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Space Earth

Strange New World Discovered: The "Mega Earth" 147

Posted by samzenpus
from the thing-that-should-not-be dept.
astroengine (1577233) writes "Meet 'mega-Earth' a souped-up, all-solid planet that, according to theory, should not exist. First spotted by NASA's Kepler space telescope, the planet is about 2.3 times larger than Earth. Computer models show planets that big would be more like Neptune or the other gas planets of the outer solar system since they would have the gravitational heft to collect vast amounts of hydrogen and helium from their primordial cradles. But follow-up observations of the planet, designated as Kepler-10c, show it has 17 times as much mass as Earth, meaning it must be filled with rock and other materials much heavier than hydrogen and helium. 'Kepler-10c is a big problem for the theory,' astronomer Dimitar Sasselov, director of the Harvard Origins of Life Initiative, told Discovery News. 'It's nice that we have a solid piece of evidence and measurements for it because that gives motivations to the theorists to improve the theory,' he said."
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Strange New World Discovered: The "Mega Earth"

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  • "2.3 times larger" is grossly ambiguous in at least 2 different ways:

    Until we read further, we are left to guess whether that means 2.3 times the diameter, 2.3 times the volume, or what. A few sentences later they clarify a bit, but it's still sloppy writing.

    Second, "times larger" is ambiguous in English. If Earth has diameter 1, then a diameter 2.3 times as large would be 2.3. Technically, a diameter 2.3 times larger would be 3.3 (1 + 2.3).

    Call that nitpicking if you want, but it's still sloppy wr
    • The second one is not at all ambiguous. "2.3 times larger" means "multiply how large the first thing is by 2.3" to absolutely anyone. It's kinda ambiguous when you're talking percent, but not a literal multiplier.

      The first one is totally ambiguous, though.

      • by Arker (91948) on Monday June 02, 2014 @04:55PM (#47150095) Homepage
        "The second one is not at all ambiguous. "2.3 times larger" means "multiply how large the first thing is by 2.3" to absolutely anyone."

        No, that would 2.3 times the size. 2.3 times *larger* strongly implies the correct answer (for x=1) is 3.3, not 2.3.
        • by Zorpheus (857617)
          Funny that we have exactly the same in German. The conclusion from the logical meaning is 3.3, but no one uses it this way. People who value the logical meaning say 2.3 times as large, they just would not use it, and the others use it the way that it is commonly used, although it is illogical.
          • by TeknoHog (164938)

            Same here in Finland, it's an endless battle. One common argument for the "illogical" way is to separate the "larger" and "2.3 times" -- it's larger than the original, and it's 2.3 times the original. Of course, if you want to say "2.3 times the original" then you don't need the extra "larger" qualifier.

            My usual argument for the logical way is to ask "what about 50% more". It's obviously not half of the original. The illogicians are quick to point out that the meaning changes when you go below 100%.

            For

            • by AK Marc (707885)

              Of course, if you want to say "2.3 times the original" then you don't need the extra "larger" qualifier.

              That doesn't work when people say things like "2.3 times smaller". So "2.3 times the size of" is ambiguous if it could be larger or smaller.

              I'm not arguing it's correct. I'm arguing that I hear it, thus it's in use.

              In fact, the case of "double" is interesting in that there is no ambiguity, it's always interpreted as "two times the original". However, Finnish doesn't have a direct native equivalent of "double", so we even get the confusion of someone saying "two times larger" when meaning "two times as large". Fortunately, we do have a loan of "double" ("tupla, tuplasti"), but it hasn't quite replaced the "two times" expressions.

              How odd. In English, we have double, triple, treble, quadruple, quintiple, and so on. I'm not sure how far up it goes, but I can't recall hearing much past triple.

              • by TeknoHog (164938)

                In fact, the case of "double" is interesting in that there is no ambiguity, it's always interpreted as "two times the original". However, Finnish doesn't have a direct native equivalent of "double", so we even get the confusion of someone saying "two times larger" when meaning "two times as large". Fortunately, we do have a loan of "double" ("tupla, tuplasti"), but it hasn't quite replaced the "two times" expressions.

                How odd. In English, we have double, triple, treble, quadruple, quintiple, and so on. I'm not sure how far up it goes, but I can't recall hearing much past triple.

                Of course we have a construct for this, for example two is "kaksi", time (of repetition) is "kerta", so double is "kaksinkertainen". But it's a bit awkward, as it is basically just saying "two times" instead of a shorter idiom.

                • by AK Marc (707885)

                  Of course we have a construct for this, for example two is "kaksi", time (of repetition) is "kerta", so double is "kaksinkertainen". But it's a bit awkward, as it is basically just saying "two times" instead of a shorter idiom.

                  English borrows from other languages. "Double" is the only special, then it's tri-ple, quadru-ple, quinti-ple. It's basically greek/latin roots of numbers, with "ple" on the end, even duo-ple almost works for double. We just steal smaller words to combine.

        • by mythosaz (572040)

          Is that font 2.3 times larger?

        • "2.3 times smaller" would mean divide. Larger is directional. I've never heard "times larger" used otherwise. Neither the Charlottean transplants nor my Appalachian relatives were ever confused about that.
      • by Jane Q. Public (1010737) on Monday June 02, 2014 @05:21PM (#47150307)

        The second one is not at all ambiguous.

        If it's not ambiguous, then it's just wrong.

        1 + 1.3 = 2.3. Thus 2.3 is 1.3 more (or larger) than 1.

        Similarly, 1 + 2.3 = 3.3. I.e., 3.3 is 2.3 larger than 1.

        2.3 is 2.3 times 1. But not "times larger". That confuses addition and multiplation.

        If the article had said "2.3 times", and left out "larger", it would have been correct.

        • by AK Marc (707885)
          And what if it said "2.3 times smaller"? How is "2.3 times" any more unambiguous when "2.3 times smaller" is in common use (even if you don't like it, that doesn't change reality). "2.3 times larger" is unambiguously "2.3 times the original size". At least everywhere I've lived.
          • by Pfhorrest (545131)

            I wouldn't know how to make sense of "2.3 times smaller" in any context. Except maybe... you have things A, B, and C, and B is smaller than A, as is C, and the A-C = 2.3 * A-B. But I wouldn't know what to make of it if you just said "C is 2.3 times smaller than B!" without the comparison to A. And I don't know how you would phrase that comparison... "C is 2.3 times smaller than A than B?" That's just confusing.

            • by AK Marc (707885)
              Everywhere I've lived, people have used 2.3 times smaller to mean X/2.3. Yes, it's bad English, but it's in common use.
    • by Chas (5144) on Monday June 02, 2014 @05:26PM (#47150339) Homepage Journal

      "2.3 times larger" is grossly ambiguous in at least 2 different ways:

      Until we read further, we are left to guess whether that means 2.3 times the diameter, 2.3 times the volume, or what. A few sentences later they clarify a bit, but it's still sloppy writing.

      Second, "times larger" is ambiguous in English. If Earth has diameter 1, then a diameter 2.3 times as large would be 2.3. Technically, a diameter 2.3 times larger would be 3.3 (1 + 2.3).

      Call that nitpicking if you want, but it's still sloppy writing.

      Okay from the Wikipedia page: http://en.wikipedia.org/wiki/K... [wikipedia.org]

      The sidebar states 17.2 +/- 1.9 M (M = Earth masses)
      It also states that the Radius is aproximately 2.35 R (R = Earth radius)

      Surface Gravity is a little over 3x that of Earth.
      Unfortunately this probably isn't going to be a liveable world. It's only about a quarter of the distance from its sun that the Earth is. It's mean surface temperature is a whopping 400+ degrees Fahrenheit (so yes, paper would auto-ignite there).

      • by AK Marc (707885)
        Thanks for that. I didn't get around to reading yet, but my guess was that it would have been closer. The sun's gravity would pull loose gases, and the atmosphere could be burned or blown off. Leaving the low density gas giants for more remote orbits.
      • (so yes, paper would auto-ignite there).

         
        Ah, home sweet home.

    • "Times larger" is not ambiguous. "X is Y times larger than Z" means "X is Y times Z larger than Z. "Y times" is in relation to Z. There is no other correct way to interpret it. It's often used and interpreted incorrectly, but that doesn't make it ambiguous - it makes marketers liars and people morons.

      Of course, there's the completely senseless uses as well. "X is Y times smaller than Z" where Y is greater than 1 implies a negative sieze for X, and "DSL is 10 times slower than cable" implies a negative

      • by AK Marc (707885)

        "Times larger" is not ambiguous.

        Correct. In unambiguously means "X is Y times Z". The only people who think otherwise 100% understand it as written and object on pedantic grounds. Oh, and someone looked it up, in this case, they said X is 2.3 times larger than Earth, meaning X=2.3*E. So you are not only theoretically wrong, but we can verify this use with actual numbers, and you are provably wrong as well.

    • You're being pedantic.

      diameter and volume would be the same since ones used to calculate the other.

      "larger" is used to denote size. So it's the correct word to mean a larger diameter/volume

      • by Derec01 (1668942) on Monday June 02, 2014 @07:48PM (#47151279)

        A little bit pedantic, but it certainly matters as they vary as different powers of the radius. Having 2.3 times the radius would be almost 12.2 times the volume. If the volume was only 2.3 times the Earth's volume, then the radius would only be 1.32 times larger.

      • by gstoddart (321705)

        diameter and volume would be the same since ones used to calculate the other.

        Hmmm ... calculus was a very long time ago, but the volume of a sphere goes up according to 4/3 pi r^3. They are related, but not the same.

        So if you double the diameter, you more than double the volume.

        I would say "twice the diameter" and "twice the volume" are very different metrics. Twice the weight is also different.

        • by qwak23 (1862090)

          Technically the volume expands at a rate of 4 pi r^2 with respect to the radius ( d/dr 4/3pi r^3 ). But yeah, should be obvious to people anyway based on 4/3 pi r^3 alone.

    • Your last phrase proves your point in the way that different people understand things differently. I always thought 2.3 times larger means that whatever the reference is will be multiplied by 2.3, so if reference is 1, then end result is 2.3.

      So yeah, point proven: TFS should be referring to absolute numbers and then infer relative numbers from that.

    • The real problem (or interesting thing about this if you don't like "problem") with this is scaling. 2.3^3 = 12.2. If this mystery planet is 2.3 times the size of Earth, one would expect it to have 12.2 (give or take a hair) times the mass of Earth, presuming that it has a similar core structure. It is almost half again more massive. This in turn suggests that the mantel is proportionally less of the total volume of the sphere, or rather, that it has a disproportionately larger core (nickel-iron core de

      • by rtb61 (674572)

        The real problem with current planetary formation theory is the silly expectation that catastrophic formation is rare and stable systems within a specific range are the norm. Likely catastrophic impact is the norm and when analysing planetary formation theory to align measured outcome's we have to be able to exclude unusual outcomes and put them down to catastrophic impacts rather than attempt to adjust the theories.

    • The diameter is 2.3x. The mass is around 20x. The density is about 1.5x. The length of year is a shade under 1/3. The surface temperature is estimated at 10x. The gravity is around 4x. The magnetic field at Earth's current age was probably 3.375x. Tea time is a universal constant.

  • by HeckRuler (1369601) on Monday June 02, 2014 @04:49PM (#47150037)

    The galaxies are ACCELERATING away from each other, and we don't have a real solid answer for why.
    Cosmology, the study of where all these planets and stuff came from and how, is still a young field with really big and really interesting discoveries yet to be made.

    For all of those people claiming that there's nothing new to discover, point them to the stars and ask how the hell that happened.

    And the state of the art is getting to the point where we don't need placeholders to conveniently fill in the gaps.

    Exciting times.

    • Re: (Score:2, Insightful)

      by Anonymous Coward

      The galaxies are ACCELERATING away from each other, and we don't have a real solid answer for why.

      Yes we do: space is inflating. Why this is happening is the more pertinent question.

    • Maybe. There is a theory that time itself is multidimensional which would account for the appearance of red shift we assume is the universe expanding, but might just be the effects of time upon the light as it travels interstellar distances.

  • by macklin01 (760841) on Monday June 02, 2014 @05:03PM (#47150147) Homepage

    Shouldn't this be 1.7 decaearths?

    Since the sun is about 333 kiloearths in mass, wouldn't a megaearth be about 3 solar masses? :-)

    • by TeknoHog (164938)

      Since the sun is about 333 kiloearths in mass, wouldn't a megaearth be about 3 solar masses? :-)

      I'm trying to picture 333000 times the collective human stupidity on Earth. But assuming that population scales with the surface area (R^2) instead of mass or volume (R^3) it wouldn't be quite as bad.

  • Dense (Score:4, Informative)

    by rossdee (243626) on Monday June 02, 2014 @05:07PM (#47150179)

    Something that was 2.3 times the size of the earth would be only about 12 times the mass of the earth if it were the same density
    since it is 17 times the mass it must be denser than the earth, presumably more iron/nickel than silicate rock.

    way too much gravity for 'life as we know it, Jim'\

    • by symbolset (646467) *
      Life yes. Even fish. Giraffes? Probably not.
    • by daveewart (66895)

      The article covers this. It's thought to be more dense because, with the increased gravity which comes from a larger size, the rocks will be more compressed; thus, more dense.

  • by tragedy (27079) on Monday June 02, 2014 @09:40PM (#47151923)

    Other people have commented on the lousy "size of Texas"-style "2.3 times larger than Earth" bit, but there's so much more wrong with this. There's the now standard "artists representation" header artwork/slideshow teaser that doesn't even have any sort of disclaimer that it's not a representation of any kind of this planet. There's also an appalling lack of any of the figures people really want to know such as what the surface gravity would be on this planet. I'm getting about 3.3 G based on the diameter and mass they give. Surface area is about 5 times that of Earth. The year is about 1 and a half Earth months. The temperature is over 200 degrees celcius, close to the melting point of tin.

  • At 11 billion years of age, it clearly hosts one of the oldest civilizations in the universe. At an apparent mass of 20x Earth, which is quite impossible for a planet of this vintage, it is clearly a Dyson sphere built round a black hole constructed by the stellar engineer Omega as a power source for Rassilon's space-time capsules.

    The reason it is in Draco is that it was shunted from its original universe into ours during the Third Time War.

  • by Ralph Spoilsport (673134) on Tuesday June 03, 2014 @12:00AM (#47152471) Journal
    It's a large planet orbiting a star. It has no massive hydrogen/helium atmosphere, and that's a mystery, WHY? Well, let's see, park a planet about 20 million miles from its host star for ELEVEN BILLION YEARS and see how long the atmosphere hangs around, in the face of ELEVEN BILLION YEARS of stellar evolution, coronal mass ejections, and all the rest of it, and they're PUZZLED as to why it's not hte size of Neptune?WTF? I'm surprised it still exists at all...
    • Exactly. Its probably just the remaining core of a gas giant that has slowly spiraled in over the eons.

    • by delt0r (999393)
      Why is that when the topic is Climate change, no scientist can ever be wrong or corrupt. But on every other topic they are apparently soo stupid on their own field of expertise random internets people think they worked it all out. Without showing any working I mite add.

      Seriously, run the numbers, a gas planet will still have the bulk of its mass as helium and hydrogen. It not that close and these stars are not that hot.
  • The best discoveries in science come when someone looks at something and says "that's not right..."

Every nonzero finite dimensional inner product space has an orthonormal basis. It makes sense, when you don't think about it.

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