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View Full Version : If the Earth's Moon were not tidally locked.....



Spacedude
2015-Jun-06, 09:50 PM
...would it make much of a difference back here on Earth, if say, the moon had a similar 24 hour rotation period?

schlaugh
2015-Jun-06, 10:16 PM
Off the top of my head I'd say no, or at least not much. The moon already has a sidereal rotation of 27.3 days, give or take.

Fiery Phoenix
2015-Jun-07, 05:44 AM
I can't think of anything that would affect us, besides of course being able to see more of the Moon's surface due to its faster rotation.

Tidal locking is just an inevitable consequence of orbital dynamics. It doesn't really mean much to objects other than the tidally locked body itself (or in this case, the Earth).

Spacedude
2015-Jun-07, 01:25 PM
I couldn't think of anything that might be altered or influenced on the Earth either, other than perhaps how our ancestors "saw" the moon. Back when they thought the Earth was flat maybe that concept was at least partially related to seeing the moon as being a flat disk rather than a sphere or globed shape?

Jeff Root
2015-Jun-07, 02:25 PM
Although rotation of the Moon relative to the Earth would
certainly be a plus, I'd think the phases would have been
enough to show that the Moon is spherical.

-- Jeff, in Minneapolis

schlaugh
2015-Jun-07, 02:49 PM
Ah, I read your question in the context of orbital mechanics and possible tidal effects on Earth.

On a societal or cultural basis, a rotating moon might have led to interesting variations of those religions in which the moon and sun were dieties. Maybe a moon goddess such as Selene (Luna to you Romans) would be multi-faced. Or the moon god would now be several gods, each with its own face and the time of day would dictate which god was in control of events on Earth.

A visibly rotating moon might lead to a somewhat earlier understanding of planetary behavior - but I doubt it.

Noclevername
2015-Jun-07, 03:28 PM
I couldn't think of anything that might be altered or influenced on the Earth either, other than perhaps how our ancestors "saw" the moon. Back when they thought the Earth was flat maybe that concept was at least partially related to seeing the moon as being a flat disk rather than a sphere or globed shape?

They really didn't think that the Earth is flat for very long or in many places. Sailors, for instance, always knew it was round because objects visibly moved up over the horizon.

Fiery Phoenix
2015-Jun-07, 07:42 PM
They really didn't think that the Earth is flat for very long or in many places. Sailors, for instance, always knew it was round because objects visibly moved up over the horizon.
The problem is the 'official story' was that the Earth was flat, and that actually lasted a good while. You're right that a lot of people like sailors and explorers had different ideas, but they all pretty much kept those ideas to themselves.

Noclevername
2015-Jun-07, 07:48 PM
The problem is the 'official story' was that the Earth was flat, and that actually lasted a good while. You're right that a lot of people like sailors and explorers had different ideas, but they all pretty much kept those ideas to themselves.

In that case, evidence was not the core problem, and the Moon spinning probably would not have made much difference to the Powers That Be.

swampyankee
2015-Jun-08, 12:06 AM
The problem is the 'official story' was that the Earth was flat, and that actually lasted a good while. You're right that a lot of people like sailors and explorers had different ideas, but they all pretty much kept those ideas to themselves.

Which "Powers that be" and at what time? A spherical Earth was accepted by the Classical Greeks.

Jeff Root
2015-Jun-08, 12:26 AM
I would think that anyone who lived close to the sea
would believe that the Earth is spherical, while anyone
who lived far from the sea would believe the Earth is
more-or-less flat. With a lot of bumps. Which hide
the curvature very effectively.

-- Jeff, in Minneapolis

Fiery Phoenix
2015-Jun-08, 05:38 AM
Which "Powers that be" and at what time? A spherical Earth was accepted by the Classical Greeks.
The Greeks were among the first to formally recognize that the Earth was spherical. A little excerpt from Wiki (http://en.wikipedia.org/wiki/Spherical_Earth) says this:


The concept of a spherical Earth dates back to around the 6th century BC, when it was mentioned in ancient Greek philosophy, but remained a matter of philosophical speculation until the 3rd century BC, when Hellenistic astronomy established the spherical shape of the earth as a physical given. The paradigm was gradually adopted throughout the Old World during Late Antiquity and the Middle Ages.

There was a slow transition for the concept to be recognized and accepted by the general population, but it happened eventually.