Here's a twist, using water as a UV shield for other molecules

Here on Earth, it seems we would be screwed if our precious water wasn't
protected by other molecules against UV radiation. We have our magnetic
shield, our ozone shield, our nitrogen shield, etc. All protect the
water from dissociating in the Sun's UV. During the solar system's
formation period, it may have been that water itself was protecting
organic chemicals from dissociating in the Sun's UV.

Also there's some indication from this research that there was plenty of
water present right within the inner solar system at formation, such
that there wasn't a need for later cometary transport of the water from
outer solar system. Another surprising twist.

Yousuf Khan
***

How Water Protected Our Molecules | Universe Today
"UV light is pretty hard on molecules because it readily breaks them up
into their constituent parts. Larger organic molecules that coalesced in
the dusty disk out of which our planets formed billions of years ago
would have been broken apart by the Sun's rays, but calculations by two
astronomers at the University of Michigan show that thousands of oceans
worth of water present in a protoplanetary disk can shield other
molecules from being broken up."
http://www.universetoday.com/2010/01...our-molecules/

On 1/15/10 11:52 PM, Yousuf Khan wrote:
Here on Earth, it seems we would be screwed if our precious water wasn't
protected by other molecules against UV radiation. We have our magnetic
shield, our ozone shield, our nitrogen shield, etc. All protect the
water from dissociating in the Sun's UV. During the solar system's
formation period, it may have been that water itself was protecting
organic chemicals from dissociating in the Sun's UV.


How come atmospherics water vapor isn't dissociating?

Yousuf Khan wrote:

Here on Earth, it seems we would be screwed if our precious water wasn't
protected by other molecules against UV radiation. We have our magnetic
shield, our ozone shield, our nitrogen shield, etc. All protect the
water from dissociating in the Sun's UV. During the solar system's
formation period, it may have been that water itself was protecting
organic chemicals from dissociating in the Sun's UV.


UV doesn't disassociate water.

Also there's some indication from this research that there was plenty of
water present right within the inner solar system at formation, such
that there wasn't a need for later cometary transport of the water from
outer solar system. Another surprising twist.

Yousuf Khan
***

How Water Protected Our Molecules | Universe Today
"UV light is pretty hard on molecules because it readily breaks them up
into their constituent parts. Larger organic molecules that coalesced in
the dusty disk out of which our planets formed billions of years ago
would have been broken apart by the Sun's rays, but calculations by two
astronomers at the University of Michigan show that thousands of oceans
worth of water present in a protoplanetary disk can shield other
molecules from being broken up."
http://www.universetoday.com/2010/01...our-molecules/

Yousuf Khan wrote:

Here on Earth, it seems we would be screwed if our precious water wasn't
protected by other molecules against UV radiation. We have our magnetic
shield, our ozone shield, our nitrogen shield, etc. All protect the
water from dissociating in the Sun's UV. During the solar system's
formation period, it may have been that water itself was protecting
organic chemicals from dissociating in the Sun's UV.

You would do best to learn some chemistry then post the aforesaid
under somebody else's name.

A cm of water has optical absorbance A = 0.01 at 190 nm. Its first UV
absorption peak (gas phase) is at 166.5 nm, from excitation of the
occupied p_z^2-type molecular 1b_1 orbital. Photodissociation into H
+ OH radicals requires ~125 nm, pumping the 3a_1 orbital. There is no
chemistry anywhere near your assertion short of two-photon transitions
- that have a quadratic dependence upon illumination intensity.

http://www1.lsbu.ac.uk/water/h2oorb.html

Water is a terrible UV shield. Water is stable to contemporary solar
illumination everywhere except at the very top of the atmosphere. The
young sun was much redder, evidenced by the action spectrum of
chlorophyll.

Also there's some indication from this research that there was plenty of
water present right within the inner solar system at formation, such
that there wasn't a need for later cometary transport of the water from
outer solar system. Another surprising twist.

Speculation is just that. A whole library can be filled with 350
years of gushing critical praise for Michelangelo's Sistine Chapel
ceiling - its masterful use of light and shadow in muted colors and
sepia tones. After 400 years of candle soot was cleared away... it
was bright as a Marvel comic book.

How Water Protected Our Molecules | Universe Today
"UV light is pretty hard on molecules because it readily breaks them up
into their constituent parts. Larger organic molecules that coalesced in
the dusty disk out of which our planets formed billions of years ago
would have been broken apart by the Sun's rays, but calculations by two
astronomers at the University of Michigan show that thousands of oceans
worth of water present in a protoplanetary disk can shield other
molecules from being broken up."
http://www.universetoday.com/2010/01...our-molecules/

All one needs to survive vacuum UV irradiation is shadow, or being 1
mm below an opaque rock surface, or being in orbit around a cool sun,
or being in equilibrium formation vs. dissociation.

U of M has more than 80 diversity programs...

http://www.diversity.umich.edu/

and not one - not a single program - for the Gifted. It is good to
see that ecumenical social activism has now extended to science
faculty.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz4.htm

Sam Wormley wrote:
On 1/15/10 11:52 PM, Yousuf Khan wrote:
Here on Earth, it seems we would be screwed if our precious water wasn't
protected by other molecules against UV radiation. We have our magnetic
shield, our ozone shield, our nitrogen shield, etc. All protect the
water from dissociating in the Sun's UV. During the solar system's
formation period, it may have been that water itself was protecting
organic chemicals from dissociating in the Sun's UV.


How come atmospherics water vapor isn't dissociating?

Because it doesn't get high enough to be affected by UV. On Earth, there
is a cold trap for water beyond which water vapor doesn't rise, that is
low enough down in the atmosphere to be protected from the UV. On Venus,
that cold trap was much higher up and UV dissociated the hydrogen and
oxygen, letting most of the hydrogen escape into space. There's some
residual hydrogen left on Venus in the form of sulphuric acid, but not
in the form of water.

Yousuf Khan

Uncle Al wrote:
Yousuf Khan wrote:
Here on Earth, it seems we would be screwed if our precious water wasn't
protected by other molecules against UV radiation. We have our magnetic
shield, our ozone shield, our nitrogen shield, etc. All protect the
water from dissociating in the Sun's UV. During the solar system's
formation period, it may have been that water itself was protecting
organic chemicals from dissociating in the Sun's UV.

You would do best to learn some chemistry then post the aforesaid
under somebody else's name.

I'm just linking, with a bit of commentating here, that's all. The rest
is upto you to read or not.

A cm of water has optical absorbance A = 0.01 at 190 nm. Its first UV
absorption peak (gas phase) is at 166.5 nm, from excitation of the
occupied p_z^2-type molecular 1b_1 orbital. Photodissociation into H
+ OH radicals requires ~125 nm, pumping the 3a_1 orbital. There is no
chemistry anywhere near your assertion short of two-photon transitions
- that have a quadratic dependence upon illumination intensity.

http://www1.lsbu.ac.uk/water/h2oorb.html

Yup, UV of a high enough frequency is required. The Sun does produce
those high enough frequencies, available in space.

Water is a terrible UV shield. Water is stable to contemporary solar
illumination everywhere except at the very top of the atmosphere. The
young sun was much redder, evidenced by the action spectrum of
chlorophyll.

They're talking about several thousand oceans' worth of water here.

Also there's some indication from this research that there was plenty of
water present right within the inner solar system at formation, such
that there wasn't a need for later cometary transport of the water from
outer solar system. Another surprising twist.

Speculation is just that. A whole library can be filled with 350
years of gushing critical praise for Michelangelo's Sistine Chapel
ceiling - its masterful use of light and shadow in muted colors and
sepia tones. After 400 years of candle soot was cleared away... it
was bright as a Marvel comic book.

Of course, nobody should instantly believe anything new that they're
told without critical judgement. But if you don't even know that
something new has been found or speculated, then you can't critically
judge either.

How Water Protected Our Molecules | Universe Today
"UV light is pretty hard on molecules because it readily breaks them up
into their constituent parts. Larger organic molecules that coalesced in
the dusty disk out of which our planets formed billions of years ago
would have been broken apart by the Sun's rays, but calculations by two
astronomers at the University of Michigan show that thousands of oceans
worth of water present in a protoplanetary disk can shield other
molecules from being broken up."
http://www.universetoday.com/2010/01...our-molecules/

All one needs to survive vacuum UV irradiation is shadow, or being 1
mm below an opaque rock surface, or being in orbit around a cool sun,
or being in equilibrium formation vs. dissociation.

True, but this is very early solar system, where most everything is dust
and molecules still at this point. Probably not a lot of rocks yet.


Yousuf Khan

Yousuf Khan wrote:

Uncle Al wrote:
Yousuf Khan wrote:
Here on Earth, it seems we would be screwed if our precious water wasn't
protected by other molecules against UV radiation. We have our magnetic
shield, our ozone shield, our nitrogen shield, etc. All protect the
water from dissociating in the Sun's UV. During the solar system's
formation period, it may have been that water itself was protecting
organic chemicals from dissociating in the Sun's UV.

You would do best to learn some chemistry then post the aforesaid
under somebody else's name.

I'm just linking, with a bit of commentating here, that's all. The rest
is upto you to read or not.

As a scientist you bear the professional responsibility of critical
thinking. Podkletnov was trivially untenable by trivial example -
gravitational potential energy of the building and atmosphere above
his "antigravity" beam plus conservation of mass-energy when he turned
it on and off. NASA need not have spent upward of $5 million trying
to reproduce it.

In this case (truly awful illustration aside), the spew is at trivial
variance with the facts. One could as easily have said the
proto-planetary disk had a self-generated and entrained magnetic field
and that diverted solar wind, leaving dissociated molecules to
recombine in interesting ways but not be lost to sweeping out of the
solar system.

Was their massive sustained lightning in teh proto-planetary nebula
from tribo-charging and solar wind-shorting? Clouds is clouds water
vapor in the atmosphere, moving dry corn through a Lucite sight pipe,
or spinnign a big rubber band inside a van de Graaf generator. CRACK!

Your citation is crap not for its assertion but for its content that
does not support said assertion vs. laboratory measurements -
trivially available through Google.

A cm of water has optical absorbance A = 0.01 at 190 nm. Its first UV
absorption peak (gas phase) is at 166.5 nm, from excitation of the
occupied p_z^2-type molecular 1b_1 orbital. Photodissociation into H
+ OH radicals requires ~125 nm, pumping the 3a_1 orbital. There is no
chemistry anywhere near your assertion short of two-photon transitions
- that have a quadratic dependence upon illumination intensity.

http://www1.lsbu.ac.uk/water/h2oorb.html

Yup, UV of a high enough frequency is required. The Sun does produce
those high enough frequencies, available in space.

Availablility is not utility. The young sun was very red. It's UV
output was vastly smaller than that of today - by the fourth power of
its absolute temperature in the extreme high tail of its blackbody
curve. The assertion simply does not work. No Referee should have
vetted it.

Water is a terrible UV shield. Water is stable to contemporary solar
illumination everywhere except at the very top of the atmosphere. The
young sun was much redder, evidenced by the action spectrum of
chlorophyll.

They're talking about several thousand oceans' worth of water here.

In a solar system volume. What are we talking, one water
molecule/m^3?

Also there's some indication from this research that there was plenty of
water present right within the inner solar system at formation, such
that there wasn't a need for later cometary transport of the water from
outer solar system. Another surprising twist.

Speculation is just that. A whole library can be filled with 350
years of gushing critical praise for Michelangelo's Sistine Chapel
ceiling - its masterful use of light and shadow in muted colors and
sepia tones. After 400 years of candle soot was cleared away... it
was bright as a Marvel comic book.

Of course, nobody should instantly believe anything new that they're
told without critical judgement. But if you don't even know that
something new has been found or speculated, then you can't critically
judge either.

Uncle Al has a CRC Handbook, the Google, and a multiply tested IQ more
than double that of average Los Angeles high school graduates. Uncle
Al is sufficiently intelligent and experienced to read, write, and do
simple sums. Add an HP-15C with new batteries (only got 23 years on
the original set) and Uncle Al doesn't swallow Official Truth from
academic poobahs or industrial managers.

How Water Protected Our Molecules | Universe Today
"UV light is pretty hard on molecules because it readily breaks them up
into their constituent parts. Larger organic molecules that coalesced in
the dusty disk out of which our planets formed billions of years ago
would have been broken apart by the Sun's rays, but calculations by two
astronomers at the University of Michigan show that thousands of oceans
worth of water present in a protoplanetary disk can shield other
molecules from being broken up."
http://www.universetoday.com/2010/01...our-molecules/

All one needs to survive vacuum UV irradiation is shadow, or being 1
mm below an opaque rock surface, or being in orbit around a cool sun,
or being in equilibrium formation vs. dissociation.

True, but this is very early solar system, where most everything is dust
and molecules still at this point. Probably not a lot of rocks yet.

If it is all dust it has MORE shadow. Only projected area matters.
Big lumps could be hollow and cast the same shadows. Interior fill is
not shadow-active, and wasted.

Think twice, speak once. You are better than this, and it is your
burden to maintain those high standards.

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz4.htm

Yousuf Khan wrote:
Here on Earth, it seems we would be screwed if our precious water wasn't
protected by other molecules against UV radiation. We have our magnetic
shield, our ozone shield, our nitrogen shield, etc. All protect the
water from dissociating in the Sun's UV. During the solar system's
formation period, it may have been that water itself was protecting
organic chemicals from dissociating in the Sun's UV.

Also there's some indication from this research that there was plenty of
water present right within the inner solar system at formation, such
that there wasn't a need for later cometary transport of the water from
outer solar system. Another surprising twist.

Hydrogen is still escaping the Earth leaving oxygen
and nitrogen behind:
http://www.flickr.com/photos/11040835@N07/1150815679
Compared to Europa and Titan, Earth lost ~99% of its water ! John
Curtis

http://www.universetoday.com/2010/01...our-molecules/

John Curtis wrote:
Hydrogen is still escaping the Earth leaving oxygen
and nitrogen behind:
http://www.flickr.com/photos/11040835@N07/1150815679

Apparently we're also gaining hydrogen ions (in the form of protons)
from the solar winds, as it hits the poles.

Compared to Europa and Titan, Earth lost ~99% of its water ! John
Curtis


Well sure, it's easy to protect the water if it is in the mainly solid
phase on the planet's surface. Liquid is a little harder to protect, and
gas even harder as they can escape the planet's surface easier.

Yousuf Khan