Timeline for How far can you propagate something, anything, before it becomes 'background noise'?
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10 events
| when toggle format | what | by | license | comment | |
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| May 19, 2015 at 4:40 | comment | added | CuriousOne | There is no such thing as "all" in physics. It's always a "none", "some", "much" or "most" game. The mechanism that degrade the information that one can obtain from experimental data depend on the circumstances. The question you were asking was "how far can we propagate something" and you got the correct answer which is "almost all the way". Is the CMB signal degraded by galactic background etc.? Yes, but it has plenty of information left. That's all you ever get in physics and in this case it's plenty good. | |
| May 19, 2015 at 2:38 | vote | accept | ARMATAV | ||
| May 19, 2015 at 2:13 | comment | added | ARMATAV | The question is; can you theoretically pull all of the information out of the background radiation in reverse to find their origins. You're saying yes. What I'm saying is that all of that information eventually becomes garbled as it propagates further. That clashes with you saying you can pick out the sources. -- Why is a particular wave, "hello" for instance, not slowly stretched and broken as it propagates through space. -- Why do you say we can pull it back out? | |
| May 19, 2015 at 1:31 | comment | added | CuriousOne | The CMB has a thermodynamic temperature and a certain spectrum. As long as the signal you are trying to detect has a different spectrum, it can be discerned from the CMB, even if is is weak. If the signal carries an actual modulation that distinguishes it from noise, virtually any level of SNR can be overcome with integration over a long enough time period. At this point I am not sure what your real question is. | |
| May 19, 2015 at 1:31 | answer | added | user46925 | timeline score: 1 | |
| May 19, 2015 at 1:04 | comment | added | ARMATAV | Anything coherent carrying information. Hawking radiation propagates away from a black hole and into cosmic background radiation, that's not one source. | |
| May 19, 2015 at 0:47 | comment | added | Cicero | Define signal @ARMATAV. Cosmic microwave (not general) background radiation came from one point source and hence I would consider that it came from one source. | |
| May 19, 2015 at 0:02 | comment | added | ARMATAV | Cosmic background radiation is a collection of signals though. Once a signal 'becomes' part of it, its information is permanently lost. So how is it a signal? It's just noise, right? You cannot pick out the first SETI broadcasts (or whatever signal you want) from it. | |
| May 18, 2015 at 23:47 | comment | added | CuriousOne | If you have enough energy, you can propagate light across the entire visible universe. We are seeing an electromagnetic signal, the cosmic microwave background, that originated just 300,000 light years from the longest possible distance from us (at least in the current distance scale, I think one still has to throw the expansion since the big bang in there to get the real scale, but I am not completely sure). | |
| May 18, 2015 at 23:45 | history | asked | ARMATAV | CC BY-SA 3.0 |