Why is Venus hotter than Mercury?

[Stryder50]

I don't get your point?
The ideal gas laws do include temperature, but more as input, in how it effects volume and pressure.
Since the atmosphere of Venus is open to space and not contained in a pressure cylinder, it is not possible to compress it artificially, in order to increase the temperature.
What effects the temperature of the atmosphere of a planet is how much of the solar heat is retained, and how much is radiated back out into space.
And that is where the greenhouse effect comes into play.
The point being that CO2 converts solar radiation into vibratory heat, which then can not leave the planet, since it is surrounded by vacuum that can not conduct vibratory heat.

The reason it is called "runaway" is that once the atmosphere got hot enough to evaporate the oceans of water on Venus, then the fact water vapor is 17 time more of a greenhouse gas than CO2, ensured that it could never again lose heat by radiation out into space, and cool off.

If that is so, then Mars, which also has an atmosphere that is mostly CO2 (95.97%) should also be warmer than it is.

Mars - Wikipedia

en.wikipedia.org

 

[miketx]

If that is so, then Mars, which also has an atmosphere that is mostly CO2 (95.97%) should also be warmer than it is.

Mars - Wikipedia

en.wikipedia.org

It's too far away from the star. Plus the atmo is very very thin.

 

[Stryder50]

I don't get your point?
The ideal gas laws do include temperature, but more as input, in how it effects volume and pressure.
Since the atmosphere of Venus is open to space and not contained in a pressure cylinder, it is not possible to compress it artificially, in order to increase the temperature.
What effects the temperature of the atmosphere of a planet is how much of the solar heat is retained, and how much is radiated back out into space.
And that is where the greenhouse effect comes into play.
The point being that CO2 converts solar radiation into vibratory heat, which then can not leave the planet, since it is surrounded by vacuum that can not conduct vibratory heat.

The reason it is called "runaway" is that once the atmosphere got hot enough to evaporate the oceans of water on Venus, then the fact water vapor is 17 time more of a greenhouse gas than CO2, ensured that it could never again lose heat by radiation out into space, and cool off.

Yet the water vapor in Venus' atmosphere is only 0.0020% of total composition.
Where did those oceans go ?

 

[Rigby5]

True dat. Venus is mainly hot not because of the CO2 but because the atmosphere is about 90X denser and so thick and clouded that nearly all energy from the sun is absorbed and trapped. Throw in intense volcanism along with an increasingly bright and hot Sun and I doubt Venus would be in a good way no matter what the level of CO2 was.

When the atmosphere traps heat and not let it be radiated out, that IS the greenhouse effect.
Density has nothing to do with it.
You could have as dense of an atmosphere as you wanted and it would not matter at all because where the heat is either trapped or re-radiated back out into space, it the very last fringes of the atmosphere.
It is only at this boundary layer between atmosphere and space, that determines how much heat is retained by the atmosphere of the planet.
Molecules that are known to vibrate more than they radiate, like water vapor for example, will retain more heat.

 

[Stryder50]

It's too far away from the star. Plus the atmo is very very thin.

Even so, per Rigby5, that CO2 continues to collect the IR and transforms it into vibratory heat, which can't escape. So would build-up, steady increase.
It may not get as hot as Venus, but it shouldn't get cooler at night.

 

[Stryder50]

When the atmosphere traps heat and not let it be radiated out, that IS the greenhouse effect.
Density has nothing to do with it.
You could have as dense of an atmosphere as you wanted and it would not matter at all because where the heat is either trapped or re-radiated back out into space, it the very last fringes of the atmosphere.
It is only at this boundary layer between atmosphere and space, that determines how much heat is retained by the atmosphere of the planet.
Molecules that are known to vibrate more than they radiate, like water vapor for example, will retain more heat.

Yet each molecule can only retain a limited amount of heat, hence the volume/density is a controlling, limiting factor.

 

[Rigby5]

Yeah it's far more likely that the CO2 ppm is being driven by ocean temp and not the other way around....meaning that we don't actually know why we are warming.

Well of course ocean warming will cause it to release CO2 that was absorbed at cooler temperatures, but clearly global warming was caused by increased CO2 concentrations.

Solar heat hits the earth on the form of photonic radiation.
How much of that solar energy is retained and how much of it gets re-radiated back out into space, is totally and completely determined by the CO2 at the fringe boundary layer between the atmosphere and space.
If there is no greenhouse gas like CO2 in the atmosphere, then the heat would be radiated out into space easily, and the planet would be cold.
If there is lots of CO2 at this boundary layer, it converts photonic radiation into vibratory heat, which then can not leave the planet, since the vacuum of space can not conduct heat.

 

[westwall]

I don't get your point?
The ideal gas laws do include temperature, but more as input, in how it effects volume and pressure.
Since the atmosphere of Venus is open to space and not contained in a pressure cylinder, it is not possible to compress it artificially, in order to increase the temperature.
What effects the temperature of the atmosphere of a planet is how much of the solar heat is retained, and how much is radiated back out into space.
And that is where the greenhouse effect comes into play.
The point being that CO2 converts solar radiation into vibratory heat, which then can not leave the planet, since it is surrounded by vacuum that can not conduct vibratory heat.

The reason it is called "runaway" is that once the atmosphere got hot enough to evaporate the oceans of water on Venus, then the fact water vapor is 17 time more of a greenhouse gas than CO2, ensured that it could never again lose heat by radiation out into space, and cool off.

The atmosphere on Venus is hot because of the density. Period.

 

[Rigby5]

Yet the water vapor in Venus' atmosphere is only 0.0020% of total composition.
Where did those oceans go ?

First of all, the water vapor content of the earth is only about 0.4%, so no planet has a lot of water vapor in its atmosphere.
But with the heat of Venus, most likely is that complex chemical reactions have broken down the hydrogen and oxygen of water, to be combined into larger and more complex molecules.
But when I looked it up, they said the most common theory is that the "electric wind" from the sun.
{...
Venus has an “electric wind” strong enough to strip traces of water from its upper atmosphere. Scientists think Venus did once host large amounts of water on its surface over 4 billion years ago, but as it heated up, much of this water evaporated into the atmosphere, where it could then be ripped apart by sunlight and subsequently lost to space1.
...}

 

[Rigby5]

Yet each molecule can only retain a limited amount of heat, hence the volume/density is a controlling, limiting factor.

Sure, I will buy that.
You need mass to hold heat.

 

[odanny]

Yet the water vapor in Venus' atmosphere is only 0.0020% of total composition.
Where did those oceans go ?

They turned to steam, which accelerated the runaway greenhouse effect.

 

[Rigby5]

The atmosphere on Venus is hot because of the density. Period.

Huh?
If you compress a gas it will heat, but the heat of Venus if from solar radiation, not compression.
The atmosphere at the fringes of the Venusian atmosphere is not at all dense.
The upper atmosphere of Venus is going to be a gradual transition to pure vacuum.
That can't be "high density".
And if it were only density that cause the hot temperatures, the upper atmosphere of Venus, that is not dense, would be cold and constantly chilling off the rest of the planet.
But it doesn't, and that is because the cause of high Venus atmosphere temperatures is solar radiation energy, which is prevented from leaving the planet by the fact CO2 converts photonic radiation into vibratory energy.

 

[toobfreak]

When the atmosphere traps heat and not let it be radiated out, that IS the greenhouse effect.

No shit, Professor Proton.

Density has nothing to do with it.

Density has EVERYTHING to do with it! A dense atmosphere traps and holds more heat.

 

[odanny]

No shit, Professor Proton.


Density has EVERYTHING to do with it! A dense atmosphere traps and holds more heat.

Have you considered signing up for an online science class? You should.

 

[justoffal]

Well of course ocean warming will cause it to release CO2 that was absorbed at cooler temperatures, but clearly global warming was caused by increased CO2 concentrations.

Solar heat hits the earth on the form of photonic radiation.
How much of that solar energy is retained and how much of it gets re-radiated back out into space, is totally and completely determined by the CO2 at the fringe boundary layer between the atmosphere and space.
If there is no greenhouse gas like CO2 in the atmosphere, then the heat would be radiated out into space easily, and the planet would be cold.
If there is lots of CO2 at this boundary layer, it converts photonic radiation into vibratory heat, which then can not leave the planet, since the vacuum of space can not conduct heat.

Yeah... If it's that delicate... What kept it in check for
Millennia?... I don't buy it.
It's far more probable that CO2 is effect...not cause.

 

[toobfreak]

Have you considered signing up for an online science class? You should.

Asshole, I've forgotten more science than you will ever know.

You probably got your knowledge of Venus from watching the Three Stooges.

 

[odanny]

Asshole, I've forgotten more science than you will ever know.

You probably got your knowledge of Venus from watching the Three Stooges.

Just get your feet wet, something basic, if you have questions, feel free to ask.

 

[toobfreak]

Just get your feet wet, something basic, if you have questions, feel free to ask.

Sure. What are the three related approximations made in the newtonian equations of motion pertaining to the Poisson equation?

 

[toobfreak]

Just get your feet wet, something basic, if you have questions, feel free to ask.

Still waiting.

 

[westwall]

Still waiting.

You'll be waiting forever.