It's a great program, it's free, runs under Windows, and it's fans claim it can do everything Adobe Photoshop can do.
Trouble is, no manual. No overview. The program has a zillion options, and it's very difficult to figure out what they do. The on-line help is full of "alpha channels" and "layers" and other strange words all of which lack a definition in ordinary English.
With all the fancy options, GIMP cannot, or I cannot figure out how to make GIMP, do a cut and paste. My needs were very simple, I wanted to print out a stone wall texture that I could use to cover up the wood basement of a HO railroad building to make the wood look like a cut stone basement. I had a snippet of stone wall and all I wanted to do was copy and paste the snippet to fill up a 8.5 * 11 piece of paper.
I finally had to use plain old Microsoft "Paint" to do the copy and paste. Fancy GIMP just would not do it.
Monday, February 28, 2011
Saturday, February 26, 2011
Sea Turtle mythology (navigation)
An article in "Wired" claims that sea turtles navigate by sensing the earth's magnetic field (quite possible) and can sense longitude magnetically (not likely at all). The author is clearly unfamiliar with magnetic compasses, magnetic variation, and magnetic dip, all subjects well known to seamen for hundreds of years. Nor has he read the classic investigation of homeing pigeon navigation done many years ago.
Finding longitude at sea has been intensively studied for centuries. The only way to do it magnetically is to measure magnetic variation. The magnetic poles are not exactly at the geographic poles which means magnetic north varies from true north. Variation ranges from zero to maybe 20 degrees, depending upon where you are. Variation is measured by comparing magnetic north (compass reading) with true north. For human navigators true north is found by observing Polaris, the north star, or by use of a gyro compass (invented around the time of WWI). It is doubtful that sea turtles can use either method.
The earth's magnetic field lines run horizontally at the equator and run nearly vertically right at the magnetic poles. The angle of the magnetic field with respect to the ground is known as magnetic dip, and can be measured with a simple apparatus, essentially a magnetic compass mounted on its side. Human navigators do not use magnetic dip to find latitude because measuring the height of the sun at noon gives a much more accurate latitude indication than magnetic dip does. But the magnetic dip method could be used by sea turtles.
I doubt that sea turtles are better animal navigators than homing pigeons are. Homing pigeons are so good at finding their way back to their homes that they were used to transmit messages up until the invention of portable two way radios in WWII. Pigeons navigate partly by observing the sun and partly by sensing the earth's magnetic field. On overcast days pigeons depend upon magnetic navigation. Attaching small permanent magnets to the pigeon's feet will disable their magnetic sensing. Pigeons released with magnets on overcast days always get lost.
I suspect the real truth of the sea turtle story is that the turtles can sense the earth's magnetic field and can navigate about as well as homing pigeons, using the same techniques. I do not think the turtles, or the homing pigeons can sense longitude.
Finding longitude at sea has been intensively studied for centuries. The only way to do it magnetically is to measure magnetic variation. The magnetic poles are not exactly at the geographic poles which means magnetic north varies from true north. Variation ranges from zero to maybe 20 degrees, depending upon where you are. Variation is measured by comparing magnetic north (compass reading) with true north. For human navigators true north is found by observing Polaris, the north star, or by use of a gyro compass (invented around the time of WWI). It is doubtful that sea turtles can use either method.
The earth's magnetic field lines run horizontally at the equator and run nearly vertically right at the magnetic poles. The angle of the magnetic field with respect to the ground is known as magnetic dip, and can be measured with a simple apparatus, essentially a magnetic compass mounted on its side. Human navigators do not use magnetic dip to find latitude because measuring the height of the sun at noon gives a much more accurate latitude indication than magnetic dip does. But the magnetic dip method could be used by sea turtles.
I doubt that sea turtles are better animal navigators than homing pigeons are. Homing pigeons are so good at finding their way back to their homes that they were used to transmit messages up until the invention of portable two way radios in WWII. Pigeons navigate partly by observing the sun and partly by sensing the earth's magnetic field. On overcast days pigeons depend upon magnetic navigation. Attaching small permanent magnets to the pigeon's feet will disable their magnetic sensing. Pigeons released with magnets on overcast days always get lost.
I suspect the real truth of the sea turtle story is that the turtles can sense the earth's magnetic field and can navigate about as well as homing pigeons, using the same techniques. I do not think the turtles, or the homing pigeons can sense longitude.
Friday, February 25, 2011
Boeing wins the tanker contract
I've posted on this before. The Air Force announced Boeing gets the tanker contract ($30 billion) and Airbus, aka EADS, looses. Let's see if the contract award survives a challenge, last time Boeing challenged an EADS win and their challenge was upheld in the courts. Barring a successful challenge by EADS, Boeing has a nice fat contract that will give them business for the next decade. We are talking 180 big 767 airliners with the seats removed and fuel tanks in stalled. That's a big and lucrative job.
Obama and Defense of Marriage Act (DOMA)
On a slow news day Obama knows how to get our attention. He declared a recent act of Congress, the Defense of Marriage Act, unconstitutional. He distracts the newsie's attention from his weirdo responses to Egypt and Libya by bringing up a hot button topic, (a wedge issue) that his left wing base will love, and perhaps the independents will not be offended by.
As a matter of process, Obama is way out in left field by declaring an act of Congress to be un constitutional all. The standard procedure is to propose new legislation to Congress, rather than declaring existing legislation unconstitutional.
As a practical matter, Obama will solidify his left liberal base, attract a lot of press coverage, and outrage the Republicans. Where the vast mass of independents really stands is unknown, clearly Obama thinks this will rally them to his banner. I hope he is wrong but you never know, Obama was clever enough to get elected president, so you cannot write him off as a dunderhead.
As a matter of process, Obama is way out in left field by declaring an act of Congress to be un constitutional all. The standard procedure is to propose new legislation to Congress, rather than declaring existing legislation unconstitutional.
As a practical matter, Obama will solidify his left liberal base, attract a lot of press coverage, and outrage the Republicans. Where the vast mass of independents really stands is unknown, clearly Obama thinks this will rally them to his banner. I hope he is wrong but you never know, Obama was clever enough to get elected president, so you cannot write him off as a dunderhead.
The American Revolution
It's a DVD I borrowed from the Franconia town library. It's good. It's a four DVD set of lectures on the revolution by Allen Guelzo of Gettysburg College. I've watched the first two DVD's, some 12 lectures. Professor Guelzo clearly knows his subject backwards and forwards. He speaks at length without notes. The format is the classic college course lecture, Professor Guelzo stands at a podium and delivers a lecture. There are some audio visual aids, maps, portraits of revolutionary war participants, the sort of thing a professor might use in a real college.
This guy is good. I watched all 12 lectures in the first set of DVD's and stayed wide awake. He presents the generally accepted history of the revolution, in plain and clear speech, no jargon. No conspiracy theories, no politically correct deviations, professor Guelzo tells the story straight, with lots of detail.
If you have a child looking for a college, consider Gettysburg College. If they have one guy this good on the faculty, they probably have more.
This guy is good. I watched all 12 lectures in the first set of DVD's and stayed wide awake. He presents the generally accepted history of the revolution, in plain and clear speech, no jargon. No conspiracy theories, no politically correct deviations, professor Guelzo tells the story straight, with lots of detail.
If you have a child looking for a college, consider Gettysburg College. If they have one guy this good on the faculty, they probably have more.
Wednesday, February 23, 2011
What's Boeing to do?
Boeing's best selling product is the plain vanilla 737 single aisle jet liner. It's a good plane, it's been in production for a long time, it has orders that will take years to fill.
But, arch rival Airbus has announced a "New Engine Option" (NEO) for it's bread and butter airliner, the A320, direct competitor with Boeing's 737. Airbus will put Pratt & Whitney's new geared turbofan engine on the A320. Airbus publicity claims a 5% fuel savings. It is already beginning to gather orders, dispite the fact that it won't be delivered for years.
Question for Boeing. Should Boeing start design on a 737 replacement? Downside is enormous costs, embarrassing delays, an engineering department still tied up in knots with the long delayed 787 program. Plus the Boeing engineers can't come up with a plane that would be much better than the existing 737. Plus, as soon as a 737 replacement is announced, customers will delay orders, waiting for the new model to become available.
Driving Boeing toward a new design is the fear that the new Airbus plane will be decisively superior to the long-in-the-tooth 737 and capture the market. The 737 is the market, or at least the largest part of the market. Boeing sells ten 737's for every other model they sell.
As of now, Boeing hasn't said what they plan to do.
But, arch rival Airbus has announced a "New Engine Option" (NEO) for it's bread and butter airliner, the A320, direct competitor with Boeing's 737. Airbus will put Pratt & Whitney's new geared turbofan engine on the A320. Airbus publicity claims a 5% fuel savings. It is already beginning to gather orders, dispite the fact that it won't be delivered for years.
Question for Boeing. Should Boeing start design on a 737 replacement? Downside is enormous costs, embarrassing delays, an engineering department still tied up in knots with the long delayed 787 program. Plus the Boeing engineers can't come up with a plane that would be much better than the existing 737. Plus, as soon as a 737 replacement is announced, customers will delay orders, waiting for the new model to become available.
Driving Boeing toward a new design is the fear that the new Airbus plane will be decisively superior to the long-in-the-tooth 737 and capture the market. The 737 is the market, or at least the largest part of the market. Boeing sells ten 737's for every other model they sell.
As of now, Boeing hasn't said what they plan to do.
Sunday, February 20, 2011
Language Drift
I've noticed a change in the meaning of "pistol". Used to be, pistol meant the same as handgun, and came in two flavors, revolvers and automatic pistols. Recent usage in the trade seems to use "pistol" to mean "automatic pistol" and not revolver. Handgun is now the generic word that includes revolvers and automatic pistols.
This change has filtered thru to the dictionary. A great big 1967 dictionary defines pistol to be the same as handgun, a firearm designed to be fired with one hand. A newer 1997 dictionary drops the "fired with one hand" bit and defines pistol as a handgun with a single chamber, which rules out revolvers.
Part of the change comes from Charles Weaver, who taught us all the two hand hold for combat shooting. Weaver had something. I was taught to shoot single handed. Only after I switched over to Weaver's two hand grip did I win an Air Force sharpshooter ribbon. And if you watch TV, the cops now always grab their guns with two hands, which kinda makes the "designed to be fired with one hand" definition passe.
This change has filtered thru to the dictionary. A great big 1967 dictionary defines pistol to be the same as handgun, a firearm designed to be fired with one hand. A newer 1997 dictionary drops the "fired with one hand" bit and defines pistol as a handgun with a single chamber, which rules out revolvers.
Part of the change comes from Charles Weaver, who taught us all the two hand hold for combat shooting. Weaver had something. I was taught to shoot single handed. Only after I switched over to Weaver's two hand grip did I win an Air Force sharpshooter ribbon. And if you watch TV, the cops now always grab their guns with two hands, which kinda makes the "designed to be fired with one hand" definition passe.
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