BadgerBadger92
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- Is the earth getting closer to the sun from gravity? Will we ever collide into the sun?
Is the Earth getting closer to the sun from gravity?
The Earth is not getting closer to the Sun due to gravity, as it is in a stable free-fall orbit. Gravitational wave emission, as predicted by General Relativity (GR), is negligible for the Earth-Sun system and does not significantly affect Earth's orbit. The Sun's mass loss from solar wind and radiation is a more impactful factor, but it is still insufficient to cause a notable change in Earth's distance from the Sun within any relevant time frame. Future changes in Earth's orbit will be dominated by the Sun's evolution into a red giant rather than gravitational wave effects.
PREREQUISITESAstronomers, astrophysicists, and students of physics interested in celestial mechanics and the long-term dynamics of planetary systems.
Theoretically, according to GR, any planet orbting a star should emit gravitational waves that will, after enough time has passed, cause its orbit to decay. However, for the Earth orbiting the Sun, this effect is many, many, many orders of magnitude too small to matter; lots of other things will happen (like the Sun turning into a red giant and probably becoming large enough to engulf the Earth) on time scales many, many, many orders of magnitude shorter than any orbital changes due to gravitational wave emission would even be detectable by our most sensitive instruments, let alone get large enough to bring the Earth significantly closer to the Sun.BadgerBadger92 said:Is the Earth getting closer to the sun from gravity?
I wonder if the Sun's loss of mass via solar wind and radiation beats the effect of gravitational waves on Earth's orbit. Any idea?PeterDonis said:Theoretically, according to GR, any planet orbting a star should emit gravitational waves that will, after enough time has passed, cause its orbit to decay. However, for the Earth orbiting the Sun, this effect is many, many, many orders of magnitude too small to matter;
You'd need to consider accretion by both bodies, too.Drakkith said:I wonder if the Sun's loss of mass via solar wind and radiation beats the effect of gravitational waves on Earth's orbit. Any idea?
I haven't done the calculation, but I would expect it to beat GW emission by many orders of magnitude. The GW emission rate for the Earth-Sun system as calculated by GR is really, really, really tiny.Drakkith said:I wonder if the Sun's loss of mass via solar wind and radiation beats the effect of gravitational waves on Earth's orbit. Any idea?
What work have you already done to answer this? (It's okay...we all know the answer)BadgerBadger92 said:Summary:: Is the Earth getting closer to the sun from gravity? Will we ever collide into the sun?
Is the Earth getting closer to the sun from gravity?