Monday, December 21, 2009

The Inventions of Thomas Edison

Phonograph - History

Replica of original phonograph

The first great invention developed by Edison in Menlo Park was the tin foil phonograph. While working to improve the efficiency of a telegraph transmitter, he noted that the tape of the machine gave off a noise resembling spoken words when played at a high speed. This caused him to wonder if he could record a telephone message. He began experimenting with the diaphragm of a telephone receiver by attaching a needle to it. He reasoned that the needle could prick paper tape to record a message. His experiments led him to try a stylus on a tinfoil cylinder, which, to his great surprise, played back the short message he recorded, "Mary had a little lamb."

The word phonograph was the trade name for Edison's device, which played cylinders rather than discs. The machine had two needles: one for recording and one for playback. When you spoke into the mouthpiece, the sound vibrations of your voice would be indented onto the cylinder by the recording needle. This cylinder phonograph was the first machine that could record and reproduce sound created a sensation and brought Edison international fame.



August 12, 1877, is the date popularly given for Edison's completion of the model for the first phonograph. It is more likely, however, that work on the model was not finished until November or December of that year, since he did not file for the patentuntil December 24, 1877. He toured the country with the tin foil phonograph, and was invited to the White House to demonstrate it to President Rutherford B. Hayes in April 1878.

In 1878, Thomas Edison established the Edison Speaking Phonograph Company to sell the new machine. He suggested other uses for the phonograph, such as: letter writing and dictation, phonographic books for blind people, a family record (recording family members in their own voices), music boxes and toys, clocks that announce the time, and a connection with the telephone so communications could be recorded.



Electricity and Lightbulb - History
Replica of original lightbulb - patent # 223,898
Thomas Edison's greatest challenge was the development of a practical incandescent, electric light. Contrary to popular belief, he didn't "invent" the lightbulb, but rather he improved upon a 50-year-old idea. In 1879, using lower current electricity, a small carbonized filament, and an improved vacuum inside the globe, he was able to produce a reliable, long-lasting source of light. The idea of electric lighting was not new, and a number of people had worked on, and even developed forms of electric lighting. But up to that time, nothing had been developed that was remotely practical for home use. Edison's eventual achievement was inventing not just an incandescent electric light, but also an electric lighting system that contained all the elements necessary to make the incandescent light practical, safe, and economical. After one and a half years of work, success was achieved when an incandescent lamp with a filament of carbonized sewing thread burned for thirteen and a half hours.

There are a couple of other interesting things about the invention of the light bulb: While most of the attention was on the discovery of the right kind of filament that would work, Edison actually had to invent a total of seven system elements that were critical to the practical application of electric lights as an alternative to the gas lights that were prevalent in that day.

These were the development of:

  1. the parallel circuit,
  2. a durable light bulb,
  3. an improved dynamo,
  4. the underground conductor network,
  5. the devices for maintaining constant voltage,
  6. safety fuses and insulating materials, and
  7. light sockets with on-off switches.
Before Edison could make his millions, every one of these elements had to be invented and then, through careful trial and error, developed into practical, reproducible components. The first public demonstration of the Thomas Edison's incandescent lighting system was in December 1879, when the Menlo Park laboratory complex was electrically lighted. Edison spent the next several years creating the electric industry.

The modern electric utility industry began in the 1880s. It evolved from gas and electric carbon-arc commercial and street lighting systems. On September 4, 1882, the first commercial power station, located on Pearl Street in lower Manhattan, went into operation providing light and electricity power to customers in a one square mile area; the electric age had begun. Thomas Edison's Pearl Street electricity generating station introduced four key elements of a modern electric utility system. It featured reliable central generation, efficient distribution, a successful end use (in 1882, the light bulb), and a competitive price. A model of efficiency for its time, Pearl Street used one-third the fuel of its predecessors, burning about 10 pounds of coal per kilowatt hour, a "heat rate" equivalent of about 138,000 Btu per kilowatt hour. Initially the Pearl Street utility served 59 customers for about 24 cents per kilowatt hour. In the late 1880s, power demand for electric motors brought the industry from mainly nighttime lighting to 24-hour service and dramatically raised electricity demand for transportation and industry needs. By the end of the 1880s, small central stations dotted many U.S. cities; each was limited to a few blocks area because of transmission inefficiencies of direct current (dc).

The success of his electric light brought Thomas Edison to new heights of fame and wealth, as electricity spread around the world. His various electric companies continued to grow until in 1889 they were brought together to form Edison General Electric. Despite the use of Edison in the company title however, he never controlled this company. The tremendous amount of capital needed to develop the incandescent lighting industry had necessitated the involvement of investment bankers such as J.P. Morgan. When Edison General Electric merged with its leading competitor Thompson-Houston in 1892, Edison was dropped from the name, and the company became simply General Electric.

Also see the History of the Lightbulb timeline.

Work with Lighting
His greatest challenge was the development of a practical incandescent, electric light.
Westinghoused
Was Thomas the inventor of the electric chair?


Edison Motion Pictures - History
Kinetoscope - Motion Pictures Projector
Thomas Edison's interest in motion pictures began before 1888, however, the visit of Eadweard Muybridgeto his laboratory in West Orange in February of that year certainly stimulated his resolve to invent a camera for motion pictures. Muybridge proposed that they collaborate and combine the Zoopraxiscope with the Edison phonograph. Although apparently intrigued, Edison decided not to participate in such a partnership, perhaps realizing that the Zoopraxiscope was not a very practical or efficient way of recording motion. In an attempt to protect his future, he filed a caveat with the Patents Office on October 17, 1888, describing his ideas for a device which would "do for the eye what the phonograph does for the ear" -- record and reproduce objects in motion. He called it a "Kinetoscope," using the Greek words "kineto" meaning "movement" and "scopos" meaning "to watch."

One of Edison's first motion picture and the first motion picture ever copyrighted showed his employee Fred Ott pretending to sneeze. One problem was that a good film for motion pictures was not available. In 1893, Eastman Kodak began supplying motion picture film stock, making it possible for Edison to step up the production of new motion pictures. He built a motion picture production studio in New Jersey. The studio had a roof that could be opened to let in daylight, and the entire building was constructed so that it could be moved to stay in line with the sun.

C. Francis Jenkins and Thomas Armat invented a film projector called the Vitascope and asked Edison to supply the films and manufacture the projector under his name. Eventually, the Edison Company developed its own projector, known as the Projectoscope, and stopped marketing the Vitascope. The first motion pictures shown in a "movie theater" in America were presented to audiences on April 23, 1896, in New York City.

The Kinetoscope
"Kinetoscope" comes from the Greek words "kineto" meaning "movement" and "scopos" meaning "to watch."
Timeline for Inventing Entertainment
The following timeline focuses on major events in Thomas Edison's personal life and on his motion picture and phonograph innovations.
Film Projectors for Motion Pictures
The Edison Company developed its own projector known as the Projectoscope or Projecting Kinetoscope in November 1896, and abandoned marketing the Vitascope.
History of Edison Motion Pictures
Origins of motion pictures, the Kinetoscope, and Edison Motion Pictures.


Thomas Alva EdisonThe Life of Thomas Edison (1847-1931)

The Genius of Menlo Park - Biography
He was a poor student. When a schoolmaster called him "addled," his furious mother took him out of the school and proceeded to teach him at home. Thomas Edison said many years later, "My mother was the making of me. She was so true, so sure of me, and I felt I had some one to live for, some one I must not disappoint." At an early age, he showed a fascination for mechanical things and for chemical experiments.
Biography
Born on February 11, 1847 in Milan, Ohio; the seventh and last child of Samuel and Nancy Edison. When he was seven his family moved to Port Huron, Michigan and Edison lived there until he struck out on his own at the age of sixteen. He had very little formal education as a child, attending school only for a few months. He was taught reading, writing, and arithmetic by his mother, but was always a very curious child and taught himself much by reading on his own. This belief in self-improvement remained throughout his life.
Inventions that Failed
Not everything Thomas Edison created was a success - he also had a few failures.


The Edison Laboratory, West Orange, New Jersey
The Edison Laboratory, West Orange, New Jersey NPS Photo

Additional Biographies and History
A List of Thomas Edison's Patents
A database of all 1,093 patents. This is a long list please be patient for the download.
The Muckers
Other inventors who worked for Thomas Edison.


http://inventors.about.com/library/inventors/bledison.htm

如何改善產後掉髮?

如何改善產後掉髮?

Q:2個多月前生產,產後頭髮掉得很厲害,是因為氣血太虛嗎?可多吃什麼來改善?

‧燕芳

A:產後若哺乳或急速減肥,可能造成體內蛋白質快速流失,若又未額外攝取營養,就很容易產生落髮現象。

就中醫角度來說,產後掉髮屬腎虛,可多吃黑色食物,例如黑芝麻、帶殼薏仁、黑麥汁、魚湯、雞精、紫米、紫蘇等,建議每餐可選吃1到2種黑色食物,持續吃到感覺落髮況好轉為止。

另外,吃太多的黑木耳會消除瘀青,有凝血問題者更不能吃,而吃黑豆、黑麥啤酒等則可能因食物屬性太涼,容易造成腹瀉,造成身體更虛弱,頭髮掉得更厲害。

‧中醫師張家蓓

光明日報/良醫‧2009.12.16

Thursday, December 17, 2009

Good Sources of Calcium

Good Sources of Calcium

Of course, milk and other dairy products are good sources of calcium, and most contain added vitamin D, which is also important for bone health.

But don't overlook the many other healthy calcium-fortified foods, including orange juice, soy products, and bread. Here are some dairy and nondairy products that boast quite a bit of this vital nutrient:

Serving SizeFood or BeverageCalcium
8 ounces (237 milliliters)milk300 milligrams
8 ounces (237 milliliters)calcium-fortified orange juice300 milligrams
2 ounces (57 grams)American cheese300 milligrams
1½ ounces (43 grams)cheddar cheese300 milligrams
4 ounces (113 grams)tofu fortified with calcium260 milligrams
6 ounces (177 milliliters)yogurt225 milligrams
½ cup (118 milliliters)collard greens
(cooked from frozen)
178 milligrams
4 ounces (113 grams)ice cream, soft serve120 milligrams
½ cup (118 milliliters)white beans110 milligrams
1 ounce (28 grams)almonds80 milligrams
½ cup (118 milliliters)bok choy80 milligrams
½ cup (118 milliliters)rhubarb, cooked75 milligrams
4 ounces (113 grams)cottage cheese70 milligrams
½ cup (118 milliliters)red beans40 milligrams
½ cup (118 milliliters)broccoli, cooked35 milligrams

Monday, November 30, 2009

剪了指甲为什么还会长?


在每一个手指的指尖处,有一个地方叫做甲根,就是指甲的生产工厂。指甲是由一种硬角质蛋白组成的。这种蛋白是从表皮细胞演变而来的,因为表皮细胞从出生一直到死亡,都在不断地进行新陈代谢,所以指甲角质蛋白也会不断生成,因此,指甲也不停止生长。所以,在人们剪了指甲后,指甲还能够长出来。另外指甲的生长速度不是永恒不变的,它是受各种因素影响的,例如:年龄、健康等。不同年龄的人,指甲的生长速度不一样。一般而言,少年儿童的指甲生长速度最快,成人其次,老年人最慢,这与人的新陈代谢是有关的。此外,一个健康的人表皮细胞合成角质蛋白的能力要明显高于一个生病的人。除了以上原因外十万个为什么再告诉您,指甲的生长速度还跟一些习惯有关,例如,爱咬指甲的人,或者是用手和指甲工作多的人,如理发师等,他们的指甲因为受到不断的摩擦刺激,生长速度就相当快