What new knowledge and Technologies enabled 15th century mariners to make long overseas voyages? Where did much of this technology originate?

Columbus and Dead Reckoning (DR) navigation

At the end of the fifteenth century, celestial navigation was just being developed in Europe, primarily by the Portuguese. Prior to the development of celestial navigation, sailors navigated by "deduced" (or "dead") reckoning, hereafter called DR. This was the method used by Columbus and most other sailors of his era. In DR, the navigator finds his position by measuring the course and distance he has sailed from some known point. Starting from a known point, such as a port, the navigator measures out his course and distance from that point on a chart, pricking the chart with a pin to mark the new position. Each day’s ending position would be the starting point for the next day’s course-and-distance measurement.

In order for this method to work, the navigator needs a way to measure his course, and a way to measure the distance sailed. Course was measured by a magnetic compass, which had been known in Europe since at least 1183. Distance was determined by a time and speed calculation: the navigator multiplied the speed of the vessel (in miles per hour) by the time Traveled to get the distance.

In Columbus’s day, the ship’s speed was measured by throwing a piece of flotsam over the side of the ship. There were two marks on the ship’s rail a measured distance apart. When the flotsam passed the forward mark, the pilot would start a quick chant, and when it passed the aft mark, the pilot would stop chanting. (The exact words to such a chant are part of a lost oral tradition of medieval navigation). The pilot would note the last syllable reached in the chant, and he had a mnemonic that would convert that syllable into a speed in miles per hour. This method would not work when the ship was moving very slowly, since the chant would run to the end before the flotsam had reached the aft mark.

Speed (and distance) was measured every hour. The officer of the watch would keep track of the speed and course sailed every hour by using a toleta, or traverse board. This was a peg-board with holes radiating from the center along every point of the compass. The peg was moved from the center along the course traveled, for the distance made during that hour. After four hours, another peg was used to represent the distance made good in leagues during the whole watch. At the end of the day, the total distance and course for the day was transferred to the chart.

Columbus was the first sailor (that we know of) who kept a detailed log of his voyages, but only the log of the first voyage survives in any detail. It is by these records that we know how Columbus navigated, and how we know that he was primarily a DR navigator.

Since DR is dependent upon continuous measurements of course and distance sailed, we should expect that any log kept by a DR navigator would have these records; and this is exactly what Columbus’s log looks like. If Columbus had been a celestial navigator, we would expect to see continuous records of celestial observations; but Columbus’s log does not show such records during either of the transatlantic portions of the first voyage.

It has been supposed by some scholars that Columbus was a celestial navigator anyway, and kept his celestial records hidden for some unknown reason. (This supposition is necessary to support some theories of the first landfall.) But this hypothesis does not hold water. Columbus’s ships were steered by helmsmen at a tiller, below the quarterdeck. The helmsmen could not see the sky, so the only way they could keep a course was by magnetic compass. The officer of the deck had his own compass, and would call down course changes as necessary. This means that the courses used aboard ship (and in the log) would have been magnetic courses.

Now suppose that Columbus was making unrecorded celestial checks on his latitude as he sailed west on his first voyage. In that case, as magnetic variation pulled his course southward from true west, he would have noticed the discrepancy from his celestial observations, and he would have corrected it. In other words, if Columbus were a celestial navigator, we would expect to see a series of small intermittent course corrections in order to stay at a celestially determined latitude. These corrections should occur about every three or four days, perhaps more often.

But that is not what the log shows. On the first voyage westbound, Columbus sticks doggedly to his (magnetic) westward course for weeks at a time. Only three times does Columbus depart from this course: once because of contrary winds, and twice to chase false signs of land southwest. In none of these cases does he show any desire to return to a celestially-determined latitude. This argument is a killer for the celestial hypothesis, and was first made by Rear Admiral Bob McNitt (USN) in 1992.

Well then, could Columbus have corrected his compasses by checking them against the stars — and thus avoid the need for course correc

Success in Internet Marketing can be extremely hard to come into, but there is an easy way with really no cash involved and it is by finding a niche and building a eccommere storefront around it. So you say how do you learn how to do that? Well the only way I know of that leads you to success is to invest in Niche Blueprint 2.0 by a couple successful marketers knows as Steven Clayton and Tim Godfrey. If you would like to read a review of the product please visit this link – http://wwwcommissionblueprint2.com/niche-blueprint-20/

In today’s business landscape, IT firms are constantly in search of new expertise to fill the gaps created by the speed in which information systems are changing. Here at Caravan Technologies, it is our aim to provide creative and customized solutions to meet these needs.

We provide a reliable and specialized service where our clients benefit from our hands-on experience. As well as creating effective processes to meet your business, financial, and technical goals, we also reduce costs through taking responsibility for the sourcing and training of new staff, reducing the burden created by hiring salaried personnel.

Caravan Technologies specializes in both front-end and back-end Web development to ensure that our clients receive an expert service that does not just look attractive but that also works. As well as developing the necessary visual appeal, we never neglect the importance of making sure that the correct coding and product databases all work smoothly together to create a functioning and professional end result.

Our comprehensive industry knowledge and IT expertise mean that we constantly deliver the results our clients are looking for. We provide solutions to their needs whatever the requirement, allowing them to gain the edge in an increasingly competitive market.

We consistently deliver high-quality IT services whenever they are needed. Offering a combination of Business strategy consulting, in-depth application knowledge, and a vast technological skills base, it is no wonder our clients come back to us time and time again to take advantage of our services.

Caravan Technologies is an established IT consulting and outsourcing firm, offering technical expertise, comprehensive support, and direct solutions to clients across the globe. Founded by a highly-skilled team of entrepreneurs with a wealth of hands-on experience in all areas of IT, it has always been our aim to significantly improve the performance of our clients through maximizing returns on their technology investments.

caravantech
http://www.articlesbase.com/web-design-articles/welcome-to-caravan-technologies-providers-of-advanced-industry-solutions-in-it-consulting-and-outsourcing-727945.html

Success in Internet Marketing can be extremely hard to come into, but there is an easy way with really no cash involved and it is by finding a niche and building a eccommere storefront around it. So you say how do you learn how to do that? Well the only way I know of that leads you to success is to invest in Niche Blueprint 2.0 by a couple successful marketers knows as Steven Clayton and Tim Godfrey. If you would like to read a review of the product please visit this link – http://wwwcommissionblueprint2.com/niche-blueprint-20/

October 4, 2006 SearchInform Technologies Inc. introduces a new version of SearchInform, a program of full text search and search for documents similar in their content, featuring a significantly enhanced indexing and information search algorithms as well as a new request caching system, influencing the work of the system as a whole and its speed. Due to the enabled cache request option, the speed of query processing has risen considerably.

New functions in SearchInform 3.0
The program now performs at a higher speed, which makes the query processing, and an ensuing from it display of results stunningly fast.

SearchInform 3.0 attained such results thanks to its new request caching system, developed by the SearchInform Technologies technical specialists. The number of unique queries generated by the users comes up to around 20% of all queries. That is why SearchInform 3.0 search tool with the help of query caching has to fully process only an insignificant one fifth of all queries. All other queries have ready results available in cache.

The innovation is especially remarkable when an already existing index is being modified. Though the number of documents in the index increases, cache system is exempt from collecting queries and results all over again it only adds the new information, which is much less complicated and time-consuming.

For instance: after the integration of request caching system, SearchInform 3.0 can easily process from 50.000 to 100.000 user queries on a total data size of 0,5 terabytes in just one hour.

Main features of SearchInform 3.0:
- Phrase search with due consideration to stemming and thesaurus
- New SoftInform Search Technology of search for similar documents
- High indexing speed (from 15 to 30 Gb/hour),
- Index size of 15-25% from the actual size of the text data
- Query caching system
- Support of over 60 most popular text formats, Outlook & TheBat electronic messages, mp3 & avi tags, and logs of MSN and ICQ instant messaging programs
- Correct work with archives
- Universal data sources (indexing of DBMS)

About SearchInform Technologies
SearchInform Technologies was founded in 1995 and has been operating in the area of information technologies with special focus on information searching, storing and processing. The range of company’s products is quite large and encompasses from mass production of single user-oriented products to ready Business solutions to be integrated into corporate systems. Owing to its extensive experience in various projects, the company offers its services on developing custom information systems of any complexity.

More information on our website:
http://www.searchinform.com/

For all inquiries mailto:alena.siameshka@searchinform.com
Alena Siameshka, SearchInform Technologies PR Manager

Softinform
http://www.articlesbase.com/software-articles/october-4-2006-searchinform-technologies-inc-introduces-a-new-version-of-searchinform-a-program-of-full-text-search-and-search-for-documents-simi-61993.html

Success in Internet Marketing can be extremely hard to come into, but there is an easy way with really no cash involved and it is by finding a niche and building a eccommere storefront around it. So you say how do you learn how to do that? Well the only way I know of that leads you to success is to invest in Niche Blueprint 2.0 by a couple successful marketers knows as Steven Clayton and Tim Godfrey. If you would like to read a review of the product please visit this link – http://wwwcommissionblueprint2.com/niche-blueprint-20/

What Technologies are available to prevent formation of aluminum oxide ?

I really do not understand the question. On exposing aluminum to air, it almost instantly forms a thin layer of Al2O3 on its surface. As far as I know there is no way of stopping this (other than not exposing it to air). I suppose a thin coat of a non-oxygen bearing polymer would stop that happening. Once the alumina layer has formed there is no further reaction as the layer effectively seals the Al off. That is why Al is so corrosion resistant.

Success in Internet Marketing can be extremely hard to come into, but there is an easy way with really no cash involved and it is by finding a niche and building a eccommere storefront around it. So you say how do you learn how to do that? Well the only way I know of that leads you to success is to invest in Niche Blueprint 2.0 by a couple successful marketers knows as Steven Clayton and Tim Godfrey. If you would like to read a review of the product please visit this link – http://wwwcommissionblueprint2.com/niche-blueprint-20/

As you browse the Web, you will find sites that implement just about every type of navigation scheme you can think of and then even some more! However, certain common factors do emerge. The use of menu bars, either horizontally or vertically oriented, are the most common way of allowing users to move through your site.

Sites with a great deal of content often implement dynamic menu bars that change to present the most relevant options on each page. Sites often use some kind of “feedback” or special effect to let users know where certain navigation elements are located, such as graphics that change colors when the users point their mouse at them.

You can use a variety of technologies and design elements to implement Web site navigation. As you consider different navigation techniques, keep the following seven basic comparison factors in mind:

Visual

Does the technique look and like a navigation element that users are accustomed to seeing? In other words, is it a button or a menu that users will recognize as a navigation element?

Feedback

Does the technique offer some form of feedback to indicate that a user has pointed at or clicked a particular navigation element? This type of feedback can be important because users often explore a site by moving their mouse around to see what happens. Navigation techniques that allow individual elements to respond to this activity make the overall navigation more likely to succeed.

Accessibility

How does the technique work when a visually impaired person attempts to use the site with a specially equipped Web browser? If this demographic is important to your company, pay special attention to this capability.

Overhead

Some techniques require the Web browser to server to transfer more data to the Web browser than is required by other techniques. If your customers will be accessing the site over slower connections, then using techniques with a high overhead will result in slow page loads, and possibly bored customers who will give up and move on to the competition.

Scalability

Does the technique offer any particular advantages to make growing the site easier? Some navigation designs may require you to redesign the entire site every time a new feature is added. Others may simply require a few minor modifications to add several new departments to a menu.

Space

Some techniques, combined with your site’s browsing philosophy, require considerable space on the screen. Other techniques allow you to present a wider array of navigation choices while using less screen space. Keep in mind that your navigation elements should never occupy the majority of the screen. It is the content that your customers came for, not the menu bars.

Compatibility

How well wills this technique work within the available range of Web browsers? If one of your objectives is to have your site usable by as many customers as possible, pay attention to the techniques that offer a broad range of compatibility, and steer away those that are limited to a smaller set of browsers.

Navigation Technologies

To implement Web site navigation, you can use one of four primary Technologies. The oldest and simplest of these technologies is the basic, static HTML page. A step up from that is the static HTML page, which is dynamically generated on the Web server. Web pages can be given more interactive capabilities with Dynamic HTML (DHTML), whether programmed in VBScript or JavaScript. Java presents the opportunity to program a complete, standalone application to use as a navigation aid.

Static HTML

Static HTML links are the oldest and simplest form of navigation on the Web. They can be less exciting than their dynamic counterparts, but remain one of the most effective navigational techniques on the Web.

Dynamically Generated Static HTML

If your site is constantly growing and changing, static HTML will require a constant effort to keep the navigational elements in line with the site’s growth. A common solution to this problem has been to dynamically generate the navigation elements when the page displays. When using the DHTML, you don’t have to manually update elements as the site grows, because an automated process generates the navigation elements as necessary, based on the information in a database.

VBScript and JavaScript Dynamic HTML

DHTML is a technology that allows you to embed programming code in the Web pages that are sent to user’s computers. DHTML code actually executes within the users Web browser, and can change the appearance and content of the Web page in response to the user’s actions on the page.

In Finality

You can use a variety of technologies and design elements to implement Web site navigation. As you consider different navigation techniques, keep the above seven basic comparison factors in mind. Visitors are becoming rare and rare in this competitive globe of e-commerce. Retain those who visit to your site for longer period in order to convert them as customers. Site navigation techniques help you to do so.

Dave Davis
http://www.articlesbase.com/communication-articles/technologies-and-design-elements-to-improve-website-navigation-62897.html

What types of technologies should we rely on to modify any harmful effects that humans bring about in the environment? How do we mandate or legislate these Technologies?

Most harmful Environmental effects can be ameliorated through discoveries in chemical and electrical engineering. For example, techniques are being developed for cleaner petroleum distillation, so that greenhouse gases are not released into the atmosphere during gasoline production. Likewise, greenhouse gases are being reduced at electric plants that generate energy from coal combustion. Chemical engineers continue to develop better methods for removing toxic byproducts, or industrial wastes, instead of dumping them into sewage, landfills, or water sources.

Electrical engineers are developing alternatives to fossil fuels, such as wind turbines, geothermal facilities, solar panels, and battery-powered vehicles, all of which will reduce global warming and energy dependency on foreign nations.

Legislators can enact laws which stimulate scientific research and technological development, including tax policies which allow R & D to be deducted from tax liability, government subsidies that support development of new energy sources, and laws that mandate automobile manufacturers to build electrical cars, or that requre electrical utility companies to reduce carbon emissions.

We’ve heard them all before-the wheel, the car, the rocket ship, the airplane, the atomic bomb, the Internet. There are a few technologies that have obviously changed our world-some for the better, some for the worse. But in all the hubbub over these obviously world-changing inventions, some equally important Technologies have been forgotten. Below are some inventions that have had an undeniable impact on our world-technologies that you wouldn’t at first suspect.

The stirrup. That’s right, that little metal hoop that hangs off a saddle. The partnership of horse and human is undeniably important in the development of warfare-a horse can run approximately three times faster than a person. But the stirrup gave added stability. It gives riders the support that makes it possible to ride all day-no conquering force could travel as far and as quickly as they needed to without it. It also gives an undeniable advantage in battle: maneuverability. A warrior with stirrups can stand, lean from side to side, swing an axe, shoot a bow, or throw a spear without danger of falling off. Chances are, without the stirrup, many battles that have shaped the political landscape and history of our world would have gone differently.

The battery. Everyone thinks the invention of electricity was extremely important-and it was. But the battery gives us that electricity in a portable form, making it possible for us to have flashlights, mobile phones, cars, mp3 players, pacemakers-anything that relies on electric power and that isn’t practical to plug into the wall. Batteries have made devices both lifesaving and mundane possible, and our world wouldn’t look the same without them.

Traffic sensors. Most people would cite cars as an important invention. But traffic sensors are an invention that makes car Travel possible-especially in crowded cities. In bucolic towns, sensors are a convenience-they sense when your car is waiting at a light, and if there is no car at the opposing light, it will change early and let you go through. But in a big city with millions of intersections to coordinate, traffic sensors play a crucial role in keeping lights properly timed and congestion to a minimum. Traffic would be much more complicated to manage without traffic sensors.

Cement. Without it, we would have no skyscrapers or highways. We would also have no Egyptian Pyramids or Appian Way. Cement has played an incredibly important role throughout the history of civilization, as a durable building material that holds up under extreme stress and seriously long-term erosive forces. It’s strong yet flexible enough to support a skyscraper, durable enough to hold up under millions of cars and trucks per day on our nation’s busiest highways, and long-lasting enough to have held the Great Pyramid together for over four thousand years.

These inventions are all undeniably crucial-although they wouldn’t be at the top of the list for best-known important technologies. So next time you drop your keys at night, read about the fall of Rome, sit in traffic at an intersection, or take to the highway, think about where we’d be without the battery, the stirrup, the traffic sensor, and cement. We’re lucky these technologies came along.

Meas-spec.com
http://www.articlesbase.com/Business-articles/four-unsung-technologies-that-have-changed-our-world-82053.html

Typically any rewarding career will require some form of specialized training. Specialized training is indispensable when it comes to Careers in HVAC technologies. Career opportunities in the HVAC field are ample and aspiring HVAC technicians today can obtain proper training with ease. HVAC career courses could be your stepping stone to a rewarding HVAC career with much potential for progress and success.

Getting Trained For Your First Job In HVAC
HVAC technicians are in high demand today but firms typically hire technicians based on their knowledge, experience and training background. The vast ocean that is HVAC technology requires specialized training that focuses on not just the student’s strong points but their weaknesses as well; making them a well-rounded HVAC technician capable of completing any job and solving any problem.

Phoenix AC programs and an AZ AC program provide very strong training and support for aspiring HVAC technicians. One reason the AZ AC Program and the Phoenix AC Programs are highly touted is because they are accredited by the accrediting Commission of Career Schools and Colleges of Technology. Simply put, these refrigeration training schools comply with all local, state, and federal regulations. Not to mention the fact that the best HVAC training schools, refrigerationschool.com for example, provide placement assistance for students and graduates. Completing a program at such a school can kick start the career of any HVAC technician as doors open and job prospects increase.

HVAC Training Is Good For A Career Change Or Career Upgrade
If you are feeling frustrated and stuck in a career rut, unable to progress and move forward, HVAC training offers an exciting career changing opportunity in a field where jobs are expected to remain consistent and prosperous. Training at some of the better training schools, like “The Refrigeration School”, also known as RSI, can help aspiring HVAC technicians reach maximum career potential. A career switch to HVAC Technologies is great for anyone who enjoys working with their hands with minimal work stress or pressure. Moreover, the huge demand today for the services of HVAC technicians could conceivably help you earn more income than your prior career.

The Best Training Schools For HVAC Technologies
When it comes to training schools for HVAC training, the best ones are located right in the Tempe and Mesa areas of Arizona. RSI (The Refrigeration School) is a very popular HVAC career training school that provides students with remarkable training and career assistance. Moreover, they provide assistance for wannabe students in need of financial aid. Graduates of RSI can potentially race past others on the road to success in the field of HVAC technologies. With the well experienced staff and years of experience, RSI has developed many great professional HVAC technicians over the years.

Bottom line
If you are a well trained HVAC technician, many rewarding careers are waiting for you. As the old saying goes “strike the rod while it’s hot”, this is the perfect time to get into a career in HVAC. The huge demand for HVAC technicians will help you earn great income in a rewarding service-oriented career. Considering all these benefits, HVAC training is perfect for anyone wanting a rewarding career in 2009.

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Kristin Kronstain
http://www.articlesbase.com/Education-articles/the-need-to-get-trained-in-hvac-technologies-713696.html

Homework Help!

What Technologies are available to determine the acidity of a solution?

These days we have electronic pH meters. These work by sticking an electrode in a solution and measuring the current that flows, and hence the ions present. Most use glass membranes to only let H+ ions in.

You can calibrate these by sticking them in a buffer solution of known pH.

They are pretty quick and easy to use, and give fairly accurate readings.

We also have pH paper and indicators- indicators change colour at a certain pH. By combining indicators, you can establish a pH range.

What is a Computer Printer?

A computer printer is a device that would allow a user to create a hardcopy of a document or image that is electronically created. Normally, the electronic data is created through a computer. Today, printers can now be attached to a digital camera or a scanner to develop the hard copy of the document or image.

Kinds of Computer Printer Technology

Computer technologies found in printers that are available in the market today can be grouped into two: impact and non-impact.

Impact printers refer to printers where the image or text is developed by the printer head touching the paper to be printed on. These kinds of printers were developed based on the concept followed by the typewriter. Impact printers usually use a printer ribbon to transfer the text and the image to the paper surface. These kinds of printers are often limited in functions and only produced low resolution text and images. Because of the process of transferring the text and image on the paper with the printer head touching the ribbon and paper, these printers can be quite noisy to use. The most common kind of impact printers that is still being used today is the dot-matrix printer.

Common Non-Impact Printers

Inkjet printers
Laser printers
Solid ink printers
Thermal printers
Dye sublimation printers
Non-Impact Printer Technology

Modern-day printers use a number of Technologies that allow them to create high quality images and text at a short amount of time. The most common non-impact printer technology is the use of liquid ink. This is commonly found in inkjet printers. The liquid ink is sprayed directly onto the paper surface through ultra fine nozzles located on the printer head.

Another printing technology that is found in modern-day printers is the use of heat. A special paper is passed through and then heated using varying temperatures in order to develop the text and image.

Some printers use a combination of these printer technologies in order to provide high quality text and images. One example is the solid ink printer. It combines the technology used in inkjet printers and thermal printers. First, the printer uses heat to melt the solid ink sticks before it is then sprayed on the paper before it hardens.

Another printer that uses a number of printer technologies is the laser printer. The printer first uses electrostatic charges to allow the toner to stick onto the light-sensitive drum. It then uses a beam of laser light to keep the static energy from dissipating. This forms the text or image to be printed. The toner is then transferred to the paper. Finally, the paper is then heated to embed the toner onto the paper permanently.

John C. Arkin
http://www.articlesbase.com/hardware-articles/all-you-need-to-know-about-printer-technologies-676666.html