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Janus

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Posts posted by Janus

  1. TIL, after receiving the results from my DNA test, that I am apparently 2% Inuit.

    This initially took me a bit off guard, as I have a pretty good grasp of my ancestry, and there seemed to be little to no chance of that.

    Then I remembered something that I saw once dealing with halpogroups and migrations.

    There is a Q halpogroup which migrated across Siberia to the Bering Strait and then to the Americas. But there was also one part of that group which branched off and headed East, In the general direction of the Nordic countries. 

    I'm guessing that some of that group found its way to Finland, where the vast majority of my ancestry is from, and contributed a bit to that ancestry.

    So, while I have no Inuit in my ancestry, I do share a genetic marker with the Inuit.

  2. Three words: Relativity of simultaneity.

    For the cosmic ray, the white dwarf would not be of uniform temperature.

    In the astronomers frame, as the ray enters one side of the star, the opposite side will be, at that moment, at the same temperature.

    But for the cosmic ray, the events of the opposite sides being the same temp would not be simultaneous. The exit point would already be cooler than the entry point at the moment of initial contact.  The star cools at a slower rate as a whole, but since the exit point had a "head start" the Temp there will be much lower when the cosmic ray exits than you would get by just taking the entry point temp an subtracting the rate of cooling times the time it took to cross the star.

     

  3. 1 hour ago, DanMP said:

    Not all. An extra scattering and absorption due to higher interstellar gas density would decrease luminosity of the source in any scenario. How was this addressed? 

    Scattering and absorption doesn't mean that the light energy energy goes away.  For example, our atmosphere scatters Sunlight, largely in the blue end of the spectrum.  We see that blue light as coming from all parts of the sky. Scattered light from a distant object would also aririve, just not directly from the object.

      Likewise, with absorption, the dust will reach thermal equilibrium and radiate energy at the rate it is receiving it. In the case of interstellar gas, in the infrared or radio frequencies.  

    In addition, light coming from a distant object which has had light scattered or absorbed won't be dimmed equally in all frequencies, but would instead show absorption bands in its spectrum.  And since some electromagnetic frequencies are more subject to scattering/absorption than others, Observations are made over a wide range(visible, infrared, radio...) to get a picture of what is happening.

     

  4. 11 hours ago, studiot said:

     

     Please be aware that I was referring very specifically to the trampoline analogy when I talked about an extra dimension. The dimension is in no way "higher" than the others by the way, as they are all supposedly equivalent. For the trampoline the extra dimension is required.

     

    By "higher" I simply meant an an "extra" dimension.  Again, you don't need one.  You just need for the rules of geometry to not be Euclidean. 

    The trampoline is an analogy of non-Euclidean geometry that is just simpler to visualize.

     

  5. 17 hours ago, studiot said:

    Simply put the trampoline is a 2D membrane that is distorted in the third dimension by a force acting in that dimension.

    That's all fine and dandy, but we live in a 3D universe - as far as we can tell there is no 4th dimension - but scaling up the 'trampoline' would require a 4th dim.

     

    There are proper astrophysicists here that can offer multicolour explanations @Janus?

     

     

    It's a common misconception that you'd need a "higher" dimension (four spatial dimensions) for a a 3D universe to "curve into".  All you need is a universe that does not adhere to Euclidean rules of geometry, but is rather non-Euclidean. 

    While non-Euclidean geometry is often modeled as a plane projected onto a surface of a sphere or other 3D object, that's not what is "really" happening. This is just a way for us to more easily visualize Non-Euclidean geometry. 

    Here is an animation I did that gives a way to visualize the trampoline example in 3D:

    That being said, we do live in a 4D universe. Space-time is three spatial and one time dimension.

  6. 2 hours ago, swansont said:

    What does this have to do with what I said?

     

    This isn’t what “woke” means to a lot of people - to those who coined it, it means alert to prejudice and discrimination.

     

    In fact, according to a recent poll, in the US, a solid majority of people see the term "woke" in a positive light.  It is only a vocal minority that tries to paint it as being negative. 

    9 hours ago, Intoscience said:

    Yet there is lots of media exposure & fuss on transgender rights, but we are to dismiss the rights of those affected by this.

    Again, that media exposure on transgender rights is driven by the fact that there are group and political bodies that are working to take those rights away.

    For example, I am of Finnish decent. As such, I am part of a small minority in the US (~0.2% of the population). Yet you don't hear about a push for "Finnish rights" in the media, for the very basic reason that there is no major attempt right now to take rights away from Finnish-Americans. ( Though this was not always the case)

  7. 5 hours ago, Intoscience said:

    Well there is certainly many more important things to worry about in this world that's for sure. But with the current media exposure that this subject (and related) are generating then I guess the discussion is current. At least in Western society. 

     

    The media exposure is only there due to the people who are making such a big fuss about it. People that. in my opinion, are blowing an issue way out of proportion.  Just because the local news does a story about the guy claiming that the "sky is falling", doesn't mean that there is any credence to his claim.  

     

  8. In addition to swansot's comment, putting a spy satellite that high would make it pretty useless as its image resolution would not be very good.

    Generally, they would be put into much lower polar orbits.

    sun-synchronous.png

    So the Earth rotates under it, allowing it to observe pretty much any point on the surface over time. The particular orbit in the image is a Sun synchronous one. This means that as the satellite passes over a particular point of the Earth's surface, it is being lit the same by the Sun. This assures that differences in images between successive passes aren't due to different lighting angles from the Sun.

  9. 8 hours ago, mistermack said:

    It's been shown in research that humans instinctively have an exaggerated sense of fairness, even to their own detriment. Researchers would offer children differing amounts of treats, and the kids would refuse offers that were not considered fair, even if it meant that they would get more. They would rather get less or nothing, than see someone else get more, unfairly. And I believe that Chimps do the same thing. 

    But that's not an excuse for succumbing to those instincts. One would think, as rational beings, we should be able to overcome them. 

  10. Frankly, I'm a bit confused as to why people have turned this into so much of an issue.

    1. I doubt that trans athletes are prevalent enough to make that huge of an impact.

    2. In the end, we are talking about an activity that is recreational/entertainment in nature.

    I mean, this reminds of of the folks who complained about the College football season being suspended during the pandemic, as they seemed to feel that their not being able to crowd into a stadium to watch the sport of their choice was the end of the world.

  11. On 6/29/2023 at 4:43 PM, Airbrush said:

    Interesting question.  The Earth rotates about 1,000 miles per hour at the equator.  According to Wikipedia the Moon's average orbital speed is about 1 km/second, or 2237 miles per hour.  So, the Moon's orbital speed is a over twice as fast as the Earth rotates.  That is easy to understand and remember.

    Moon - Wikipedia

    I really don't think that's a useful way of looking at it.  Consider this, The orbital speed of a geostationary satellite is 6.6 times that of the equatorial speed at the surface.  But a geostationary satellite stays in exactly the same position relative to any point on the ground at all times, so in effect, its "ground speed" is zero.

  12. Newsflash: Relativity doesn't rely on the "speed of light". It relies on there being an invariant speed "c", which is built into the Universe. Even if it were to turn out that light in a vacuum does not travel exactly at c, this would change nothing about Relativity. 

    Now, to the best of our knowledge the speed of light in a vacuum does equal c, but this is a convenience, not a requirement for Relativity.

  13. 15 hours ago, zapatos said:

    I may be mistaken, but while DeSantis as POTUS would likely do many things I object to, he doesn't strike me as someone who would purposely do structural damage to his country simply for his own benefit.

    Are we talking about the same guy who went to war with Disney, one of his state's largest economic drivers, just because they disagreed with one of his policies? 

  14. A factor you need to consider is that the Moon does not orbit over the Equator, and it's orbital plane is ~ 5 degrees from the ecliptic. 

    This video gives an idea of the Moon's path over the Earth.  The camera tracks wit the Moon, and the Red dot shows where the "Earth-Moon joining line intersects the Earth's surface.  It not ~100% accurate as I made the Moon's orbit exactly 28 sidereal days long to keep it simple.

    The path starts North of the Equator, drifts South and then back again.

  15. 15 hours ago, Logicandreason said:

    The "Light Clock" has nothing to do with Physics.  Because such a device is a physical impossibility. So you have an imaginary device that can't possibly function in reality, then you expect to be able to do Math calculations on its performance? That's equivalent to calculating how many tooth fairies would be required to lift a block of Moon Cheese.

    Just out of curiosity, exactly what about the light clock do find as being impossible?

  16. TIL I learned a new measurement:  "Poronkusema" which is roughly 7.5 km.

    It literally translates to "reindeer piss", and is the distance a reindeer can run before having to stop to take a bathroom break.

  17.  Generally, West to East.  However, there are occasions when the shadow is in upper latitudes, where the shadow has enough of a curved path over the surface, to start in one direction, and end going the other.

    TSENorAm2001.gif

  18. On 4/15/2023 at 5:35 AM, Moontanman said:

    That situation seems more than a bit contrived, how about a FTL transmission isn't possible from a small moving object? Maybe only a planet sized object can be used to house or mount an FTL transmitter? No less contrived at least? 

    How does that address the issue?  Sure, it would be impracticable to do a similar scenario just using planet-sized objects, but it is not strictly impossible. 

    As far as the basic scenario being "contrived" goes,   what does that matter?  This isn't about every or even most scenarios causing causality issues,  it is about being able to produce them at all. One way to violate causality is one too many.

  19. 22 hours ago, MJ kihara said:

    Why then bother bringing us into the existence... finding ourselves asking this question.

    This assumes that the universe has some purpose or plan.

    And even if we assume that this is the case, what makes you so sure that we are a major part of it? We could just as well be an undesirable but unavoidable side effect.

  20. 21 hours ago, NTuft said:

    What I'm arguing is that the research too was paid for using lawyers as a screen to pay a private company for campaign adjacent activities. It was improperly described precisely because they wanted what was oppo research to appear independent. The hush money was not disclosed because that's the point there, being extorted by two parties to silence their disclosures. Neither one was disclosed and both involved lawyers's fees as fronts to hide payments.
     

    So a smidgen more transparency with HC, it having been tied in and reported as part of the campaign's finances, whereas the two pay-outs for DT were mocked up as business deals--it being a campaign finance violation apparently is not sticking, as the charges are for fraudulent business practices. Some similarity if not entirely analogous. More to develop, thought, and from the AP article there is money going back and forth between Cohen and the Trump organization, which may muddy the waters.

     

     

    Apparently Judge Walton made those statements because he was in the dark--he didn't think Barr could say what he did without having read the whole thing himself, which seems fair. The reporting here says that the portions that remained redacted, after having reviewed the whole report, were sections on people being investigated for false statements who hadn't done such, i.e. they were slandered at some point in.. whatever it was the Mueller probe was based on. Walton may've claimed that before he hadn't read the report, but that claim seems to have fizzled over time and by my read Barr was correct. That last bolded paragraph statement by Walton doesn't make a lot of sense--it's from the same 23-page order where he requested the unredacted report, and yet he's already claiming the redacted material is contrary to Barr's statements? Walton's claim fizzled out.

    Did you miss the part where Mueller himself wrote to Barr to complain that Barr was understating the seriousness of the report. How can you say that Barr was correct, when the person who wrote the full report didn't think he was?

    And just to touch on something else: While he may have violated Federal campaign laws and could be charged on the Federal level for them, New York has its own campaign laws that he could be charged with violating.  And this isn't an either/or situation.  He could be tried in Federal and State court for the same thing at the same time, if it violates both Federal and State laws.  So, New York can pursue a case, even without a Federal one, unless the Feds come in and assert privilege.

    Now, is the New York case the weakest of the major cases against him? Yes.  But, from what I've heard, from people who understand the law better than I do, is that it isn't as weak as they thought it was prior to the charges being revealed.

  21. 57 minutes ago, Photon Guy said:

    Sometimes your browser might not remember your username if you've been signed out for a long time.

    I think you should at least have the option of signing in with your e-mail address instead of your username. 

    My browser keeps a list of saved signups with user name and password. Even if it doesn't bring it up when you log in, you can go to settings/passwords, bring up the list and look it up.  It is also advisable to back up the file with this info onto external storage from time to time, so you can import it to a new computer if your present one suddenly fails.

  22. 20 hours ago, NTuft said:

     

    Should be interesting. As far as I know, the Stormy Daniel's payoff may've involved moving campaign contribution money, hence should've been picked up and run by Federal attorneys. Wtih capabilities to indict a ham sandwich, a narcissistic Orangutan should've been duck soup. What this case is doing filed in New York looks like wait and see material. Hopefully soon.

    If they don't have it nailed down, it's a 'Uge nothing-burger', and he walks without time, I think it's a huge mistake.

    Back when this investigation started, the feds did step in and and told the New York to back off and they'd handle it. Of course that was back during the time that Bill Barr headed the DOJ.  The same Bill Barr that heavily redacted the Mueller report to shield Trump.  In other words: "We'll handle it meant, we'll make sure nothing is done about it.".

    The present DOJ has it hands full with the documents and Jan. 5th investigations, so I'm sure they fine with letting New York handle this one. 

  23. 11 minutes ago, npts2020 said:

    I can see the issue ending up appealed to the Supreme Court with Mr. Trump claiming he couldn't get a fair trial of his peers because he has no peers. Of course, a frivolous appeal but it would take more time to resolve (along with all of the other appeals) and push final resolution even farther into the future, possibly even beyond "The Donald's" lifetime. His people are experts at delaying and tying things up until something happens like the prosecutor leaves office or plaintiffs lose interest/run out of money. 

    Though it does seem that the courts themselves are beginning to lose patience with this tactic.  He just recently had an appeal rejected a mere 14 hrs after filing it.

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