Category Science

No one knows if we are alone in the universe. In order to try to make contact with other intelligent life forms in our galaxy, some laboratories regularly send radio signals out into space. In fact, distant constellations do emit radio waves, but so far they do not seem to have been transmitted intentionally by living creatures. Scientists watch for a regular pattern of signals that might indicate a living transmitter.

E.T. isn’t phoning us, so maybe it’s time for us to phone them. That’s the idea behind a new initiative called METI (Messaging Extra Terrestrial Intelligence), an offshoot of SETI (Search for Extraterrestrial Intelligence), that intends to begin beaming targeted messages in 2018 to other star systems that might contain intelligent life.

METI’s messages won’t be the first ones we’ve ever beamed into space. Back in 1974, astronomer Frank Drake used the Arecibo Observatory in Puerto Rico — at the time, the largest radio telescope in the world — to broadcast a long series of rhythmic pulses, 1,679 of them to be exact, with a clear, repetitive structure toward a star cluster called Messier 13, which sits over 25,000 light years from Earth.

Because that message, now known as the Arecibo message, travels at the speed of light, it won’t reach its intended target for another 25,000 years. If there are any aliens living in Messier 13 who happen to have a SETI program of their own, or some equivalent program that listens constantly for alien radio messages, and who happen to have their listening devices pointed in the right direction at the right moment, then perhaps we can expect a call back in around 50,000 years.

In other words, the Arecibo message was not exactly sent to the ideal target. There are star systems we now know of with potentially habitable planets that are much, much closer. METI wants to target these. If there are aliens in our neighborhood, there’s no reason we couldn’t make contact within our own lifetimes.

Picture Credit : Google

Morse code was ideal for sending messages by telegraph because it used only two kinds of signal: a long one, called a dash, and a short one, called a dot. By sending long and short bursts of radio waves along a wire, a transmitter could send a clear message. Samuel Morse (1791-1872) was an American engineer who invented a practical magnetic telegraph. His invention was more or less ignored on both sides of the Atlantic, until, in 1843, the United States government allotted 30,000 dollars for a telegraph line between Washington and Baltimore. Morse invented Morse Code for use on his telegraph, which became very successful.

Way back in 1836, Samuel F. B. Morse, along with Joseph Henry and Alfred Vail, invented an electrical telegraph system. Before telephones were invented, it could send messages over long distances by using pulses of electricity to signal a machine to make marks on a moving paper tape.

A code was necessary to help translate the marks on the paper tape into readable text messages. Morse developed the first version of this code.

His version included only numbers. Vail soon expanded it to include letters and a few special characters, such as punctuation marks.

The code — known as Morse code — assigned each number, letter or special character a unique sequence of short and long signals called “dots” and “dashes.”

In Morse code transmission, the short dot signal is the basic time measurement. A long dash signal is equal to three dots. Each dot or dash is followed by a short silence that’s equal to a dot.

If you wonder how they decided which combination of signals was assigned to each letter, they studied how often each letter in the English language was used.

The most used letters were given the shorter sequences of dots and dashes. For example, the most commonly used letter in the English language — E — is represented by a single dot.

The original telegraph machines made a clicking noise as they marked the moving paper tape. The paper tape eventually became unnecessary.

Telegraph operators soon learned that they could translate the clicks directly into dots and dashes. Later, operators were trained in Morse code by studying it as a language that was heard rather than read from a page.

Although Morse originally referred to code signals as dots and dashes, operators began to vocalize dots as “dits” and dashes as “dahs” to mimic the sound of Morse code receivers.

Today, it’s possible to transmit messages in Morse code in any way that dots and dashes can be communicated. This includes sounds and lights, as well as printed dots and dashes.

Morse code was critical for communication during World War II. It was also used as an international standard for communication at sea until 1999, when it was replaced by the Global Maritime Distress Safety System. The new system takes advantage of advances in technology, such as satellite communication.

Today, Morse code remains popular with amateur radio operators around the world. It is also commonly used for emergency signals. It can be sent in a variety of ways with improvised devices that can be switched easily on and off, such as flashlights.

The international Morse code distress signal ( · · · — — — · · · ) was first used by the German government in 1905 and became the standard distress signal around the world just a few years later. The repeated pattern of three dots followed by three dashes was easy to remember and chosen for its simplicity.

In Morse code, three dots form the letter S and three dashes form the letter O, so SOS became a shorthand way to remember the sequence of the code. Later, SOS was associated with certain phrases, such as “save our ship” and “save our souls.”

These were just easy ways to remember SOS, though. The letters themselves have no such inherent meaning.

Picture Credit : Google

Although several scientists, including Heinrich Hertz, experimented with sending and receiving radio waves, the first person to patent a useful system for using them to send signals through the air was an Italian engineer called Gugliemo Marconi (1874-1937) in 1896. He created enormous publicity for his work by claiming to have sent the first radio signal across the Atlantic in 1901. Today there is disagreement about whether such a signal was received, but Marconi was right that sending radio messages between Europe and the Americas was possible, and his work encouraged the enthusiasm for and development of radio communications that continues to this day. As Marconi’s messages did not pass through wires, the system was known as wireless telegraphy.

Italian physicist and radio pioneer Guglielmo Marconi succeeds in sending the first radio transmission across the Atlantic Ocean, disproving detractors who told him that the curvature of the earth would limit transmission to 200 miles or less. The message–simply the Morse-code signal for the letter “s”–traveled more than 2,000 miles from Poldhu in Cornwall, England, to Newfoundland, Canada.

Born in Bologna, Italy, in 1874 to an Italian father and an Irish mother, Marconi studied physics and became interested in the transmission of radio waves after learning of the experiments of the German physicist Heinrich Hertz. He began his own experiments in Bologna beginning in 1894 and soon succeeded in sending a radio signal over a distance of 1.5 miles. Receiving little encouragement for his experiments in Italy, he went to England in 1896. He formed a wireless telegraph company and soon was sending transmissions from distances farther than 10 miles. In 1899, he succeeded in sending a transmission across the English Channel. That year, he also equipped two U.S. ships to report to New York newspapers on the progress of the America’s Cup yacht race. That successful endeavor aroused widespread interest in Marconi and his wireless company.

Marconi’s greatest achievement came on December 12, 1901, when he received a message sent from England at St. John’s, Newfoundland. The transatlantic transmission won him worldwide fame. Ironically, detractors of the project were correct when they declared that radio waves would not follow the curvature of the earth, as Marconi believed. In fact, Marconi’s transatlantic radio signal had been headed into space when it was reflected off the ionosphere and bounced back down toward Canada. Much remained to be learned about the laws of the radio wave and the role of the atmosphere in radio transmissions, and Marconi would continue to play a leading role in radio discoveries and innovations during the next three decades.

In 1909, he was jointly awarded the Nobel Prize in physics with the German radio innovator Ferdinand Braun. After successfully sending radio transmissions from points as far away as England and Australia, Marconi turned his energy to experimenting with shorter, more powerful radio waves. He died in 1937, and on the day of his funeral all British Broadcasting Corporation (BBC) stations were silent for two minutes in tribute to his contributions to the development of radio.

Picture Credit : Google