3 ms·

Another testable variation of this is the gravitational effect of voids. Voids[1]are regions of the universe devoid of visible matter (stars), as far as we can

by maaku 12y ago

Another testable variation of this is the gravitational effect of voids. Voids[1]are regions of the universe devoid of visible matter (stars), as far as we can tell. These are predicted by the inflationary model as regions of low energy distribution in the early universe. But if we find a void that appears to have gravitational effects on its neighbors, what an astronomer might call "a concentration of dark matter", that could be a Type III civilization. I'd look around the edges and see if we can find any half-eaten galaxies... [1] https://en.wikipedia.org/wiki/Void_%28astronomy%29 https://en.wikipedia.org/wiki/Void_%28astronomy%29

danieltillett 12y ago
Another testable variation of this is the gravitational effect of voids. Yes, the only problem might be that we don't yet have a good explanation for dark matter so it would be hard to know if a void with mass is due to a Type III civilisation or just a local concentration of dark matter. A spiral galaxy with a perfectly spherical void would be pretty hard to explain as anything other than the result of intelligence.
marcosdumay 12y ago
There are stuff out there normaly tough of as "concentrations of dark matter"[1], altought nobody is really sure. I never heard about a "half eaten" galaxy, but I'd guess you hypostesis keep them that way for a very short time, so this is not surprizing. The biggest problem I have with this family of explanations is that, unless the aliens discovered how to revert the Second Rule of Thermodynamics, they must irradiate some low temperature wave. And we measure nearly every candidate nowadays. Unless they are extremely far away, the only thing that could escape us is some very narrow band that happens to be out of range of all current telescopes - and those are not the features of a good heat sink. [1] http://en.wikipedia.org/wiki/Dark_galaxy http://en.wikipedia.org/wiki/Dark_galaxy

by maaku 12y ago

danieltillett 12y ago

Another testable variation of this is the gravitational effect of voids. Yes, the only problem might be that we don't yet have a good explanation for dark matter so it would be hard to know if a void with mass is due to a Type III civilisation or just a local concentration of dark matter. A spiral galaxy with a perfectly spherical void would be pretty hard to explain as anything other than the result of intelligence.

marcosdumay 12y ago

There are stuff out there normaly tough of as "concentrations of dark matter"[1], altought nobody is really sure. I never heard about a "half eaten" galaxy, but I'd guess you hypostesis keep them that way for a very short time, so this is not surprizing. The biggest problem I have with this family of explanations is that, unless the aliens discovered how to revert the Second Rule of Thermodynamics, they must irradiate some low temperature wave. And we measure nearly every candidate nowadays. Unless they are extremely far away, the only thing that could escape us is some very narrow band that happens to be out of range of all current telescopes - and those are not the features of a good heat sink. [1] http://en.wikipedia.org/wiki/Dark_galaxy http://en.wikipedia.org/wiki/Dark_galaxy