Gravity and our expanding Earth

[DrWhat]

So I'm not really getting fatter! Well that's a relief.

[Jim Williams]

The tidal bulges on Earth are carried ahead of the Earth–Moon axis by a small amount as a result of the Earth's rotation. This is a direct consequence of friction and the dissipation of energy as water moves over the ocean bottom and into or out of bays and estuaries. Each bulge exerts a small amount of gravitational attraction on the Moon, with the bulge closest to the Moon pulling in a direction slightly forward along the Moon's orbit, because the Earth's rotation has carried the bulge forward. The opposing bulge has the opposite effect, but the closer bulge dominates due to its comparative closer distance to the Moon. As a result, some of the Earth's rotational momentum is gradually being transferred to the Moon's orbital momentum, and this causes the Moon to slowly recede from Earth at the rate of approximately 38 millimetres per year. In keeping with the conservation of angular momentum, the Earth's rotation is gradually slowing, and the Earth's day thus lengthens by about 17 microseconds every year. (This would make each Earth day one second longer every 60,000 years or so, and one minute longer every four million years). Looking back, the day was 15 minutes shorter when the dinosaurs roamed the Earth 65 million years ago.) See tidal acceleration for a more detailed description and references.

The Moon is gradually receding from the Earth into a higher orbit, and calculations[3][4] suggest that this would continue for about fifty billion years. By that time, the Earth and Moon would become caught up in what is called a "spin–orbit resonance" in which the Moon will circle the Earth in about 47 days (currently 29 days), and both Moon and Earth would rotate around their axes in the same time, always facing each other with the same side. However, the slowdown of the Earth's rotation is not occurring fast enough for the rotation to lengthen to a month before other effects change the situation: about 2.1 billion years from now, the increase of the Sun's radiation will have caused the Earth's oceans to vaporize, removing the bulk of the tidal friction and acceleration.

Wikipedia

[Fletcher]

Note nothing about the year lengthening or shortening which one might expect if mass were significantly increasing or decreasing for example !

The expanding earth theory should see a lengthening in the year due to conservation of momentum between sun & earth moon couple to be true ?!

[beapilot]

I didn't post a good post. Sorry for this empty post.

[Fletcher]

The earth has a hot molten interior - the moon & mars do not - there is no magnetic shield around them because they have no turning molten interior to generate magnetic flux which protects us from the solar wind & radiation.

As things cool they release heat which radiates out into space i.e. the heat radiated is greater than the incoming solar radiation as heat in - so net result should be a condensing of the planet as it cools, though probably not noticeable in our time scale.

EDIT: this was in relation to beapilot's post he withdrew.

[Grimer]

The earth has a hot molten interior - the moon & mars do not - there is no magnetic shield around them because they have no turning molten interior to generate magnetic flux which protects us from the solar wind & radiation.

As things cool they release heat which radiates out into space i.e. the heat radiated is greater than the incoming solar radiation as heat in - so net result should be a condensing of the planet as it cools, though probably not noticeable in our time scale.

EDIT: this was in relation to beapilot's post he withdrew.

It is annoying when that happens. This is why I try to cut and paste other people's posts when the quote box isn't showing - as I have done in this case. It's a bit of a fag since one has to first cut and paste, then select all and click the Quote box in the header, then put in ="" and insert the name of the poster you are quoting between the inverted commas.

I don't know why the quote facility doesn't appear immediately people make a post. No doubt there is a good reason for it. Perhaps it is to allow time for second thoughts - or something,

[jim_mich]

A long time ago Scott eliminated the the quote feature on the last post because people would simply quote the entire previous post each time which strained Scott's server computer.

[Grimer]

Thanks for satisfying my curiosity, Jim. I'm glad to see my guess that there was probably a good reason for omitting the quote box was correct. :-)

In order to conform with our admin's wishes I shall continue to use ellipses (...) to eliminate irrelevant text when replying to long posts.