretching of space, permeates the entire universe. Additionally, the observation of the redshift phenomenon, first described by Edwin Hubble, shows that light from distant galaxies shifts toward longer wavelengths as they move away from Earth [3]. This relationship, known as Hubble's Law, confirms that galaxies are drifting apart [4]. While Type Ia supernovae are used to measure the rate of expansion [5], and the movement of asteroids is localized gravitational behavior, the primary foundational evidences for cosmic expansion in standard scientific discourse are the CMB and galactic redshift.

Sources

1. [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 1: The Universe, The Big Bang Theory, Galaxies & Stellar Evolution > Cosmic Microwave Background (CMD) > p. 4
2. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 1: The Universe, The Big Bang Theory, Galaxies & Stellar Evolution > Doppler-Shift or Redshift and Blueshift > p. 3
3. [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 1: The Universe, The Big Bang Theory, Galaxies & Stellar Evolution > The Importance of Type Ia Supernovae > p. 13
4. [4] https://www.jpl.nasa.gov/edu/resources/teachable-moment/exploring-the-mystery-of-our-expanding-universe/
5. [5] https://supernova.lbl.gov/collab/observing/schedule2002/semester2002A/noao/working/scp02a9070399838.pdf