SciChallenger

Regarding I wonder what fantastic explanations you would have come up with before Neptune and neutrinos were discovered Since we are discussing the dark matter here, In your analogy with the Uranus orbit anomalies, should astronomers introduce the invisible "dark matter" that does not interact with our world and has the only purpose to explain the anomalies of Uranus orbit? Or they should use the Occam razor and look for our world object (Neptune), which was not known at that time?

Hi Strange, Thank you for your comment. Sorry I did not reply yesterday, I was too busy. Basically you are repeating the same mistakes as before, and namely posting the criticism without reading the source. >1. The discussion you link to is about hiding a single Dyson sphere by pumping all the excess heat to, say, another nearby planet. I provided link to this discussion because it contains calculations of Dyson sphere surface temperature made by Rod Vance (what I specified in my post). These calculations show that for DS with the size of Pluto orbit the temperature would be 0.01 of Sun surface or about 60 degrees. >2. And as you are assuming that there are 5 times as many of these spheres as there are visible stares, that would be readily detectable. Can you provide any link (or reference to offline article) that supports your statement that object with temperature about 60 K on the distance of several light years would be "readily detectable" by their radiation? (Yes, we detect exoplanets, but by their gravity, not by radiation.) If you cannot prove this, your comment becomes incorrect and misleading. >3. So now you have twice as much chance of detecting them: gravitational lensing... The gravitational lensing detection of DS was analyzes in details in the article published on IntellectualArchive.com . Basically, gravitational lensing researches expected the lambda-shaped graphs (like letter "A"), since the size of objects (brown dwarfs, black holes, planets etc.) are small and their "shadows" rarely influence the brightness of stars passing behind them. The DS have much bigger size and therefore were excluded from the objects detected by A-shaped graph of star brightness, which microlens researchers looked for. For DS we can expect the M-shaped or even U-shaped graph of star brightness when it travels behind the DS. These graphs were not analyzed by gravitational lensing researches. However with their material they can make this analysis and confirm the DS existence or absence. >4. And you think this is simpler than the rather mundane idea of yet another type of particle that does not interact with other matter? Absolutely. If there is nothing that contradicts the DS explanation of hidden masses - we definitely do not need to introduce new type of matter, which is not detectable and which has the only purpose - to reconciliate the math. Question is – does astronomy have material of observations that rejects the DS explanation? The mentioned article on www.IntellectualArchive.com is merely question, not statement. >5.Teeny-weeny aliens taking energy away from atomic nuclei? No comments, sorry.

>Re: Dyson sphere's would still need to radiate away waste heat. This is the only way that a civilization can make use of the energy it would trap from the star it surrounds.(basic thermodynamics) Found nice calculations of DS surface temperature if it would be built around our Sun at Pluto orbit. Posted by Rod Vance from Australia at http://physics.stackexchange.com/questions/69649/thermodynamically-possible-to-hide-a-dyson-sphere I.e. in accordance to "basic thermodinamics" temperature of DS would be about 60 degrees, or undetectable. (Even if we do not count the m=E/c^2 option).

Hi Janus, Thank you for your comments. Here are few replies. >1. Why would a civilization build Dyson spheres around all the stars above and below the galactic disk and not those in the galactic disk? Why not? How we can tell them where to locate their stars? We equally can ask “Why would a civilization build Dyson spheres in the galactic disk and not above and below the galactic disk?” >2. Dyson sphere's would still need to radiate away waste heat. This is the only way that a civilization can make use of the energy it would trap from the star it surrounds.(basic thermodynamics) No. It is NOT the only way. The answer presented in article. (Hint: m=E/c^2, remember? ) >3. The extra mass for the Dyson spheres would be in the from of everyday baryonic matter. There are very strong reasons as to why the universe cannot contain very much more baryonic matter than what we visibly see. (for one thing, the relative ratios of elements would be much different) Models that cosmology tested a ‘priory included the dark matter as one of parameter and did not include the Dyson spheres. Quoting mentioned article "Another argument in favor of dark matter arrives from the analysis of cosmic microwave background radiation. Without access to this data it is difficult to say if it contradicts, is neutral or supports the “Dyson Spheres” hypothesis. For example, authors of the article Spergel at al. (2003), state from the beginning that they consider the model of “a flat Universe with radiation, baryons, cold dark matter and cosmological constant, and a power-law power spectrum of adiabatic primordial fluctuations”. They ruled-out the warm dark matter, but they never tested the model where “Dyson Spheres” is responsible for the hidden mass." Thank you for comments any way!

Hi Strange, Thank you for comments. For me it was not a problem to find this article in IntellectualArchive.com. I even put the reference number #1321 in my initial post. Here is direct link for your convenience: http://www.intellectualarchive.com/?link=item&id=1321 Article answers almost all the questions you asked (like excessive heat, microlensing graphs etc) . Obviously I cannot put the entire article here. Always read articles first and criticize later.

Recently on www.IntellectualArchive.com I read the article that states that effects of hidden mass in galaxies can easily be explained if "Dyson Spheres" are real. If "Dyson Spheres" exist - they produce gravity but do not produce radiation. In this case the dark matter is not required at all. Current observations (like analysis of gravitational microlens) also do not reject this hypothesis, because "Dyson Spheres" have big enough size and analysis of gravitational microlens rejects only small objects. I can not put all details here. You can read it on IntellectualArchive.com. Number #1321 in Astronomy. (It is also published in "IntellectualArchive" journal). Even if this hypothesis appears weird, in accordance to Occam razor it is more preferable than introduction of new type of matter.