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Q:
Is there anything in nature that occupies space but that is without mass?
- Udaybhanu Chitrakar (age 65)
Kolkata, West Bengal, India
A:
Not that I know of.
Even things that have zero rest mass, such as photons, have some energy and you can always define an 'equivalent mass' , m
equiv=E/c
2 which affects and is affected by gravitational fields. The bending of starlight that passes nearby the sun is a well measured and predicted by the theory of General Relativity.
LeeH
(published on 10/08/2011)
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