Dear Respectful Researchers,
Here come several "strange" and probably unique questions about deep space detection which is motivated by an important recent scientific discovery and publication (in the journal Nature) about Fast Radio Bursts, "A second source of repeating fast radio bursts" as referring to these links as follows:
https://www.bbc.com/news/science-environment-46811618
https://www.nature.com/articles/d41586-019-00089-x
https://www.nature.com/articles/s41586-018-0864-x
https://www.cnn.com/2019/01/09/world/second-repeating-fast-radio-burst-detected/index.html
Researchers at UBC, Canada, have discovered the second so-called “repeating fast radio burst” (FRB) recorded six times coming from the same location, 1.5 billion light-years away. It seems that, CHIME was able to record some of the bursts as low as 400 MHz. My quick and first question is, can we statistically exclude its origin from the extraterrestrial (ET) civilizations?
Here come my rudimentary thoughts and reasoning as an electronics/telecommunications engineer, just out of strong curiosity.
I’ve conducted some quick and simplistic calculation of the link budget from communication perspective. Assume that the 400 MHz radio signals (assuming constant without shifting although actually not) do not significantly suffer from planets/galaxies introduced (all types of) attenuation and are thus deemed in an ideal free-space propagation model.
1.5 billion light-years distance is equal to around 1.419e22 kilometers, which will introduce a Free Space Path Loss (FSPL) of 537.5 dB at 400 MHz. On the other hand, assume that the receiver at ground station is able to achieve an ultra-low sensitivity of -160 dBm thanks to very large high gain phased array antennas, which also means the power at the origin (output) is at least 377.5 dBm, or 5.62e33 Watts (56.2 Decillion Watts).
On the other hand, the Sun releases an estimated 384.6 Yotta Watts (3.846e26) of Energy [1], the power output of all power plants of the world in 2008 is only 2.31e12 Watts. Therefore, we may be talking about an Energy (1.5 billion light year away) equivalent to at least 14.6 millions times the Sun !
This comparison makes one feel that this energy resource can be hardly from an ET civilization, unless it is from the so-called Type-III civilization categorized in the Kardashev Scale [3]. Could it be ?
Another thing I am concerned with and would like to ask is, what could the "super-macro galaxy-level" propagation channel models look like? Would there be some multi-path fading effects? Would there be some time delay/frequency shifting among different bursts, and in the order of months/years?
Thanks for your correction, discussion, and suggestions.
References
[1] https://en.wikipedia.org/wiki/Sunlight#Composition_and_power
[2]https://en.wikipedia.org/wiki/Electricity_generation#Production_by_country
[3] https://en.wikipedia.org/wiki/Kardashev_scale
Yours Sincerely,
Yiming Huo (Jimmy), Ph.D.,
Jan. 12, 2019
Dear Yiming,
It is good that one thinks about what is happening in our surrounding universe.
The frequency of 400 MHz lies in the UHF range. When the stars radiates electromagnetic radiations normally they radiate blackbody spectrum. Since the temperature of the star is very high so, it radiates only a small radiation of its power in this frequency. This means that the power you estimated may be much less than the real value. This points out a very huge star which may be even much much greater than the sun. So, it will be even very less probable to be due to activity of other creatures.
Best wishes
This is interesting
Please think of this experiment. Let us say we have two stars. As the earth moves or perpendicular coming waves we detect the spectrum. Can we find something from this spectrum??
This is interesting because the number of light years is equal to the time of a man life in seconds.
Thanks to Dr. Zekry for your insightful inputs. Actually, my simplistic calculations (formulated in the question) gave us this result: it outputs an power (at the origin 1.5 billion light years away) of at least 5.62e33 (5620000000000000000000000000000000) Watts, equivalent to 14.6 Millions (14600000) times the Sun.
Admittedly, this energy is too big for us, human beings, now to imagine. So there are some speculations that, in the progress for a star to transit to a neutron star, the gravitational collapse generates huge energy in seconds which equals to what the Sun outputs for many years (e.g. hundreds of thousands of years).
However, according to Kardashev Scale, for A Type III civilization—also called a galactic civilization—can control energy on the scale of its entire host galaxy, this huge amount of energy can be easily manipulated.
Thanks to Mr. Sobih for your insightful inputs. For a simpler calculation and easier estimation, as emphasized in the question that I've excluded the redshift induced frequency shift of between "that origin" and earth. But I think I will do a more careful calculation later. I am indeed curious about the macro (galactic level) radio propagation models. How exactly to statistically formulate the impacts from the planets, gravity, scattering, attenuation, etc., on the radio signals......
Thanks for your pointing out the interesting or magic number, 1.5 Billion, this actually inspires some analogy between a human being and universe. If there are couple of years between the first and second FRB, it would be like "couple of seconds (or even milli seconds)" for the universe in its own temporal domain if personifying the universe. In other words, this is more or less like a situation that a human being receiving two radio signals with an interval of couple milli-seconds, in a multi-path channel model.
Please look at my two books
1- The American University Laboratories For Electrical Engineering Part 1
2- The American University Laboratories For Electrical Engineering Part 2
You might find some answers
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