DR JON HERAS /SCIENCE PHOTO / CORBIS
Illustration showing the absorbance of electromagnetic waves by the Earth's atmosphere.
Posted on 07/06/2013 4:54:09 AM PDT by NYer
Illustration showing the absorbance of electromagnetic waves by the Earth's atmosphere.
Michael D. Lemonick
Editorial
Senior Science Writer
Email: mlemonick@climatecentral.org
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Mr. Lemonick covered science and the environment for TIME magazine for nearly 21 years, where he wrote more than 50 cover stories, and has also written for Discover, Scientific American, Wired, New Scientist and The Washington Post. Lemonick is the author of four books, and a cover story for TIME was featured in the anthology “Best American Science and Nature Writing 2007.” He has taught science and environmental journalism at Princeton, Columbia, Johns Hopkins and New York Universities.
Nice picture, thanks. I think the word you are looking for is “absorption” or maybe attenuation.
The interaction of radio waves with the atmosphere is highly dependent on angle of incidence, rainfall and time of day. For instance, during daylight hours, AM radio waves are absorbed in the stratosphere, making AM daytime radio a local medium. At night when the stratosphere deionizes, AM radio zips right through the stratosphere, to ionosphere, which looks like a highly polished mirror to AM and signals can travel half way round the globe. (WBZ-AM 1030 Boston has been received in New Zealand, for instance.)
Anyway, believe it or not, it’s more complicated than that simple picture.
Also, the above-referenced article states that the bursts have a wavelength of about 1 meter (300 MHz) and have been observed to repeat at intervals of 77 minutes.
There are hundreds of millions of galaxies and billions of planets. That is an immensity that is beyond the conceptual concept of most people. It is logical to assume that the universe teems with life. Yet given the huge distances separating these platelets and the laws of physics, it is simply not possible for an alien biological or a mechanical entity to visit. However Earth has been transmitting huge amounts of digital alogarithmic data for the past twenty five years. It is not inconceivable that within the next twenty some computer on earth will receive a truly wondrous communication.
IOW, he’s a dilettante, like Al Gore. The article was mildly provocative, but not particularly informative. He does give the impression of not really understanding what he is talking about.
Yes. And decadence is a place of sin.
The decadent do not even believe that there is such a thing as sin, so lost are they.
Except for the single irrefutable fact that there is no evidence that life exists anywhere except earth. Not a single piece of data.
Now I GET that our ability to search for life is limited by technology to a certain sphere but that doesn't change the fact that we have no evidence for life anywhere else.
Doesn't seem to be the same phenomenon. The article is dated prior to the discovery of the sources in the Time article and refers to sources in the center of the Milky Way, not extra galactic sources.
The article did not say that the sources were "broadband", but occurred over a very large bandwidth. I take that to mean that any single source is coherent, i.e., narrowband, but the population includes sources at various wavelengths. (For objects within the Milky Was, it is unlikely that Doppler shift could cause very large Doppler shifts.)
...Its a super-galactic submarine single ping alert.
I should not have paraphrased material from the article I referenced. Here is the exact quote:
One important clue to understanding the origin of the radio bursts is that the emission appears to be “coherent,” Hyman said. “There are very few classes of coherent emitters in the universe. Natural astronomical masers — the analog of laser emission at microwave wavelengths — are one class of coherent sources, but these emit in specific wavelengths. In contrast, the new transient’s bursts were detected over a relatively large bandwidth.”
The "Hyman" referenced here is Dr. Scott Hyman, professor of physics at Sweet Briar College.
I would just say - in my own defense - that I can't figure out how they could have detected "coherence" without getting fairly high-res spectral information from the signals.
If a signal has a relative bandwidth of 1% I’d call it coherent. It could have a lot of noise modulation, or whatever, but that’s still coherent to me. Good commercial RF sources have RMS bandwidths in parts per trillion, but for a natural source to exhibit 1% relative bandwidth is provocative.
Your theory has no real basis because it is impossible to know what we don’t know. That is especially true if 99.9% of human knowledge is excluded
I accept your reasoning.
To me, having been raised in the age of lasers (I was in kindergarten when Ted Maiman announced his sensational ruby laser) I've always thought of "coherence" as being something involving parts-per-million stability.
I can see how, when one considers galactic distance and time scales, that is an unrealistic standard.
If nothing else, relative bandwidths on the order of 1% indicate a very high "Q" somewhere in the transmission chain. High "Q" in turn indicates that large amounts of electro-magnetic energy are being stored somewhere, somehow.
At least, E-M energy storage is the only cause I can think of that doesn't definitely involve intelligent design.
Absorbance is indeed what is illustrated. It is the quality of optical density - absorption and attenuation are verbs relating to the process of absorbance.
Of course, the Milky Way, vast as it is, is only one of hundreds of billions of galaxies that are known to be out there...so far.
No doubt that there are many other planets teeming with life out there, some more primitive by Earth standards, others way more advanced. Even the ones that are far more advanced will probably never develop the technologies to make contact with this little outpost called Earth.
Yes, I agree.
But look at the length of time he has been making a living writing about things he does not understand. Amazing.
But also remember, this is TIME magazine, the people who put “We are all Socialists Now” on the cover.
It Is All Illusion.
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