Showing posts with label Radio. Show all posts
Showing posts with label Radio. Show all posts

June 2 - News on Wires and Wireless Day

Posted on June 2, 2021

 

This is an update of my post published on June 2, 2010:

On this day in 1875, Alexander Graham Bell and Thomas A. Watson first transmitted sound over wires. Watson twanged a spring near one device, and Bell heard it through the other device. It took about nine more months for the two to create that more famous first—transmitting understandable words through the world's first telephone.




On this day in 1896, Guglielmo Marconi obtained his first radio patent in England. It was termed a wireless telegraphy apparatus.

The first half of the 1800s had seen a revolution in communication through electricity: the invention and improvement of the telegraph. The telegraph required wires for the message to travel across, and it also required trained operators who could translate messages into Morse Code (and Morse Code back into messages).


In the later half of the 1800s, many people continued to work with electricity and communications. Bell's and Watson's telephone was an improvement over the telegraph in that translators and codes were not required. Marconi's radio was an improvement in that no wires were needed.

Of course, we now have wireless networks and satellite communication – with the internet and cellular phones making communications worldwide much faster, cheaper, and more reliable than ever before. And people are still working on making our newest systems even better.



Did you know...?

Marconi did not discover any new principles or hatch any new ideas in his successful radio device. Instead, he improved and combined components others had already invented, adapting them to his system.

Bell was very interested in sound partly because of his mother's gradual deafness, which began when he was just12 years old.

Marconi was born and died in Italy, although he did much of his work in England and some in the U.S.

Bell was born in Scotland, moved to Canada, and did much of his work in the U.S.

Marconi's “marvelous invention” was given credit by some for the rescue of the survivors of the Titanic, because wireless technology was used by the Titanic, the rescue ship Carpathia, and Marconi International Marine Communication Company.

Bell decided that his most famous invention was a source of unwanted interruption, and he wouldn't allow a telephone to be installed in his study.

Explore Some More

The classic soup-can-and-string telephone can help us understand how early telephones worked.

Little kids might need to practice learning phone numbers (including emergency phone numbers such as 9-1-1). This DLTK worksheet can help.

Read more about the history of radios here.

People still build their own crystal radios! Remember, radio can be a two-way communication device (like ham radios and the radios used by police and boats) as well as the more familiar one-way device (tuning into commercial radio transmissions).

 


Here are some directions for building a crystal radio receiver.

There are broadcast and Internet radio stations meant just for kids. Pandora delivers six different kids' stations!

Here's a fairly simple explanation of how radios work.


Also on this date:













Clean Air Day in Canada
(First Wednesday in June)






Plan ahead:


 



December 12 - Anniversary of the First Trans-Atlantic Radio Transmission

Posted on December 12, 2020

This update is from my earliest December 12 post from 2009:

Back in the 1800s, people were busily changing the world by making communications across long distances MUCH quicker than it used to be.

And when I say "it used to be" - pre-1800s, getting news somewhere fast may be sending a messenger on foot with an urgent message. Or sending it tied to the leg of a bird. Or sending the message by train, or stagecoach, or horse-and-rider, or maybe even by ship!



Those urgent messages had better not be TOO urgent, because they took a while to get to the intended recipient!

Like I said, in the 1800s people invented telegrams and telephones. These technologies took messages and converted them into electric signals that could be carried over wires and then reconverted into understandable messages.
Well, on this day in 1901, Italian inventor Guglielmo Marconi made an important experiment - part of a whole series of experiments - to make communication WITHOUT wires practical!


Ever since 1893, Nikola Tesla and 
Marconi had (separately) been inventing and reinventing the radio, but the devices, which were called “wireless telegraph,” still could not send music or speech. Instead, they sent signals such as Morse Code. Some people said that radio would never be able to compete with telegraphy (which involves Morse Code signals sent along wires) because radio waves could only be transmitted along line-of-sight and at limited distances.

That's one reason the December 12th experiment was important; Marconi showed that a radio transmission from a high-power station could be detected as far away as 3,500 km (2,200 miles).

It would be another five years before the first true AM radio messages—speech and music!—would be made.

What is radio?

Radio waves are just like light, but with slower frequency and much longer wavelengths.

A radio is basically an antenna to catch radio waves, some electronics to turn the waves ba
ck into sounds, and a loudspeaker so we can hear the sounds.




Einstein explained radio this way:
“You see, wire telegraph is a kind of very, very long cat. You pull his tail in New York, and his head is meowing in Los Angeles. Do you understand this? And radio operates in the same way: You send signals here; they receive them there. The only difference is that there is no cat."
Here is a nice explanation of how radio works.
And here is a short 
movie on the same topic.

Are radios still being invented and reinvented?

Remember, invention goes on even for devices that work pretty well, because people can think of ways to make things smaller / bigger / faster / cheaper, and so forth. Right now the biggest thing in radio is probably satellite radio, which is like satellite TV. Sirius users in the U.S. can get their favorite sat radio stations everywhere they go, as long as they have a clear view of the satellites. They get a choice of more than 150 stations, and many of the stations are commercial-free. Users do have to pay a subscription for the service, of course (again, like satellite TV).


Kids' Music on Kids' Radio

Find a station near you here.

Cosmic Radio
Did you know that stars, pulsars, nebulae, and galaxies emit radio waves?

Our huge, dishlike radio antennae not only collect our own radio waves from satellites, but al
so collect natural, random-sounding hisses from all over the sky. We can learn a lot about astronomical objects using an array of radio telescopes.


Here's something weird to think about:

We have been sending radio and television transmissions out into space for more than 100 years. So it is possible that any aliens who live within 100 light years of is have detected those signals and are, perhaps, learning our languages, enjoying our old shows (do aliens love Lucy, too?), or shrugging in bewilderment over our rock-n-roll.


What would aliens think about humans from listening to and watching our current radio and TV?


Also on this date:










(Second Saturday of December)





(Second Saturday in December)








August 20 - National Radio Day

Posted on August 20, 2019



August 20, 1920, Detroit residents operating under an amateur radio license with the call sign "8MK" began daily broadcasts as the Detroit News Radiophone.

That news broadcast grew into an all-news radio station WWJ, which is an AM radio station based in Detroit, Michigan. 








"All news" includes traffic and weather, which WWJ broadcasts every ten minutes, "on the eights." On the eights means the times that end with the digit "8," such as 7:08, 7:18, 7:28, 7:38, 7:48, and 7:58...and so forth. The exception to this frequent updating of traffic and weather is when the station is broadcasting a Detroit sports team's game, live.


In 2015, KDKA celebrated its 95th
anniversary. This year it will be 99!
But KDKA also claims to be the first. A ham radio operator named Dr. Frank Conrad, who lived in Pittsburg, was asked by a radio manufacturer, Westinghouse, to begin regular transmissions like the ones he made for his friends; Conrad's radio broadcasts grew to be KDKA. 

However, I noticed that the first day of the Pittsburg broadcasts was election day, November 2, 1920 - more than two months after the WWJ broadcasts. I'm not sure if KDKA fans make the claim that the Detroit station's news broadcast doesn't count as commercial, or if they've never heard the claim, or...?

No matter who was "first," it wasn't long before the amusing techie hobby of radio became a huge commercial success and then a virtual necessity...




Radio waves, of course, are super important in communication - including two-way communication like police radio and walkie talkies, space communication, and radio broadcasts - plus scientific research and remote control technologies and GPS and radar and and and and...