Dysonian Approach to SETI Using E.D.A and
Machine Learning.
Anumanchi Agastya Sai Ram Likhit1
1 Department
of Physics
Student ID:20048
24th November, 2022
Abstract We test a variant of the methodology outlined in Zackrisson et al. (2018)
by modeling the g magnitude of 64K stars as a function of Gaia DR2 parallax and
spectrophotometric features available in RAVE DR5. We also train a meta-model
of the model’s absolute residuals, and define ”anomaly” as a residual divided by the
expected absolute residual. Anomalously dim candidates are selected at a cutoff
of 3-sigma in the anomaly distribution.We note that anomalously dim candidates,
particularly those in the main sequence or below it, exhibit stellar clustering.
1
Introduction
The search for extraterrestrial intelligence (SETI) is a collective term for scientific searches
for intelligent extraterrestrial life in different ways,like monitoring electromagnetic radiation for
signs of transmissions from civilizations on other planets,The possibility of using interstellar
messenger probes in the search for extraterrestrial intelligence was first suggested by some
Scientists, and the technical feasibility of this approach was demonstrated by the British
Interplanetary Society’s starship study Project Daedalus in 1978. Starting in 1979, Robert
Freitas advanced arguments for the proposition that physical space-probes are a superior mode
of interstellar communication to radio signals. See Voyager Golden Record.
2
Methods
The Dysonian Star would be like a Mega Structure Wrapped around the Star gaining the
energy from it, like it makes the star as source of energy and live.
Dysonian SETI is a proposed approach in the search for extraterrestrial civilizations,Instead
of performing radio searches, the approach involves looking for stars that host artificial
megastructures,Dysonian stars should be dimmer than their spectral characteristics would
indicate.It’s possible to approximate the absolute magnitude of a star, and therefore its probable
distance, given the star’s color. With additional spectral features, a better approximation
of the absolute magnitude can be derived.So cluster them and get the H-R Diagram and
predict some stars,We will test machine learning algorithms that are able to deal with complex
nonlinearities. Specifically, we will blend Gradient Boosting Machines (GBMs) and a Neural
Network. Then we will build a meta-model of the model’s absolute residuals, given that each
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Anumanchi Agastya Sai Ram Likhit
Fig. 1. Example of a Dyson Sphere.
star’s measurements have errors that depend on its distance and other features. All model
responses will be out-of-bag, as we rely on k-fold cross-validation.
3
Results and Discussion
Here we have produced a model of stellar magnitude as a function of Gaia DR2 parallax
distance and spectrophotometric features from the databases.Model RMSE is 0.23 magnitudes,
when we select only stars with parallax of 2.5 or more and parallax error of 0.2 or less. This
RMSE is nearly a third of the discrepancy between Gaia parallax and RAVE spectrophotometric
distance moduli;In a Gaia-only H-R diagram, anomalously bright sources are typically giants.
Anomalously dim sources are sometimes giants as well, but most occur in the main sequence.
We find statistically significant stellar clustering in the group of anomalously dim candidates.
Clustering is more evident among candidates that are in the main sequence or below.
One idea is that, since the model uses galactic latitude and longitude as variables, it might
have introduced random regional irregularities in model responses. This hypothesis is easily
discarded by removing latitude and longitude from the set of variables.
A significant problem is the vastness of space. Despite piggybacking on the world’s most
sensitive radio telescope, Charles Stuart Bowyer said, the instrument could not detect random
radio noise emanating from a civilization like ours, which has been leaking radio and TV signals
for less than 100 years. For SERENDIP and most other SETI projects to detect a signal from
an extraterrestrial civilization, the civilization would have to be beaming a powerful signal
directly at us. It also means that Earth civilization will only be detectable within a distance of
100 light-years.
Anumanchi Agastya Sai Ram Likhit
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Fig. 2. H-R Diagram.
4
Conclusion
With Help of Exploratory Data Analysis and rigorous modeling we first made a chart of
modeled absolute magnitude vs. observed absolute magnitude of 1000 random stars from our
data set and next we set different colours to dim and bright stars;set of anomalously dim stars
is shown in green. The set of bright Stars are shown in orange and from this we are able to
construct the Hertzsprung–Russell (H-R) diagram;We found the anomalously dim candidates,
particularly those in the main sequence or below it, exhibit stellar clustering.
Fig. 3. Clustering Results
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Anumanchi Agastya Sai Ram Likhit
References
1. Zackrisson et al. (2018). SETI with Gaia: The observational signatures of nearly
complete Dyson spheres. arXiv:1804.08351.
2. Bradbury et al. (2011). Dysonian Approach to SETI: A Fruitful Middle Ground? Journal
of the British Interplanetary Society, vol. 64, p. 156-165.
3. Griffith, R. L., Wright, J. T., Maldonado, J., et al. 2015, ApJS,217, 25.
4. Hastie, Friedman, and Tibshirani, The Elements of Statistical Learning, 2001.
Thank You !!