energy is related to mass.mass is related to gravity.?

Question

if sun has used 1/2 of its fuel during its life why the gravity of the sun is still keeping us in orbit
sorry for the improper experession of the question but i m just a cook

i understand its nuclear energy but it doesnt release anything?wouldn't that mean that with a small piece of mass we could have infinite energy even if the mass is changing form ( helium to hydrogen )
photons are considered as having mass or not?

Answer 1

Do not be confused by the answer alluding to the sun's mass not changing because it is fusion and not fission energy. As you point out in your question, the sun is indeed converting some of its mass to energy.
When the hydrogen atoms are fused into helium, the total mass of the helium atoms is less than the sum of its parts - in short, the sun is indeed loosing mass.
The sun, however, is huge (I once read that a million earths would fit inside a sphere the size of the sun) and the total mass it is loosing over a reasonable and measurable amount of time by mankind is trivial compared to the time these processes take in universal context.
It is reasonable to expect that given enough time, the earth and other planets, assuming their rotational velocities remain constant, will expand their orbits.
The time span of this phenomenon is something for the mathematicians and physicists to compute merely to build up their knowledge base, and certainly nothing that will directly affect us or our future generations for eons to come.
Good question.

Answer 2

The sun expels lots of energy and thus mass all the time. Because of this, its gravitational effect on planets such as Earth has weakened. This may all be true. However, the sun is still really really big and the Earth is still comparatively small. Earth's orbit has in fact changed because of this but not nearly enough for Earth to escape or collapse into the sun. Also, this loss is done slowly over time. For the period of time that life has been on Earth, there hasn't really been much of a change (otherwise, drastic and fatal climate changes would occur).

Answer 3

Energy is released during one massive atomic reaction over there. The mass isn't lessening, as much as it's changing form.

Answer 4

If the mass of the sun is getting smaller then our orbits would grow larger. Maybe they have. Have you checked into it?

Answer 5

There is a universal gravitational constant by Newton.

Answer 6

i enegery from the sun is the form of fusion not fission!!