 |
Science Fiction
Dictionary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
|
 |
Acoustic Time Reversal Underwater Broadband
Acoustic time reversal can lead to transfer rates of up to 15 kilobits per second at a range of four kilometers. This is far better than existing techniques and, over long distances, even compares to what whales can do.
William Kuperman and colleagues at the Scripps Institution of Oceanography in La Jolla, California, US, and researchers from the NATO Undersea Research Centre in La Spezia, Italy, have been testing the technique in the Mediterranean.
Time reversal exploits the way undersea acoustic signals typically arrive clouded by echoes that travel at different speeds. For example, a "ping" may arrive as three separate sounds – one that travelled directly, an echo from the surface and then an echo from the ocean floor.
If the receiver transmits the same sequence of sounds backwards, they will take the same routes back to the original source. But because the sound that took the longest to travel is sent first, the second-slowest next, and the fastest last, all three will arrive at about the same time at the original source.
In effect, they converge in time, reconstructing the original signal. The retransmitted sounds will create echoes of their own, but the original signal is strong enough to stand out, say the researchers.
A similar system is used in SeaQuest DSV, a television show that ran from 1993-96.

(SeaQuest DSV)
Via 'Time reversal' allows wireless broadband under the sea; thanks to Moira for writing in with the tip.
Scroll down for more stories in the same category. (Story submitted 6/27/2008)
Follow this kind of news @Technovelgy.
| Email | RSS | Blog It | Stumble | del.icio.us | Digg | Reddit |
Would
you like to contribute a story tip?
It's easy:
Get the URL of the story, and the related sf author, and add
it here.
Comment/Join discussion ( 1 )
Related News Stories -
("
Communication
")
Birds Learn To Sing Pictures ala Frank Herbert's Distrans
'We will fight in the time of fighting.' - Frank Herbert, 1965.
Polish Turns Your Nail Into A Stylus
'He wrote on it, using the pointed fingernail of his right forefinger...' - Cordwainer Smith, 1950.
Huawei Pura X Folding Phattie Phone
Why can't we get more innovative phone configurations?
Positioned Cybertrucks With Free Starlinks WiFi In LA
'Several thousand of them formed the positioning grid on the rubble pile.' Vernor Vinge, 1999.
Technovelgy (that's tech-novel-gee!)
is devoted to the creative science inventions and ideas of sf authors. Look for
the Invention Category that interests
you, the Glossary, the Invention
Timeline, or see what's New.
|
 |
Science Fiction
Timeline
1600-1899
1900-1939
1940's 1950's
1960's 1970's
1980's 1990's
2000's 2010's
Current News
Prairie Madness - And Space Sickness
'Space-sickness is one of the most unpleasant sensations that a human being can experience. Not all are subject to it...'
Can Stratospheric Aerosol Injection Control The Weather?
'...I saw a nice black heavy-looking cloud sailing by just now, and I can get the electrical machine out in five minutes to draw it down.'
SETI Suggests Prospecting The Solar System Without Landing
'From a distance it could resolve the cosmic rays reflected from various substances.'
Wolfram Alpha Mathematica Predicted by Science Fiction in 1948!
'The answer to the dumb student's prayer.'
Cislunar Space And The Space Lanes of Golden Age Science Fiction
'He had travelled the space-lanes of the solar system for the greater part of his life...'
NASA Moonbase Update
'The dinner was excellent. It was completely vegetarian — grown in specially prepared gardens in this Moon base...'
Neuralink Will Allow Humans To Communicate With ... Animals?
'Telepaths had their sensitiveness enlarged to an immense range by the pin-sets, which were telepathic amplifiers adapted to the mammal mind.'
Special Lights For Driverless Cars!
'That light is actually the Anamorphic Equalizer...'
'Old People Began to Cross The Continent In Their Own Cars'
'It was a relief to enter one of the comfortable autos, whisper a direction down the tube, and just know that you would be taken to your destination in the quickest, safest, and cheapest manner.'
Harrison Bergeron, Illustrated And Practiced
'But he didn't get very far with it before another noise in his ear radio scattered his thoughts. George winced...'
Starfall Manufacturing Drugs In Space
'The vast spinning sphere of Factory in the Sky loomed above and ahead of us, gleaming white against the unfathomable jet depths of surrounding space.'
The Solar Oberth Slingshot
'And if it doesn’t work,' inquired Lazarus, 'what does that make us? Sunspots?'
'Maybe The Woman Of Your Life Is Still Under Production'
'The Dillard people had performed a miracle and put all the works in a girl-modeled case.'
'If Anyone Is Watching Earth...'
'Our study of your race has convinced us that you are not fitted to leave your planet in the present state of your civilization.'
Epirus High-Power Microwave Defeats Drones
'...the spreading beam of the deranging ray struck them, and Then one toppled and fell. Then another.'
Cloud Of Space Rubbish From China's Long March Rocket
'Within seconds the material was spread out over fifty yards, in a matter of hours it might occupy several cubic miles of space...'
More SF in the News Stories
More Beyond Technovelgy science news stories
|
 |