Question

question 13 (multiple choice worth 3 points) ou 04the theories on the origin and expansion of the universe have changed from time to time. which of these best explains why the theories about the universe change over a period of time? new scientific investigations lead to new theories modern scientists reject old theories in every century the universe evolves constantly and requires new theories to describe it the discoveries of all scientists in different centuries have to be incorporated question 14 (multiple choice worth 3 points) ou 01gamma rays are produced by applying electric and magnetic fields at right angles to each other

Explanation:

To determine why theories about the universe change, we analyze each option:

• Option 1: New scientific investigations lead to new theories. Scientific progress is driven by research; new evidence from investigations prompts theory updates. This aligns with how scientific knowledge evolves (e.g., new telescopes, experiments reveal new cosmic data).
• Option 2: "Modern scientists reject old theories in every century" is incorrect. Science builds on prior work, not wholesale rejection. Old theories with merit are refined, not rejected arbitrarily.
• Option 3: "The universe evolves constantly and requires new theories to describe it" – while the universe changes, the primary driver of theory change is new scientific methods/investigations (not just the universe's evolution alone). Theories change because we learn more through research, not just the universe's state.
• Option 4: "The discoveries of all scientists in different centuries have to be incorporated" – Theories change due to new, relevant discoveries (not just incorporating all past discoveries). Many old, incorrect discoveries are discarded, so this is not the main reason.

So the best explanation is that new scientific investigations lead to new theories.

Answer:

A. new scientific investigations lead to new theories