I know, let's go there and find out. Unfortunately, that's the one thing we won't be able to do for a long long time, if ever.

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Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.

I find that in my recent post about the temporal spacing of the dips in light output from Tabby's Star, one of the figures was in error. The first group of multiples of 48 &1/2 days should have read: 2, 9, 15, 1.

A better, more convincing evocation of the numbers connected with the dips in light output of Tabby's Star, referred to above, appears to exist. The well known numerical/geometrical construction known as centered triangular numbers contains seven of eight of these numbers. See link below for an explanation and illustration of centered triangular numbers. It's difficult to understand how all these numbers could exist in a geometrical construction, and in the relevant data from Tabby's Star, by chance.
A single dot at the center gives us 1. The surrounding triangle, with a dot at each corner makes 3. The one around that, with three dots per side makes six, and the outer one, with four dots per side equals 9. The last two, added together makes 15.
Again, the number of multiples of the basic period of 48 & 1/2 days, in the two offset groups are:
2, 9, 15, 1 . And 6, 15, 6, 1 .

http://mathworld.wolfram.com/CenteredTriangularNumber.html

A better, more convincing evocation of the numbers connected with the dips in light output of Tabby's Star, referred to above, appears to exist. The well known numerical/geometrical construction known as centered triangular numbers contains seven of eight of these numbers. See link below for an explanation and illustration of centered triangular numbers. It's difficult to understand how all these numbers could exist in a geometrical construction, and in the relevant data from Tabby's Star, by chance.
A single dot at the center gives us 1. The surrounding triangle, with a dot at each corner makes 3. The one around that, with three dots per side makes six, and the outer one, with four dots per side equals 9. The last two, added together makes 15.
Again, the number of multiples of the basic period of 48 & 1/2 days, in the two offset groups are:
2, 9, 15, 1 . And 6, 15, 6, 1 .

http://mathworld.wolfram.com/CenteredTriangularNumber.html

So if I understand you correctly, you're not suggesting that the dimming events are the shadows of an actual geometrical object such as you describe, but might instead be separate objects that are spaced to act as a semaphore spelling out centered triangular numbers?
Why those? Would that be easier or more efficient than something like, say, a series of prime numbers?

I wouldn't necessarily assume that there is a communicative intent in the apparent spacings of the dips. It might merely reflect an orderly plan of construction.

Of course there could be an attempt to communicate, but what the message might be, other than an intelligent awareness of centered triangular numbers, isn't clear. It's not clear, either that it would be easier, or more efficient to communicate triangular numbers, rather than primes, or visa versa.

It's difficult to say why an alien intelligence might place more importance on triangular numbers than on primes, but it seems possible that this could be the case. It could be a cultural trait, conceivably. It at least seems intelligible.

It's possible that any supposed structures orbiting the star could be equilateral triangles. Triangles are the strongest of any geometric shape. Equilateral triangles of the same size are one of only two shapes that can be combined together to make larger versions of themselves. This might simplify construction.

Which makes me wonder - could a similar pattern of dimming be created by a geodesic sphere under construction?

A single structure entirely enclosing a star seems to run into a couple of problems:
1.) It appears to be structurally unstable against the star's gravity, and prone to collapse.
2.) It would seemingly not behave like separate orbiting objects, but would tend to drift with respect to the star, with one side eventually touching it, and presumably being destroyed.
A dense swarm of separate objects would probably be a more reasonable possibility. These could still be quite large. Dr. Freeman Dyson worked out many years ago that conventional materials, as we then knew them, could be used to make stable structures up to diameter of a good-sized star (~ 1,000,000 miles) in stellar orbits.

I've always thought Dyson spheres were fantasy, at best. Seriously - could any civilization that could endure long enough to even contemplate building something like that not have already figured out how to do more with less? How probable is it that anyone so advanced would still be driven by an insatiable need for more and more energy?
I think the idea of a semaphore makes more sense. Without FTL everyone is confined to their own systems. Radio is limited and may prove to be impractical as a means of finding others. If you wanted to tell anyone else out there who may be wondering whether or not they're alone, what better way than a signal that would continue to function for millions of years and could be seen everyone everywhere? That would be a hell of a legacy for any civilization.

We use energy much more efficiently now than in the past, but that hasn't kept us from using about 10 times as much of it as we did a century ago.
We don't really know what's causing the dimming of Tabby's Star. A Dyson Swarm is just a popular idea about this, based on our own, very limited notions of how a highly advanced civilization would conduct its affairs. The real explanation might be something stranger than we can imagine, at present.
The semaphore idea has also been discussed in the SETI context. There's nothing to prevent an advanced civilization from combining the functions of a stellar semaphore with a partial Dyson swarm, either.

If they're collecting stellar energy with giant solar panels, these could be purposely arranged to have an obviously artificial distribution; some kind of orderly plan. Where star light is collected we see a dimming. Where they aren't, we see bright star light. The combination of light and dark sectors could be made to give a simple message.

Perhaps the numbers from the Tabby's Star data being connected to centered triangular numbers seemed coincidental, and insignificant.
That seems less likely now. I discovered that the ratio of the areas of the three equilateral triangles concerned is as follows: 1, 4, 9. These also happen to be the squares of the first three positive integers--
1^2, 2^2, 3^2. It was the perimeter lengths of these same three triangles that gave several of the numbers found in the intervals between dips in light output from KIC 8462852.

Could we be seeing interstellar launch megamirrors?
http://nextbigfuture.com/2016/02/physics-phd-reader-of-nextbigfuture.html

On further thought, I think we will get a clue in about 15 months.
One of two things is going to happen in May 2017: Either KIC 8462852 will dim, or it won't (I think that is a safe prediction :-) ).
If it doesn't, that rules out a lot of models, like the supergiant planet in a 750 day orbit around an oblate star.
If it does, THIS TIME WE"LL BE WATCHING!

Could we be seeing interstellar launch megamirrors?
http://nextbigfuture.com/2016/02/physics-phd-reader-of-nextbigfuture.html

Made your link clickable, Tom.

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rOZZ
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Thanks, Julie.
If there are a billion or more Dysons in the MW, *maybe* we caught one in the process of being constructed. But otherwise it is just too unlikely for me (but I'm still wishing).

There are roughly 200 billion main sequence stars in the galaxy. The Kepler Space Telescope, which found Tabby's Star, scrutinized about 145,000 of these. So, if only one main sequence star in ~13,800 hosts a civilization currently building a megastructure, the odds are, we'd have found it.

Sorry, a math error in the post above. That last sentence should read: If one main sequence star in 1,380,000 hosts a civilization currently building a megastructure, the odds are. we'd have found it.

Here is the thread on this one on Cosmoquest:
http://cosmoquest.org/forum/showthread.php?158813-Up-to-22-Dips-Detected-in-Starlight-1-500-LY-Away

Thanks, Tom. I made your link clickable from this site.

http://cosmoquest.org/forum/showthread.php?158813-Up-to-22-Dips-Detected-in-Starlight-1-500-LY-Away

Could be a close-in hot Jupiter, Brown dwarf or bad adjustment on equipment.

Could be a close-in hot Jupiter, Brown dwarf or bad adjustment on equipment.

Or a type of variable star we don't yet understand.

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