contrails

bildan wrote:

That sounds good, practical, even. I've seen film of power trailers
behind Landrovers which seemed remarkably good at ploughing through mud
in off-road tests. Do you know if there are stability problems with these
rigs at highway speeds? I ask because I expect mining trailers would be
somewhat slower and the film didn't show anything operating at much over
10 mph.


I guess it could be done wrong so stability problems ensued. However,
electric wheel motors create an opportunity for dynamic stability
control. One motor could be instantly braked while the other powered
forward to counter sway. Since the motors are directly coupled to the
wheels, this could happen at the speed of electronics. Accelerometers
in the trailer would sense sway. I would think it could be done in a
way to create dead solid stability.

SparrowHawk owners, and maybe PW-5 owners, probably are looking forward
to towing with EV!

A lot of the glider pilots I know bring the glider over the mountains to
Ephrata and leave it there all season, then take it home. They could
borrow or rent a vehicle to do that, and use an EV or other high mpg car
to go soaring the rest of the time. Pilots with self-launchers often
avoid a lot of towing, since they can fly from a nearby airport instead
driving to someplace with a tow plane, and don't need retrieves. Works
for me.

I like the idea of a powered trailer, though.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

On Jan 12, 6:16*am, Gary Evans wrote:

Eric, have you looked at all of the information on Rutan's web site?http://tinyurl.com/pfy9tk

The silence is almost deafening.

Rutan has an immense measure of credibility. He has spent his career
analyzing and making sense of large quantities of often conflicting
data. History has shown that he is very, very good at it. He also
has nothing, at least financial, to gain one way or the other.

Regards,

-Doug

bildan wrote:

"Recently published research by Barber and colleagues shows that the ice
cover was even more fragile at the end of the melt season than satellite
data indicated, with regions of the Beaufort and Chukchi Seas covered by
small, rotten ice http://nsidc.org/cgi-bin/words/word.pl?rotten%20ice
floes."

There is no good news from the National Snow and Ice Center, regardless
of the The Mail says.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly


Look at this:

http://climate.nasa.gov/news/index.c...ews&NewsID=242

I had no idea the mass loss was accelerating. No good news at the South
Pole, either.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

On Jan 13, 9:28*pm, Doug Hoffman wrote:
On Jan 12, 6:16*am, Gary Evans wrote:

Eric, have you looked at all of the information on Rutan's web site?http://tinyurl.com/pfy9tk

The silence is almost deafening.

Rutan has an immense measure of credibility. *He has spent his career
analyzing and making sense of large quantities of often conflicting
data. *History has shown that he is very, very good at it. *He also
has nothing, at least financial, to gain one way or the other.

Regards,

-Doug

It's amazing that all the 'scientific' climate deniers have zero
credibility as climatologists.

My leading aeronautical engineering hero is Kelly Johnson of
Lockheed. Jack Northrop and "Dutch" Kindelburger make the list too -
Burt Rutan doesn't.

Gary Evans wrote:
"Only 19 percent of the ice cover was over 2 years old, the least in the
satellite record and far below the 1981-2000 average of 52 percent."

Finally, look at fig. 3 on this page:

http://nsidc.org/news/press/20091005_minimumpr.html

No good news at the NSIDC, unfortunately, despite The Mail's spin on it.




Eric, have you looked at all of the information on Rutan's web site?
http://tinyurl.com/pfy9tk

I just finished reading the Dec 2009 presentation. It was truly
depressing experience, because Burt Rutan has been one of my heroes.
It's sad to see him sucked into a field where he has no expertise, and
yet is so absolutely certain of his abilities, he thinks he can demolish
50 years of climate science, produced by thousands of scientists around
the world, in a few pages. Even with my very modest understanding, I
could see some grave mistakes.
There is just so much conflicting information out there and both sides
are soooo convinced that they have it right.
There appears to be just as good an argument on either side but as I
mentioned before religions require both faith and sacrifice.
There is very little conflicting _scientific_ information. There is a
ton conflicting _misinformation_, and plenty of confusion, and I
certainly do not think science is a religion.
If you
really think the ice is going away there are two choices. One is to
try and convince everyone else that they must join the new religion of
self-flagellation and some how turn this whole thing around by paying
third world countries not to cut down any more trees. The other more
direct action would be to measure exactly how high your house is above
the sea level and act accordingly while prices are still up. You do
live on high ground right?
In fact there much better choices than either one. 190 countries did not
show up in Copenhagen to debate about which to those two "choices" was
the best one!

If you want to discuss Burt's presentation, contact me privately. I
still think RAS is not a good place to do this.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

Doug Hoffman wrote:
On Jan 12, 6:16 am, Gary Evans wrote:


Eric, have you looked at all of the information on Rutan's web site?http://tinyurl.com/pfy9tk


The silence is almost deafening.

I try not to make RAS my life, so I usually read it only in the evening
;-)
Rutan has an immense measure of credibility. He has spent his career
analyzing and making sense of large quantities of often conflicting
data. History has shown that he is very, very good at it. He also
has nothing, at least financial, to gain one way or the other.
Rutan is one of my heroes, and he has had a remarkable career as an
engineer and business man, but he has NO credibility as a climate
scientist. Would you climb into an airplane designed and built by any of
the leading climate scientists? No, and neither would I. It doesn't make
any more sense to assume Rutan is going to do climate science well, either.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

On Jan 13, 10:43*pm, Eric Greenwell wrote:
Doug Hoffman wrote:
On Jan 12, 6:16 am, Gary Evans wrote:

Eric, have you looked at all of the information on Rutan's web site?http://tinyurl.com/pfy9tk

The silence is almost deafening.

I try not to make RAS my life, so I usually read it only in the evening *
;-) Rutan has an immense measure of credibility. *He has spent his career
analyzing and making sense of large quantities of often conflicting
data. *History has shown that he is very, very good at it. *He also
has nothing, at least financial, to gain one way or the other.

Rutan is one of my heroes, and he has had a remarkable career as an
engineer and business man, but he has NO credibility as a climate
scientist. Would you climb into an airplane designed and built by any of
the leading climate scientists? No, and neither would I. It doesn't make
any more sense to assume Rutan is going to do climate science well, either.

On 1/13/2010 9:43 PM, Eric Greenwell wrote:
bildan wrote:

"Recently published research by Barber and colleagues shows that the ice
cover was even more fragile at the end of the melt season than satellite
data indicated, with regions of the Beaufort and Chukchi Seas covered by
small, rotten ice http://nsidc.org/cgi-bin/words/word.pl?rotten%20ice
floes."

There is no good news from the National Snow and Ice Center, regardless
of the The Mail says.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

Look at this:

http://climate.nasa.gov/news/index.c...ews&NewsID=242
I had no idea the mass loss was accelerating. No good news at the South
Pole, either.

Hmmm. 24 cubic miles of ice loss per year since 2002 across Antarctica.
Sounds pretty bad. Thats a lot of ice.

But the area of Antarctica is 5.5 million square miles. Average ice
depth across the interior is estimated to be 1.2 km. Thats a couple
million cubic miles of ice. Now that's a lot of ice.

Makes 24 cubic miles seem pretty trivial. But maybe its wildly abnormal
to loose that much. Or maybe it really is trivial normal variation. I
don't know.

But watch out for scale and context. Big numbers can be used to
illustrate, impress, or deceive.

A seven knot thermal may sound pretty impressive. But on a strong day at
Parowan, its not even worth slowing down for

-Dave

Speaking of big numbers, here's a recent article that explains how the
temps at the Vostok research station in Antarctica dropped to a record
-89 C in 1983; http://insciences.org/article.php?article_id=8087

-Scott

On Jan 13, 4:33*am, Bruce Hoult wrote:
On Jan 13, 6:40*am, T8 wrote:

Back to trailers: *From fuel consumption numbers, I can back out that
my Komet trailer/glider has an effective fuel consumption of 120 miles
to the gallon at 60 - 65 mph on level road, no wind.

That's pretty impressive.

When I was towing a Grob two seater in (admittedly a pretty crappy
trailer) it reduced the range of my 2.5l Subaru on a 56l fill up from
about 620 km to about 350 km. *Say, from 32 mpg to about 18 mpg.

http://hoult.org/bruce/Subaru_with_TA.jpg

To put it into the normal units used here, the car alone normally uses
about 9 l/100 km on a long trip, and the combo used about 16 l/100km.
That implies that the trailer used about 7 l/100 km, or 40 mpg.

I'm sure a Komet with a single seat glider would be much better, but
I'm surprised it's three times better.

The Komet wins on aerodynamics. My old Schreder trailer, despite
being lighter, had twice the incremental fuel consumption at 65 mph,
so 60 mpg. It is similar in shape to your Grob trailer. Relative to
the Komet, it was like towing a parachute! I tow 'em all European
style behind small hatchbacks. Martin's correct, towed behind a large
RV or similar, there would be less difference.

-Evan Ludeman / T8