SMBH and super extraterrestrial civilizations（the IAAQ press version）

Dr Makoto Inoue published a hypothesis last year, trying based on scientific logic to expand the

limit of SMBH imagination. It is to discuss how SMBH can be utilized as an energy source by

Type III civilizations of Kardashev classification, if there indeed is one.

【Kardashev classification of advanced civilizations】

Physicists, when they say to search extraterrestrial intelligence, they are not to find“little green

man” or “ET”, but to search highly advanced civilizations of Kardashev classification. This

index was first proposed by a Russian astronomer Nikolai Kardashev, who classify

extraterrestrial civilizations into three types according to energy that is required and can be

managed to sustain and advance the technology level of civilization. Type I with energy

consumption at 4x1012

watts has a technological level that can utilize successfully all energy

sources an entire colonial planet can provide. Type II with energy consumption at 4x1026

watts is

a civilization capable of harnessing all energy radiated by its own star. To achieve this, a Dyson

sphere or the similar surrounding the mother star is built, which is a huge power plant web to

collect, transmit and convert radiated energy. This concept was proposed by Freeman Dyson.

Type III as the most advanced civilization can control energy on a galactic scale, which can

possibly contain thousand of millions of star systems. The energy consumption level is at 4x1037

watts, about the scale our milky way is possessed. Type III can adopt similar technology and

system that Type II has to collect radiations from stars in the galactic system, they may even

utilize energy from SMBH that is often found at the center of many galaxies. There are scholars

proposed that civilization on earth of the present one is leveled somewhere between Type 0 and

Type I.

Although based on mathematic calculation, it is said there should be at least a thousand of Type I

to III of Kardashev civilizations, yet none is ever observed or detected.

【SMBH and super extraterrestrial civilizations】

There are two key assumptions in Inoue’s hypothesis. That is, Type III of Kardashev scale is

not an “isolated”civilization, but a galactic club formed by many civilization members of a

kind in a galaxy, like what we see in the film Star Trek. The energy source of a galactic club is

the SMBH at the center of the galaxy. Habitants in a galactic club are not necessarily living

nearby the dangerous SMBH to utilize its energy. Alternatively, power grid system can be

developed to collect and to deliver energy to club members. In the power network, there are

power collectors near central SMBH doing energy generation and disposition, mid-way power

plants to transmit energy to different habitat solar systems, and local power stations to convert

and distribute energy to club members. The system could even be remotely controlled by

individual intelligent habitat. But the design of the power network will be different from Dyson

sphere of Type II civilization. The “sphere” has to be broken into “Dyson shells” to keep

some area uncovered to give way to emanating jets and accreting flows around SMBH.

Energy transmitted by Dyson shells and such to the habitat should be accomplished presumably

by electro-magnetic radiation. The transmission efficiency is primarily important and therefore

selection of the wavelength region becomes the key. Take the example of Sgr A*, the SMBH in

our Galactic Center, near infrared is possibly the best efficient wavelength choice. This suggests

when we choose the transmission frequency; some points need to be taken into account,

including the spectral energy distribution of the radiation from the accretion disk, the energy

conversion efficiency of the power plant for the transmission, and the transmission efficiency

through the interstellar medium of the galaxy. Inoue had detailed discussion of various accounts

in his thesis. Energy transmitted by a sharp beam of coherent electro-magnetic waves from

SMBH may provide a new clue for SETI for the detection of energy transmission signals. This

may also help expand their search window for other intelligences in the Universe.

In addition, if there is indeed an efficient usage of SMBH energy by advanced Type III, we will

need to emphasize more careful discrimination to the radiation beams detected surrounding

SMBH. They can be emanations from jet or accretion flows, but there is also the possibility that

the emissions are from the power grid system. It is expected that many unknowns will be there

awaiting us to seek further. For example, in what form the SMBH energy can be transmitted

from collectors to civilizations, radio, optical, or infrared? And, where would be the proper sites

to place those power plants, in other words, where can be the orbits of the power plants in the

galaxy?

This hypothesis of Inoue is his private kick, and is an interesting and pioneer one. He emphasizes

this hypothesis is not rootless imagination like time travel and such. To propose this hypothesis is

to explore possibility and limit of some scientific thinking based on known science and

technology, and so to ground a foundation for further exploration or future development.

Hypothesis is to raise new idea for discussion or debating, and after all the challenging, some

may be declined, some be proved and become theories. It is these repeatedly logical challenges

and discussion that pushes science forward, isn’t it? Whether Inoue’s hypothesis will become

a theory, perhaps science of future will have a say. (Plain draft by Joyce Chen, Reviewed by Dr

Makoto Inoue)

(Full version on https://sites.google.com/a/asiaa.sinica.edu.tw/iaaq-on-web/)

論文出處：Makoto Inoue and Hiromitsu Yokoo, Type III Dyson Sphere of Highly Advanced

Civilisations around a Super Massive Black Hole, JBIS Vol. 64, pp.58-61, 2011

天聞季報人物專訪網路全文版由中央研究院天文及天文物理研究所陳筱琪製作，

以創用 CC 姓名標示-非商業性-禁止改作 3.0 台灣 授權條款釋出。

超出此條款範圍外的授權，請與我們聯繫。

創用 CC 授權可於以下網站查閱諮詢 https://isp.moe.edu.tw/ccedu/service.php。