Seiche Wave Corner

New Bern, NC

Well the big bad weather front that passed us last night turned out to be a non event.   The wind blew like crazy all day long from the south.   That hit Tarwathie on the side hard enough that Libby had to free the gimbals on the stove to keep supper from sliding off the top.  When we are at anchor, the wind is always from the front; never from the side for very long.  We're not used to that.

We feared lightning, and tornadoes.  The front looked very ugly on the Doppler Radar.  But when it passed, the wind shifted from 30 S to 40 W and it rained, nothing more.

More dramatic was when I went ashore this morning.  The water levels had dropped three feet.   Other times since staying here we've seen the levels rise three feet.  So I guess the variations are six feet or more.  For a place with essentially zero tide, that's remarkable.  10 hours later it had recovered one foot.

Presumably, when I was seeing -3 foot levels here in New Bern, the water levels up by Elizabeth City were +3 feet.



The technical term for that is a seiche wave.  A wave enclosed by a bounded perimeter. The longest natural period for a seiche in an enclosed rectangular body of water is usually represented by Merian's formula:

  

where T is the period, L is the length, h is the depth, and g is the gravitational constant.  Consider Pamlico Sound plus the Neuse River as a rectangle (it is far from that shape but I don't have the formula for any other shapes.)    That gives a seiche wave period of about 6 miles.   What does that mean? I don't know, it doesn't seem to relate to anything I see.   Below is a plot of a big seiche on Lake Erie.  That's pretty dramatic with a 14 foot difference between Buffalo and Toledo.

Strange Sights and Sounds

New Bern, NC

 

We are back on the boat after nearly 2 weeks on shore. Yesterday it was 72 degrees and today it will be 75, but this afternoon it will blow 45 and winter weather will return. Brrrrr

Last night, about an hour after sunset, I was up on deck. I heard a very strange loud sound. I looked all around, especially up in the sky, and saw nothing. A few seconds later I turned around and saw a huge disturbance in the water. It looked like the continent of Atlantis was trying to surface. OK, now is the time to insert the Twilight Zone theme music. I couldn't figure out the cause. A minute or two later I heard the noise again. I whipped my head around in time to see it. It was an incredibly dense school of fish who were getting excited about something. Wow! We have never seen anything quite like that in nearly eight years on the water.

Then I noticed another coincidence. A brilliant and nearly full orange moon was rising in the East. Then I remembered some local history that I read recently. It was about the native Indians who taught the black watermen how to fish the North Carolina inland waters. One key trick they taught them was which moon brought in the annual schools of shad, and which moon brought the schools of menhaden. I don't know which kind of fish it was last night. I bet that some blog reader could tell me. Anyhow, I now think that the time of year, the full moon and the appearance of that school of fish are a pattern, not a coincidence. Awesome!!!

That 50 foot wide school of fish was so impressive. My mind boggles at the thought of the enormous schools that populated these waters in colonial times. My they must have been impressive. My mind also boggles at the accounts of dinner plate sized oysters. How sad it is that the pressure of seven billion people on this planet has so drastically suppressed other species.

At Sea in Winter

Zebulon, NC

 

It is really cold and windy here today. Brrrrrrrr. Libby and I have no cold tolerance left. The cold wind seems to cut like a knife.

Just for fun, I looked up the marine weather. Out by Frying Pan Shoals, in addition to cold, the winds are 30-40 knots and the seas 18-20 feet. It will stay like that for 4 days. Man oh man does that should horrible. I imagine being out there in our open cockpit. No thank you.

It makes me appreciate more that the sailors of fore were a different breed of men than I or most of m contemporaries. Think of all those men who rounded Cape Horn. Of course part of their secret was that they didn't do it when they were 68 years old. Still, their fortitude was amazing.

If you would like to read a realistic account of what it was really like for those men in 1840, try one of my all time favorite books. "Two Years Before The Mast" by Richard Henry Dana. His account and his English sound modern , so the reading is easy. You can get a free copy here.

 

Winterizing Run

Zebulon, NC


I screwed up. [I can hear the readers now.  "What's new about that Dick?"]   I regularly skip articles about winterizing boats, smug in the certainty that it is a subject I'll never need to worry about.   Now I regret that.

Yesderady Libby and I listened to the New Bern weather report.  It called for overnight lows of 19F, and subfreezing.   They said it will be the coldest night in NC in many years.  YIPES!  I have no anti-freeze solution in the raw water part of the cooling system.   What should I do?   On one hand, the engine would probably be OK.   Even if air temperatures are below 19F, the river temperatures are above 32F.   But am I confident enough in that to take the risk?  No.

So last night I drove 218 miles in a round trip to New Bern, just to put anti-freeze in the engine and in the head.    I really regret not having done that before leaving the boat.

Who was it that said, "Merely owning a car leads one to making unnecessary trips."  How true.

Away from the Boat

Zebulon, NC

We are spending two weeks away from the boat.  In part we are house/dog sitting as Dave & Cathy take off for a weeks vacation.   As usual, when away from the boat my blogging activities are much reduced.

Below you'll find a post called Frajectives.  It is a piece I wrote that I'm particularly proud of.  I think it is good writing.   But alas, I submitted it to the NY Times with no reply.  I submitted it to the Washington Post and they rejected it.

Obviously, I'm fond of writing.  At the same time, I'm put off by the hassles of getting something published.   I don't mind rejections but I get really frosted at the usual result of no reply at all.  I'm also impatient.  I wrote a neat article suitable for boating magazines recently and sent it in.  I was shocked to find, for example, that Cruising World is fully booked for 2013 and that the delay to get published is closer to 18 months.  Some of what I wrote would be seriously dated by than.  

So, I guess I'll stick more with this blog.  It suits me better, and I hope that it entertains a few people out there.

Frajectives

Zebulon, NC

We all lament the poor quality of today’s public discourse.  Whether
in Congress, in the media, in political campaigns, on the Internet, or
simply in conversation, the prevalence of vitriol over rationality is
discouraging.  I blame our misuse of language for at least part of the
problem.

What I have in mind are adjectives and phrases that indefinitely
describe fractions.  Specifically, I mean fractions between all and
none, percentages between 1 and 99.  I’ll coin the word frajective for
this specific meaning.

All means 100%, none means 0%.  Those words are not frajectives, yet
90% of the time they are not heard in public debate.  We know that for
every human rule there is an exception somewhere.  Therefore, using
“all”, “none”, or “everyone” in public debate is just an invitation to
contradiction and being proven wrong.   It seems smarter to use the
frajective “some”.

Objectively, “some” seems pretty unambiguous.  “Some” means more than
none, less than all, 1-99%.  In the phrase, “some do, some don’t,” we
have two uses of “some” with indefinite meaning but which must add up
to 100%.  But in real life debate, “some” can be polarizing.  Suppose
Bob says, “Some welfare recipients are cheats.”  Alice says, “Some
welfare recipients richly deserve public investment.”  Objectively,
there is no disagreement in these statements, but in the arena of
public debate they are miles apart.  On a radio talk show, Bob would
soon be challenged by a caller who says, “I know someone who is not a
cheat,” thus proving Bob wrong.   Even though Bob said ”some,”
listeners heard “all” or “none” because only “all” or “none”
assertions can be proved false by a counter example.

"Many" is a word that we think means more than "some".  “Very many”
should mean even more than “many”.   If Bob says “There are many
people on my left and very many people on my right," clearly he means
there are more people on his right than on his left.   But if Tom says
exactly the same thing can we compare Tom’s meaning with Bob’s?  No.
When Tom says “very many” he could mean than Bob’s meaning of “few.”
In English, there are hundreds of frajectives to choose from, all with
overlapping meanings.  In the context of public debate, with many
unknown speakers, all frajectives are effectively synonyms to “some.”
Using frajectives is caustic to the quality of discourse.

How can we correct our language?  I recommend using numbers in place
of frajectives wherever possible in public debate.   It is far more
honest to say what you really think, such as “20 percent of people are
… whatever,” rather than hiding behind an indefinite phrase like “many
people.”   Even if you have no factual basis for choosing the number
20, "20" is better than “some.”  If you say 20, then people who
disagree may be stimulated to counter, “No. It is 40% not 20%,” and we
have a factual dispute.  If you say “many” opponents are likely to
respond “you are wrong, it is not many it is few,” thus contributing
only heat but no information and inviting ad holmium attacks.

I do not call for us to expunge those words from our vocabulary
entirely, but only to stop using them as frajectives in public
discourse.

If you have no actual data or facts, I recommend the 80-20 rule as the
default.   Choose either 80 or 20 as your best guess and say what you
mean.  Opponents can respond in kind, and the quality of the public
dialog will be improved.

Even with numbers, we must be careful of selection bias.  The phrase
“80% of people” should never be allowed without specifying the
selection group.  Too often speakers like to extrapolate “all people I
know” to “all people.”

I further call upon copy editors and public critics, to join with us
and to refrain from the use of indefinite words to conceal lack of
foundation.  If a journalist uses a number such as 80%, a traditional
editor may demand a foundation for use of such a definite number.  But
if inadequate foundation exists, it is not an improvement to
substitute “some” or “many” for 80.  Ambiguous words may help conceal
the lack of foundation, but at the expense of obscuring the meaning.
After all, saying what we mean as clearly as possible should be the
ultimate goal of all public speakers

A Day To Learn

New Bern, NC

The past 24 hours have been great fun.  I'm a person who loves to learn, and I've learned greatly in three very different domains.

1. I've been working for months on a series of video courses on theoretical physics taught by Professor David Susskind, one of the fathers of string theory.  I'll blog more about that when I'm done with all the lessons.  But this morning, as I watched, a whole bunch of things clicked.  Now, I think I truly understand tensors and general relativity and several other very difficult concepts.  I'm tickled pink over that.
   
2. I went over to George's house to use his saw to cut a piece of teak that I'm using to repair my cap rail.  I'll blog on that too when the project is finished.   But more than using a saw, George taught me a bunch of things about woodworking.   One was the mystery of the wooden plugs.  All over on Tarwathie's woodwork we see circular spots were plugs were inserted.  I've been puzzled to learn that many of those do not cover screw heads.  Today, George showed me how to fix blemishes in the wood by boring and plugging but even better how to use a "plug cutter" to make my own plugs from a scrap piece.  Ah ha!  One needs knowledge, a teacher and lots of the right tools.
   
3. I learned from Libby that a Camellia is a kind of plant.  That makes sense.  You see, last night at the New Bern Library, the meeting room was packed with women and the sign on the door said, "Camellia Waxing Demo"  I thought is really strange that this woman named Camellia would consent to being waxed in public for demo purposes.   Camellia as a plant makes more sense.

A New Heirloom?

New Bern, NC

Dave gave me a neat coffee mug for Christmas.  At first, I though he was fond of this mug because of its clever carabiner clip/handle.  That allows you to hang it on the strap of a backpack, or on the lifeline of a pitching sailboat.  Cool.

After using it a bit, I realized that it is much more.   This Stanley brand cup is made with the same materials and same design principles as my beloved thermos.  I blogged before about my thermos.  I even said that when I die I would like my ashes to be stuffed in my thermos and thrown in the sea.  This Stanley cup will last a lifetime.

To be sure, I don't have enough remaining in this lifetime to make this cup as beat up and worn as my thermos.  I have nearly 1 million miles of travel logged on the thermos.  I'll never come close with the cup.  Nevertheless, I guess this cup is destined to become a new Mills family heirloom.  Heck, I could even will it back to Dave when I die.  He has his own Stanley cup, but he could hang mine on the wall or pass it on to his son Bobby.

Tours Of The Trent River.

New Bern, NC

Libby was helping me with a task yesterday when she remarked that her arms felt weak. She hasn't had her usual quota of rowing exercise since leaving Lake Champlain. Fortunately, this week the weather is great with near 70 F temperatures every day, so Libby set out to explore the Trent River by dinghy.

Isn't that dangerous with the frigid water temperatures. I did insist that she wear a life jacket and stay close to shore. However, Libby is about as expert a rower as one could find. In 8 years she hasn't fallen out once, even though she's rowed though some pretty rough conditions. I think she's safe enough.

Speaking of Libby's rowing skills, I've had people in Boot Key Harbor remark that she looks like an Olympic rowing athlete as she zips around the harbor. How did that come to be? Just fortunate chance. When we bought Tarwathie, she came with a Fatty Knees dinghy but with no outboard motor. The Fatty Knees is the finest dinghy ever made for rowing properties. So put those things together and Libby got lots of practice and learned to love it. (She was not at her best yesterday. Note in the picture that her weight is too far forward. )

By the way, what is today's finest dinghy? We boaters were having a discussion about that yesterday in the lobby. We agreed that the Portland Pudgy is the finest hard dinghy made today. I think the Trinka, made in Vero Beach, is second. But the Trinka has a smooth bottom which does not aid in directional stability.

The Portland Pudgy rows very well (ask Bob on Carpe Diem), but the Fatty Knees has many lapstrake grooves which make it the best for rowing. Alas, they stopped making Fatty Knees in 2012, so they are not current.

In addition to rowing, the Portland Pudgy has a long list of superior features that set it apart. It is as if someone gathered 30 years of dinghy suggestion box slips and implemented all of them. Pudgies are very expensive but are probably worth it. (And no. I am not paid to plug the Pudgy.)

My comments apply only to hard dinghies. We never owned an inflatable, so I can't say much about them.


p.s. the other open secret to rowing pleasure is to use the longest oars possible. We have 7.5 foot oars; the longest we can stow in an 8 foot dinghy. Even the difference between 7 and 7.5 foot oars is dramatic. If we could stow 8 or even 9 foot oars we would do it. We see many frustrated rowers with 4 or 5 foot oars. I suspect that many of them don't realize the source of their frustration.

It-itis

New Bern, NC

Men joking with men about getting old like to say, "You know, it is not the brain that goes first."  Chuckle, chuckle, fear.

With Libby, it seems to be the specific part of the brain that deals with nouns.  Libby's faculties and intellect are just fine; as good as ever.  However, she has increasing difficulty coming up with the name of the particular noun she needs to complete her sentence.   I can usually guess what she means, but I consider it impolite to finish other people's sentences for them, so I just wait for her.  In recent years that has led to some long embarrassing pauses.  Increasingly, Libby resorts to "it" as the generic noun to substitute in all cases where she can't remember the noun. I call it it-itis; like a sickness.

On a boat, use of the indefinite "it" clashes with nautical culture.  Every standard thing on a boat has a specific name, and all members of the crew are strongly encouraged to use the proper name at all times.  We don't say left and right, we say port and starboard.  Other directions on a boat are fore and aft, above, below, aloft, windward and leeward.  In a locker we store ropes, but when a rope is brought out of the locker and put to use it becomes a line.  Each line has a unique name, such as main halyard, starboard stay sail sheet, or maybe port jack line.  There are good reasons for the discipline.  The best reason is that they allow us to communicate when we can not see each other, in the dark when we see nothing, and when the boat could be pointing in any direction.  

For example, if I said "turn left," it is unclear if I mean your left or the boat's left, and if I am below decks I don't know if you are facing forward or aft, or whether the boat is moving forward or aft, or which way the wind is coming from.  The concept of "turn left" can be extremely unclear but the meaning of "turn windward" is unique and unchanging.

Visitors on board are sometimes offended by a captain who insists that they should learn this special language and use it on board the boat.   The guests should be more sympathetic.  The captain is probably most afraid that he and his crew will regress in maintaining their own discipline  

if they speak to guests in a different language.

Of course all the jargon become second nature if you use it long enough.  That is unless you catch it-itus.  The other day Libby and I were bending the main (there's some hard core jargon) when she said, "You should move it over."  Which "it" I wondered.   There were dozens of its she might have meant;  so I just froze for 40 seconds.  Finally, it came to her and she said, "Move the boom."

I don't think there is a cure for it-itis any more than there is a cure for getting old.  We'll just have to avoid situations where rapid precise communications involving nouns is vital.   The most urgent category of communications are mostly verbs and don't require nouns.  STOP! LOOK OUT! HELP!  COME HERE!  DICK!    

Readers are invited to prove me wrong.   Name an urgent and critical communication that ends with an exclamation mark but needs a specific noun to be understood.

p.s. If I ever come down with a case of verb-itis it will take a team effort with both Libby and I to complete any sentence.   That might be romantic and bring us closer together, but it would not make us safe drivers or captains.

Trial Run

New Bern, NC

This week the winter weather here will be great.   Sunny most of the time and warm, with daily high temperatures approaching 70F.   That gave Libby and I a bit of spring fever so yesterday we went out for a day-long drive.

Where did we go?   Libby's friends won't have a hard time guessing.   We went after pine needles. So far we've gathered needles from Maine south to Key West and west to Arizona and east to The Bahamas.  The best place of all those is Carolina Beach State Park.  That's the place with needles 13 inches or longer.   It happens to be only two hours from here by car.  So that's where we went.

We also gathered a little driving data on our car thinking ahead to next summer.  We traveled a bit more than 200 miles round trip, all over very flat terrain and never driving faster than 50 mph.   Our mileage for the trip was 25.6 mpg.  That's not very good compared to many modern cars that get 38 or more mpg.

If we drive 6,000 miles next summer at 25.6 mpg, we'll burn 235 galllons of gas, costing about $900.  If we had a newer car getting 38 mpg, we would burn 158 gallons costing about $630.  The difference is less than $300.   I guess that's less of a big deal that I thought.  A more modern car would cost us much more than $300.   My economic thinking on the whole subject is dominated by the plan to keep the car only a few months.

Skyman Bob Sets Me Straight

New Bern, NC

Long time readers of this blog are familiar with the picture above taken by Brian McPhee.  I blogged about it here.  Yesterday I was stunned to learn some very subtle points about physics that are evident in that photo.  I'll share them with you.

I learned these things at skymanbob.com in Bob Berman's blog.  Bob Berman is a famous astronomer and explainer.  The blog post's title was "Can Rainbows Cast Reflections?"  "Of course then can," I thought, "Just think of this rainbow picture on my own blog."  But I read further, and of course Bob was right.

Look more closely at the picture above.  You can not see recognizable reflections of the sky, or the clouds, or even of Tarwathie sitting in the foreground, but you can see a very recognizable rainbow image on the water surface.   What's going on?

First, a rippled water surface reflects light, but it does not reflect recognizable images very well.  It is analogous to a heap of broken mirror glass fragments.   In the extreme, it is like the surface of frosted glass.   So the surprising answer is that the image of the rainbow you see in the water is not a reflection, it is a segment of rainbow refracting sunlight back toward your eye.

Like a vampire in a Hollywood movie, a rainbow can not be reflected in a mirror.  Wow!  I never knew that before..  Here it is in Bob Berman's words.

If you and I look at a car, we both see the same object. But a rainbow is a specific set of reflections and refractions within water droplets that essentially appear on the surface of an invisible cone whose radius is 42 degrees, whose orientation is the antisolar point, and whose apex is your eye, and your eye alone.
An apparent rainbow reflection in a mirror or on a lake, is that of a different rainbow. It may not even look like yours, since if it intercepts larger droplets it will be brighter but also deficient in blue. It is a different rainbow. Moreover, if the rainbow you’re seeing is nearby (as from a lawn sprinkler) then a mirror just ten feet to either side of you will show no reflection of it at all — no matter how the mirror is angled. It’ll show the same water droplets but with no rainbow within it.

Try it sometime. Or at least, think about it, and you’ll understand why you can never see a rainbow and also the reflection of that same rainbow.

Some readers have noted that they’ve seen or captured rainbows using cameras or reflector telescopes. But I never said that photons from rainbows somehow cannot bounce off glass: In these cases you’re seeing the rainbow, but not simultaneously seeing its reflection. The central point is that you cannot see a rainbow AND this same rainbow’s reflection. That’s because any reflection of an object is that object viewed from a different angle — and a rainbow, not being a real 3D object, cannot be viewed from any other angle except exactly where your eye (or camera) is located, completing the required geometry.

Cruiser's Status Symbols

New Bern, NC

According to Libby, it took me a lot of years to stop being an engineer and a project manger to start being a true cruiser.   Years or not, I'm a cruiser now and I really love it.

What is the difference between a cruiser and a retired person?  First, you don't need to retire to be a cruiser.  We've met cruisers of all ages from 19 to 91.  More important, retired people have different status symbols.  They have their condos, their golf handicaps, and maybe a polyester sports coat.  We enjoy more what some might call anti-status-symbols.

• I'm proud of the fact that a woman on the bus in Vero once said, "I can't tell the difference between you boaters and the homeless people."
  
• I'm proud of the fact that our income is so low that our tax liability is zero on federal returns or in any of the 50 states.  A tax preparing accountant advised us to stop filing tax returns altogether.  Despite that, we life a life that many consider luxurious.
  
• I'm proud of the fact that with the onset of winter in New Bern, I had to dig out my long pants.  I didn't even remember that I owned long pants.  If we weren't contemplating a year off, we would be in Marathon and those long pants would still be buried and forgotten.
  
• I put on sneakers today and my toes feel pinched.   That reminded me that I haven't worn any shoes other than Crocs for several years.   I still wear socks, but only because I'm afraid my feet will get sunburned.   I don't blog about underwear.
  
• When we bought a car two weeks ago, the dealer ran credit checks on us.  This month I got two letters in the mail from the credit agencies.  The first agency said that credit was denied because they couldn't find any information on us; we don't exist.  The second agency said that our score was 798 but that we had "insufficient debt history" to qualify for credit.  Hooray, we did indeed "drop out" of conventional society and we're proud of it.  [p.s. we did get the car loan anyhow; the dealer never waited for the results of the credit checks before processing the loan.]

I won't presume to speak for all cruisers and their status symbols, but I do believe we are in the main stream.

Now, however we have one foot back in the conventional life style.  It is our intention to pull that foot back out next fall and resume 100% cruising.  Wish us luck.

Perfect Moonrises/Moonsets 2013

New Bern, NC

I blogged several times before about perfect moonrises.  The idea fascinates me.   In short, I define a perfect moonrise as being at the right place at the right time to see the moon rise perfect synchronism with the sun set.

For example. On January 27, 2013 at 05:38 GMT you were sailing in the Pacific Ocean in the neighborhood of Tonga.this is what you would see looking out toward the East and the West.  The key point is that the moon is rising while the sun is setting.  On the other side of the world, 180 degrees away, at the same instant of time, another person would see the moon setting in West as the sun rose in the East.  (By the way, I made these pictures using the free planetarium program called Stellarium.)

Looking East

Looking West

I also once published a year's forecast of when and where to be on the globe to witness a perfect moonrise.  I was about to repeat it for 2013 when I realized that I did it wrong.  I considered only longitude and not latitude.  On January 27, 2013 the sun will not rise in the far North nor set in the far South.  You can see the entire loci of points to view the perfect moonrise at that instant in the picture below.  It ranges from Greenland, to Helsinki, to Madagascar for perfect moonrises and from Hudson Bay to San Diego, CA to Antartica for moonsets.  

View of the globe at the instant of the next full moon.

Anyhow, below you can see the times of 2013 full moons.  You will have to figure out for yourself where to be to view the perfect moonrises.

Year	Month	Day	GMT	Day of Week
2013	Jan	27	5:38	Sun
2013	Feb	25	21:26	Mon
2013	Mar	27	10:27	Wed
2013	Apr	25	21:57	Thu
2013	May	25	6:25	Sat
2013	Jun	23	13:32	Sun
2013	Jul	22	10:15	Mon
2013	Aug	21	3:44	Wed
2013	Sep	19	13:12	Thu
2013	Oct	19	1:37	Sat
2013	Nov	17	16:15	Sun