For example, the motions and rotations of celestial bodies such as planets may appear perpetual, but are actually subject to many processes that slowly dissipate their kinetic energy, such as solar wind, interstellar medium resistance, gravitational radiation and thermal radiation, so they will not keep moving forever.
Misalnya, gerakan dan rotasi benda langit seperti planet dapat muncul abadi, tetapi sebenarnya tunduk pada banyak proses yang perlahan-lahan menghilangkan energi kinetik mereka, seperti angin surya, ketahanan medium antarbintang, radiasi gravitasi dan radiasi termal, sehingga mereka tidak akan terus bergerak selamanya.