Light has no mass so it also has no energy according to Einstein, bit how can sunlight warm the Earth without Energy ?
Answers
Answer:
Light has no mass so it also has no energy according to Einstein, but how can sunlight warm the earth without energy?
Firstly, I would like to clarify one thing. Your question contains an assumption made by you.
“Light has no mass so it also has no energy according to Einstein” —Einstein never said like this.
We should be careful while using the word ‘mass'. Mass indicates the ‘rest mass' of an object which is at rest and has no speed relative to an observer. As photon(light particle) is in motion continuously, it can never be at rest and so it can't have a rest mass.
Even though photon can't have rest mass, it carries energy and has momentum. And its mass comes out of its energy, and it is called relativistic mass. And Einstein's equations explain this as,
=>>>>>>>>>>>>>>>> E = m_rel * c^2 and E = pc
m_rel =>relativistic mass of photon(light)
p => momentum of photon(light)
c => speed of photon(light)
And coming to the second part of your question, as light(or sunlight) is bundles of energy(photons) travelling in a medium or space, it can warm the planet as the Earth(and it's atmosphere) absorbs light's energy and releases it back into the atmosphere.
Answer:
there is your answer.
Explanation:
Light indeed carries energy via its momentum despite having no mass. ... Since photons (particles of light) have no mass, they must obey E = pc and therefore get all of their energy from their momentum. beeeeeeee happy, thanks.