If you’re on the hunt for intelligent extraterrestrial life out there in the Cosmos, waste heat may be the signal of detection.
A recent paper in The Astrophysical Journal is led by Jason Wright at Pennsylvania State University.
Titled “The G Infrared Search For Extraterrestrial Civilizations With ˆ Large Energy Supplies. I. Background And Justification,” the extensive paper offers the view that any advanced civilization is likely to churn out large amounts of energy – and the energy should be visible in the infrared.
“We argue that detectably large energy supplies can plausibly be expected to exist because life has potential for exponential growth until checked by resource or other limitations, and intelligence implies the ability to overcome such limitations,” explains Wright and his co-authors.
Moreover, there’s the promise of using new mid-infrared surveys to spot the ETI hot spots, such as that of NASA’s Wide-field Infrared Survey Explorer (WISE).
The informative paper offers the belief that at least one of the following must be true about galaxy-spanning alien civilizations in the search volume:
• They do not exist, or are sufficiently rare that they are not in our search volume
• They exist, but their total energy supplies are universally below the search’s detection threshold
• ETI’s with large energy supplies universally expel waste heat at low temperatures (i.e. wavelengths longer than the capabilities of the search), perhaps because their energy supply is not starlight
• Spacefaring ETI’s inevitably discover and universally employ physics that makes their civilizations effectively invisible in the mid-infrared despite having large energy supplies (for example, expelling their waste heat as neutrinos, efficiently using their energy supply to emit low-entropy radiation, employing energy-to-mass conversion on a massive scale, or by violating conservation of energy).
Consequences of detection
Continuing, the paper serves up a list of consequences if, indeed, there is a positive detection of waste heat from an alien civilization
“Beyond demonstrating that alien life exists, it would also allow us to essentially “peek ahead” at the nature of engineering of a vastly more advanced species, and perhaps allow us to test our current theories of fundamental physics,” the authors of the paper note.
Such a detection would:
• Demonstrate that there are no insurmountable obstacles to energy supplies comparable to the luminosities of stars or galaxies
• Demonstrate that conservation of energy and the laws of thermodynamics, as we understand them, are not circumvented on a large scale by at least some very advanced civilizations, and so may be absolute. This might imply that attempting to overcome them at our level of technology would be fruitless.
• Allow analysis of the extent of the alien supercivilization, and so a measure of characteristic travel speed, potentially revealing the practicalities of travel near the speed of light.
To access the full paper, go to: