Slashdot Mirror
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."
Cell phones only use enough power to make contact with their cell. If the cell is 20 feet away its going to put out a lot less signal than if the cell is 20 miles away.
Douglas P. Price
A picocell can use a different frequency than the ones the phones use, a frequency that is less likely to mess with astronomers / etc. The cellphones will see a "tower" very close by, and use minimal broadcast strength.
-Jesse
Nothing says "unprofessional job" like wrinkles in your duct tape.
As TFA clearly states, cellphones adjust their power output as necessary - the closer the cell tower the weaker the signal a phone puts out. With a picocell on board the airplane all the phones would put out a minimal signal. If the picocell wasn't there then the phones would have to significantly increase their power output to reach the terrestrial towers 40,000 feet below.
Then of course there's the Sagan hypothesis that itellegant life has such a narrow time fram of existence before anihilating itself that either you dont overlap in time with you interplanetary peers or if you do they'll be dead by the time you manage to travel there.
Some drink at the fountain of knowledge. Others just gargle.
Radio astronomers also use those frequencies, so there is more involved than SETI, or some group's software.
Mea navis aericumbens anguillis abundat
SETI is a lot more than just the SETI@home software you're thinking about. And this has implications for all radio astronomy, not just SETI. The solution is clear - don't let consumer-level technology get in the way of truly ground-breaking discoveries.
Cyde Weys Musings - Scrutinizing the inscrutable
They don't want to resrve the whole sky, they just want their 2% to continue to be a valuable tool for their research. It's not just SETI either, radio telescopes are used for other less outlandish research.
In case you haven't worked it out yet, SETI uses radio astronomy equipment to listen for radio signals from outer space.
:)
/. blurb, I have pasted it here:
Reading comprehension is fun
The grandparent poster is claiming that this affects more than just the SETI people, this affects all radio astronomy. In case you cannot be bothered to read the article or the
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.
There you go, actual science being disrupted, not searching for little green men.
Finkployd
Your underlying assumption is the signals we may dectect are accidentally or incidentally broadcast into space.
Deliberate broadcasts suffer from none of the drawbacks you describe.
You also assume that our use of the EM spectrum is the same as some other civilization's use of the EM spectrum.
Also an assumption everyone agrees with.
So your conclusion SETI won't work does not follow from your argument.
True, it probably won't work, but not in the manner you describe.
Judging by the mod points he received, bashing right-wingers, regardless of relevance to the topic, appears to be a guaranteed way to get modded +5 Insightful.
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.
Free MacMini
More's the pity.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Not that the search for extra terrestrial life isn't a worthy cause, but there's a better reason for picocells on airplanes.
Please, correct me if I'm wrong. When you make a connection to a cell phone tower, you'll connect to the closest towers. Usually this is only two or three. While you're on an airplane though, you tend to pick up many more (several dozen?) towers, and connect to all of them. You're also moving through a coverage area faster, taking up a whole swath of towers.
I know, boo hoo, they're using up the poor phone companies resources. But I'd rather not have to wait for a passing 747 to get out of range before I can make a call.
It makes more sense to have the plane be its own cell phone tower, and route the calls out through it and not taking up channels on normal cell phone towers. Oh yeah, and it'd be nice to cut out some of the interference.
Then again, I could be completely talking out of my ass. Hopefully someone in the know will come along and smite me or expend on this though/
There are some people that if they don't know, you can't tell 'em.
Lufthansa are putting picocells on their aircraft so you will be able to connect to it and pay them a hefty fee to use your own GSM/GPRS enabled cellphone As for you being a mechanic, well, if you tried to establish a position of authority you failed miserably. Phones in the air Mobile phones could soon be following Wi-Fi into the stratosphere. WirelessCabin, an EC-funded consortium led by the German Aerospace Centre with members including Airbus, Siemens and Ericsson, will this summer trial a system that puts a short-range mobile phone "picocell" on board aircraft. Phones transmit to the picocell at very low power, eliminating interference with on-board avionics and terrestrial base stations. WirelessCabin's system is compatible with any infrastructure, so it could be added on to Tenzing or Connexion's offerings; the consortium is planning trials with Lufthansa. http://www.techworld.com/features/index.cfm?featur eID=512&printerfriendly=1
The mobile phone option could prove popular by allowing business travellers to remain available to receive calls, just as they do when roaming on international networks. "That sort of thing could be more usable (on planes) than the Internet, and would be likely to bring in more revenue," says Mark Darby, managing director of Aviation Strategy. "People might want the option to take their calls."
As long as the windows are smaller than one wavelength.
"I'm not impatient. I just hate waiting." - My Dad
There is more to radio astronomy than the search for other life in the universe. There is more to..
The atmosphere is almost completely transparent to the signals they're looking at. Receiving ability depends on two things: directionality of the antenna and area of the antenna. You can simulate the first one with interferometry, but that won't help you pick up weak signals. To paraphrase muscle car owners: There's no replacement for area. (dang there's gotta be a way to make that rhyme.)
Can you be Even More Awesome?!
I don't know whether they say in TFA, but if you had even bothered to read the summary you'd have seen the following:
That's incidentally the "real" reason to put pico bases on air planes. Allowing mobiles to connect to the network directly wreaks havoc with the network as that's not dimensioned to allow a single mobile to see dozens of cells at the same time, taking up "space" (i.e. bandwidth and added interference) in all of them.
The mobile cell based networks work on the principle that a single mobile will only see a handfull of cells at the same time. A 747 flying over a metropolitan area would potentially swamp the network of that area given the max range of e.g. GSM at ca 20km and typical flying altitudes of around 10km.
Stefan Axelsson