Our Galaxy has 'billions of Earths'

I asked because you are backtracking from your original claim that NASA should have put a gigapixel detector on Kepler to pixel size claims. I did google the subject and came up with detectors that are deployed on the ground and small (~1 megapixel) detectors on currently flying and planned satellites. As far as I can tell, the CSA is not flying or thinking of flying a gigapixel detectors in space.

 

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Not for much longer, though. Europe has already transitioned to DTV and the US will soon do so. Those DTV transmissions are pretty much indistinguishable from noise.

 

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A good way to hide ourselves. Not that we are unknown of course.

 

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I do not understand why this would be the case. Is not DTV still relatively narror (6 meg hertz wide) radiation? I do not know any thing about DTV, but that 6meg Hz is what each channel of analog TV has. If anything I had the impression that DTV was squeezing same data in less band width (or more data in the same old 6 meg hz channels)

I think just a narror band of un-modualted carrier that appeared at 12 hour intervals would be strong indication of artificiality. Not necessary For ET to watch old "I love lucy" shows to know the star we call sun has life. Note that the assigned frequencies would follow each other with the same relative temporal spacing.

As noted before the radiation patten of TV transmission is like a quite flat pancake, Usually the full 360 sectors of the pancake. TV antenna may have 20 or more indivual radiators so constructive interference makes this pancake tangent to the Earth quite well. Energy sent up 5 degrees or more is wasted as no receivers up there.

They know our day length and with ~365 of them and Doppler observations the year length too probably. I do not think it would be hard to reconsturct the transmitted images even with DTV, but perhaps I am missing something in my ignorance about how the digital signal is structured (I.e. I assume there will still be "frames" for the sequential pictures that make a regularity easily noticed etc.)

 

As a starter, google "DTV signal looks just like random noise". You'll find things like (each paragraph is a separate hyperlink):

The DTV data signal is actually randomized in order to create a "flat noise like" spectrum common with digital signal transmission. This permits maximum channel efficiency and keeps the signal from interfering with nearby channels (so we can have three HDTV channels right next to each other).

To assure that the data signal looks like random noise at all times, the data is [sic] randomized at the transmitter and de-randomized in the HDTV receiver. ... In this way, the spectral power density per hertz of spectrum is extremely low and independent of time and frequency, just as if the transmitter were a source of random noise.

The mask of a DTV signal is just like the mask of random noise filtered by a bandpass filter to 6MHz of bandwidth. That is, DTV looks like noise on a spectrum analyzer, and that is what itlooks like to a DTV receiver before demodulation. In conducting this study, NPR was concernedwith how the noise presented by the density of the DTV mask might alter the FM interference experienced with NTSC television in the past.

 

Is it me or does it sound like we are trying to hide from something?
This is probaly where some one is going to start calling me a conspiracy nut, and, or say this topic should be started up in a new thread.
LOL

 

To D H (and others interested in SETI, etc.):

Thanks for the links, but I think you have missed my point. Even if NYC's CBS TV station were hijacked and was actually broadcasting random noise, as the Earth horizonal pancake beam sweeps by star 7462, for a few minutes they see something in Frequency space like:

........................v^v^v
____________.........____________________
.......................a........b

Ignore all ....... as they are there only because sciforum's computer compresses multi spaces down to one.

The frequency difference (b-a) is 6MHz. and "v^v^v" is my attempt to show random noise (with a non-zero average or DC term). This "DC term" would not be a constant intensity in time but more like an inverted parabola as the beam sweeps across their receiver's antenna. Note also there is more noise in the adjacent band b to c where frequency of c is (b+6)Mhz and the peak of its parabola is different and very slightly delayed (Or advanced) in time. (Some of NYC's TVs have their transmitters in NJ.) It took months of averging data records to note the small temporal shifts between peaks, but the NYC, cluster of 6n Mhz wide noise was noted immediately as separated from Chicago's similar wide band of noise.
(Actually there are two such bands: The TV Channels 2 thru 13 make a 66Mhz wide noise band, and even it has a fixed gap, and then the larger UHF band, but it has lots of 6Mhz holes in it,)

Every 12 hours later the 6Mhz wide bands of noise repeat*, but a & b are ever so slighly doppler shifted. After watching for more than an Earth year these ETs know not only the rotation of the source but its orbital parameters about the sun quite well - Their confidence that their SETI funds were well spent is very strong now as this planet is in a nearly circular orbit with water always liquid on most of its surface. They have faint indications that the Planet has a moon, but more observations will be required to be sure.

When the reality of the moon was confirmed, professor #%%*&*$@ was very happy to see evidence that the only ET's their SETI has found live on a planet with a relatively large moon to make tides which facilitate the emergence of intelligent life onto the land, just as was the case on their planet he had claimed. They know this moon planet system has (28+)24 hour period and that years later when in its orbital plane it has crossed in front of the beam once in those years they have ben observing, they learned moon's size and density. (Not always bad luck geometry in their POV as they and Earth are both with angular monemtum sort of perpendicular to the glactic plane. They expect a better occult in 154 years as NYC should be blocked!)

Not only that 6nMhz wide NYC band but about an hour later there always are more such continuous 6n Mhz wide patterns observed (from Chicago with every permitted TV channel in use) with same As & Bs frequencies and all these (B-A) are 6Mhz with often adjoining sets so that the noise bands are with different strengths each 6Mhz but continuious for 6n Mhz, with occasional 6MHz gaps. (stations do shut down for cleaning or repair, typically a few hours each month)

These ET have pretty good idea that there are two oceans on the observed planet (one about three or four times wider than the other) as the multitude of 6Mhz noise transmissions stop for about 3 and 9 hours. The ETs have concluded that there must be some small islands in the bigger ocean as regular as clock work Hawaii's TV is heard and there are many smaller cities in the land masses where there are 6Mhz gaps in the 6n Mhz bands. In fact, there seems to be a pattern of alternate gaps (TV Channel 3, 5 7 etc absent as they were still only getting the early analog signals.)

With in a few hours after the first DTV signal was recieved, their "CIA / NSA" had cracked the psuedo random code. They had known already a lot about the inhabitents of Earth from the old "I love Lucy" etc. analog shows they first recieved. - That helped as they understood how the Lucies "thought" if you can call their irrational process "thought."

----------------
*Some of the weaker bands repeat only every 24 hours - minor TVs that shut off at night. Also the slight Earth rotation Doppeler shift (lots of periods averaged to measure) tells the tangential velocity of the Earth, which with fact it rotates in 24 hours tells it size. The ETs are still working on the mass as the Earth moon system data is not quite refined enough. The will soon have it and know the average density of the Earth. That it has a iron core, etc. Yes the SETI folks there are happy - their funding has been trippled! Earth mission probes are being planned. (Based on I love Lucy, it is clear Earth's intelligence is very primative.) Earth needs their help badly.

PS1 Based on the fact that DTV has three diffenent encodings (why it took an additional hour to crack each of the last two), there seems to be three main tribes on Earth but each speaks several languanges.

PS2 their sociologist are in deep discussion about why Earth has several languages. - Some think the "Lucies" have difficulty interbreeding, but the dominate POV is correct. - Earth inteligence is still too primative to have achieved stability.