Become a fan of Slashdot on Facebook


Forgot your password?
Get HideMyAss! VPN, PC Mag's Top 10 VPNs of 2016 for 55% off for a Limited Time ×
Earth Space News Science

Is the Earth Gaining Or Losing Mass? 356

Hugh Pickens writes writes "BBC recently asked physicist and Cambridge University professor Dave Ansell to draw up a balance sheet of the mass that's coming in to the earth, and the mass going out to find out if the earth is gaining or losing mass. By far the biggest contributor to the world's mass is the 40,000 tonnes of dust that is falling from space to Earth every year. 'The Earth is acting like a giant vacuum cleaner powered by gravity in space, pulling in particles of dust,' says Dr. Chris Smith. Another factor increasing the earth's mass is global warming which adds about 160 tonnes a year because as the temperature of the Earth goes up, energy is added to the system, so the mass must go up. On the minus side, at the very center of the Earth, within the inner core, there exists a sphere of uranium five mile in diameter which acts as a natural nuclear reactor so these nuclear reactions cause a loss of mass of about 16 tonnes per year." (Read more, below.)
Pickens continues: "What about launching rockets and satellites into space, like Phobos-Grunt? Smith discounts this as the mass is negligible and most of it will fall back down to Earth again anyway. But by far the biggest factor in earth's weight loss are the 95,000 tonnes of hydrogen that escape from the atmosphere every year. 'The other very light gas this is happening to is helium and there is much less of that around, so it's about 1,600 tonnes a year of helium that we lose.' Taking all the factors into account, Smith reckons the Earth is getting about 50,000 tonnes lighter a year, which is just less than half the gross weight of the Costa Concordia, the Italian cruise liner that recently ran aground."
This discussion has been archived. No new comments can be posted.

Is the Earth Gaining Or Losing Mass?

Comments Filter:
  • by elrous0 ( 869638 ) * on Thursday February 02, 2012 @04:06PM (#38906745)

    It would have given me a nice excuse the next time my wife noticed I had gained weight. "It's not the junk food, honey. The earth is gaining mass and causing me to weigh more!!!"

  • No wonder my TV is always covered. Time for a bubble dome to keep it all out.

  • by kehren77 ( 814078 ) on Thursday February 02, 2012 @04:28PM (#38907133)

    But Americans are attempting to even things out.

  • Don't think so. It is a pretty far out theory which has no real evidence and plenty of reasons why it does not hold up. But as I can't tunnel down to look, I guess anything is possible.
  • Wait (Score:5, Interesting)

    by Baloroth ( 2370816 ) on Thursday February 02, 2012 @04:35PM (#38907261)

    So you count the 16 tonnes a year from a nuclear reaction that may or may not be there, but you ignore the effects of space rockets, some of which have payloads in the hundreds of metric tonnes? (the Saturn V can carry 45 tonnes to a Lunar Injection orbit and over twice that to LEO.) Huh, interesting.

    Also, what is this about the weight of the Costa Concordia? I want to know how many Libraries of Congress that is per year, damnit.

    • by krlynch ( 158571 )

      16 tons/yr for m(b)illions of years is in aggregate a lot more than a few hundred tons a year for the last few decades.

    • The Library of Congress has " roughly 10 terabytes of uncompressed textual data." Wikipedia []

      12 terabytes is ~5 billion sheets of paper (typewritten), so assuming a linear relation then 10 terabytes = ~4.16 billion sheets. Neatorama []

      So with Wolfram Alpha this is about 20,800 metric tons, so a bit less than a quarter of the Costa Concordia gross weight. Wolfram Alpha []

    • (147,093,357 items [source []]) * (2.5 kg / item [source []]) / 50,000 tonnes = 7.35466785 Libraries of Congress per year.
  • Another factor increasing the earth's mass is global warming which adds about 160 tonnes a year because as the temperature of the Earth goes up, energy is added to the system, so the mass must go up.

    Wait, what? Isn't the mass already there but is just being distributed differently? What am I missing here?

  • at the very center of the Earth, within the inner core, there exists a sphere of uranium five mile in diameter which acts as a natural nuclear reactor so these nuclear reactions cause a loss of mass of about 16 tonnes per year.

    Sounds like the ultimate source of geothermal energy, so let's start drilling for it. Got to get there before Iran goes and makes a bomb out of it.

  • by scharkalvin ( 72228 ) on Thursday February 02, 2012 @04:41PM (#38907377) Homepage

    One thing that most posters overlooked was the statement that the Earth's GeoReactor may be shutting down (in anywhere from 100 years to 1 billion years). The theory states that when this happens the earth will lose its magnetic field and then its atmosphere. Scary!

  • AGW science uses sophisticated computer modelling to show that the Earth's climate is driven by the carbon dioxide concentration in the atmosphere...the 'forcing function'. The nuclear core theory provides for a nuclear reactor generating 4 terawatts of heat that must be continuously radiated into space. Moreover, the nuclear reactor output varies over time from full production to zero production to full production. []

    Such variation obviously has never happened

    • by mbkennel ( 97636 ) on Thursday February 02, 2012 @05:25PM (#38908021)


      The knowledge and certainty level about nuclear georeactors is quite low (understatement), and it is a minority opinion that it exists. If it does we certainly don't know enough about its prehistory either and what the consequences to climate would have been, so the climatological record isn't remotely conclusive on this.'s_energy_budget#Incoming_energy []

      Incoming solar radiation is 173 petawatts, 44 to 47 terawatts from "stored heat and radioactive decay" (probably not from fission), which is 0.025%.
      So a variation of 4 terawatts is about 0.002% of solar insolation. Now the climate can be sensitive but I doubt it's that sensitive. It probably wouldn't be possible to pick up a fluctuation in a 4 terawatt core georeactor in climate data.

      The core georeactor should be actually reasonably easy to detect if you can analyze neutrino scattering data and get initial angle and energy distribution of the incoming particles. That fact that I haven't heard of such a signal (the neutrino experimentalists would have found an unusual pesky background that they couldn't get rid of when trying to measure solar neutrinos) leads me to believe far more directly and without reference to climate that it's unlikely there's any signifcant core georeactor. Maybe it's possible it was just missed, and was in the data.

      Atmospheric physics and dynamics is much, much better understood since we've had experiments and theory for 50 years or so.

  • by Diamonddavej ( 851495 ) on Thursday February 02, 2012 @05:07PM (#38907741)

    There's no evidence of a georeactor in the Earth's core. We know this by measuring the abundance of geoneutrinos - neutrinos generated by radioactive decay and nuclear fission. The KamLAND, Japan and Borexino, Italy discovered a ~50% deficit in geoneutrinos i.e. 22 of 44 TerraWatts of heat comes from radioactive decay. The rest is primordial, left over from the Earth's cataclysmic formation. If there was a georeactor there would have been an anomalous abundance in geoneutrinos (KamLAND detected fission neutrinos from nearby Japanese nuclear reactors).

    The hypothesis of a georeactor, powered by a 16km diameter sphere of Uranium, was put forward by maverick scientist J. Marvin Herndon. He also believes the Earth is expanding and he rejects plate tectonics. Despite that, mainstream science did not ignore him but enthusiastically tested this georeactor theory.

    Gando, A. et al., 2011. Partial radiogenic heat model for Earth revealed by geoneutrino measurements. Nature Geoscience 4(9), 647-651.

    • by pz ( 113803 ) on Thursday February 02, 2012 @05:51PM (#38908397) Journal

      If you read the linked article, it all sounds very interesting, and reasonable plausible, and even perhaps worth serious investigation. That is, until you hit first the part that sounds like a crank complaining about being ignored by mainstream science, and then the absurd notion that the fusion reaction in stars can only ignite from a running fission core (where did that fissile material come from then?), or the equally absurd notion that thermonuclear bombs are proof that stars can ignite in that way.

      That said, I'm glad that someone took the idea of a sustaining nuclear reactor seriously enough to test it.

"If truth is beauty, how come no one has their hair done in the library?" -- Lily Tomlin