Black holes can be explained based on the theories of gravity. 請問此句為何要用過去分詞 based?為什麼要這樣寫,? 謝謝?

Black holes can be explained "when the explanation is based on the theories of gravity."
述部修飾語是一個「副詞子句」。

Black holes can be explained "based on the theories of gravity."
述部修飾語是一個「分詞構句」(participle clause / participial construction)

If you base "one thing" on "another thing", the first thing develops from the second thing.
Scientists "base" their explanation of black holes on the theories of gravity.
Their explanation of black holes "is based" on the theories of gravity.
用過去分詞當修飾語時，屬「被動」關係。
用「分詞構句」來寫會比用「副詞子句」精簡。

黑洞之所以可以重力理論為基礎來進行解釋，是某科學家或科學界的想法，是人為的，黑洞是物質，非生物，沒有思考能力，會用重力來解釋它，是由人類知識而來。此事對人類言是主動，因此操之在人，非黑洞，故對它而言是被動的（即不是它主動去拿重力來解釋）故使用過去分詞，即被動式來陳述。