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After 35 Years, Another Message Sent From Arecibo
0xdeadbeef writes "Two weeks ago, MIT artist-in-residence Joe Davis used the Arecibo radio telescope to send a message to three stars in honor of the 35th anniversary of the famous Drake-Sagan transmission to M13 in 1974. It was apparently allowed but not endorsed by the director of the facility, and used a jury-rigged signal source on what will now be known as the 'coolest iPhone in the world.' The message encoded a DNA sequence, but no word yet on whether it disabled any alien shields. You can get the low-down on Centauri Dreams: Part 1, Part 2."
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If this transmission stimulates even one young person to do that calculation for themselves, or to otherwise conclude that it's a foolish waste of money, it will have been money well spent.
We are very tasty snacks! Here, have our DNA, and grow some appetizers for the long journey!
I suffer from attention surplus disorder.
We could never pick up a radio signal from an alien civilization because the power of a signal from a point source drops off exponentially..
Umm..... its not a "point source" its a spherical reflector..... the whole point of the construction of big antennas is to allow you to do precisely what it is you friend appears to believe is impossible.
We now return you to your usual /. chaos
-jon
Actually I believe calculations have been done which show that two Arecibo type telescopes could communicate across the galaxy.
http://michaelsmith.id.au
Without any context --- e.g., our biochemistry, amino acid structure, nature of DNA --- this message amounts to about the worst practical joke in the history of interstellar communication. It has a relatively non-random structure, so clearly must mean something, and yet they'll never figure it out.
Dear citizens of Centauri. I have a large sum of gold, 300 metric tons, I need to move off planet. If you'll deposit a small transfer fee, 3 metric tons of gold, in a local bank I will make arrangements to ship the gold to you. Signed crowned prince of Iowa.
These guys must be loaded. Would you believe the rates they're charging for interstellar calls?
Oddly, we just solved this problem in E&M class. If you had antennas with 80 dBi gain at both ends and a megawatt of power, that would be sufficient to transmit 10^5 bits per second over a lightyear gap with a received power level above the thermal noise floor (e.g. the antenna does enough work on the receiver to flip a bit). Raise the distance to 100 lightyears and reduce the gain to 73 dBi (e.g. Arecibo) and you lose 5.5 orders of magnitude in bit rate. Up the power to three megawatts (not hard to imagine) and you get back half an order of magnitude. So the achievable rate over 100ly using only current Earth technology at both ends is about a bit per second. Useless, perhaps, but not technically impossible.
Not to mention the fact that even point source radiation falls off as the inverse square of the distance, which isn't at all the same thing as falling off exponentially.
This just in - they got a response:
Dear Earthling,
Hello! I am a creature from a galaxy far away, visiting your planet.
I have transformed myself into this text file. As you are reading it, I
am having sex with your eyeballs. I know you like it because you are
smiling. Please pass me on to someone else because I'm really horny.
You have no idea about what you are talking about. It is true that omni directional radio sources are subject to inverse square law, but directional signals degrade less slowly. Scientists have calculated that using the Arecibo dish at one megawatt the signal could be received by a similarly sized dish 10000 lightyears away. I think I trust calculations done by people with PhDs in astronomy more than calculations done by you and your friend
The entire Wikipedia section on the production of titanium is a little under 4 kilobytes, which would take a bit over an hour to transmit at those rates. Imagine an alien species has a new ultra-efficient titanium refining process - would you wait a day to get the summary of it downloaded for your scientists? I sure as hell would.
The two-hundred-year transmission lag to go a hundred lightyears is a far bigger issue than the bandwidth.
Breaking Into the Industry - A development log about starting a game studio.
I'ma let you finish, but we already got a reply to the original message!
--
"Open source is good." - Steve Jobs
"Open source is evil." - Microsoft
We could have rickrolled them so they could get a taste of our culture!
My Dear Friend and Earthling, My name is Mr. Zebel Braumat, I am a senior priest in the highest order of our race. We are conducting a standard process investigation/Recommendation on behalf of all Advanced Common Civilization (ACC). This investigation involves an ancient race who shares similar DNA as with yours from which we have previously received messages from. The circumstances which surrounding investments made by this race at ADB Gold Account, the Private Banking arm of ACC. The ACC Private Banking client died intestate and nominated no successor in title over the investments made with the bank amounting to over galactic 9.5 Gazillion dollars. The essence of this communication with you is to request that you provide us information/comments on any or all of the four issues as regards nominating your race to inherit the fund left behind by this previous race. You are therefore being contacted to be legally nominated as next of kin(inheritor) to this race after all enquiries and investigation has yielded results showing that there is no known successors. You are required therefore to answer this questions to enable us make our recommendation. 1-Are you aware of any relative/relation born on the 2nd of February 1951, who shares your same name whose last known contact address was West Africa? 2-Are you aware of any investment of considerable value made by such a person at the Private Banking Division of ADB Bank PLC? 3-Can you confirm your willingness to accept this inheritance if you are legally and legitimately nominated and approved to stand as inheritor to this huge investment in regards to the bank account with ADB? 4-Would you agree to donate part of this inheritance to charity if you are officially approved to stand as the inheritor? It is pertinent that you inform us ASAP whether or not you are familiar with this personality or and your interest towards the issues mentioned. You must appreciate that we are constrained from providing you with more detailed information at this point. Please respond to this mail as soon as possible to afford us the opportunity to provide you with more information on this investigation and recommendation. Thank you for accommodating our enquiry. Mr. Zebel Braumat For: Advanced Common Civilization Kappa Ceti (G5B)
So if you're going to send a message, you have to choose one. What did he choose? The DNA sequence for an enzyme.
We used Apple's "Speak" option to vocalize the phonetic code which I then recorded on my iPhone. Here is a fragment of the total message, the whole of which can be decoded unambiguously into the gene for RuBisCo:
Tell me how, exactly, the recipient is going to decode a DNA sequence, even if the basic message can be identified as strings of 2-bit numbers? Not only is DNA specific (as far as we know) to Earth chemistry, but the meanings of the codons, and even the choice to interpret them in triplets is the result of chance evolution on this planet. It's like sending a message in Navajo to Paris, with the assumption that it can be "decoded unambigiously"... because the sender knew what it meant. The meanings of DNA codons are absolutely not a universal constant like binary math is.
knowyourself riddleoflife amthe riddleoflife amthe amthe riddleoflife riddleoflife
<facepalm> Not that the choice of words would mean anything to them, but this shows the touchy-feely-ness that goes along with the lack of foresight that was already demonstrated.
Say what you will about Sagan's message, but at least they put some thought into making a message that gave hints as to how to decode it, rather than just sending some unframed binary mish-mash.
--
"Open source is good." - Steve Jobs
"Open source is evil." - Microsoft
As it is a linear partial differential equation, all solutions to the wave equation and equations of its type are governed by what is known as the "fundamental solution" or "Green's function" of the equation. In the case of wave type equations(in 3 or more dimensions), this solution will be a delta function type solution which decreases inversely with distance from the source. Squaring its amplitude to obtain energy gives an inverse square energy decrease.
It must be stressed that all solutions of the wave equation, no matter what the sources, or boundary or initial conditions, must all be functions derived, more or less, from convolutions of the fundamental solution with the source terms. You cannot escape the inverse square behaviour of wave propagation over long distances with finite wave sources. The fundamental solution characterises all waves because of the linearity of the wave equation.
Now, there is a second fundamental solution for the wave equation; the so called "acausal" Green's function, which represents an inwardly collapsing wave, or by some conventions, a wave travelling backwards through time. Naturally, these waves are not considered in the context of the transmission of signals. Even if they were, these waves also display and inverse square relation for signal strength( going backwards in time of course).
This has been your daily mathematical public service announcement. Complaints to be directed to the Dean.
May the Maths Be with you!
Based on human behavior, we can roughly guess that at least 10% of any/all intelligent receivers will be agressive.
Really want to mess with your head? Try this on for size. Based on human behavior, we can roughly guess that at least 90% of any/all intelligent receivers will believe in some form of supernatural friend in the sky whom runs the whole show. Now how are they going to freak out when a dude in the sky starts talking to them?
See, now slashdotters whom watch too much BSG are worried about fighting the cylons, but the average (and below average) moron on the street is going to be worried about the supernatural implications.
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
Pointless Calculation...
What if they tried to send the exact same information to a neighbor, using Verizon wireless...
As a text message:
Base Pairs in DNA: 3,080,000,000
Total # Characters 6,160,000,000.00
Text Message Limit 160
# Text Messages: 38,500,000.00
Rate per Text Message: $0.20
Cost: $7,700,000.00
Using Verizon's 1.99/MB data rate:
Megabytes Data 770
Cost Per Megabyte $1.99
Total Cost $1,532.30
Mailing a Baggy full of sperm:
44 cents.
Seeing the look on your neighbor's face when she opens her envelope:
priceless