That thread about the Earth stopping spinning got me thinking:

Could the Earth become tidally locked with the Sun (hypothetically; say
the Sun has increased in size to allow it), or would the presence of the
Moon prevent it from happening?

--
Abo

Abo wrote:
Could the Earth become tidally locked with the Sun (hypothetically; say
the Sun has increased in size to allow it), or would the presence of the
Moon prevent it from happening?

The presence of /any/ other body exerting significant gravitational
influence would be likely to break the tidal lock.

On May 15, 7:58*pm, Mark McIntyre wrote:
Abo wrote:
Could the Earth become tidally locked with the Sun (hypothetically; say
the Sun has increased in size to allow it), or would the presence of the
Moon prevent it from happening?

The presence of /any/ other body exerting significant gravitational
influence would be likely to break the tidal lock.

Copernicus reasoned that the seasons were due to variable axial/
equatorial inclination however that view has to be modified -

"..the equator and the earth's axis must be understood to have a
variable inclination. For if they stayed at a constant angle, and were
affected exclusively by the motion of the center, no inequality of
days and nights would be observed."
Copernicus Chapter 11 De Revolutionibus

However tricky it may be,the seasonal inequality of daylight and
darkness emerges from an orbital component and likewise the variations
in the natural noon cycle.It is a 100 % certainty that a modification
is required to the reasoning of the great Copernicus for in order for
the Earth to keeps it rotational orientation pointed in the same
direction,its orbital orientation must change to the central Sun as
that change is strictly an orbital component -

http://www.youtube.com/watch?v=YV9WkQkUHZ4

http://physics.uoregon.edu/~jimbrau/...13/FG13_06.jpg

In the animation,the crank pin represents the rotational orientation
of the Earth pointing to the same external point,but as the crank
turns around the central shaft,representing orbital motion,the crank
pin turns 360 degrees to the central shaft determining that a location
changes its orientation and takes an entire orbit to do it.

This is extremely important and I strongly suggest you either treat
it as such or withdraw

"Abo" wrote in message
...
Could the Earth become tidally locked with the Sun (hypothetically; say
the Sun has increased in size to allow it), or would the presence of the
Moon prevent it from happening?

--
Abo

As long as the Earth has a Moon, Earth's rotation will not synchronise with
the orbit around the Sun. Earth could eventually synchronise with the Moon,
but this state takes so long to occur (c. 50 Gyr) that the Sun will run
through its entire remaining life cycle first (5 Gyr). It would be a very
dim white dwarf when that happens.

Anyways, these are the calculated predictions that have been published as
best I recall.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)