Therefore, these mysterious matters are invisible, but astronomers know about their existence through the exploration of the gravitational interaction between them and ordinary matters.
因此这些神秘的物质是看不见的，但天文学家通过探测它们和普通物质之间的引力相互作用得知了它们的存在。
2
In oil exploration, the gravitational and seismic integrated interpretation has been employed in other countries for some time, but it is not the case in our country.
重力与地震联合解释在国外已有不少人用于地热勘探与石油勘探。但在国内却没有得到应有的重视。
3
Celestial gravitational wave source and the exploration to low frequency gravitational wave have also been discussed.