what kind of internet connection does this guy have that this is not slashdot-ed into oblivion ? very nice job, but a bit too messy for my taste
... also free advertising ;)
At those frequencies (ELF/VLF) there's isn't too much bandwidth. Maybe enough for sensor buoys to send a few bytes every few minutes. But it's not even going to get close to even 1200 bps.
And yet another high level layer to cope with high-error-rate and slow physical layers. But the problem remains the attenuation of RF underwater. Where are the interesting details, like the carrier frequency, modulation type, bandwidth, power efficiency etc
Well a 70 Hz carrier doesn't quite give you enough bandwidth to run even a silly 1200 bps UART. With radiowaves in the microwave range (like your 2.4GHz) water absorbs most of the energy and turns it into heat. Like your microwave oven does. The water dipole attempts to continuously reorient in electromagnetic radiation's oscillating electric field. Dependent on the frequency the dipole may move in time to the field, lag behind it or remain apparently unaffected. When the dipole lags behind the field then interactions between the dipole and the field leads to an energy loss by heating.
In many radio reception techniques the signal is down-converted to a much lower frequency for easier processing. This is done through so called "heterodyning", which takes the carrier signal and mixes it with the signal from a Local Oscillator (LO) to create an Intermediate Frequency (IF). The IF and LO signals will radiate and need to be properly shielded.
"the highly elliptical orbit of the spacecraft will limit its usefulness as a relay for operating landers on the surface." while the summary says "Maintaining communications with the rovers is considered essential, hence the preparations and launch will proceed. "
Just slap on an 8bit mcu like an AVR of PIC or whatever over SPI/I2C/USART/... to do the real time stuff.
60 Hz would be terrible. Let's imagine they can IQ modulate 64 symbols (6 bits per symbol) with a samplerate of 60 Hz, that gets you 6 * 30 (Nyquist) = 180 bits per second.
I can't find anything in the article that would support that. As far as I can tell this water has been in direct contact with spent fuel and contains amongst other things strontium-90, which is also used in RTG's.
That doesn't sound very plausible. http://en.wikipedia.org/wiki/Decay_heat
how does that work with only 3 spacial dimensions ?
DNF was fun to play through once, but has absolutely no re-playability imo.Go get Saints Row 4 !
If any one of your contacts has your phone number with your gmail address in their phone as a single (or merged) contact, google already knows your mobile phone number.
I already submitted this early this morning. http://slashdot.org/submission/2615491/dutch-cable-technicians-discover-street-cabinet-full-of-spy-equipment
It seems the strategy is as follows : DDoS the exchanges to drop the value, buy btc, then DDoS the mining pools to raise the value, sell btc. Slush's pool has been under attack for two days now. The value is also going up again since today.