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SETI Disrupted By Cell Phones in Airplanes?
Iphtashu Fitz writes "If, as recently mentioned, the FCC does allow wireless access on airplanes, could it effectively mean the end of the search for ET? NewScientist has a new article that explains how radio interference from airborne cellphones could drown out faint radio signals from space. Among other concerns astronomers have is that the second harmonic of many cell phones falls in a frequency band that reveals the molecular signature of newborn and dying stars, which is among the 2% of frequencies in this part of the electromagnetic spectrum reserved for use by radio astronomers. Michael Davis, director of projects at California's SETI Institute, stated that a single cellphone on an airplane 100 miles from a radiotelescope could exceed recommended radio noise levels by 10 times. A potential solution that astronomers have suggested is to install a miniture cell transceiver on each airplane, called a picocell, that would act as a relay using a frequency that wouldn't interfere with their work."
That's just it. It's RF noise. Cell phones create modulated RF signals with harmonics on frequencies that radiotelescopes need to be listening on. Imagine trying to hear someone playing a flute from 30 miles away. Now imagine you're trying to hear that flute, standing 50 yards from a raging waterfall. That's like what radio telescopes do right now; it's tricky, but picking signals out of full-spectrum RF noise is what they are designed to do.
NOW imagine trying to hear that distant flute while standing 50 yards from a raging waterfall, and a band starts playing Sousa marches right in your ear. Even if the sound of the distant flute is still reaching you, you'll never ever be able to pick out its waveform from the sound of the band AND the white noise of the waterfall. Especially during the picolo solo.
End of lesson. You may press the button.
This is not the first time that this argument has been made. ...but the first time was 20-30 years before cell phones were invented.
Humanity has unleashed a veritable plethora of rf emitting devices. Television broadcast towers, satellites, anything electrical... they all leak rf that's thousands (if not millions) of times more powerful then the signals coming in from distant stars.
Banning cell phones on planes BECAUSE of this is like using a Sharpie marker to turn a sucking chest wound into a smiley face. You (the pen wielder) might feel better, but it's not going to solve the real problem one iota.
The real solution is to invest in building radio telescopy infrastructure on the far side of the moon. Either there, or in a heliocentric orbit on the opposite side of the sun at 1 AU. Those are the only two places in the universe that have are always shadowed from Earth based broadcasts.
Additionally, there are frequencies that are absorbed by the O2 in our atmosphere, so radiotelescopes in space would have better 'bandwidth' to observe.
Finally, it's unlikely that the cell phone industry will finally be convinced to go to pico-repeaters because of the inconvenience that radio telescopy scientists encounter. It'll be because pico-repeaters will make cell phones work in places they don't currently. Deep garages, underground installations, steel buildings, small valleys... these are economically driven reasons to adopt the technology. Scientists (the normal kind, not the mad kind) are usually poor, so the money just isn't there.
Pick your battles, and pick a winning strategy to get the tech you want. Radio telescopes... they ain't it.
ET: "Can you hear me now?"
SETI Scientist: "Damn cell phone interference."
I write this from my doctor's waiting room, and of the 3 people using their phone, I'm the only one doing so silently.
One old fart is planning a fish fry while complaining about his high blood pressure, while a very large woman text messages with the key beep volume set one click below WMD.
The problem isn't technology, but rudeness.
Sol (our sun) is a 3rd generation star, in what is considered one of the original galaxies in the 13.7 billion year old universe ( http://www.space.com/scienceastronomy/earth_age_04 0817.html ) Sol about 5 billion years old and located 2/3 of the way out on the Orion arm which extends some 42,000 light years from the stellar nursury at the center. ( http://www.encyclopedia.com/html/section/MilkyWay_ SizeandShapeoftheMilkyWay.asp ) IIRC, centripital acceleration slowly pushes stars out from the center towards the edge. The Milky Way is approximately 10,000 lightyears thick at the edge and 30,000 light years think in the centre.
If we assume that intelligence and time since your sun was born have a positive correlation, this means the smarter aliens would be further from the galactic core, and this space covers approximately 11 billion cubic lightyears of a total 169 billion cubic lightyears, about 6.5% of the space. If we assume that the galaxy's 200 billion stars are evenly distributed over this volume (they aren't, the galaxy is denser towards the center), that gives us 13 billion stars with the possibility of intelligent life smarter than us. If we assume that 1% of them actually do harbor intelligent life (and that figure is probably way too high), that leaves us with 130 million stars, spread out over 11 billion cubic lightyears. Since we have an even distribution of stars, that means intelligent life will happen once every 85 million light years.
So the nearest intelligent life with an advanced society is 85 million light years away. Unless the alien race has discovered a means to FTL travel, if they left 85 million years ago, they would be arriving right now. Serious SETI research isn't aimed at meeting ET, or having a conversation, but confirming that extraterrestrial intelligence exists.
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