55500
Charged particles can move at relativistic speeds nearing field propagation speeds , but , as Albert Einstein showed , this requires enormous field energies , which are not present in our everyday experiences with electricity , magnetism , matter , and time and space .
 Albert Einstein
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 Albert Einstein