Driver to drive?

[Nobody]

On Mon, 04 May 2009 21:55:51 +0000, Jim Yanik wrote:

didn't Jimmy Carter get attacked by a killer rabbit in the water while he
was canoeing?

That incident was the back-story to the NYT math problem which is being
discussed in this thread.

"Jimmy Carter's Killer Rabbit Puzzle"

http://tierneylab.blogs.nytimes.com/2009/04/13/jimmy-carters-killer-rabbit-puzzle/

 

[Nobody]

On Tue, 05 May 2009 00:17:39 +0100, Eeyore wrote:

How about hiring some bots to perform a DoS attack on Google ?

DoS-ing Google is probably an impossibility. Even generating enough
extra traffic to make a visible blip on their traffic graph would be hard
enough.

 

[Eeyore]

Don Klipstein wrote:

Eeyore wrote:
Don Klipstein wrote:
Raveninghorde wrote:

The antartic ice is above long term trend:

http://arctic.atmos.uiuc.edu/cryosphere/iphone/images/iphone.anomaly.antarctic.png

Antarctic sea ice area is indeed above long term trend of since
observations began, but to a lesser extent in square kilometers than
Arctic sea ice has been running low over the past few years. The world
has experienced a loss of sea ice.

Sea Ice is an irrelevance. It merely shows mild warming of the oceans
which we know about anyway. It won't flood anywhere since it occupies no
more space when melted.

The issue here is that sea ice loss is an indicator of warming, and also
a positive feedback mechanism for warming.

I am very well aware that melting of ice floating on the sea does not
change sea level. The big problem of sea level increase would come from
warming progressing to causing significant melting of the thick ice sheets
over land area of Greenland and Antarctica.

Not going to happen EVER in Antarctica unless temps rise by 40+ C.

Greenland's thick ice sheet
may not melt much until/unless global surface temperature gets to warmer
levels achieved in the previous interglacial period, 2-3 degrees C/K above
1961-1990 average.

The satellites are saying the total mass of Greenland ice is stable.

Antarctica's thick ice sheet will need more to melt,
but probably did not exist the last time global surface temperature was
about 22 degrees C.

I wonder how the Earth has survived these billions of years.

Graham

 

[Jon Kirwan]

On Tue, 05 May 2009 01:05:08 +0100, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:

Jon Kirwan wrote:

On Mon, 4 May 2009 23:41:47 +0000 (UTC), don@manx.misty.com (Don
Klipstein) wrote:

In article <49FF72C5.5B08D62F@hotmail.com>, Eeyore wrote:

Bob Eld wrote:

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote

In the mean time the Arctic, Greenland and the Antarctic keep melting
and ice breaking up. Explain that. Me thinks you are "out to lunch."

No, the Arctic ice is recovering, can't say much about the others but
these things happen normally all the time. Temps go up and down without
human
intervention. AGW is treating the planet as if it should be in stasis.

Graham

Wrong! The arctic sea ice recovered slightly from the 2006 minimum but as of
April 2009, it was less in area than 1979-2000 average.

Picking numbers at random again. The current trend is that the Arctic ice is
thickening.

It is not thickening - it is at an extreme of thinness, notably with
much more than usual of its coverage being by thin first-year ice.

The area coverage compared to 1979-2000 average did indeed make a major
uptick in the past few months, almost up to the 1979-2000 average. And
last time it was lowest compared to 1979-2000 average for a specific time
of year may be as recently as late January 2009.

http://www.nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png

SNIP

- Don Klipstein (don@misty.com)

Yes, though I wouldn't call it "up tick." It's just that the seasonal
loss of surface area is a bit slow, so far. They note: "Compared to
previous Aprils, April 2009 is near the middle of the distribution
(10th lowest of 31 years). The linear trend indicates that for the
month of April, ice extent is declining by 2.8% per decade, an average
of 42,400 square kilometers (16,400 square miles) of ice per year."

Fretting over one year to the next is INSANE.

Strawman. No scientist is doing that. They are just providing the
equation constants for a linear trend equation. It is developed by
looking at more than 30 years of data.

They might as well have said 848,000 km^2 per 20 years. I suppose
that if they had done that for you, you would shut up because you then
imagined that they were fretting over 20 year periods.

Are you that incompetent to realize what a constant factor means and
that it has nothing to do with "fretting over one year" here? Let's
walk through this slowly for you.

If a linear equation uses a variable expressed in terms of years,
the constant factor by which it is multiplied will be expressed in
"per year" terms so that the units work out, correctly. The fact
that it is expressed in "per year" terms in no way suggests that
only one year was examined in developing it or that anyone is
"fretting over one year."

There you go, Graham.

Cripes. And I used to wonder why Graham used sites suggesting that
relativity and cosmological theories are religious and manufactured by
atheists to prove there is no god. No longer.

Jon

 

[William Hughes]

On May 4, 11:43 am, Tim Williams <tmoran...@gmail.com> wrote:

On May 4, 9:56 am, Anon <a...@domain.invalid> wrote:

Some very basic calculus is helpful. A solution is given at
http://www.mathrec.org/old/2003jul/solutions.html

Riddle:

There is a rabbit in the middle of a perfectly circular pond. An
agent is trying to get the rabbit. The rabbit swims exactly away from
the agent. After a few seconds, the agent's head explodes. Why?

Ya know, if the agent always seeks the closest path (with no
underlying intelligence to escape the following scenario), the rabbit
(if it were more intelligent) could follow a zig-zag path. As soon as
it moves somewhat to the right, the agent sees this and moves in that
direction. The rabbit, noticing the reduced distance, changes
direction immediately. As it crosses the diameter

No, if the rabbit is far enough from the center of the circle
it cannot swim fast enough to cross the diameter so the agent
does not have to change direction. Indeed the agent's optimal
strategy is to
always seek to minimize the angular separation.

the agent is
standing on, the agent reverses direction. The opposite then happens,
ad nauseum, until the rabbit reaches the shore safely.

Theorem 1: The rabbit can reach the shore regardless of the agent's
relative speed.
Theorem 2: Either the agent's head explodes, or the Church-Turing
Theorem is false.

Theorem 2 follows from taking the limit as delta x approaches zero
(that is, the width of the zig-zag). In the limit, the rabbit appears
to proceed in a straight line, exactly opposite the agent (this also
works if the rabbit simply moves in exactly this path, with no
infinnitessimal shaking). The agent cannot decide which direction to
go, because his distance-o-meter is saying both directions are equal.

Nope. The agent knows that there are two optimal strategies.
The agent knows that it is suboptimal
not to choose between the two optimal strategies, but the method of
choice
is arbitrary. The agent will choose one of the optimal strategies
(either at random
or by some arbitrary rule, e.g. alphabetical order).


- William Hughes

 

[Sylvia Else]

riverman wrote:

On May 4, 8:10 pm, Nick <3-nos...@temporary-address.org.uk> wrote:
Sylvia Else <syl...@not.at.this.address> writes:
riverman wrote:
On May 3, 10:17 am, Sylvia Else <syl...@not.at.this.address> wrote:
Mark-T wrote:
DId anyone here see the problem presented in
the Science section of NY Times last week?
Quite startling, to see something so sophisticated
in a 'general readership' publication.
Is it solvable without a calculus of variations approach?
--
Mark
Yes.
Spoiler below 13
0
1
2
3
4
5
6
7
9
10
11
12
13
Since the agent can run four times as fast as the rabbit can swim, no
matter what the agent does, the rabbit can swim away from the centre,
and keep the agent on the far side as long as the rabbit is no more than
1/4 of the radius from the centre. So the rabbit can reach a point 3/4
of a radius from the edge while the agent is still on the opposite side.
Only if the agent stands still until the last possible moment. I think
the agent will move continuously, and as soon as the rabbit starts
moving in any direction, the agent will move toward the point that is
the closest to the rabbit at that moment. Let's call the agent 'Xeno'.
No - until the rabbit is 1/4 of the radius away from the centre, he
can swim fast enough, in a suitable direction, to keep the agent
exactly opposite. So it doesn't matter if the agent moves.
Which shows, I think (to return to the very original question about
whether this needs horrible maths to solve) that there is a simple proof
that pretty-well anyone can follow that shows the rabbit can escape in
the specific case (it goes to where it can just swim faster than the
agent, swims round in a circle until it gets to 180 degrees away from
the agent, and can then make it to the shore faster than the agent can
run round), but that the optimum strategy, and hence the answer to the
unasked question about which size of ponds or relative speeds allow the
rabbit to escape do require the horrid maths.
--
Online waterways route planner:http://canalplan.org.uk
development version:http://canalplan.eu- Hide quoted text -

- Show quoted text -

I'm not convinced about the 'keep the agent on the opposite side'
logic. Lets expand the problem to their being TWO agents, already on
opposite sides. If the rabbit swims in any direction, off-center, then
both agents will move together to be at the point the rabbit is
apparently aiming for, then the rabbit moves slowly back towards
center and the problem is reduced to the original one. So the rabbit
can escape with TWO agents around the pool...or even an INFINITE
number of them? (well, slightly less than infinite, in this case....)

When the rabbit moved back towards the centre of the pool, the agents
would move back to positions oppoisite each other.

It appears that the rabbit cannot escape if there are two agents.

Sylvia.

 

[Don Klipstein]

In article <j99uv45ce1n1poeek80utpj6cn1s637eqj@4ax.com>, Raveninghorde wrote:

On Mon, 4 May 2009 09:21:41 -0700, "Bob Eld" <nsmontassoc@yahoo.com
wrote:

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:49FE534C.A53AB854@hotmail.com...

In the mean time the Arctic, Greenland and the Antarctic keep melting
and ice breaking up. Explain that. Me thinks you are "out to lunch."

No, the Arctic ice is recovering, can't say much about the others but
these things happen normally all the time. Temps go up and down without
human intervention. AGW is treating the planet as if it should be in
stasis.

Wrong! The arctic sea ice recovered slightly from the 2006 minimum but as of
April 2009, it was less in area than 1979-2000 average. Furthermore, the
trend line is a downward slope and the Arctic on average has lost 40% of its
pre 1980 ice. Also, new ice formed is now very thin and is vulnerable to the
present melt season. You delude yourself if you think GW does not exist. The
evidence is clear for anybody with half a brain to observe. See
http://nsidc.org/arcticseaicenews/index.html

Just last week a chunk of ice the size of Manhattan broke of one of the
Antarctic shelves and Greenland is melting at an advanced rate. Because of
the loss of ice the earth's albedo is decreasing causing a positive feedback
effect with increased solar absorption.

The antartic ice is above long term trend:

http://arctic.atmos.uiuc.edu/cryosphere/iphone/images/iphone.anomaly.antarctic.png

Antarctic sea ice area is indeed above long term trend of since
observations began, but to a lesser extent in square kilometers than
Arctic sea ice has been running low over the past few years. The world
has experienced a loss of sea ice.

It appears to me that the explanation is that the Atlantic Multidecadal
Oscillation is in a phase that shifts heat northward.

The period of the AMO is about 65, maybe 70 years. Let's see how sea
ice in each polar region is doing 30-35 years from now.

- Don Klipstein (don@misty.com)

 

[Jon Kirwan]

On Tue, 5 May 2009 01:09:36 +0000 (UTC), don@manx.misty.com (Don
Klipstein) wrote:

In article <49FF8C09.C6D7DB89@hotmail.com>, Eeyore wrote:
snip

The satellites are saying the total mass of Greenland ice is stable.

That will probably change if global surface temperature gets to 2-3
degrees C warmer than 1961-1990 average.

Last I looked, and Isabella Velicogna and John Wahr are two
investigators to read from, GRACE shows a significant decline in ice
mass balance. The last paper I read on it was "GEOPHYSICAL RESEARCH
LETTERS, VOL. 32, L18505, doi:10.1029/2005GL023955, 2005" and titled
on my copy, "Greenland mass balance from GRACE." Isabella sent me
some of her papers a few years ago.

Some:

Velicogna, I., J. Wahr, Acceleration of Greenland Ice Mass Loss in
Spring 2004, Nature 022 Sep 2006|doi:10.1038/nature05168, 21 Sep
2006.

Velicogna, I., J. Wahr, Ice Mass Balance in Greenland from
GRACE, Geophys. Res. Lett.,Vol. 32, No. 18, L18505,
10.1029/2005GL023955, 2005.

Velicogna, I., J. Wahr, E. Hanna, P. Huybrechts, Short term mass
variability in Greenland, from GRACE, Geophys. Res. Lett. 32,
L05501, doi:10.1029/2004GL021948., 2004.

Gawk at her here:
http://www.faculty.uci.edu/profile.cfm?faculty_id=5518

A quick search also finds that K. Fleming, Z. Martinec and I. Sasgen
have done some comparisons of GRACE and altimetry.

Also,
http://www.engr.utexas.edu/news/articles/200608101082/index.cfm
http://www.arctic.noaa.gov/reportcard/essay_hanna.html

I don't know of another satellite that does this job. Perhaps Graham
can point me.

Jon

 

[riverman]

On May 4, 8:10 pm, Nick <3-nos...@temporary-address.org.uk> wrote:

Sylvia Else <syl...@not.at.this.address> writes:
riverman wrote:
On May 3, 10:17 am, Sylvia Else <syl...@not.at.this.address> wrote:
Mark-T wrote:
DId anyone here see the problem presented in
the Science section of NY Times last week?
Quite startling, to see something so sophisticated
in a 'general readership' publication.
Is it solvable without a calculus of variations approach?
--
Mark
Yes.

Spoiler below 13

0

1

2

3

4

5

6

7

9

10

11

12

13

Since the agent can run four times as fast as the rabbit can swim, no
matter what the agent does, the rabbit can swim away from the centre,
and keep the agent on the far side as long as the rabbit is no more than
1/4 of the radius from the centre. So the rabbit can reach a point 3/4
of a radius from the edge while the agent is still on the opposite side.

Only if the agent stands still until the last possible moment. I think
the agent will move continuously, and as soon as the rabbit starts
moving in any direction, the agent will move toward the point that is
the closest to the rabbit at that moment. Let's call the agent 'Xeno'.

No - until the rabbit is 1/4 of the radius away from the centre, he
can swim fast enough, in a suitable direction, to keep the agent
exactly opposite. So it doesn't matter if the agent moves.

Which shows, I think (to return to the very original question about
whether this needs horrible maths to solve) that there is a simple proof
that pretty-well anyone can follow that shows the rabbit can escape in
the specific case (it goes to where it can just swim faster than the
agent, swims round in a circle until it gets to 180 degrees away from
the agent, and can then make it to the shore faster than the agent can
run round), but that the optimum strategy, and hence the answer to the
unasked question about which size of ponds or relative speeds allow the
rabbit to escape do require the horrid maths.
--
Online waterways route planner:http://canalplan.org.uk
           development version:http://canalplan.eu- Hide quoted text -

- Show quoted text -

I'm not convinced about the 'keep the agent on the opposite side'
logic. Lets expand the problem to their being TWO agents, already on
opposite sides. If the rabbit swims in any direction, off-center, then
both agents will move together to be at the point the rabbit is
apparently aiming for, then the rabbit moves slowly back towards
center and the problem is reduced to the original one. So the rabbit
can escape with TWO agents around the pool...or even an INFINITE
number of them? (well, slightly less than infinite, in this case....)

--riverman

 

[Tim Little]

On 2009-05-04, riverman <myronbuck@yahoo.com> wrote:

Lets expand the problem to their being TWO agents, already on
opposite sides. If the rabbit swims in any direction, off-center,
then both agents will move together to be at the point the rabbit is
apparently aiming for

No, that is not their best cooperative strategy even if it would be
their best strategy individually. Though actually it is not even
their best individual strategy, as the rabbit could then dictate which
direction they run with arbitrarily little cost by "feinting" motion
toward any arbitrary point on shore.


- Tim

 

[Don Klipstein]

In article <49FF72C5.5B08D62F@hotmail.com>, Eeyore wrote:

Bob Eld wrote:

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote

In the mean time the Arctic, Greenland and the Antarctic keep melting
and ice breaking up. Explain that. Me thinks you are "out to lunch."

No, the Arctic ice is recovering, can't say much about the others but
these things happen normally all the time. Temps go up and down without
human
intervention. AGW is treating the planet as if it should be in stasis.

Graham

Wrong! The arctic sea ice recovered slightly from the 2006 minimum but as of
April 2009, it was less in area than 1979-2000 average.

Picking numbers at random again. The current trend is that the Arctic ice is
thickening.

It is not thickening - it is at an extreme of thinness, notably with
much more than usual of its coverage being by thin first-year ice.

The area coverage compared to 1979-2000 average did indeed make a major
uptick in the past few months, almost up to the 1979-2000 average. And
last time it was lowest compared to 1979-2000 average for a specific time
of year may be as recently as late January 2009.

http://www.nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png

<SNIP>

- Don Klipstein (don@misty.com)

 

[Don Klipstein]

In article <pan.2009.05.04.19.48.46.333776@example.net>, Rich Grise wrote:

On Mon, 04 May 2009 00:41:58 +0000, Don Klipstein wrote:
"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message

Some REAL science at last, notably illustrating that the effect of CO2
in the atmosphere is nearly already at saturation level and more can
contribute very little to temperature rise.

http://brneurosci.org/co2.html

Which claims that water vapor accounts for 90-95% of the "Greenhouse
Effect", and that CO2 accounts for 4.2-8.4% of it.

The Wiki article on "Greenhouse Effect" says 9-26% for CO2 and 36-70%

The very concept of "greenhouse gases" is ludicrous in the first place.

Not only is it based on Venus, which has so much CO2 with H2SO4 clouds
that its atmospheris pressure at ground level is approx. 90 atmospheres,
or 1350 PSI, but it very studiously evades the fact that a living, dynamic
atmosphere is NOT a huge pane of glass.

Then why is Earth warmer than the 255 Kelvin that a greenhouse-gas-free
planet with same insolation and same albedo of Earth would achieve?

- Don Klipstein (don@misty.com)

 

[flipper]

On Mon, 04 May 2009 23:50:39 +0100, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:

flipper wrote:

"marcodbeast" <its@casual.com> wrote:
Eeyore wrote:
Archimedes' Lever wrote:
Jim Thompson wrote:

Success!

See...

http://analog-innovations.com/SED/TROLLFEEDER.jpg

Had to resort to NewsProxy until Agent gets a "References:" filter.

Will now just add, to Agent...

999 Delete: Subject:TROLLFEEDER

Then I won't even see the "TROLLFEEDER" tag.

Someone tell NymNuts, it _is_ universal, presently covering NymNuts,
Eeyore and Slowman follow-ups.

So, as far as I'm concerned, these "folks" don't exist anymore ;-)

...Jim Thompson

JimBob Brainlees Fart's head finally exploded.

It has been quite enjoyable watching him sink deeper and deeper
into his stupidity based seclusion desires.

Have fun being a net recluse. That has to be one of the most
retarded acts ever performed.

I have to agree with you.

The USA claims to be so in favour of 'free speech' yet it's the
Americans here who don't want to hear views that are contrary to
their own.

That's how they retain their cockeyed worldview. The right wing lie
aquariums (Fox, CNS, Newsmax, WND, etc.) their keepers built for them have
one universal feature - they're designed from the bottom up to make them
think that any other info sources, where they might hear actual facts, are
out to get them. There is literally no right wing k00khaus that doesn't
expend quite a bit of effort demonizing what they call the Mainstream Media,
can't have the dupes finding out they are in a fantasy world. =)

Congratulations on the near perfect emulation of a dog barking at his
own reflection.

DOPE !

A "dope" is someone who makes rash assumptions and then fantasizes
them into an alternate reality, like you just did.

If you want to see or hear what foreign media are saying, there's this thing
called the 'internet' that'll give you the full picture. You know, you can read
foreign newspapers and stuff.

When there's shit going on in the Middle East, I often visit Al Jazeera to see
their take on it. You might be surprised to see it's not all one sided.
http://english.aljazeera.net/

And by what fantasy do you presume to know where I've been and read?

Now here's a tip for you. When I see/hear some pin head 'tell me' what
someone 'said' or what is 'in a bill' or in a document I go look up
the original and read it for myself.

I don't blindly trust any 'news source' but as for 'bias' in the
'mainstream media', that became apparent long before FOX and
'alternate' news even existed as I'm a prolific C-SPAN watcher and
often saw first hand what was later 'reported'. Not that C-SPAN was
necessary to see the bias but it was more easily provable.

Graham

 

[Don Klipstein]

In article <49FF81FC.F91B604E@hotmail.com>, Eeyore wrote:

Don Klipstein wrote:

Raveninghorde wrote:

The antartic ice is above long term trend:

http://arctic.atmos.uiuc.edu/cryosphere/iphone/images/iphone.anomaly.antarctic.png

Antarctic sea ice area is indeed above long term trend of since
observations began, but to a lesser extent in square kilometers than
Arctic sea ice has been running low over the past few years. The world
has experienced a loss of sea ice.

Sea Ice is an irrelevance. It merely shows mild warming of the oceans
which we know about anyway. It won't flood anywhere since it occupies no
more space when melted.

The issue here is that sea ice loss is an indicator of warming, and also
a positive feedback mechanism for warming.

I am very well aware that melting of ice floating on the sea does not
change sea level. The big problem of sea level increase would come from
warming progressing to causing significant melting of the thick ice sheets
over land area of Greenland and Antarctica. Greenland's thick ice sheet
may not melt much until/unless global surface temperature gets to warmer
levels achieved in the previous interglacial period, 2-3 degrees C/K above
1961-1990 average. Antarctica's thick ice sheet will need more to melt,
but probably did not exist the last time global surface temperature was
about 22 degrees C.

- Don Klipstein (don@misty.com)

 

[Don Klipstein]

In article <49FF8277.9EE0C292@hotmail.com>, Eeyore wrote:

Don Klipstein wrote:

Eeyore wrote:
Bob Eld wrote:

Wrong! The arctic sea ice recovered slightly from the 2006 minimum
but as of April 2009, it was less in area than 1979-2000 average.

Picking numbers at random again. The current trend is that the Arctic
ice is thickening.

It is not thickening - it is at an extreme of thinness, notably with
much more than usual of its coverage being by thin first-year ice.

Right, the ice is recovering. Maybe I should have been clearer ?

Every trend is going the opposite way to the AGW hypothesis.

The arctic sea ice coverage has gone from maybe roughly matching a
post-1979 record low for time of year to almost up to 1979-2000 average in
about 13 weeks.

Latest report from nsidc.org shows this 13-week-long recovery taking a
reversal, from a bit short of the 1979-2000 average.

I don't see 13 weeks showing a trend as well as 5-plus years does.

- Don Klipstein (don@misty.com)

 

[Don Klipstein]

In article <49FF82B4.8D7B6A9C@hotmail.com>, Eeyore wrote:

Jon Kirwan wrote:

On Mon, 4 May 2009 23:41:47 +0000 (UTC), don@manx.misty.com (Don
Klipstein) wrote:

It is not thickening - it is at an extreme of thinness, notably with
much more than usual of its coverage being by thin first-year ice.

The area coverage compared to 1979-2000 average did indeed make a major
uptick in the past few months, almost up to the 1979-2000 average. And
last time it was lowest compared to 1979-2000 average for a specific time
of year may be as recently as late January 2009.

http://www.nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png

SNIP

- Don Klipstein (don@misty.com)

Yes, though I wouldn't call it "up tick." It's just that the seasonal
loss of surface area is a bit slow, so far. They note: "Compared to
previous Aprils, April 2009 is near the middle of the distribution
(10th lowest of 31 years). The linear trend indicates that for the
month of April, ice extent is declining by 2.8% per decade, an average
of 42,400 square kilometers (16,400 square miles) of ice per year."

Fretting over one year to the next is INSANE.

Then what would you call a 13 week uptick from maybe matching lowest on
record for date of year (with the record roughly-matched or
possibly-broken-by-a-small-margin established probably in 2006 or 2007) to
a bit short of the 1979-2000 average?

- Don Klipstein (don@misty.com)

 

[Don Klipstein]

In article <49FF8C09.C6D7DB89@hotmail.com>, Eeyore wrote:

Don Klipstein wrote:

Eeyore wrote:
Don Klipstein wrote:
Raveninghorde wrote:

The antartic ice is above long term trend:

http://arctic.atmos.uiuc.edu/cryosphere/iphone/images/iphone.anomaly.antarctic.png

Antarctic sea ice area is indeed above long term trend of since
observations began, but to a lesser extent in square kilometers than
Arctic sea ice has been running low over the past few years. The world
has experienced a loss of sea ice.

Sea Ice is an irrelevance. It merely shows mild warming of the oceans
which we know about anyway. It won't flood anywhere since it occupies no
more space when melted.

The issue here is that sea ice loss is an indicator of warming, and also
a positive feedback mechanism for warming.

I am very well aware that melting of ice floating on the sea does not
change sea level. The big problem of sea level increase would come from
warming progressing to causing significant melting of the thick ice sheets
over land area of Greenland and Antarctica.

Not going to happen EVER in Antarctica unless temps rise by 40+ C.

Both Antarctica and Greenland lacked permanent ice in the past with mere
global temp. a mere 8 degrees C warmer than 1961-1990 average, with
temperature change being greater in polar changes than worldwide. A major
positive feedback mechanism is concentrated to portions of the globe where
ice coverage is able to change from year to year.

Greenland's thick ice sheet
may not melt much until/unless global surface temperature gets to warmer
levels achieved in the previous interglacial period, 2-3 degrees C/K above
1961-1990 average.

The satellites are saying the total mass of Greenland ice is stable.

That will probably change if global surface temperature gets to 2-3
degrees C warmer than 1961-1990 average.

Antarctica's thick ice sheet will need more to melt,
but probably did not exist the last time global surface temperature was
about 22 degrees C.

I wonder how the Earth has survived these billions of years.

Often with sea level a couple hundred meters higher than it is now,
which I see being probably mostly what was the case in the particular past
times since pre-Cambrian when atmospheric CO2 concentration was by
best-available-determination above 800 PPMV or so and global surface
temperature was about 22 degrees C, about 8 degrees C warmer than
1961-1990 average.

- Don Klipstein (don@misty.com)

 

[Joerg]

Rich Grise wrote:

On Mon, 04 May 2009 18:21:31 +0000, Charlie E. wrote:
On Sun, 03 May 2009 10:51:21 -0700, Joerg
RFI-EMI-GUY wrote:
In my house attic, I have several 4 inch white PVC vent stacks which are
simply white PVC drain pipe extending from the wall headers through the
attic and the roof. On the roof, these are covered with lead flashing to
prevent water from getting inside the house. I have been doing a lot of
work in the attic, and have noticed that these pipes "glow" quite
noticeably as a result of the sunlight outside. As this often happens
when the sun is at the horizon and thus at an angle below which direct
coupling into the pipe would be possible, I am very curious as to the
reason that the visible infrared portion is so much more visible than
white light spectrum. Has anyone else noticed this? What is going on?

White PVC sticking out the roof? 4"? Wow. White PVC usually becomes
rotten from UV pretty quickly. If it isn't painted it begins to turn
brown within 2-3 years in our area. After some more years you can
sometimes crumble it by hand.
Around here, it takes considerably less time than that. The pipes I
ran to my pools solar heater were quite dark within a year, even the
ones by the pumphouse that are mostly in the shade!

Would it make any difference if they were black ABS? It would obviously
dramatically minimize the "glow", but how's black ABS's UV susceptibillity
vs. white PVC?

The vent pipes sticking out the roof on our house are like that.
Deterioration over >35 years: None.

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

 

[krw]

On Mon, 04 May 2009 17:53:27 GMT, Rich Grise <richgrise@example.net>
wrote:

On Mon, 04 May 2009 09:42:42 -0700, alertjean wrote:
On May 4, 8:58 am, "keith...@gmail.com" <keith...@gmail.com> wrote:
On May 4, 12:46 am, alertj...@rediffmail.com wrote:

Based on trends in mask and design costs for standard cells, vs. FGPA
capabilities, do
you believe the number of new designs per year executed in standard
cells will increase
or decrease in the future as compared with a baseline of 2007 ?

I think it will increase, what do you think ?

I think you're nuts, but you can ignore history at your peril.

Dave..You are smart..It was an exam question. But I am not convinced
by the answer professor gave me...that FPGAs will takeover standard
cell designs thereby reducing the number of standard cell designs. I
think as the performance and power of FPGAs will be bad compared to SC
designs, SC designs are always going to be winners
and I dont think FPGAs will take over.

What's the difference between an "FPGA" and a "standard cell", other than
my (more than likely inaccurate) assumption that an FPGA is simply a
collection of interconnectible standard cells?

There is no 'FP' in an ASIC and FPGAs aren't 'AS'.

I have no doubt someone here will correct me if I'm inaccurate,
misinformed, or am making a WAG and missing the point entirely. ;-)

 

[krw]

On Mon, 04 May 2009 16:34:20 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@My-Web-Site.com> wrote:

On Tue, 5 May 2009 08:25:21 +1000, "David L. Jones"
altzone@gmail.com> wrote:

alertjean@rediffmail.com> wrote in message
news:98e3f191-fdd5-4ee2-900d-347854303bf4@j12g2000vbl.googlegroups.com...
On May 4, 8:58 am, "keith...@gmail.com" <keith...@gmail.com> wrote:
On May 4, 12:46 am, alertj...@rediffmail.com wrote:

Based on trends in mask and design costs for standard cells, vs. FGPA
capabilities, do
you believe the number of new designs per year executed in standard
cells will increase
or decrease in the future as compared with a baseline of 2007 ?

I think it will increase, what do you think ?

I think you're nuts, but you can ignore history at your peril.

Dave..You are smart..It was an exam question. But I am not convinced
by the answer professor gave me...that FPGAs will takeover standard
cell designs thereby reducing the number of standard cell designs. I
think as the performance and power of FPGAs will be bad compared to SC
designs, SC designs are always going to be winners
and I dont think FPGAs will take over.

It's very hard to quantify this stuff. Do you base the figures on actual
shipped chip quantity?, number of design implemented? etc.
Standard cell ASIC's require a massive NRE investment, and this effectively
puts a cap on the number of customers who can afford to design ASIC's.
If you base the argument on number of people implementing new designs, then
FPGA's will win hands down, as even Joe Blog Hobbyist can implement FPGA's.
If you look at the EDA market, then ASIC customers are getting fewer and
fewer (like down to a number you can start to count on your hands), but FPGA
tool use has been exploding in numbers for a long time. So in that respect
your professor is right.

Cost-conscious digital can't help but go to some form of
array-based...

Sometimes cost isn't the driving issue. Sometimes the line gets drawn
in different places.

But there will always be a big niche for custom ASIC's, the market won't
vanish.

Dave.

And analog/mixed-signal ASIC's will continue... which is why I
continue to get requests.

There is real money to be made in niches. One could argue that that
*is* where the money is. Competition, and all.