Many places on the ocean floor are so deep
that sunlight cannot penetrate. Because there
is no sunlight in these places, there can be no
photosynthesis. But the deep ocean floor still
supports an ecosystem. How is this possible?

i think the answer is

mass

this is a good question! i'll do some research and come back when i have the answer!

evidence and logical support is essential for a scientist to do in order to maintain credibility. this is because no one can believe without any logic and without any evidence.hence a scientist can maintain credibility by proving himself and by answering logically so experiments prove very beneficial. logical hypothesis give conclusion which is acceptable. therefore, there are two main factors to maintain credibility by a scientist is evidence and logical support.