Hedy Lamarr #TBT

We're going all the way back in time to November 9, 2015:

Today's blog post is brought to you by today's Google Doodle. I had Hedy Lamarr on my list of subjects that I wanted to blog about, but I didn't know when I was going to post it. I went on Google to look up another subject I was going to blog about and I saw this Google Doodle for today:

And when I hovered my mouse over it, it said "Hedy Lamarr's 101st birthday". If you click on the image on Google (not here), you'll get to watch a little cartoon about her (make sure your volume is up). So that's why I'm writing about Hedy today instead of another day. But why am I writing about her at all? Because not only was she a beautiful actress

but she was also an inventor.

Per Wikipedia:

Early inventions

At the beginning of the war, she was told that she could better help the war effort by using her celebrity status to sell war bonds, which she did with great success. But she wanted to do more, particularly by using her interest in science to aid in the defeat of Nazism. This desire only intensified as Hitler continued his relentless attacks on Europe. When German submarines began torpedoing passenger liners, she said at one point, "I've got to invent something that will put a stop to that". This desire would give rise to the invention for which she would become famous many years later. 

Lamarr's earliest inventions include an improved traffic stoplight and a tablet that would dissolve in water to create a carbonated drink. The beverage was unsuccessful; Lamarr herself claimed it tasted like Alka-Seltzer.

Also from the same article in Wikipedia:

Frequency-hopping spread-spectrum invention

Copy of U.S. patent for "Secret Communication System" 

Lamarr's reputation as an inventor is based on her co-creation of a frequency-hopping system with George Antheil, an avant garde composer and neighbor of Lamarr in California. During World War II, Lamarr was inspired to contribute to the war effort, and focused her efforts on countering torpedoes. In her home, explains author Richard Rhodes during an interview on CBS, she devoted a room to drafting her designs for frequency-hopping.

Lamarr and Antheil discussed the fact that radio-controlled torpedoes, while important in the naval war, could easily be jammed by broadcasting interference at the frequency of the control signal, causing the torpedo to go off course. Lamarr had learned something about torpedoes during her marriage to Mandl. Lamarr and Antheil developed the idea of using frequency hopping to avoid jamming. This was achieved by using a piano roll to unpredictably change the signal sent between a control center and the torpedo at short bursts within a range of 88 frequencies in the radio-frequency spectrum (there are 88 black and white keys on a piano keyboard). 

The specific code for the sequence of frequencies would be held identically by the controlling ship and in the torpedo. It would be practically impossible for the enemy to jam all 88 frequencies, as it would require too much power. The frequency-hopping sequence was controlled by a player-piano mechanism, which Antheil had earlier used to score his Ballet Mécanique.

On 11 August 1942, U.S. Patent 2,292,387 was granted to Hedy Kiesler Markey, Lamarr's married name at the time, and George Antheil. Although novel, this early version of frequency hopping soon met with opposition from the U.S. Navy and was not adopted. The idea was not implemented in the U.S. until 1962, when it was used by U.S. military ships during a blockade of Cuba after the patent had expired. Lamarr's work was honored in 1997, when the Electronic Frontier Foundation gave her a belated award for her contributions. In 1998, an Ottawa wireless technology developer, Wi-LAN Inc., acquired a 49% claim to the patent from Lamarr for an undisclosed amount of stock.

Lamarr's and Antheil's frequency-hopping idea served as a basis for modern spread-spectrum communication technology, such as GPS, Bluetooth, COFDM (used in Wi-Fi network connections), and CDMA (used in some cordless and wireless cell phones). Blackwell, Martin, and Vernam's 1920 patent seems to lay the communications groundwork for Lamarr and Antheil's patent, which employed the techniques in the autonomous control of torpedoes.

As the last paragraph says, frequency hopping spread spectrum is used in wifi and cell phones. 2G cell phone service was divided into 2 main technologies...TDMA (Time Division Multiple Access) and CDMA (Code Division Multiple Access). CDMA is based on Hedy's invention. 3G phones use a variation of CDMA called Wideband CDMA (also known as UMTS) while in 4G LTE networks, UMTS is the fallback technology when VOLTE (Voice Over LTE) is not available.

So, we have Hedy Lamarr to thank, in part, for our cell phone and wifi communications. Happy 101st birthday Hedy!

Interesting days

Today - Chaos Never Dies Day and World Freedom Day I love this video "Freedom"

Tomorrow - Sesame Street Day and Area Code Day How were area codes originally assigned?

Per Wikipedia:

Dialing a complete 10-digit telephone number could take up to ten seconds, during which hardware resources had to be dedicated to a circuit. The time to dial a digit was directly proportional to the digit, with the exception of the 0, which required ten pulses or one second. The area codes for a few large cities in the US were initially assigned based on the volume of telephone calls made in each area. The most populous areas received codes that required the least time for dialing using a rotary dial telephone. The densely populated areas of New York City, Chicago, Los Angeles, and Detroit had large incoming call volume and were assigned the shortest area codes, 212, 312, 213, and 313, respectively. Areas that covered an entire province or state had 0 as the middle digit. The first area code installed was 201 for New Jersey, while the District of Columbia received the second code (202). 

The second digit of all original area codes was 0 or 1, while the second digit of the three-digit exchange code was never 0 or 1, thus facilitating the recognition of whether a user was dialing a full 10-digit number or merely dialing within the local area code. Toll operators were able to differentiate between the two types of areas from the middle digit of the area code when a routing operator had to be consulted.

Next Thursday - Social Enterprise Day, Fast Food Day, International Day for Tolerance, Beaujolais Nouveau Day, Button Day (not to be confused with Count Your Buttons Day) and Have a Party with Your Bear Day (not to be confused with Bring Your Teddy Bear To Work & School Day)

December 9 - Gingerbread Decorating Day, Christmas Card Day, International Day of Veterinary Medicine, Pastry Day,  International Anti-Corruption Day and Techno Day