Are the planets growing?

Beyond the boundaries of established science an avalanche of exotic ideas compete for our attention. Experts tell us that these ideas should not be permitted to take up the time of working scientists, and for the most part they are surely correct. But what about the gems in the rubble pile? By what ground-rules might we bring extraordinary new possibilities to light?

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Re: Are the planets growing?

Unread post by allynh » Fri May 24, 2013 10:30 am

This is another clear example of where they totally miss the obvious. HA!

Earth's Mantle Affects Long-Term Sea-Level Rise Estimates ... 143743.htm
Equally compelling is the fact that the shoreline is not flat, as it should be, but is distorted, reflecting the pushing motion of Earth's mantle.

This is big news, says Moucha, for scientists who use the coastline to predict future sea-level rise. It's also a cautionary tale for those who rely almost exclusively on cycles of glacial advance and retreat to study sea-level changes.

"Three million years ago, the average global temperature was two to three degrees Celsius higher, while the amount of carbon dioxide in the atmosphere was comparable to that of today," says Moucha, who contributed to a paper on the subject in the May 15 issue of Science Express. "If we can estimate the height of the sea from 3 million years ago, we can then relate it to the amount of ice sheets that melted. This period also serves as a window into what we may expect in the future."

Moucha and his colleagues -- led by David Rowley, professor of geophysical sciences at the University of Chicago -- have been using computer modeling to pinpoint exactly what melted during this interglacial period, some 3 million years ago. So far, evidenced is stacked in favor of Greenland, West Antarctica and the sprawling East Antarctica ice sheet, but the new shoreline uplift implies that East Antarctica may have melted some or not at all. "It's less than previous estimates had implied," says Rowley, the article's lead author.

Moucha's findings show that the jagged shoreline may have been caused by the interplay between Earth's surface and its mantle -- a process known as dynamic topography. Advanced modeling suggests that the shoreline, referred to as the Orangeburg Scarp, may have shifted as much as 196 feet. Modeling also accounts for other effects, such as the buildup of offshore sediments and glacial retreats.

"Dynamic topography is a very important contributor to Earth's surface evolution," says Rowley. "With this work, we can demonstrate that even small-scale features, long considered outside the realm of mantle influence, are reflective of mantle contributions."

Building a case

Moucha's involvement with the project grew out of a series of papers he published as a postdoctoral fellow at the Canadian Institute for Advance Research in Montreal. In one paper from 2008, he drew on elements of the North American East Coast and African West Coast to build a case against the existence of stable continental platforms.

"The North American East Coast has always been thought of as a passive margin," says Moucha, referring to large areas usually bereft of tectonic activity. "[With Rowley], we've challenged the traditional view of passive margins by showing that through observations and numerical simulations, they are subject to long-term deformation, in response to mantle flow."

Central to Moucha's argument is the fact that viscous mantle flows everywhere, all the time. As a result, it's nearly impossible to find what he calls "stable reference points" on Earth's surface to accurately measure global sea-level rise. "If one incorrectly assumed that a particular margin is a stable reference frame when, in actuality, it has subsided, his or her assumption would lead to a sea-level rise and, ultimately, to an increase in ice-sheet melt," says Moucha, who joined SU's faculty in 2011.

Another consideration is the size of the ice sheet. Between periods of glacial activity (such as the one from 3 million years ago and the one we are in now), ice sheets are generally smaller. Jerry Mitrovica, professor of geophysics at Harvard University who also contributed to the paper, says the same mantle processes that drive plate tectonics also deform elevations of ancient shorelines. "You can't ignore this, or your estimate of the size of the ancient ice sheets will be wrong," he says.

Rise and fall

Moucha puts it this way: "Because ice sheets have mass and mass results in gravitational attraction, the sea level actually falls near the melting ice sheet and rises when it's further away. This variability has enabled us to unravel which ice sheet contributed to sea-level rise and how much of [the sheet] melted."

The SU geophysicist credits much of the group's success to state-of-the-art seismic tomography, a geological imaging technique led by Nathan Simmons at California's Lawrence Livermore National Laboratory. "Nathan, who co-authored the paper, provided me with seismic tomography data, from which I used high-performance computing to model mantle flow," says Moucha. "A few million years may have taken us a day to render, but a billion years may have taken several weeks or more."

Moucha and his colleagues hope to apply their East Coast model to the Appalachian Mountains, which are also considered a type of passive geology. Although they have been tectonically quiet for more than 200 million years, the Appalachians are beginning to show signs of wear and tear: rugged peaks, steep slopes, landslides, and waterfalls -- possible evidence of erosion, triggered by dynamic topography.

"Scientists, such as Rob, who produce increasingly accurate models of dynamic topography for the past, are going to be at the front line of this important research area," says Mitrovica.

Adds Rowley: "Rob Moucha has demonstrated that dynamic topography is a very important contributor to Earth's surface evolution. … His study of mantle contributions is appealing on a large number of fronts that I, among others of our collaboration, hope to pursue."

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Re: Are the planets growing?

Unread post by dfinsandsr » Tue Jun 25, 2013 10:36 am

Based on transmutations by Solar Fusion, LENR, Plasma, EU I agree with the growing planets. EU models coupled with elemental and atomic transmutations to my observations should not only validate this theory but predict more growth. There seems to also be some minor subductions and techtonic plate movements. So that shouldn't be totally discarded. Then again my reasoning could be totally skewed.

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Re: Are the planets growing?

Unread post by allynh » Mon Jul 01, 2013 12:56 pm

Here is a fun note about volcanos sinking. Ignore the mention of subduction. HA!

Mega-quakes 'caused volcanoes to sink'
Massive earthquakes can cause distant volcanoes to sink, according to research in Japan and Chile.

The magnitude 9.0 tsunami-generating quake that occurred off northeastern Japan in 2011 caused subsidence of up to 15 centimetres in a string of volcanoes on the island of Honshu as much as 200 kilometres from the epicentre, a Japanese study published on Sunday said.

And the 8.8-magnitude Maule quake in Chile in 2010 caused a similar degree of sinking in five volcanic regions located up to 220km away, according to a US-led paper.

It was not clear whether the phenomenon boosted eruption risk, the authors wrote.

Both the Japan and Chile quakes were of the subduction type, caused when one part of Earth's crust slides beneath another.

If the movement is not smooth, tension can build up over decades or centuries before it is suddenly released, sometimes with catastrophic effect.

In both cases, the sinking occurred in mountain ranges running horizontally to the quake.

The 2011 quake "caused east-west tension in eastern Japan," Youichiro Takada of the Disaster Prevention Research Institute at Kyoto University told AFP in an email.

"Hot and soft rocks beneath the volcanoes, with magma at the centre, were horizontally stretched and vertically flattened. This deformation caused the volcanoes to subside."

The researchers for the Chilean volcanoes said subsidence occurred along a stretch spanning 400km.

As in Japan, the ground deformation in Chile occurred in huge ellipse-shaped divots up to 15km by 30km in size, although the cause appears to be different.

Pockets of hot hydrothermal fluids that underpinned the volcanic areas may have escaped through rock that had been stretched and made permeable by the quake.

Two earthquakes in the Chilean subduction zone in 1906 and 1960 were followed by eruptions in the Andean southern volcanic zone within a year of their occurrence.

However, no big eruptions in this volcanic hotspot can be associated with the 2010 temblor, says the study led by Matthew Pritchard of Cornell University in New York.

Takada said the impact of the 2011 quake on volcano risk on Honshu was unclear.

The studies, published in the journal Nature Geoscience, used data from satellite radar which mapped terrain before and after the quakes.

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Re: Are the planets growing?

Unread post by allynh » Thu Sep 05, 2013 9:37 am

This is starting to sound like one of my favorite movies, Crack in the World. HA!
Researchers to drill world’s deepest hole to unearth mysteries locked inside our planet ... story.html
The deepest hole ever made is more than 40 years old, and quite dead. In 1970, the Soviet Union began to drill on the Kola Peninsula, close to the Finnish border, in an attempt to penetrate the skin of the Earth. Ten years later, the drill passed the six-mile record then held by a hole in Oklahoma made by an oil company, which failed when its drill bit hit a lake of molten sulphur. Five more years took it to seven-and-a-half miles — but then the temperature rose so high that to go any further would have melted the bit.

In 2008, the money ran out and the site was abandoned (although some fundamentalists still cite the hoax that the drill was stopped because it had broken into Hell itself).

Now, a new programme of ocean-drilling is under way, attempting to reach parts of the planet’s interior never before penetrated. The problem with drilling on land is that the Earth’s outermost layer — the crust — is so thick that there is little chance of getting through.

Under the sea, however, its intimate secrets are easier to probe. A century ago, the Croatian meteorologist Andrija Mohorovicic was studying the shock waves made by earthquakes as they passed through the continents. He noticed that the waves travelled much faster through the rock about 35 miles below the surface than they did above that depth. That shift — the Mohorovicic discontinuity, or “Moho” — hinted that the Earth has distinct layers of rock above its liquid metallic core, with the Moho forming the boundary between the outer crust (which makes up less than one hundredth of its mass) and an inner zone called the mantle.

Beneath the deep oceans, where the surface is younger and thinner as it has been extruded from the molten depths, the Moho may be less than four miles down.

In 1957, the Americans set out to penetrate it in a deep trench off Mexico, and managed to extract a short core of mantle. However, the project was plagued with difficulties in keeping the ship in place and manipulating the drill through two miles of water, and was abandoned.

With GPS, and today’s oil-well technology, both those problems have been solved — so the International Ocean Discovery Programme has set out to break through the Moho and find what lies below. It is now investigating sites off Hawaii, California and Baja California, to find the right balance between new, thin (but hot) crust and older, thicker, but cooler material that will not melt the drill. Already the Baja hole has reached roughly a mile down.

One aim is to work out the role in the global carbon cycle of the liquid that bubbles from the mantle at the ocean ridges; another is to insert sensors into the hole to check the temperature, pressure and intestinal movements of our planet. The geologists hope to examine the mantle’s balance of metallic elements, which may be depleted in platinum, gold, cobalt and others that have been sucked in by the liquid iron core.

Biologists are involved, too. Already, single living cells have been found more than a mile below the sea floor, and we know that bacteria from ocean vents can survive at 115C; which means that, in principle at least, they or their relatives could exist three miles below the surface. It might hint at what the first life, on a searing-hot planet more than 4 billion years ago, looked like.

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Re: Are the planets growing?

Unread post by allynh » Fri Sep 06, 2013 1:02 pm

Here we go. Now we are starting to GET detailed information about the variations in gravity. The key point is this one.
Earth's gravitational pull is smallest on the top of the Huascaran mountain in the South American Andes, and largest near the North Pole.
Think about it, as has been mentioned up thread: the gravity under the highest places on Earth is lower than on the oceans crust.

- That goes against commonsense. The gravity over mountains should be greater. It is not.

Gravity Variations Over Earth Much Bigger Than Previously Thought ... 105345.htm
Using detailed topographic information obtained from the US Space Shuttle, a specialist team including Associate Professor Michael Kuhn, Dr Sten Claessens and Moritz Rexer from Curtin's Western Australian Centre for Geodesy and Professor Roland Pail and Thomas Fecher from Technical University Munich improved the resolution of previous global gravity field maps by a factor of 40.

"This is a world-first effort to portray the gravity field for all countries of our planet with unseen detail," Dr Hirt said.

"Our research team calculated free-fall gravity at three billion points -- that's one every 200 metres -- to create these highest-resolution gravity maps. They show the subtle changes in gravity over most land areas of Earth."

The new gravity maps revealed the variations of free-fall gravity over Earth were much bigger than previously thought.

Earth's gravitational pull is smallest on the top of the Huascaran mountain in the South American Andes, and largest near the North Pole.

"Only a few years ago, this research would not have been possible," Dr Hirt said.

"The creation of the maps would have required about 80 years of office PC computation time but advanced supercomputing provided by the Western Australian iVEC facility helped us to complete the maps within a few months."

High-resolution gravity maps are required in civil engineering, for instance, for building of canals, bridges and tunnels. The mining industry could also benefit.

"The maps can be used by surveyors and other spatial science professionals to precisely measure topographic heights with satellite systems such as the Global Positioning System (GPS)," Dr Hirt said.

The findings of the research team from Curtin and Technical University Munich have recently appeared in the journal Geophysical Research Letters.

Earth's gravity field gallery: ... allery.cfm
This is the main site.

GGMplus 200m-resolution maps of Earth's gravity field

GGMplus Earth gravity field model

Look at the pictures. The bluer the color, the greater the gravity. The redder the color, the less the gravity. The difference is caused by the greater electrical charge under the mountains due to the piezoelectric effect generated in the rock.

Gravity disturbances over South America ... _large.jpg

Gravity disturbances over North America ... _large.jpg

Gravity disturbances over Australia and parts of South-East Asia ... _large.jpg

Gravity disturbances over Africa ... _large.jpg

Gravity disturbances over Europe ... _large.jpg

Gravity disturbances over Himalayas, India and parts of South-East Asia. ... _large.jpg

The areas of major earthquakes are associated with the difference in color. The electrical charge changes the orientation of the water dipole in the rock, flipping the direction of gravity, just like in clouds. When that electrical charge is reduced the crust collapses causing earthquakes.

- North America is curved up to a mile, with the mountains going up from there.

- South America is curved up to two miles, with the mountains going up from there.

- China is curved up three miles, with the mountains going up from there.

- Africa is flat, most of it below a mile.

Over time, as the charge bleeds away, those gravity variations will all move to an even blue, and the elevations will drop. All of the continents will look like Africa.

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Re: Are the planets growing?

Unread post by Sparky » Fri Sep 06, 2013 3:46 pm

That goes against commonsense. The gravity over mountains should be greater.
so, will astronauts in low earth orbit weigh more? :? ///.. :D
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"Doubt is not an agreeable condition, but certainty is an absurd one."
"Those who can make you believe absurdities, can make you commit atrocities." Voltaire

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Re: Are the planets growing?

Unread post by GaryN » Fri Sep 06, 2013 4:02 pm

Look at the pictures. The bluer the color, the greater the gravity. The redder the color, the less the gravity.

I think that is the other way around isn't it?
That volcano showing more red at the rim is interesting, and suggests that, as I interpret it, more acceleration where I would expect there to be greater charge density, as with all pointy objects.
In order to change an existing paradigm you do not struggle to try and change the problematic model. You create a new model and make the old one obsolete. -Buckminster Fuller

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Re: Are the planets growing?

Unread post by allynh » Fri Sep 06, 2013 6:00 pm


What happens is that the orbit drops at those points of high gravity and rises at points of low gravity. They compare their actual height with where they should be. Its like a car driving through dips and rises in the road.

They combine all five sets of information on that main page to get the actual reading.

The electrical charge is in the crust beneath the mountains. We're not talking accumulated charge like at the tips of lightning rods.

The charge in the crust powers the water in the crust to flip the direction of the dipole, lifting the crust the way water in clouds are lifted. That's why major earthquakes are in the same areas as the red.

The greater the difference in color over a small area, the greater the chance for earthquakes as the electrical charge starts to drain out.

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Re: Are the planets growing?

Unread post by Spektralscavenger » Wed Sep 11, 2013 4:48 pm

In Nikola Tesla I trust! I think planets grow but planets like Earth very very slow. Gaseous giants and stars, on the other hand, grow at significant rates.

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Re: Are the planets growing?

Unread post by allynh » Wed Sep 25, 2013 12:34 pm

This is interesting. There are some videos on Youtube, but they are not in english. Just search on the key words - new island pakistan

Pakistan earthquake kills at least 200, as tremor creates a new island in the sea ... ea/4979084
Updated Wed 25 Sep 2013, 2:34pm AEST
Photo: This island rose from the sea off the southern coast of Pakistan following the earthquake. (Twitter: @NewsweekPak)

A major earthquake has hit a remote part of western Pakistan, killing at least 200 people and prompting a new island to rise from the sea just off the country's southern coast.

Tremors were felt as far away as the Indian capital of New Delhi, hundreds of kilometres to the east, where buildings shook, as well as Dubai in the Gulf and Pakistan's sprawling port city of Karachi.

The quake caused scores of houses to collapse in remote mountainous areas near the Iranian border, Pakistan's Frontier Corps said.

Local officials confirmed that 208 have been killed with the death toll expected to rise.

Asad Gilani, one of the most senior officials in the Baluchistan administration, said 100 people had been injured in the quake and Awaran police chief Rafiq Lassi added that officials feared the death toll would rise.

The United States Geological Survey said the 7.8 magnitude quake struck 235km south-east of Dalbandin in Pakistan's quake-prone province of Baluchistan, which borders Iran.

It issued a red alert, warning that heavy casualties were likely based on past data.

The earthquake was so powerful that it caused the seabed to rise and create a small, mountain-like island about 600 metres off Pakistan's Gwadar coastline in the Arabian Sea.

Television channels showed images of a stretch of rocky terrain rising above the sea level, with a crowd of bewildered people gathering on the shore to witness the rare phenomenon.

Officials said scores of mud houses were destroyed by aftershocks in the thinly populated mountainous area near the quake epicenter in Baluchistan, a huge barren province of deserts and rugged mountains.

Baluchistan assembly deputy speaker Abdul Qadoos said at least 30 per cent of houses in the impoverished Awaran district had caved in.

He said damage to the mobile phone network was hampering communications in the area.

200 soldiers, medical teams mobilised to help with relief effort

The provincial government declared an emergency in Awaran and the military mobilised medical teams as well as 200 soldiers and paramilitary troops to help with the immediate relief effort.

"We have received reports that many homes in Awaran district have collapsed. We fear many deaths," Baluchistan government spokesman Jan Muhammad Baledi told the ARY news channel.

"There are not many doctors in the area but we are trying to provide maximum facilities in the affected areas."

Television footage showed collapsed houses, caved-in roofs and people sitting in the open air outside their homes, the rubble of mud and bricks scattered around them.

Awaran district has an estimated population of around 300,000, scattered over an area of more than 21,000 square km.

In the regional capital of Quetta, officials said some areas appeared to be badly damaged but it was hard to assess the impact quickly because the locations were so remote.

Office workers in Pakistan's largest city Karachi rushed out of their buildings.

"My work table jerked a bit and again and I impulsively rushed outside," 28-year-old resident Noor Jabeen said.

Government worker Owais Khan said: "It was not so intense, but it was terrible."

Amjad Ali, a 45-year-old information technology worker, says whenever there is a jolt "it reminds me of the 2005 earthquake in Kashmir".

The 7.6 magnitude quake in 2005 killed at least 73,000 people and left several million homeless in one of the worst natural disasters to hit Pakistan.

Map data ©2013 AutoNavi, Basarsoft, Google, MapIT, Mapa GISrael, ORION-ME

Map: Awaran District in Pakistan

Topics: earthquake, disasters-and-accidents, pakistan

First posted Tue 24 Sep 2013, 10:38pm AEST

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Re: Are the planets growing?

Unread post by marengo » Mon Sep 30, 2013 4:45 am

Wow! 161,000 views on a pointless question.
let's get serious folks.
A series of scientific papers on the new Aether physics.

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Re: Are the planets growing?

Unread post by red44 » Wed Oct 16, 2013 1:30 pm

Someone contacted TB about a broken link in this forum thread. Hope this is helpful to anyone needing the link:

"While researching for a lesson plan I’m putting together for the “Great ShakeOut” Earthquake Drill (on Oct 17), I came across your site and found a broken link to a page on the US Geological Survey site. I thought I’d share the information with you in case you’d like to update your site. The link that is no longer working is: I believe that resource is gone, but I’d suggest the main earthquake resource page on the USGS site as a good replacement:

I found the broken link on this page of your site: ... &start=870."


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Re: Are the planets growing?

Unread post by Aardwolf » Thu Oct 17, 2013 5:01 am

marengo wrote:Wow! 161,000 views on a pointless question.
let's get serious folks.
There's more evidence is support of a growing Earth than there is in relativistic effects.

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Re: Are the planets growing?

Unread post by allynh » Thu Oct 17, 2013 9:24 am

Thanks red44, as the Earth grows so does this thread. Mountains rise and fall, deep ocean opens up, and along the way links break. HA!

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Re: Are the planets growing?

Unread post by allynh » Thu Dec 05, 2013 1:18 pm

This is somebody who started out with the right question, but never actually understood what he was asking. HA!

What a Habitable Planet Twice the Size of Earth Would Be Like ... 1476308959
To date, astronomers have catalogued over 1,000 exoplanets — some of them rocky and parked within their host star's habitable zone. But a good portion of these planets are bigger than Earth, prompting us to ask: What would it actually be like on a habitable planet twice the size of ours?


A first complication: "twice as large" is not the same thing as double the mass. A double-mass Earth is relatively simple to analyze, but if we stipulate that the radius is twice as big, then it depends on what it is made of.

Note that if the component rock contributes to water as it does on Earth, a planet with 15 times the mass but only 4 times the area will have a 3.75 times deeper hydrosphere, assuming everything equal. That means 16 km deep oceans - "Dry" might still be a waterworld.

A lot hinges on whether we assume Double-Earth started out beyond the ice-line of the solar system and moved inwards, in which case it will be really wet, or started out close to the sun and never got much volatiles. In the first case, "Wet Double-Earth," the mass will be about 3 Earths and the average density 37% of Earth, with a surface gravity of 0.73 g and an escape velocity of 13.6 km/s. This will have an ocean hundreds of kilometres deep, surrounding a rocky core covered with high pressure warm ices. In the second case, "Dry Double-Earth," the mass will be 15 Earths, the density will be 167%, gravity 3.4 g and escape velocity 30 km/s. (I used the model of Sotin et al. in Sotin, C., Grasset, O., Mocquet, A. 2007. Mass-radius curve for extrasolar Earth-like planets and ocean planets. Icarus191, 337-351.)

How large is the core of Wet? Assuming it to be Earth density (5520 kg/m^3) and surrounded by water (1000 kg/m^3), I get a core 1.22 times the radius of Earth (7,772 km), surrounded by 0.78 Earth radii of water (4,969 km). This is of course just a first approximation, since there is a high pressure ice crust that begins when pressures go above 1 GPa. A bit more calculation gives me an estimate o a 6,060 km core (0.95 Earth) with an ice VI/VII crust out to 12,600 km (1.97 Earths), leaving "just" a 160 km deep ocean. If the deep ocean is colder the depth might be just 104 km.


Now we need to make some guesses at atmosphere and temperatures. The basic temperature for a greybody with Earth-like albedo at this orbital distance (1 AU around a sun-like star) is 250 K, if we add the 36 K greenhouse correction of Earth this becomes 13 degrees C average.

There is another equilibrium similar to "snowball Earth" where the entire surface is cold and glacial (and ocean worlds can of course get completely iced over), reflecting away energy efficiently. For albedo 0.8 we end up with an temperature of -15 C. Of course, the vast oceans will in any case stay liquid, especially since the freezing point of water decreases beyond a few megaPascals of pressure.

In the wet case the scale height is 11.3 km — air pressure will be 36% less at this altitude. The temperature needed for a molecular species to escape is 1.49 times that on Earth: in this case hydrogen certainly escapes and I think helium will escape (it depends on the exosphere temperature, something that is hard to calculate). Methane and ammonia could be retained, but if there is life and oxygen they will have been turned into carbon dioxide and nitrogen.

In the dry case scale height is 2.4 km: clouds will be squat and close to the ground. The retention temperature is 7.5 times Earth — Dry could potentially retain hydrogen gas. This means that potentially it could have gathered a much denser atmosphere from the beginning, potentially turning into a gas giant. Note however that by assumption we had it form in the "dry" zone near the star, so it might not have accumulated that much. We should still expect it to have a denser atmosphere than the wet case.

If we make the assumption that the surface pressure is proportional to surface gravity (might make sense in this particular case), Wet has surface pressure 0.73 and Dry surface pressure 3.4 atmospheres.

In this case Wet gets air density 0.9 Earths. Quite manageable for humans.

Let's also assume the mean wind speed is a terrestrial 10 m/s - again, this is hard to evaluate without running a full circulation model. Finally, most doubtfully, let's assume the rotation period is 24 hours. The radiative timescale of 18 days and advection timescale of 14 days — this means that the weather is complex like on Earth, and responds rather quickly to seasons (ah, I implicitly assumed an Earth-like axial tilt: things will get really strange if it is more extreme). Wet will have about 9-10 jet-streams (Earth has about 7). Dry instead has surface air density is 4.3 times Earth, fast timescales and 10 jet streams. Not too alien.

Weather is partially driven by buoyancy. On Wet this is weaker: clouds will be taller and move more ponderously, while on Dry the higher gravity will make small density differences generate more force: flatter, more intense convection.

Coriolis forces are twice as powerful, so there is a higher tendency for zonal rather than meridional winds: more east-west flow than north-south than on Earth.

A rain cloud will have an amount of water roughly proportional to its height and the atmospheric density: both Wet and Dry will have more rain from a typical raincloud than on Earth (about 30-40%, assuming my assumptions work), with Wet slightly wetter — the lower air density is compensated by a much higher scale height. In practice this will depend on more complex aspects of the atmosphere (lapse rates and similar stuff).

Hail on Wet may be truly nasty, since it has plenty of distance to form. The radius likely scales proportionally to the scale height, making the mass of large hailstones up to 3.5 times larger — the fact that they just weigh just 2.6 times more thanks to the lower gravity is not enough. Terminal falling velocity scales as sqrt (gravity/density), so the velocity of a hailstone will be just 90% of terrestrial terminal velocity of a same sized stone. On Dry it is 89% thanks to the thicker air. But this is not enough: the kinetic energy will be about three times larger. Ouch.

The strength of hurricanes depends on the temperature difference between the ocean and the stratosphere; I do not know how to calculate this simply. I note that in the absence of land they can run much longer before drifting too far towards the poles that they dissipate. If the zonal winds are strong enough hurricanes may even become semi-permanent like the red spot on Jupiter, but I suspect there is enough meridional winds to prevent this.

I am also a bit uncertain about whether latitudinal mixing is strong enough to keep the poles too warm to form ice sheets or not. I suspect the lack of land and the presence of a huge ocean thermal capacity will reduce ice formation.

If we assume 20% oxygen, then Dry will have 537 mmHg partial pressure oxygen - toxic to humans. Even worse, the partial pressure of CO2 will be 10.4 mmHg — causing hypercapnia in humans. Still, local life could likely evolve to handle that with little problem. Wet atmosphere looks pretty okay for humans.

The optical depth of the atmospheres on the Double-Earths will be the same as on Earth (because of my assumption of pressure = surface gravity), so you can see the same distance. The vertical optical depth is 1.37 times more than Earth on Wet: the sky is more milky, but not too alien. On Dry it is just 1.1: almost normal. If you were to fly a plane, it would however turn dark blue at a much lower altitude.


The radiogenic heating (assuming an Earth-like composition) of Dry is 3.34 times higher than on Earth, 0.29 W/m^2. Still not enough to melt the crust into an Io-like volcanic mess, but it is far more active - the crust is just 3 kilometers thick. Underwater volcanos are common, and there will be plentiful hydrothermal vents. The higher strength of buoyancy makes volcanism-induced convection more powerful: the deep ocean will be churned far more than Earth's deep ocean by geothermal heat.

If Dry had a sufficiently eccentric orbit (or a heavy companion) to give it extra tidal heating volcanism might be fierce enough to create an Io-like state of semi-molten crust. At this point it would likely become very different: the churning oceans would accumulate significant amounts of minerals, including lots of sulphur. A world with sulphuric acid oceans might be the result. Life might still be possible, but it would likely have to be based on more robust biochemistry. However, acid-Dry would also have to deal with plentiful carbon dioxide emissions that make the greenhouse effect stronger. Adjusting parameters to keep it in the life zone (if it is even possible) would be a bit of work. [Thanks to Andrew Snyder-Beattie for this fun possibility]

Wet has slightly less radiogenic heating than Earth (just 95%). This is still enough for continental drift (hence churning the deep ice crust). However, that direct churning is unlikely continue out to the ice surface. The energy flow at the ice surface is just 0.02 W/m^2 - not enough to drive continental drift on a rock planet, but maybe enough for some ice dynamics.

Rock mountains on Wet will tend to be 5% taller than on Earth, but they will all be on the bottom of the super-deep ocean and under an ice crust. On Dry they will be just 29% the height of Earth mountains - the local Mount Everest will be just 2.4 km. Given my guess at mean ocean depths, this means that it will indeed be a waterworld.

If one buys the idea that Coriolis-Lorenz dynamos in the core scales as sqrt (density/period) the magnetic field of Wet will be 100% of Earths, while Dry 130% - not an enormous difference.


On the oceans, waves would be moving differently. On Wet they would move at 85% of Earth speed, while on Dry 184%. The height would of course scale inversely with gravity: 136% on Wet, but just 29% on Dry. So the seas would be choppier but slower in the wet case (but the waves will have more energy per square meter), while the dry case would have fast low swells.

Light would penetrate the water just like on Earth on both worlds, with a lit zone about 200 meters deep where photosynthesis could work.

The extensive hydrospheres would tend to act as massive thermal buffers, resisting temperature changes due to day/night cycles and seasons.

Ocean currents are powered by trade winds: as the air convects around the equator and is deflected by the Coriolis effect into trade winds, some of the wind energy is transmitted to the water. This produces currents like in the central pacific: a northern and southern equatorial current flowing westwards, and between them a east-flowing counter-current. Further north there might be circular gyres, or perhaps other east-west current bands. If the currents are mainly east-west the temperature difference between equator and poles will be larger, driving a deep convection where colder water descends in the polar areas and ascends near the equator. Away from the equator there will also be deep Ekman currents down to about 100 meters, creating a more complex circulation.

The oceans will tend to be stratified, since less dense warm water overlies denser colder deep water (even the volcanic Dry has much less heat flux from beneath than from above). Some surface layer convection driven by winds and evaporation-driven salinity differences will occur, but deeper layers stay where they are. Polar water may go all the way down, at least on Dry. But there are no undersea mountains mixing layers or places where deep currents are forced up by continents. There will be some upwelling in the Intertropical Convergence Zone along the equator, which at least on Dry might be the main source of nutrient rich deep water. On Wet the ocean is so deep that the wind-driven forcing will not penetrate very far, and the upwelling will be less useful.

Volcanism might be the main factor causing upwellings of mineral-rich really deep water: even a mild temperature difference is enough to send up a thermal plume. Note that plumes ascending from very deep will be affected by Coriolis forces. This already happens on Earth, but on Wet the effect would be far stronger since they travel an appreciable fraction of the planetary radius. As they move upwards they are deflected westwards, and acquire spin if they are away from the equator.

In general, the oceans will be less salty than on Earth since there are no continents to be leached by pure rain - the only salts dissolved will come from volcanism and slow equilibration with exposed crust. Wet will be particularly fresh - there is no direct water contact with the crust, and the total water volume is many times larger than on Dry.


Both Dry and Wet could have a surface biosphere functioning like an open sea biosphere on Earth. Photosynthesis among algae would be the foundation of the nutrient web, with various forms of plankton and larger organisms harvesting them and each other. Like on Earth, most biomass would be in the lit surface layer with more scarce detritivores and predators lurking in the depths.

Just like in terrestrial oceans there is no real size limit to organisms due to gravity, just ecological limits (large animals need more food and take longer to mature, so at some point they hit diminishing returns of food-gathering capacity and survival probability to reproduction). Vertical surface plants (for example growing of rafts of organic matter, or shoots sent up by floating plants) will be much a third shorter on Dry than on Earth due to gravity considerations.

The bottom region can have hydrothermal vent ecologies like on Earth. On Wet hot water needs to penetrate a thick ice crust, making their exact structure (or possibility) dependent on issues of how hot high pressure ice behaves - I do not have a real clue here. An intriguing possibility might be counterparts to earthly lithoautotrophs living inside fissures in the ice crust. On Dry things are fairly terrestrial.

Note that there is no real need for oxygen to maintain this kind of ecosystems: on Earth they exploit available oxygen, but with enough volcanic chemical flow you can sustain life in other ways. For example terrestrial anammox bacteria turn ammonia into nitrogen using nitrites instead of oxygen, Thiobacillus denitrificans turn sulphur into sulphates using nitrates, hydrogen bacteria turn hydrogen into water using sulphates, phosphite bacteria convert phosphite into phosphate using sulphate, metanogens turn hydrogen into water using carbon dioxide, and the carboxydotropic bacteria convert carbon monoxide into carbon dioxide while turning water into hydrogen.

The lack of salts on Wet is going to be a major problem for local life. Assuming Earth-style life most of it is going to be built out of CHON, but it needs to pick up other elements for special purpose enzymes and molecules. Most likely it will employ structures that catch the rare heavier atoms needed, like terrestrial siderophores. Cells will also have an osmosis problem: if their concentration of solutes is higher than seawater (useful in order to keep reaction rates up) water molecules will seep in, threatening the cells with bursting. They need to continually pump out water to maintain stability (at an energy cost), very much like freshwater organisms. Osmoconformers that maintain the same concentration as on the outside will have largish cells with slow reaction rates.

While the surface will be four times Earth's on both Double-Earths, it will be well mixed so that there will be fewer species. Dry at the very least can run two near-independent ecosystem layers plus some stuff in-between. Intelligence evolution... well, who knows.


Both Double-Earths are waterworlds, but one is deep. Neither has any land. Both might have interesting deep sea vent ecologies, the wet case around vents in the high pressure ice and the dry case more terrestrial-style vents. Wet might turn stagnant in the depths relatively quickly, though. On the surface the ocean has weather like on Earth, either strangely tall or fiercely squat clouds. Life could probably thrive on both worlds, but would be limited by minerals: no land, no surface weathering, and hence less minerals added to the oceans. Getting into space from Wet is about as tough as on Earth, while Dry is pretty hard to get away from.

Thanks to Kelly Anderson for initiating the discussion and Tomaz Kristan for a comment.

This article originally appeared at Andart and is republished here with permission.

All images: NASA.
Here is the original version of the article.

Greetings from Double-Earth ... earth.html

xkcd had a great post showing the relative size of all the different exoplanets found.

Exoplanet Neighborhood


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