[PHOTO] Hibiscus, Dupont Street

Hibiscus, Dupont Street
Originally uploaded by randyfmcdonald

Sometimes, in the middle of winter, it's worth noting that beautiful colourful life will return.

[LINK] "The ‘I Love Lucy’ Signal"

This Centauri Dreams post explores the possibilities of extraterrestrial civilizations picking up our radio leakage--old television transmissions from the 1950s, that sort of thing. Briefly summarized, it amounts to "thank God, we're safe".

Let’s talk about [. . .] the actual status of those interesting signals from the dawn of television. Here I’m drawing on James Benford’s presentation to the Royal Society meeting “Towards a Scientific and Societal Agenda on Extraterrestrial Life,” which convened last October in Britain and included a debate on extraterrestrial messaging that was sent to me in DVD form by Astronomy Now editor Keith Cooper. Benford looks at what an extraterrestrial civilization would be able to detect from Earth.

Remember, now, we’re talking about accidental signals, so-called ‘leakage’ radiation that was never intended as a directed signal. Benford goes to work on the math to ask whether installations like those we have on Earth would be able, if located around a nearby star, to pick up what we have been sending. The answer is no. A typical large radio telescope like the Parkes instrument in Australia could not, from a vantage near Alpha Centauri, see video footage from Earth. [. . . H]ere’s his conclusion:

Picking up signals from commercial radio and television broadcasts is difficult. Because they are not intended to broadcast into space; broadcast antennas aim most of their transmitted power toward the surface. Most signal information is transmitted in bands on each side of the central frequency. What little detectable power reaches space is from many sources, not at the exact same frequencies, but in bands constrained by regulation by governments. Therefore, they are not coherent, so phase differences cause them to cancel each other out at great range.

What about over-the-horizon radars built during the Cold War? Much of their power was indeed radiated into space, but they have been replaced by frequency-hopping spread spectrum broadband radars that would likewise be undetectable by any technology like ours. The highest power emissions, it turns out, are those from interplanetary radars used for asteroid searches. But these signals are not directed at nearby stars, and Benford quantifies the issue using the specs of the Arecibo radar telescope. Again, I will hold off on the math, but the conclusion is that ‘there is a negligible chance of ETI noticing our asteroid search radars.’

So what would it take for an extraterrestrial civilization to notice us? Seth Shostak is on the record as saying that within a few hundred light years, clues to our existence could be picked up with an antenna the size of Chicago. Benford’s analysis shows that building such an antenna, given what we know of the present value of building an installation like the Square Kilometer Array, would run up a cost comparable to the entire GNP of planet Earth. If ETI were at our level of development, then, its entire science budget would be consumed by the project.

And even directed messages, Gilster observes, like the ones from Ukraine's Evpatoria radio telescope facility, won't make it 19 light years before they become indecipherable to civilizations at our levels. That facility's "A Message From Earth" was sent to Gliese 571c, 20 light years away. The challenges are daunting:

Detectability, Benford notes, depends on the bandwidth of the transmission. Low data rates can show that the signal is artificial but also carry little information, while high data rates require high bandwidth and suffer greatly from noise.

To detect a low-bit-rate signal, a number of additional factors must swing into play, including a predisposition to be looking at our system in the first place so that ETI would concentrate resources on that small patch of sky where our Sun is located. ETI would also have to guess the bit rate of the message, and would have to figure out that the message used binary frequency-shift keying instead of any other modulation method.

Go, read, be reassured.

[LINK] More on "I Love Lucy Signals"

james_nicoll picked the subject up at his blog, and the discussion's interesting, indeed. The cost of the telescope arrays needed to pick up our signals is key. Quoth carloshasanax:

Let's check Benford's numbers. The Square Kilometer Array has an estimated cost of E1.5 billion. The city of Chicago is 606 square kilometers. Using these numbers, the Honorable Richard J. Daley Array would have an estimated cost of E909 billion, or $1.24 trillion at today's exchange rate.

The current GNP of the United States is $14 trillion.

It's possible Gilster's writeup might be missing a step from Shostak to Benford. It's also possible that Benford gets his grasp on reality from his bro.

The discussion continues, with the question of whether or not the costs for large arrays would scale linearly taking on particular importance.

Go, read. I'm just a bit disappointed to find out we're not as safe as the original poster had hoped.

[URBAN NOTE] On bus-clumping on Dufferin Street (and other Toronto routes)

On the same day that a TTC worker was charged with assaulting a passenger, transit maven Steve Munro blogs about my own Dufferin Street's 29 Dufferin bus route, famously prone to clumping together one, two, three, more buses at a time. (This morning could have been so much less stressful ...)

The TTC talks a good line about service management, but a casual look at any of the routes where real-time monitoring is possible (through the open data interface to GPS vehicle data) routinely shows bunching even at 7am when there cannot possibly be “traffic congestion” effects. Two basic questions about bunching emerge from all of the service reviews I have done:

Why are vehicles allowed to leave termini very close together rather than regularly spaced?

Why are vehicles entering service from yards or from short-turns not spaced between through runs so that even headways are provided?

This does not require millions in high technology to implement, only the will to manage the service, something the TTC once did regularly with no more than route Inspectors on the street. With the tools now available for vehicle tracking, it should be much easier as all vehicle locations are available online.

The post was inspired by one disgrunted commenter.

I wrote to TTC customer service but of course I didn’t hear back from them. I would be interested to know what measures are in place to space out the buses. It seems to me that buses are just rushing to get to the end of the line; they basically do not care if they have 2-3 buses traveling together or if the last buses have no passengers.

I took this video as an example, there are 7 buses passing Bloor stop in under 3 minutes … such a waste from TTC. Just imagine being the “lucky” one that just missed all 7 buses. How long they will need to wait for another bus?

The video referred to is below.

"Junior Boys - Over It (Official Video)" (Watch on YouTube)

[LINK] "Astronomers Suggest Crowdsourcing Letters to Aliens"

Plausible suggestion, this. If you sent me a radio message of 0s and 1s without telling me that they're supposed to resolve into an image with sides made of prime numbers meant to describe schematics of planetary systems and biology, I'd be lost. The Cygnans?

“If I make a presentation on the Keynote software on Mac, you won’t be able to open it on a Windows machine here on Earth,” said physicist Dimitra Atri of the University of Kansas, a coauthor of the new paper. “Forget about sending it to a distant planet.”

The first dispatch, the Arecibo message), was fired in 1974 at a globular cluster 25,000 light-years away. It included a low-resolution graphic of a human, the numbers one through ten, and a graphic of the radio telescope used to transmit the message — though you almost can’t tell to look at it.

“It was largely just for decoration, essentially,” said astrobiologist Julia DeMarines of the International Space University in France, a coauthor of the paper. “It was cool, but it wasn’t really a directed message.”

The next four messages — the Cosmic Calls of 1999 and 2003, the Teen Age Message of 2001 and “A Message From Earth” in 2008 — were sent from a radio telescope in Evpatoria, Ukraine.

Those broadcasts went to more-local stars, between 20 and 69 light-years from Earth, where we could hope to hear back from anyone listening in. But they included recordings of classical music and photographs and drawings submitted by the public — information of sentimental value to Earthlings, but gibberish to aliens who might not even have eyes or ears.

To help increase the odds that E.T. will hear us when we call, Atri, DeMarines and astrobiologist Jacob Haqq-Misra of The Pennsylvania State University suggest designing a standard protocol for writing SETI messages.

“The paper is really a call for unity among thinking about messaging exraterrestrials,” Haqq-Misra said. “Right now it’s messy, it’s kind of all over the place. Maybe we can increase our success chances by being more unified about this.”

The protocol would cover issues like message length (keep it short at first), signal encoding (binary is probably best), transmission method (radio, or some other frequency?) and information content (math and science, or human culture?). The main idea is to keep it simple, the researchers say.

“We want to make sure we’re not being too anthropocentric, making sure the answer can be accessible to the lowest common denominator,” Haqq-Misra said. “Until we meet one, we won’t know” how to talk to them.

[LINK] "J-20 Round Up: What's New Since My Last Post "

After too long an absence, The Dragon's Tales will Baird continues his analysis of the new Chinese stealth fighter, the J-20, with links and analysis. Below are some three tidbits.

Offiziere.ch offers up an opinion on whether or not the F-117 shootdown on March 27, 1999 in the Kosovo War provided China with their materials tech to produce their own native stealth. The China Military Report rebutted that China doesn't need 30+ year old tech to do the above. If the F-117 contributed anything to the J-20 - I honestly don't know - then it would have been used as a starting place rather than a blatant cut and paste of technology. The CMR is correct that it is VERY outdated material science, but given that the information would be examined by individuals with lots of experience with composite technologies and whatnot that have been developed since, they could come up with similar and improved materials based on the observed characteristics of the F-117 samples. There are reasons why I watch my own composite samples very, very closely when dealing with others.

[. . .]

The Dew Line wonders if the J-20 is meant to be another tool to try to push the USN away from the Chinese coasts. In that vein, the USNI blog comments on how the differences between the US view of Chinese capabilities and the Chinese goals. The perception is pretty significant.

War Is Boring puts up another post similar to what I wrote about the coming manned 5th generation fighters as a contrast to the J-20, but with more detail. It also notes that the US is starting to define its 5.5 gen or 6th gen fighter requirements even before the J-20 was unveiled.

Go, read.