Give Thanks to Jupiter, Our Little Planet’s Big Protector | Hacker News Reader

Give Thanks to Jupiter, Our Little Planet’s Big Protector

nautil.us

75 pointsdnetesn25 comments

This article reflect things explored quite well in amazing BBC 5-piece documentary Earth: Power of the Planet just few years ago (I envy the guy for being narrator to this show, just see and you'll understand :))

First 4 episodes explore various elements on our planet, but last one is a true gem - it deals with uniqueness of Earth in universe - like Jupiter catching most dangerous asteroids/comets so earth gets just enough catastrophes and not too many, moon stabilizing our orbit (and adding tides which probably helped life to move from oceans), and so on.

I love documents about nature, and BBC has produced consistently great ones, but this one stands above all... after seeing it, I do look at many things in nature in a different view. I would put this little gem as mandatory at school for all kids around the world, and you'll have a eco-friendly generation guaranteed.

The fact we're assuming that all of those things are necessary highlights that you can't make a statistic from one case.

How do we know which of the conditions on Earth were really necessary and which were neutral to life?

picking out one of many mentioned in documentary goes along these lines:

moon is a remnant of young earth colliding with its twin planet, part of it was absorbed into earth (that's why we have so much iron & melted dynamic core, which btw generates strong magnetic shield protecting us from sun's solar winds). Rest formed moon over time, which is unusually big compared to its parent planet and unusually close (all those stabilizing influences + tides). If we haven't had moon, earth would be "wobbling" on its path around sun frequently, causing very frequent glacial ages.

Necessary for life itself? Never said that. Stromatolites and similar single cell organism can survive about anything short of earth being consumed by black hole. Necessary for evolution of complex life and its explosion in variety that we see today, and more importantly our society? I personally do believe so. Just watch the document and then we can discuss.

And which perhaps even detrimental?

"318 times more massive and 11 times larger than Earth"

11 times larger is technically correct if you are talking about distance across. By volume Jupiter is ~1300 times larger than Earth.

to me, the story doesnt make a lot of sense. all around the universe big rocky giants moved inwards and suddenly became gas giants of the inner solar system, but in ours for some reason Jupiter got big and gracious and it blocked Neptune and Uranus, and more perhaps.

I dont buy it, i think what others have said, that jupiter was pulled out from the inner solar system along with the other large gas giants. and that earth might have been a super earth, but its collision that created the moon threw large portions into outer space.

this 2nd hypothesis makes more sense, especially when you consider that earth is unusually dense. we should have been a larger planet, were like the denser core of something else left behind. Much denser then even venus or mars.

The tricky part is that the techniques for detecting extra-solar planets work best for large planets near its sun.

But to get to your question, see http://en.wikipedia.org/wiki/Orbital_resonance#Possible_past... :

> A past resonance between Jupiter and Saturn may have played a dramatic role in early Solar System history. A 2004 computer model by Alessandro Morbidelli of the Observatoire de la Côte d'Azur in Nice suggested that the formation of a 1:2 resonance between Jupiter and Saturn (due to interactions with planetesimals that caused them to migrate inward and outward, respectively) created a gravitational push that propelled both Uranus and Neptune into higher orbits, and in some scenarios caused them to switch places, which would have doubled Neptune's distance from the Sun. The resultant expulsion of objects from the proto-Kuiper belt as Neptune moved outwards could explain the Late Heavy Bombardment 600 million years after the Solar System's formation and the origin of Jupiter's Trojan asteroids.[43] An outward migration of Neptune could also explain the current occupancy of some of its resonances (particularly the 2:5 resonance) within the Kuiper belt.

I think your statement "that earth is unusually dense" is incorrect. Earth's density is 5.51 grams/cc and Mercury's is 5.427 grams/cc. These are quite close. Earth's density is higher because of its higher gravity. When considered as "uncompressed" density, Mercury is much more dense than the Earth. See http://en.wikipedia.org/wiki/Terrestrial_planet#Density_tren... .

> I think your statement "that earth is unusually dense" is incorrect [..] Mercury is much more dense than the Earth.

To be fair, Mercury's basically a ball of iron.

I often wonder what state science might be in Greek & Roman pantheism had persisted rather than being displaced by the monotheistic religions from the Middle East.

The line between polytheism and monotheism isn't all that clear. The veneration of saints shares a lot of features in common with the worship of lesser deities in the Greco-Roman pantheon.

That is true. Although christians like to publicize their supposed monotheism, their religion is not very different from old polytheism. For starters, the catholic church is shock-full of polytheistic symbols, and there is little evidence that it was different during the Roman empire. They follow eucharistic rituals that were common to other religions, such as the cult of Dionysius. The main difference between christianity and paganism is the replacement of the greco-roman gods with the judeo-christan pantheon (YAHWEH, his son, angels, archangels, satan, the virgin Mary) and the idea that only one divine entity should be called "god".

In addition, YHWH had many different names in the early Hebrew scriptures which reveal a strong influence from the Canaanite pantheon. It isnt until the Book of Judges that monotheism starts to become firmly established.

That's right. Early in Hebrew scriptures, there are several passages that suggest, not an outright exclusion of the existence of other gods, but rather an assertion that YHWH is the god of Israelites, which evolved into an assertion that YHWH is the only God.

Later in Christianity, not only Judaic influences, but the influences of Persian Zoroastrianism (cherubim, seraphim, and God's angels), Manichaeism (dual entities of good and evil under a single Monotheistic God), Mithraism (risen son of the chief God from the dead), the cult of Dionysius (the eucharistic ceremonies), various Pagan religions adopted by Constantine's mother redesignating Roman pagan holy sites as Christian holy sites, the cults of Mary Mother of God and Mary Magdalene in France, and finally the patron saints, which are virtually indistinguishable from the concepts of caretaker pagan gods with individual responsibilities.

Religions are all melting pots, adopting and co-opting the beliefs of the native people as they spread. This makes them neither more or less valid, and it is rather remarkable the dedication Christianity has preserved to the teachings of a single man two millennia ago.

Early in Hebrew scriptures, there are several passages that suggest, not an outright exclusion of the existence of other gods, but rather an assertion that YHWH is the god of Israelites

Indeed, even what is probably the best-known line, "I am the LORD thy God", doesn't rule out the existence of other gods; all that is commanded is that the Israelites should not worship said other gods.

http://en.wikipedia.org/wiki/Celestial_Matters

I read this book when I was a kid. The setting is a universe in the future where the greeks turned out to be correct. The earth is the center of the universe and bodies of celestial matter move in strange circular motions around the earth.

Technology is centered around this ancient interpretation of the physical world. Greeks end up actually carving out pieces of the moon in order to construct space craft that take advantage of this strange physics.

I think it would be rather different, as the Greeks & Romans never thought to search for universal physical laws, unlike the monotheists who decided that a rational God would create a rational universe subject to rules that could be understood by humans.

For the most part, we completely take that fact for granted nowadays with our scientific education, but the advances of science are quite breathtaking when you think about it.

Thales.

Monotheistic religions and Hellenistic mysteries offered a more fulfilling concept of Afterlife. They were bound to overtake the grim Hades.

The afterlife is far from a fixed concept in Christianity.

For a recent example: http://www.reuters.com/article/2007/04/20/us-pope-limbo-idUS...

Even Hell and Heaven appear to be creations of later thinkers, with little basis even in the canonical Gospels. They remind me of the Greek academic conception of the Gods: useful for controlling the masses, but not believed, and understood as a social control device, by many contemporary academics.

Does anyone know if they emptied limbo completely before they buried it - or do we have to worry about being attacked by undead philosophers now as well?

Just think of what the science of dentistry could have been if only we had gone with the Aristotlean model.

I can never understand how Jupiter can be thought to have any significant effect on the fate of Earth, given how tiny it is compared to the solar system, or even just to its own orbit.

Try playing with an online solar system simulator some time. After thousands of orbits, a tiny gravitational nudge can have a huge effect on a system. Also read about the concept of orbital resonances.

“Whether they find a life there or not, I think Jupiter should be called an enemy planet.”

-Deep Thoughts by Jack Handy.

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