George S
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Could it be that the solution to the Fermi paradox is that life takes a very, very rare event?
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Was the collision that formed Luna responsible for water and life on Earth?
- Thread starter George S
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Shadowy Man
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My understanding is that planetary scientists do not believe the collision is the source of water on Earth.
George S
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My understanding was that comets impacting provided the water. The paper making the contrary claim is explained above.
Shadowy Man
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Your link is to a youtube video not a paper. Do you have a link to a paper?
George S
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Jimmy Higgins
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Hmm...
So they are playing a bit with words there... 'look at this recent discovery which isn't a discovery at all, but a supposition'.
steve_bank
Diabetic retinopathy and poor eyesight. Typos ...
The moon astabilizwas thwe Earth giving stable seasons as I understand it.
Watched a show on a Japanese scintist who for years tried to get video of a giant squid. He finaky got it. The video was right out of a scifi movie.
There are critters living on chemical energy around undersea volcanic vents in an environment toxic to most creatures.
Depends on what you mean by life. It seems life adapts to fill all possible energy niches on Erath. The Russian spec staion became invaded by microorganism's that adapted and lived in globs of floating water in 0g..
Watched a show on a Japanese scintist who for years tried to get video of a giant squid. He finaky got it. The video was right out of a scifi movie.
There are critters living on chemical energy around undersea volcanic vents in an environment toxic to most creatures.
Depends on what you mean by life. It seems life adapts to fill all possible energy niches on Erath. The Russian spec staion became invaded by microorganism's that adapted and lived in globs of floating water in 0g..
bilby
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There are two separate issues here:
1) The conjecture that all (or most) of the Earth's water arrived in a single large collision that liquefied the Earth's crust and spat out enough material to form our (very large) moon; and
2) The conjecture that (intelligent) life in the universe is rare, and that the Earth having collided with 'Theia' to form the Moon was (one of) the essential steps towards its development - thereby resolving the Fermi Paradox
#1 seems highly unlikely, given that such a collision would tend to blast a lot of water away from the Earth - after all, water is easier to shift than rock. Furthermore, we know that water is very common in our solar system (hardly a surprise, as hydrogen makes up most of the normal matter in the universe, with our solar system no exception; and so most of the oxygen in the solar system would be expected to be in the form of water, just as most of the nitrogen is in ammonia and most of the carbon in methane). We observe that comets made of mostly water are common visitors to the inner solar system, and so the hypothesis that these brought most or even all of the Earth's liquid water is far from unreasonable.
#2 is better supported. The presence of a large moon is a prerequisite for large tides, and the resulting large inter-tidal zone between land and ocean may well have played a crucial role both in the development of life of any kind, and in the evolution of land based life, both plant and animal. Arguably purely aquatic life is inadequate to evolve the ability to produce signals detectable over interstellar distances; or indeed, many advanced technologies of any kind. Without fire (which is not easy to develop underwater), there's very little in the way of metals that can be extracted from the lithosphere, and in seawater it's presumably extremely difficult to develop even rudimentary electronics, even if metals are available. In the absence of tides, the evolutionary pressure to develop the ability to survive out of water for even short periods is greatly lessened; As are the number of sites experiencing high frequency cyclic variations in solute concentration, which may be a critical requirement for rapid abiogenesis.
The presence of a large moon might either be essential for life; essential for land-based life; or a significant accelerator of the development of one or both. If so, and if large moons are rare around earthlike planets, we could be the only (or the first) life in our part of the galaxy.
Of course, it's also possible to resolve the Fermi paradox by noting that our signals are incredibly weak at interstellar distances, and that the strongest of them were broadcast for a very short time. The universe could be teeming with life, at the same technological level as ours, and we would need to be very fortunate indeed to detect it. Space is really big.
1) The conjecture that all (or most) of the Earth's water arrived in a single large collision that liquefied the Earth's crust and spat out enough material to form our (very large) moon; and
2) The conjecture that (intelligent) life in the universe is rare, and that the Earth having collided with 'Theia' to form the Moon was (one of) the essential steps towards its development - thereby resolving the Fermi Paradox
#1 seems highly unlikely, given that such a collision would tend to blast a lot of water away from the Earth - after all, water is easier to shift than rock. Furthermore, we know that water is very common in our solar system (hardly a surprise, as hydrogen makes up most of the normal matter in the universe, with our solar system no exception; and so most of the oxygen in the solar system would be expected to be in the form of water, just as most of the nitrogen is in ammonia and most of the carbon in methane). We observe that comets made of mostly water are common visitors to the inner solar system, and so the hypothesis that these brought most or even all of the Earth's liquid water is far from unreasonable.
#2 is better supported. The presence of a large moon is a prerequisite for large tides, and the resulting large inter-tidal zone between land and ocean may well have played a crucial role both in the development of life of any kind, and in the evolution of land based life, both plant and animal. Arguably purely aquatic life is inadequate to evolve the ability to produce signals detectable over interstellar distances; or indeed, many advanced technologies of any kind. Without fire (which is not easy to develop underwater), there's very little in the way of metals that can be extracted from the lithosphere, and in seawater it's presumably extremely difficult to develop even rudimentary electronics, even if metals are available. In the absence of tides, the evolutionary pressure to develop the ability to survive out of water for even short periods is greatly lessened; As are the number of sites experiencing high frequency cyclic variations in solute concentration, which may be a critical requirement for rapid abiogenesis.
The presence of a large moon might either be essential for life; essential for land-based life; or a significant accelerator of the development of one or both. If so, and if large moons are rare around earthlike planets, we could be the only (or the first) life in our part of the galaxy.
Of course, it's also possible to resolve the Fermi paradox by noting that our signals are incredibly weak at interstellar distances, and that the strongest of them were broadcast for a very short time. The universe could be teeming with life, at the same technological level as ours, and we would need to be very fortunate indeed to detect it. Space is really big.
lpetrich
Contributor
How did the water not get lost after an impact like that?
steve_bank
Diabetic retinopathy and poor eyesight. Typos ...
Gravity. All the particulates in the atmosphere after the big asteroid strike in now Mexico eventually fell back to Earth.We do lose water to space but slowly. A
It would have been too hot for the Earth to hold it very well.
steve_bank
Diabetic retinopathy and poor eyesight. Typos ...
It does not have to be liquid water. Gravity acts on the atomic scale. One gas particle bouncing around a tank will eventually lose kinetic energy and fall to the bottom.
Gas in tank actually settles over time due to gravity.
A density gradient develops from bottom to top of a tank.
Water vapor is still water.
Gas in tank actually settles over time due to gravity.
A density gradient develops from bottom to top of a tank.
Water vapor is still water.
bilby
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No, it most certainly does not. At any temperature high enough (and pressure low enough) to keep a material in its gas phase, it remains equally distributed, in accordance with the second law of thermodynamics. The only way to get it to settle to the bottom of the tank is to liquify it by either dropping the temperature, or raising the pressure, or both.
You need planet sized gravity to prevent gas from spreading out - a noticeable gravitational gradient across the volume occupied by the gas. Essentially, a tidal effect.
There's no way you are going to get detectable settling in a container of gas on the Earth's surface, any more than you can expect detectable tides in a pail of water (and for the exact same reason).
Water vapour is liquid in small droplets - small enough that their terminal velocity is vastly greater than the velocities imparted by the surrounding air. Water in its gas phase is called steam, and it is very much a different thing from water vapour. (To the point where engineers who deal with steam turbines or steam engines talk about 'dry steam' - steam with no water vapour mixed in with it.
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fromderinside
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From: The Vapors | Electrical Contractor Magazine https://www.ecmag.com/section/safety/vapors
Gasoline is probably the best known and most widely used of the flammable or combustible liquids. ... Gasoline is very volatile when changing from a liquid to a vapor at low temperatures. Gasoline vapors are denser than air, meaning these vapors will sink and collect at the lowest point.
According to Volatile fluids are in constant flux between gaseous and liquid states in containers and elsewhere in the world. As steve_bank says gas vapor loses kinetic energy it settles toward the liquid surface and eventually will become liquid while at higher temperatures, as pressure varies, liquid gasoline near the surface will exceed energy needed to break the cohesive energy state of surface gas and become a gas vapor. So on both counts gas being heavier than air and gas vapors becoming gas liquid a reading of steve_bank's post is correct
So overall Vapor will settle and become liquid and liquid will evaporate from the liquid surface sustaining a more or less constant pressure/temperature/volume balance in a gas tank.
Of course if all there is in a gas tank is gasoline vapor and air, kept as appropriately high temperature, as bilby argues, gas will remain gas vapor above it's vaporization temperature, but since gasoline is heavier than air it will sink to the bottom of the tank again in line with steve_bank's assertion and remain a gas as bilby argues.
IMHO they are shouting past each other based on different assumptions.
As for evidence of Origin of Water in the Inner Solar System http://astrobiology.com/2017/07/origin-of-water-in-the-inner-solar-system.htmlp
and presented in NOVA presentations recently this year suggests rather than water coming from comets water on the inner planets is probably due to jupiter and the other gas planets knocking meteors out of orbit and into earth and the inner planets.
While it is true that the sun blasted a lot of water into constitutes H2 and O and O2 and is still driving that matter outward there is evidence rocky planets retained water within supported by evidence there is still water on mars and the moon.
As for evolution I think bilby covered that pretty well. OK, OK. Brilliantly.
Gasoline is probably the best known and most widely used of the flammable or combustible liquids. ... Gasoline is very volatile when changing from a liquid to a vapor at low temperatures. Gasoline vapors are denser than air, meaning these vapors will sink and collect at the lowest point.
According to Volatile fluids are in constant flux between gaseous and liquid states in containers and elsewhere in the world. As steve_bank says gas vapor loses kinetic energy it settles toward the liquid surface and eventually will become liquid while at higher temperatures, as pressure varies, liquid gasoline near the surface will exceed energy needed to break the cohesive energy state of surface gas and become a gas vapor. So on both counts gas being heavier than air and gas vapors becoming gas liquid a reading of steve_bank's post is correct
So overall Vapor will settle and become liquid and liquid will evaporate from the liquid surface sustaining a more or less constant pressure/temperature/volume balance in a gas tank.
Of course if all there is in a gas tank is gasoline vapor and air, kept as appropriately high temperature, as bilby argues, gas will remain gas vapor above it's vaporization temperature, but since gasoline is heavier than air it will sink to the bottom of the tank again in line with steve_bank's assertion and remain a gas as bilby argues.
IMHO they are shouting past each other based on different assumptions.
As for evidence of Origin of Water in the Inner Solar System http://astrobiology.com/2017/07/origin-of-water-in-the-inner-solar-system.htmlp
and presented in NOVA presentations recently this year suggests rather than water coming from comets water on the inner planets is probably due to jupiter and the other gas planets knocking meteors out of orbit and into earth and the inner planets.
While it is true that the sun blasted a lot of water into constitutes H2 and O and O2 and is still driving that matter outward there is evidence rocky planets retained water within supported by evidence there is still water on mars and the moon.
As for evolution I think bilby covered that pretty well. OK, OK. Brilliantly.
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bilby
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Gas isn't vapour. Vapour isn't gas.
Vapour is to gas, as emulsion is to solution.
A gas consists of free molecules moving independently and colliding individually with each other, and with the walls of its container.
A vapour consists of droplets of liquid, each containing huge numbers of molecules moving in concert through a gaseous substrate.
A "gas vapour" isn't anything at all, other than a confusion either between the completely different physical states "gas" and "vapour"; Or between "gas" the physical state, and "gas" the abbreviation for "gasoline" (gasoline is typically only considered in the liquid and vapour states; to render gasoline gaseous would require raising its temperature to about 126°C, or 258°F, and this isn't a common engineering scenario).
Either way, it's not a phrase that can possibly reduce confusion.
Bomb#20
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Is this perhaps a difference between American and Australian English?
https://en.wikipedia.org/wiki/Vapor
"In physics, a vapor (American English) or vapour (British English; see spelling differences) is a substance in the gas phase at a temperature lower than its critical temperature,[1] which means that the vapor can be condensed to a liquid by increasing the pressure on it without reducing the temperature. A vapor is different from an aerosol.[2] An aerosol is a suspension of tiny particles of liquid, solid, or both within a gas.[2]
For example, water has a critical temperature of 647 K (374 °C; 705 °F), which is the highest temperature at which liquid water can exist. In the atmosphere at ordinary temperatures, therefore, gaseous water (known as water vapor) will condense into a liquid if its partial pressure is increased sufficiently.
A vapor may co-exist with a liquid (or a solid). When this is true, the two phases will be in equilibrium, and the gas-partial pressure will be equal to the equilibrium vapor pressure of the liquid (or solid).[1]"
But the bleed rate is based on temperature. When the surface is magma something the size of Earth is going to do a shitty job of retaining gas of any type.
steve_bank
Diabetic retinopathy and poor eyesight. Typos ...
As I seen it regardless of form any mass has to overcomes gravity to leave the planet. When a comet hit the panet I'd think mot of the kinetic energy would end up as heat, not kinetic of motion in energy in water molecules.
3 possibilities.
1. God put water here when he crated the Erath.
2. It was created as part of the planet forming process. H2O stnthesized somehow as the panet itself formed.
3. Water came to Earth from elsewhere in the solar system.
Which moon has all the water under ice?
I do not know enough cosmology to say how water was formed as the solar system formation process began. We do know comets have water. We witnessed in real time a comet striking Jupiter. Peel away water and soil from the Earth and it looks cratered like the moon.
I believe the established theory is comets as the source.
Watched a good PBS show on the formation of the solar system. The interaction of plants gravity determined how many big objects made its way to Erath, especially the gas giants even today. During formation objects were all over the place.
3 possibilities.
1. God put water here when he crated the Erath.
2. It was created as part of the planet forming process. H2O stnthesized somehow as the panet itself formed.
3. Water came to Earth from elsewhere in the solar system.
Which moon has all the water under ice?
I do not know enough cosmology to say how water was formed as the solar system formation process began. We do know comets have water. We witnessed in real time a comet striking Jupiter. Peel away water and soil from the Earth and it looks cratered like the moon.
I believe the established theory is comets as the source.
Watched a good PBS show on the formation of the solar system. The interaction of plants gravity determined how many big objects made its way to Erath, especially the gas giants even today. During formation objects were all over the place.
steve_bank
Diabetic retinopathy and poor eyesight. Typos ...
Seems to be partly semantics. Water vapor is called the gaseous form of water.
https://en.wikipedia.org/wiki/Water_vapor
Water vapor, water vapour or aqueous vapor is the gaseous phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Unlike other forms of water, water vapor is invisible.[4] Under typical atmospheric conditions, water vapor is continuously generated by evaporation and removed by condensation. It is less dense than air and triggers convection currents that can lead to clouds.
Being a component of Earth's hydrosphere and hydrologic cycle, it is particularly abundant in Earth's atmosphere where it is also a potent greenhouse gas along with other gases such as carbon dioxide and methane. Use of water vapor, as steam, has been important to humans for cooking and as a major component in energy production and transport systems since the industrial revolution.
Water vapor is a relatively common atmospheric constituent, present even in the solar atmosphere as well as every planet in the Solar System and many astronomical objects including natural satellites, comets and even large asteroids. Likewise the detection of extrasolar water vapor would indicate a similar distribution in other planetary systems. Water vapor is significant in that it can be indirect evidence supporting the presence of extraterrestrial liquid water in the case of some planetary mass objects.
https://en.wikipedia.org/wiki/Water_vapor
Water vapor, water vapour or aqueous vapor is the gaseous phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Unlike other forms of water, water vapor is invisible.[4] Under typical atmospheric conditions, water vapor is continuously generated by evaporation and removed by condensation. It is less dense than air and triggers convection currents that can lead to clouds.
Being a component of Earth's hydrosphere and hydrologic cycle, it is particularly abundant in Earth's atmosphere where it is also a potent greenhouse gas along with other gases such as carbon dioxide and methane. Use of water vapor, as steam, has been important to humans for cooking and as a major component in energy production and transport systems since the industrial revolution.
Water vapor is a relatively common atmospheric constituent, present even in the solar atmosphere as well as every planet in the Solar System and many astronomical objects including natural satellites, comets and even large asteroids. Likewise the detection of extrasolar water vapor would indicate a similar distribution in other planetary systems. Water vapor is significant in that it can be indirect evidence supporting the presence of extraterrestrial liquid water in the case of some planetary mass objects.