From long ago, by an established tradition that can be traced to the hypothesis of immanuel kant and the marquis de laplace, astronomers have assumed that stars develop out of a scattered, diffuse medium of gas and dust . 很長時間以來,天文學家承襲了可以追溯至康德和拉普拉斯假說所建立的概念,認為恒星由散布在空中的彌漫氣塵物質演變而來。