Science Porn

[Alex K]

For my purposes, I want to go from % co2 to the factor by which that changes the radiation into space and back to earth. One approach I saw just treated it as a blanket which radiates via T^4 on top with the reduced temperature at high altitudes, and below with the full temperature. Another approach just treated it as some kind of partial insulator.

[pocaracas]

So much for back of the envelope...

You should integrate along the atmosphere how much of the IR radiation gets absorbed by the atmosphere, taking into consideration the cross section given by the percentage (or per-millage) ) of atmospheric CO2.
Considering that O2 and N2 are mostly transparent to IR, while water vapor and CO2 are not. Actually, H2O is far more absorbent, but that one falls back down as rain, while CO2 mostly stays there.
At 100% CO2 concentration, you should absorb something like 10~15% of all IR, judging by this plot (I'm just eyeballing it here):


You can then assume linearity, where 1% of CO2 in the atmosphere, leads to ~0.1% of IR being absorbed.... and just let it go on a feedback loop.
The hotter the surface gets, the more IR it emits.

[chimp3]

We live in a Swiss Cheese Universe :

https://www.sciencedaily.com/releases/20...142930.htm

[Alex K]

So much for back of the envelope...

You should integrate along the atmosphere how much of the IR radiation gets absorbed by the atmosphere, taking into consideration the cross section given by the percentage (or per-millage) ) of atmospheric CO2.
Considering that O2 and N2 are mostly transparent to IR, while water vapor and CO2 are not. Actually, H2O is far more absorbent, but that one falls back down as rain, while CO2 mostly stays there.
At 100% CO2 concentration, you should absorb something like 10~15% of all IR, judging by this plot (I'm just eyeballing it here):


You can then assume linearity, where 1% of CO2 in the atmosphere, leads to ~0.1% of IR being absorbed.... and just let it go on a feedback loop.
The hotter the surface gets, the more IR it emits.

I'll let Integrating along the atmosphere still count as back of the envelope. So I need the co2 density profile as a function of the total% and then integrate... hmmm
But what about the IR emission of the co2?

[pocaracas]

I'll let Integrating along the atmosphere still count as back of the envelope. So I need the co2 density profile as a function of the total% and then integrate... hmmm
But what about the IR emission of the co2?

That should be isotropic.... and I guess is the part responsible for the warming we feel on the surface. Thermodynamics would argue that it must be less than that which is absorbed.
How much less? If the Earth were plane, half would go to space, and half would go back to Earth.
Since the Earth is a sphere, more than half goes to space... how much? bah... might be the difference is negligible, compared to the flat earth model.

[vorlon13]

So much for back of the envelope...

You should integrate along the atmosphere how much of the IR radiation gets absorbed by the atmosphere, taking into consideration the cross section given by the percentage (or per-millage) ) of atmospheric CO2.
Considering that O2 and N2 are mostly transparent to IR, while water vapor and CO2 are not. Actually, H2O is far more absorbent, but that one falls back down as rain, while CO2 mostly stays there.
At 100% CO2 concentration, you should absorb something like 10~15% of all IR, judging by this plot (I'm just eyeballing it here):


You can then assume linearity, where 1% of CO2 in the atmosphere, leads to ~0.1% of IR being absorbed.... and just let it go on a feedback loop.
The hotter the surface gets, the more IR it emits.

I'll let Integrating along the atmosphere still count as back of the envelope. So I need the co2 density profile as a function of the total% and then integrate... hmmm
But what about the IR emission of the co2?

And now with the vorlon twist:

instead of doing math, just pick year on graph and role back CO2 level to that era.

[vorlon13]

MU69 is the final target for the New Horizons probe.  As the craft approaches, astronomers here are watching a series of 3 stellar occultations to probe MU69 for possible satellites, rings, binary status, debris, whatnot.  The more we know about MU69 prior to the flyby, the better then observations during the flyby can be planned.

First one is tonight.


Go TEAM !!!

Data successfully logged from several locations.  As expected, individual observations show limited S/N ratio due to expected brevity of occultation, but by combining observations the S/N ratio can be mitigated.

No one has 'spilled the beans' on any surprises yet, like a secondary event.  Also note, the star being occulted by MU69 might be a binary, so even if a 'stepped' occultation was observed, the weirdness would be with the star, and not the KBO.

Hopefully results will be announced 'soon'.

[Mystical]

Im just enamored by this video! And the aluminum/copper/cement filled structures made out of ant nests!!! Incredible!






And here's tiny versions people make for art or whatnot with concrete, aluminum, copper, etc.






 

[Fireball]

Cool! Do the poured metal sculptures smell like scorched ants?

[vorlon13]

This is interesting. Thanks to Hubble, for the first time, gravitational deflection of starlight has been studied and the star doing the deflecting is not our sun, but rather a white dwarf ~17 light years from earth.

http://www.astronomy.com/news/2017/06/as...hite-dwarf