15912
In special relativity , however , the distance between two points is no longer the same if measured by two different observers when one of the observers is moving , because of Lorentz contraction .
 Lorentz
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 Lorentz