Talk:Earth mass

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layout[edit]

the paragraph that starts with "One Earth mass can be converted to related units:" should be a table of noteworthy objects, rather than a list. 73.162.189.151 (talk) 21:35, 7 February 2016 (UTC) The Planetary mass article has a good example in the current best estimates section. — Preceding unsigned comment added by Hadron137 (talkcontribs) 16:57, 10 February 2016 (UTC)

changing mass[edit]

The parts about mass of the Earth changing due to heat and photon influx/outflows make no sense, right? I mean, unless the heat is changing the rate of nuclear reactions, this makes no sense. Photosynthesis and the other processes described should maintain conservation of mass. I'm calling BS. — Preceding unsigned comment added by 174.62.239.108 (talk) 03:37, 16 February 2015 (UTC)

Some of these entries are rather implausible, but many others are also insignificant. The list should be evaluated and trimmed. Furthermore, must a gas or object completely leave earth's gravitational well (achieve escape velocity) to be exempt from contributing to Earth's mass? If so, many of the items in the list don't belong there.--Hadron137 (talk) 23:19, 5 February 2016 (UTC)

Here's some data to put the thermal examples in perspective, from the article on Mass–energy equivalence. Raising the temperature of an object increases its mass... a change of 1 °C, results in a mass change of 1.5 picograms (1 pg = 1×10−12 g).

So the energy equivalent of one gram (1/1000 of a kilogram) of mass is equivalent to:

25.0 million kilowatt-hours (≈ 25 GW·h)

I propose a section to summarize all the thermal effects (input and output), and state their combined effect (it's probalby negligible in comparison to the uncertainty of the Earth mass) Hadron137 (talk) 00:26, 6 February 2016 (UTC)

measurement[edit]

How is this currently best measured? By its gravitational influence (combining satellite orbit data with Cavendish-like experiments into gravitation) or by summing its constituents (combining geographic, seismic and materials data)? Cesiumfrog (talk) 06:12, 14 December 2008 (UTC)

Anybody care to work out how many atoms this mass equates to? http://en.wikipedia.org/wiki/Abundance_of_elements_in_Earth%27s_crust would probably help. Smartse (talk) 12:24, 1 March 2009 (UTC)

How precisely is the earth's mass known? The specified value is 5.97219 × 10^24 kg, but are more significant digits known, or constrained by upper and lower limits (error bars)?

I suggest a History section for a discussion of the many ways the mass was determined, and how it's accuracy has improved through time. — Preceding unsigned comment added by 67.108.10.228 (talk) 23:32, 4 February 2016 (UTC)

It is unclear how the period of a pendulum can be used to determine the Earth mass. Until the Cavendish experiment, only the product G.M was known. Pendulum deflection near a mountain was an attempt, but the period of a pendulum cannot solve the problem of determining either G or M.88.15.246.89 (talk) 18:35, 18 September 2017 (UTC)

The period of a pendulum can be used to determine gravitational strength, and by measuring the difference in period at various altitudes, the difference in gravitational strength can be determined. This difference in gravitational strength is attributed to the additional mass above or below the point of measurement. See main article for new citation The Mean Density of the Earth, which gives more detail. Hadron137 (talk) 21:50, 3 October 2017 (UTC)

Stub[edit]

Wikipedia:Stub category applies to those articles with no more than "rudimentary" information.

While very short articles are likely to be stubs, there are some subjects about which there is very little that can be written.

This article is not a stub, there's just not much more that should be written, more could, but it would be "inflation" for the sake of it. If you really think it can never be more than a stub, then {{Copy to Wiktionary}}. HarryAlffa (talk) 11:25, 21 September 2009 (UTC)

There's quite a bit more that can be written about it, like how the mass was determined, why is the value in this article that way, how it is used, etc. It's like the kilogram article, there is something more to say. 76.66.197.30 (talk) 04:41, 23 September 2009 (UTC)

Why Kg?[edit]

The first time I ever saw the mass of the Earth is was cited as 5.98 * 1024 kg, very close to the value cited here. But why is it in kg? Shouldn't it be 5.9742 × 1027 grams? Why would this number be cited in kg if kg is not a convenient unit?  Randall Bart   Talk  05:58, 17 September 2010 (UTC)

The NASA Jupiter Fact Sheet lists it in kg. -- Kheider (talk) 08:28, 17 September 2010 (UTC)
The kilogram, rather than the gram, is the base unit in the SI system, despite the kilo- prefix. SI defines the gram a 1/1000 of a kilogram, not the kilogram as 1000 grams. This is different from, for example, the length unit, where the meter is the base unit and a kilometer is defined as 1000 meters. TJRC (talk) 20:24, 17 September 2010 (UTC)

Earth or Earth/Moon?[edit]

Is the value 5.9742 × 1024 kg the mass of Earth without the moon or Earth plus moon? I ask because when measuring the orbits of the planets, the mass of the Earth without the moon does not appear to be a useful number, while the mass of the Earth moon system would be.  Randall Bart   Talk  05:58, 17 September 2010 (UTC)

It is the mass of the Earth. This article has nothing to do with dynamical orbital simulations or barycenters. -- Kheider (talk) 08:28, 17 September 2010 (UTC)

increasing mass[edit]

Why isn't it noted that the earth's mass increases by 10 million tons a year, due to meteorites and cosmic dust? —Preceding unsigned comment added by 165.212.189.187 (talk) 20:06, 28 February 2011 (UTC)

Lower mass now?[edit]

Shouldn't Earth's mass be some .02 % lower, in kg, now that G has been measured .02 % stronger, given that GM[earth] is relatively accurate? --83.209.120.229 (talk) 22:03, 18 September 2013 (UTC)

Earth symbol[edit]

There is no explanation of the symbol ⊕ used in M. Where does that come from?

⊕ is the symbol of planet Earth. --JorisvS (talk) 09:39, 4 December 2014 (UTC)

Using the Change in the Earth-Moon distance to calculate Earth Mass Gain[edit]

The distance between the Earth and the Moon increases by about one part in 2 times the age of the Earth-Moon system. The Change is one part in 2 times 4.538 Billion = 9.706 Billion.

The change in the mass does work on both the Moon and the Earth by moving the Moon to a higher orbit relative to the Earth-Moon Barycenter, while simultaneously moving the Earth to a lower orbit relative to the same E-M BC. The mass change is thus one part in 4.538 Billion of the total mass of the Earth-Moon System. By Mass Ratio that is ( 82.30059122 / 81.30059122 ) 5.97352 E 24 KG.

That 6.047 E 24 kg / 4.538 E 9 Years = 1.3325 E 15 kg per year increase in mass. If we assume the vast majority of this increase is attributed to the Earth due to its far greater surface area, mass, and gravitational attraction, we can estimate how thick that mass gain would be if it were evenly distributed over the surface of the Earth. The surface area is 5.103 E 14 m^2.

The mass per unit area is 1.3325 E 15 kg / 5.103 E 14 m^2 = 2.6112 kg / m^2 of the Earths surface per year. If we assume dust of a similar density to that of soil of 2650 kg per cubic meter. Then 2.6112 kg/ m^2 / 2650 kg / m^ 3 = 0.000 985 meters thick. This is 0.985 mm per year increase in the average radius of the Earth. If we assume most of the newly added materials are washed down the rivers into the ocean, then the thickness of the ocean sediments accumulate about 0.985 mm / 0.71 surface area of the earth = 1.387 mm of new materials deposited eventually on the surface of the oceans abyssal plains, each year. This does not include the amount of materials removed from the continents by erosion and redeposited on the same Abyssal Plains.

For simplicity, the Earth gets just under 1 millimeter of new dust deposited from it journey thru the cosmos as it orbits the Sun each year. This increase in mass slows Earth's rate of rotation about its own axis so that the year has increased by about 0.0025 seconds since time was standardized in a prior century. The increase from 86,400 seconds to 86,400.0025 seconds per year over more than a century is due to mass gain of the Earth. The change as a linear approximation would be around 0.000019039 seconds per year, currently.

0.0025 seconds divided by 0.000019039 = 131.3078704 years ( round to 131 years ) between standardization and re-calibration. I would assume the re-calibration occurred following the invention of Atomic clocks, but I do not know for sure. Any one want to look this up ?

Mike Clark, Golden , Colorado, USA . 73.3.187.143 (talk) 01:30, 28 February 2016 (UTC)

Those are interesting calculations, but please don't add them to the article because they look like WP:original research. Also, they don't take into account lots of other factors at work in influencing the earth-moon system and the rotation of the earth. You might also have noticed that the slowing of the earth's rotation is not constant and not currently predictable. Dbfirs 09:43, 28 February 2016 (UTC)