Comments on Next Big Future: Fermi paradox, metamaterials, dark matter, recent ...

I do want to emphasize that Robert Bradbury is cor...

2008-05-05T21:17:00.000-07:00

I do want to emphasize that Robert Bradbury is correct about dyson shells (of solar orbiting objects) being the non-impossible material requiring version of a dyson sphere and that just because we cannot do better than gravity enabled fusion (stars and suns) does not mean a more advanced civilization can't.

Also, any advanced aliens would not care if primitives like us could see them, it is only about what they are doing relative to other advanced or more advanced aliens.

Thanks for the information Robert.I do not think m...

2008-05-04T18:16:00.000-07:00

Thanks for the information Robert.

I do not think metamaterials would be that unusual for any hypothetical aliens that could make Dyson shells Satellites around their star.

As some of my articles indicate I think that interstellar exploration can be become affordable energy wise by either controlling a lot more energy (K1-K2) or through more efficient propulsion schemes. Making very large and substantially improved hypertelescopes would be a first before sending interstellar probes

The problem with the "classical" view of a Dyson "...

2008-05-04T12:14:00.000-07:00

The problem with the "classical" view of a Dyson "Sphere" is that cannot be built using known materials and construction methods. Also of note is that Dyson never used the word "sphere" in his original article. What he actually envisioned was a set of orbiting O'Neill-ish "habitats". So the picture used tends to perpetuate a false conception.

As pointed out in the discussion of Matrioshka Brains, a background radiation temperature radiating the Sun's energy would have to be huge (if it had to radiate at 3K). But if one simply raises the radiation temperature to 20-50K the size becomes much more reasonable. Cool Matrioshka Brains are very difficult to detect with current telescope technologies. And if you have ships or habitats powered by fusion reactors you don't have to dispose of 10^26 watts so you can have much smaller heat radiating structures.

There is no need for unusual metamaterials to "hide" oneself. The solution to the Fermi Paradox is probably the fact that "they" can watch us if they really want to. There is no need to waste energy going "there".

I think this recent interview to doctor Michio Kak...

2008-04-09T09:56:00.000-07:00

I think this recent interview to doctor Michio Kaku its very interesting:
http://www.sfsignal.com/archives/006515.html

Another way besides looking like background temper...

2008-04-05T08:59:00.000-07:00

Another way besides looking like background temperature is to have
dust and gas surrounding and made to look like some kind of
interstellar matter structure some kind of nebula.

Allow some smaller explainable heating source to show.

A dyson shell (orbiting satellites not a solid shell) could also look like a failed planetary system.

A civilization that can take apart its jupiters to make dyson shells and spheres might also be able to disassemble its stars and use the gases in a massive stealth fleet. (they don't need gravity fusion, they will have a lot of other options.)

One point worth mentioning is that the system, eve...

2008-04-05T04:55:00.000-07:00

One point worth mentioning is that the system, even if invisible to external light, must eventually dump its energy as heat to the wider environment. Robert Bradbury's Matrioshka Brains have multiple layers, each using the waste heat of the layer below it. To dump heat just above the CMB the system's radiators would need to be immense. For a radiator temperature of 3.25 K (emits twice the CMB) the emitting surface has to be 20,768 AU in radius to dump the Sun's luminosity as low grade heat.

A more modest approach is to enshroud low mass red-dwarf stars. A 0.1 solar mass star has a temperature of ~ 2786 K, a radius of 0.125 solar, and a luminosity of ~ 1/1200th of the Sun. For the same heat-sink temperature the emitting shell is just 600 AU across. The advantage of red-dwarfs is their miserly ways with their hydrogen - they burn ~ 98% of it before going off the Main Sequence.

I read a few years back about a paucity of low-mass stars in some globular clusters. Could they be there, but be invisibly enshrouded? Also spiral galaxies are surrounded by a near spherical halo of "dark matter" - could these be enshrouded stars, moved via stellar rocketry, into far orbits to make the best use of the cosmic heat-sink? Milan Cirkovic has suggested ETIs might move to the galaxy's fringes to make best use of the cosmic heat-sink, and shifting a star (albeit slowly) would be feasible for a Type II Civilization.

I would say since the "neighborhood" is the visibl...

2008-04-01T17:10:00.000-07:00

I would say since the "neighborhood" is the visible universe (just a matter of delay the farther away you go), then showing ourselves is assuming that there are no bad aliens that would be problematic for us in the entire universe.

Thus it always makes sense to be as prudent and modest in our display as reasonably possible. Why ever hang out the space civilization equivalent of neon signs ?

I think a general rule is whoever finds the other first is probably the stronger.
If I go to your home system, I am probably stronger.
We go to Europa or Mars or comets and find single cell life or organic material... we are stronger.
ET crosses light years to us, they are stronger.
We get the tech and start going to other star systems, then the odds are that we are tougher than what we find.

Whoever is tougher/stronger gets to decide the outcome of the contact.

Very interesting post and very interesting comment...

2008-04-01T08:46:00.000-07:00

Very interesting post and very interesting comment from Al fin.
I wonder, since we cannot give for granted the good will of other alien species. When a civilization would be able to show themselves to the galaxy? only when we are sure there is no way that other civilizations can harm us? and when is that?

This is exciting speculation. Advanced civilisati...

2008-03-31T20:51:00.000-07:00

This is exciting speculation. Advanced civilisations might indeed be able to "hide in plain sight."

If you read science fiction, the fairly recent novel "Pandora's Star" uses a similar plot device.

If there are "monsters" lurking in the void, we might be wiser to keep a low profile. We are latecomers to the stellar neighborhood, much less the galactic.