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Janus

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Posts posted by Janus

  1. On 3/30/2023 at 8:37 PM, geordief said:

    I mean there needs to be evidence besides Cohen's testimony  and common sense.

    Cohen's credibility is a weak link and I have no idea how common sense  will play out.

    Cohen was "crowing"** how his testimony has be corroborated by documents and has not been rebutted by any if the other witnesses so maybe that will tell.

     

    **not crowing but very passionate nonetheless

     

    How do you know that?

    It seems highly unlikely that a Grand Jury would make the unprecedented move to indict a former President on over 30 counts if all they had to go on was the testimony of one witness.   Of course, we won't know exactly what the charges are until  he is arraigned.  One commentator  has suggested that this may go beyond the hush money case, as he can't see how that, by itself, could be stretched into more than 8 separated charges.

  2. 20 hours ago, exchemist said:

    Seems at the protest rally Trump called, the journalists outnumbered the protesters 5:1

    https://www.independent.co.uk/news/world/americas/us-politics/trump-arrested-today-indict-stormy-daniels-manhattan-b2304990.html

    If his intent was that protests by his supporters would intimate the grand jury into not indicting him, it went over like a lead balloon.  He must be seething over the lack of response.  It kind of shoots a huge hole in his recent claims that the American people would not stand for his being criminally prosecuted when the response to his potential indictment is "Meh".

  3. 1 hour ago, TheVat said:

    I'm not sure if Chomsky has it quite right, but his theory of innate language is a good starting point to the whole question of language acquisition.  Here's a little intro:

    https://plato.stanford.edu/entries/innateness-language/

     

    With advances in syntax and semantics came the realization that knowing a language was not merely a matter of associating words with concepts. It also crucially involves knowledge of how to put words together, for it's typically sentences that we use to express our thoughts, not words in isolation.

    If that's the case, though, language mastery can be no simple matter. Modern linguistic theories have shown that human languages are vastly complex objects. The syntactic rules governing sentence formation and the semantic rules governing the assignment of meanings to sentences and phrases are immensely complicated, yet language users apparently apply them hundreds or thousands of times a day, quite effortlessly and unconsciously. But if knowing a language is a matter of knowing all these obscure rules, then acquiring a language emerges as the monumental task of learning them all. Thus arose the question that has driven much of modern linguistic theory: How could mere children learn the myriad intricate rules that govern linguistic expression and comprehension in their language — and learn them solely from exposure to the language spoken around them?

    Clearly, there is something very special about the brains of human beings that enables them to master a natural language — a feat usually more or less completed by age 8 or so. §2.1 of this article introduces the idea, most closely associated with the work of the MIT linguist Noam Chomsky, that what is special about human brains is that they contain a specialized ‘language organ,’ an innate mental ‘module’ or ‘faculty,’ that is dedicated to the task of mastering a language...

     

    Using the one non-English language I'm a little familiar with, Let's take word order for example:

    "Koira etsii kissaa" and "Kissaa etsii koira", both mean "The dog is looking for a cat."

    "Koiraa etsii kissa" and "Kissa etsii koiraa", both mean " The cat is looking for a dog"

    What changes with word order is the emphasis.

    Koira etsii kissaa = The DOG is looking for a cat.

    Kissaa etsii koira = The dog is looking for a CAT.

    In a somewhat similar fashion,

    Karhut ovat tuolla = The bears are over there.

    Tuolla ovat karhut = There are bears over there.

    Or take the simple "I am"

    in English one would say:

    "I am John"

    "I am cold"

    "I am crying"

    in Finnish they are:

    "Olen John"*

    "Minulla kylmä"

    "Itken"*

    * Can be preceded by "minä", but often isn't.

  4. On 3/18/2023 at 10:00 AM, mistermack said:

    I admit there's a lot different this time. It's not in the heat of an election battle, and he would find it hard to sell it as a plot to steal the presidency. But having said that, crazies are not the most logical of people, so you can't rely on common sense to prevail. 

    Another factor is that a good number of the people that participated in the Jan 6th riot did so under the impression that they were acting on orders from the seated President, and even used that in their defense.  This is not something they could claim now(with the exception of that small subset that believe that he is somehow "secretly" still the President)

    An indication of what we could expect is what happened after the document search and seizure, There were calls then to protest and support Trump, and while some people heeded the call, it was a pretty small turnout in numbers. 

  5. 3 hours ago, PhilGeis said:

    Both FBI and DoE reviews offered as probable the "lab leak" source based on their review.  

     

    The key issue here is, what do they mean by "probable"? It does not necessarily mean the same as "probably".  There is a difference between saying "It is probable that I will be hit by a car crossing the street tomorrow, and saying "I will probably be hit by a car crossing the street tomorrow"  The first just means that there is a non-zero probability that it will occur, and the second implies a good probability that it will occur.

    In addition, for quite a while now, intelligence reports and reviews have been split into categories: High confidence, Moderate confidence, and Low confidence, depending on the reliability of the information and sources.

    From my understanding, these  particular reviews are in the Low confidence category.

    So "probable" used in a Low confidence report is not something I'd be willing to hang my hat on.

  6. 1 hour ago, Sensei said:

    Are they homeless because they were addicted to drugs?

    or

    Are they addicted to drugs because they are homeless?

    or

    Are they addicted to drugs because in North America opioids are prescribed for "everything" ?

    https://www.google.com/search?q=opioids+epidemic+in+america

    What is the sense of existence of private owned pharmaceutics companies? Unlike the public goodness, their existence, their income relies on how many people are ill (the longer they are ill, chronic deseases, the better for them)..

    What is the sense of existence of private owned arm industry? Unlike the public goodness, their existence, their income depends on how many people fight and die in wars.. The more causalities, the more wars, the better for them..

     

    or

    Are they homeless because some white collar decided to push credit on them to get a bonus for it, knowing that they won't be able to pay back.. ?

     

     

    An answer to your questions might lie in how Finland dealt with the homeless issue.  They found that if you provide housing without stipulation, then those people tend to be able to get jobs and require less and less assistance. In addition, it turns out to be cheaper in the long run than dealing with the issues caused by a large homeless population. As a result, Finland has almost no homeless problem.

    In contrast, in the US, you basically need to meet certain conditions before you become eligible for housing.  If you don't meet them, then tough luck.    

  7. 6 hours ago, Tutoroot said:

    Special relativity states that nothing can go faster than the speed of light. If something were to exceed this limit, it would move backward in time, according to the theory.

    No, not really.   I think this idea comes from a misunderstanding of time dilation.  While it is true that a clock moving relative to you would,as measured by you, tick slower and slower as it it approached the speed of light, the equation that predicts this is "undefined" for speeds greater than c (It gives a result that is the square root of a negative number. )

    Now there are some setups that could be used to create causality issues in Relativity if FTL is allowed.  Basically, this involves extended systems moving relative to each other, and rely on how these systems measures simultaneity differently.  An example of such a system would be two long trains passing each other in opposite directions. One train sends an FTL signal from one car to another. That car transfers the signal a car of the other train as they pass each other.  The second train sends an FTL answer back along it length, to be transferred back to the car that originated the message.  Under the right conditions, allowing FTL transmission can result in the answer arriving at the origin before the initial signal was sent.  

    This goes back to what swansont was referring to a few posts ago.

    The truth is that the Theory make no predictions as to what would happen if you exceeded c, as that is beyond it range of applicability.

  8. Your "de-energized" photons sound like a rehash of the Aether, a concept abandoned long ago.  And if light transmission is due to energy be transferred through this medium, and this medium is also dark matter, then how does light travel between galaxies, when dark matter tends to collect in clouds around galaxies.

    And, as joigus alluded to, if this sea of de-energized photons has neither mass nor energy of its own, then how does it generate the gravitational field needed to account for the observations that led to the need for dark matter in the first place?

  9. 14 hours ago, geordief said:

    I saw Bolton on CNN  about an hour ago  attacking the administration  for allowing it to pass over US territory on the basis that it may have  had a nuclear bomb in its payload.

     

    Seems a bit of a fanciful argument.Was he scraping the dregs of his powers of argumentation?

    Riiight.  What would be the point of China putting a nuclear bomb on it?  What good would have dropping a single nuclear bomb have done?  It would be of no significant strategic value, and would only risk starting a full nuclear exchange, and if such an exchange was their goal, they would have just done a full scale nuclear strike.

  10. Just an addition to the previous post. In the Classical Doppler shift equation, vo and vs refer to the velocity of the observer and source with respect to the medium through which the waves are propagating

    As result, you get a different answer if you have the source moving with respect to the medium than if it is the observer moving with respect to the medium.

    Whereas with the relativistic equation, there is no medium and the answer only depends on the relative velocity between source and observer.

    Also, There is a typo in the equation given for Relativistic Doppler shift. It should be v-c for upper part of the fraction.

    You will often see this equation written with 1-ß and 1+ß instead, where ß = v/c

  11. If the Earth were stationary (held suspended above the Sun by some magical string), then yes, an object on the Sun side would weigh less.

    But it is not, it is in orbit, which is a free fall trajectory.   That means everything on Earth is also following that trajectory. 

    In other words, if you suddenly removed the Earth, and left behind only the objects resting on its surface, those objects would continue to orbit the Sun on their own.

    Now let's simplify things.  Assume you have only three objects., The Earth, and objects on its Sun side and the opposite side. We will then magically remove the Earth's gravity's hold on the two objects.

    What would happen?  The Earth will continue along its orbit as usual.  The Sun side object will follow it own independent orbit.  It is closer to the Sun than the Earth's center, but starts with the same velocity as the Earth's center. It would need a higher speed to maintain this orbital distance, so it will begin to "drift" in nearer to the Sun.

    On the other hand, the object on the opposite side, being further from the Sun, and also starting off with the same speed, is moving too fast for its distance from the Sun, and will start to drift away from the Sun.

    Add the Earth's gravity back in, and you get the result that both objects are a bit lighter than objects sitting on the day/night line.  This is known as "tidal effect".

     

     

  12. 1 hour ago, Otto Nomicus said:

    You did get it work out, and without complicated equations involving squares, well done. The only reservation I have is that the velocity of the clock along its horizontal path had to be distorted for it to work. I understand the logic behind it, that the light beam was perceived as completing a longer path than 1 m during the cycle and that was used as the basis for gauging the clock's velocity, assuming that the beam had traveled that path at normal light speed so it took a longer time, thus the clock must have traveled a shorter distance relative to the cycle time.

    What if the clock were traveling along a track set up in a lab of sufficient size and we could gauge its velocity along that track? We would find that it moved 0.866 m in the time the light took to complete its cycle, because the light beam really only moved the vertical height of the clock, not a slanted path. A laser beam doesn't propagate on a slant when directed vertically, because somebody would have noticed if it did. Why, then, would it be assumed that the beam had traveled a longer path simply because the clock moved horizontally at the same time? I don't think that's logically plausible. By that logic, if you dropped an object from a certain height and simultaneously threw another matching object horizontally then the one one dropped straight down would hit the ground before the horizontally thrown one, which is not actually the case. Do you consider the thrown object to have traveled a curved path to ground at a greater velocity than the dropped object traveled straight down, or do you just consider it to have traveled horizontally at a certain velocity at the same time as traveling vertically at the speed of gravity? It was two different velocity vectors, not one.

    The clock moving horizontally is a similar situation, the light waves moved straight down at 1 c while also moving horizontally at 0.866 c, or at least appearing to move horizontally, but it's velocity was not actually a combination of the two, which would mean it exceeded normal light speed and was therefore seen as requiring correction to bring it back down to normal, using velocity contraction and time dilation. There was never a need for correction because the photons had never traveled any farther than 0.5 m up and down vertically, totally a round trip of 1 m, at a velocity of 299,792,458 m/s.

    Now there's the question of whether the light waves/photons were actually inheriting the horizontal motion of the emitter after being emitted vertically. That would make it like a ball tossed vertically by a person on a moving train. What causes the ball to keep moving with the train after being tossed? The obvious answer is inertia. Does light possess inertia? How could it when inertia is a property of mass and light has no mass? So were the vertically propagating light waves really ever moving horizontally with the clock or was it an illusion? One thing is certain, the light was never propagating on a slanted path.

    It appears that the moving clock should have been considered as if it weren't moving at all, in which case, photons would not be required to possess inertia to explain the situation. The obvious conclusion is that, when observing a moving frame with a vertical light beam in it, you should consider the situation to be that you see the light clock exactly as you would if neither of you were moving, no time dilation involved whatsoever. If you see the situation that way then how could you see the situation differently if there were two beams in the moving frame, one vertical and one horizontal? You couldn't use time dilation for the horizontal beam and not have it also effect the vertical beam, which never required time correction at all. So how is time dilation a real thing? Maybe muons just decay more slowly when accelerated, how would you know that wasn't the real explanation for muons making it to the earth's surface? Their mass would supposedly be increased, that theory may be valid, and maybe their rate of decay is slowed in direct proportion to that mass increase. That would remove the most popular proof cited for time dilation and length contraction being valid.

    To your point of a laser beam propagating at an angle, It does.  This is a well understood concept called the aberration of light.  If I put a laser on a moving cart, aimed straight up, and the cart is moving relative to me, I would measure the laser as propagating at an angle other than straight up.  Of course since the speed of light is as fast as it is. the cart would have to be moving at a pretty good clip for me to notice it without very accurate measuring equipment.

    A lot of the rest of your post revolves around motion, and appears to treat it as an absolute.  It is not.  This is something Galileo understood.

    The "Moving clock" can considered to be at rest, and the "observer" as moving.  It doesn't matter which of the two you consider as moving, the observer will observe the same thing.  Relative to himself, the light travels at angle.  The total distance traveled as measured by them, is longer than that measured by the clock.  A postulate of SR is that light travels at c relative to frame of reference from which it is being measured.

    Here's an animation comparing 2 light clocks, one moving relative to the frame, the other not. The white dots are the light pulses bouncing between two mirrors. The circles expand at c to represent the speed of light.

    time_dil.gif.fa0d4b0060980654f46d01695c08b8e8.gif

    Now as far as the moving clock is concerned, the it's pulse just goes up and down between the  mirrors at c, so it measures 1 "tick" to last the same length of time as the non-moving clock does in this animation.  So for example, both clocks would measure going from 0 to 1 as taking 1 us.

    For a horizontal pulse, you need to take length contraction into account, as the
    stationary clock would measure the moving clock as being length contracted:

    length_con2.gif.2b298f0c8b70c353a3d75faeea405139.gif

    You will also note that as far as the stationary clock goes, the horizontal pulse going in one direction take longer for the moving clock. This is an example of the Relativity of Simultaneity.

    Also, if we were to switch our viewing frame, so that we saw the clock moving to the right as "stationary" and the other other clock moving to the left. Then it would be the clock moving to the right that would be seen as ticking slower (keeping in mind that we change nothing but which clock we are "following")

    As far as muons go, their "mass" does not increase.  Their kinetic energy is high, and thus their momentum. But what is really happening is that the increase in both rise at a different rate than that predicted by Newtonian physics.  So, if you were to apply Newtonian formulas to them, it would seem as if their mass increased, but the Newtonian formulas don't apply properly here.

    Besides that, the muon example, while one of the earlier tests of Relativity, was not the only and definitely not the last.  Countless of observations have been made, all giving results affirming Relativity.  You would have to come up with multiple explanations for them all. Explanations which conspired to produce the results of Relativity.

  13. Newtonian Physics says the period of an orbiting object is T = 2pi R^(3/2)/(GM)^(1/2)

    Thus 1/(2pi) = R^(3/2) / T(GM)^(1/2)

    Square both sides:

    1/(2pi)^2 = R^3 /  GM T^2

    Move GM to the left side of the equation:

    1/GM(2pi)^2 = R^3 / T^2

    Invert both sides

    GM(2pi)^2 = T^2/R^3

    So what Kepler's law states is that for any central body, there is a specific relationship between R and T

     Newton keeps the relationship.   It just includes the mass of the central body, so if you know any two of T, R, or M. you can find the third.

     

     

  14. Dark energy is not required for the universe to expand, it is needed to explain why the rate of expansion has been increasing over time.

    The original assumption was that, starting from some initial impetus, the universe began to expand, and that over time, the mutual gravitational attraction of its matter would slow the expansion rate. 

    From this there were two possibilities:

    1. Gravity would eventually win, the universe would stop expanding and then collapse back in on itself.

    2. The universe didn't have quite enough mass to stop the expansion completely, and it would continue to expand forever.

    The study that opened the whole dark energy can of worms was trying to determine which of these was true.

    What they did was measure the recession velocity of various galaxies at various distances.  Since the further a galaxy is from us the longer it took its light to reach us, you were looking further and further into the past as you looked at more and more distant galaxies.

    You then plot a distance/recession graph.  If the rate of expansion had been constant over time, you would get a straight line. Of course, this was not what they expected to see, they expected to get a curve, the degree of which would indicate how fast the expansion was slowing. 

    They got a curve, but one that curved the opposite direction, indicating that the expansion rate had increased over time.  Something was causing it to speed up.

    They settled on calling it "dark energy" just for the simple fact that the term "dark matter" had already been in usage (And this is the only thing the two have in common).

    As to the exact nature of dark energy, it is still an unsolved mystery.

  15. 2 hours ago, DanMP said:

    You seem to know a lot about DM, so maybe you can tell us more:

    DM particles attracted by massive objects, like stars and planets, may form DM atmospheres around them?

    If not, why not?

    If yes, can we make a distinction between the mass of the planet/star and the mass of its close DM atmosphere, the denser part (assuming that DM density increases towards the planet/star center, as for regular matter atmosphere), in order to account for all the dark matter?

    Since DM does not interact (except gravitational) with regular matter, it is possible that the above mentioned hypothetical DM atmosphere to be not only around the planet/star but also inside it? The estimated 90% includes that DM?

    Genady has a point.    Gravity causes planets,etc. to form because regular matter interacts electromagnetically. Collisions, friction etc. is a result of this electromagnetic interaction.  A secondary result of this interaction is the production of electromagnetic radiation.  The production of this comes at the expense of kinetic energy from the matter involved. Two particles collide, emit some EMR and separate, but at a slower speed than they met at. This happens enough and a clump of matter of matter forms.

    DM does not interact electromagnetically, not only does that mean it doesn't "collide" like regular matter, but it doesn't have the same mechanisim to shed KE.  A DM particle can approach a planet, pass right through it, and fly off with the same speed it started with.  There's is nothing to hold it in the vicinity.

    Having said that, There are ways for DM to clump. Gravitational interactions can cause such distributions.  But compared to electromagnetic interaction, they are very,very, very, weak,  and produce results much slower.  The Universe just hasn't been around long enough for small compact collections of DM to form, Just much, much larger and diffuse collections like galactic halos.

  16. 10 hours ago, hoola said:

    with these estimations, and if the distribution is inconsistent on small scales, does our particular vicinity within the galaxy allow the possibility of a "dark matter weather", in that within small regions, perhaps "clouds"  of DM pass through the earth at various times, and contribute to the small variations in the value of G measurement?

    The first thing to keep in mind is that while 90% of the mass of our galaxy is estimated to be dark matter, This includes the entire DM halo or a spherical volume that extends well beyond the visible matter disk of the galaxy.  Once you spread it's mass throughout that huge volume, you end up with an extremely low density. 

    The other thing is that even though, if you were to take the total mass of the solar system and spread it out evenly throughout a spherical volume enclosed by Neptune's orbit, you would end up with a overall density that would put a man-made vacuum to shame,  it would still be many many times denser on average then, say, a 10 parsec radius sphere in our part of the galaxy. And that 10 parsec sphere would, still contain more regular matter than DM.

    It is estimated that the total mass of DM in the Solar system is equivalent to that of 1 small asteroid. Even a 10 fold increase in this density would be insignificant gravitationally to the Solar system.

    If this is the case, then how is it that DM can cause discrepancies in the rotation curves or galaxies? 

    The visible matter in galaxies like the Milky Way is concentrated in its central bulge and thin disk.  So if you calculate orbits based on visible matter, you need to take this distribution into account.  DM however, is spread out spherically, and the vast majority is "above" and "below" the galactic disk.  And any mass closer to the center of the galaxy than a given star, has a gravitational effect on that star's orbit around the galaxy.

    So, for example, if we take that 1 small asteroid's amount of mass spread out throughout the Solar system, and apply that density to the volume of the sphere contained within the Sun's galactic orbit, you get a total mass of DM that is a significant fraction of the total mass of the visible mass of the Milky way; enough to have a noticeable effect on the Sun's galactic orbit.  

    The upshot is that star systems like the Solar system are "matter rich dense spots", which makes their internal orbital mechanics essentially immune to the  kind of DM density variation likely to occur.

  17. 16 hours ago, Sensei said:

    The seasons are here only temporarily..
    After billions of years, the Earth will face the same problem as the Moon, i.e., a tidal lock towards a heavier space object..

    Assuming the Earth isn't engulfed when the Sun enters its red giant stage, you'd be looking at something more like trillion of years, with a lot happening along the way.

    Right now, the Moon exerts the largest tidal effect on the Earth,  So, first it will lock to it.  Tidal braking from the Sun will continue to work to slow its rotation, But the Moon will fight it. The basic effect will be that as the Sun slows the Earth, it begin begins to rotate slower than the Moon orbits.  In this scenario, the Moon-Earth tidal reaction is for the Moon to give up some of its angular momentum back to the Earth, dropping into a lower, even faster orbit.   Even if, at first, the Sun has the advantage, the Moon will eventually move in close enough to once again be the dominate tidal effect,  The Earth's rotation will begin to speed up again, with the Moon getting closer and closer.

    Then eventually, the Moon would pass below the Roche limit and break up into a ring.  With its mass spread out in evenly around the Earth as a ring, it loses it tidal influence, and now the Sun could eventually lock it to itself.

    And even being tidally locked to the Sun wouldn't guarantee an end to "seasons".  The Earth could be tidal locked to the Sun and still have an axial tilt. It would rotate once per orbit, but the North pole would still lean towards the Sun at one part of the orbit, and away half an orbit later.  We see this with the Moon, which is tidally locked to the Earth, it has a small axial tilt of 6°  It alternates between showing us more of its North pole or South pole during it orbit.

  18. When I was growing up in the '60, living in Northern Mn.,  my dad was driving to work early one morning, passing through a small town, and noticed that he was feeling chilly.  He checked the car heater and it was full on, and since it usually did a good job, he suspected something was wrong with it.  Just then, they announced the temp in the town he was in over the radio.  it was -40 degrees.  He thought, "Ah, that explains it." and continued on into work.  ( He worked in the iron mines, which were open pit mines, which,  during the Winter, sunlight never reached the bottom of, so who knows how cold it was there.)

    On 12/24/2022 at 7:21 PM, StringJunky said:

    The first time I experienced  0f in the late eighties, I remember lifting a metal bin lid and my fingers sticking to it quite rapidly.

    During one recess in grade school, someone stuck their tongue to the outside of a metal door during the dead of a MN winter. (like in "A Christmas Story")

    However, instead of the calling the Fire Dept, and pulling him loose, a teacher simply poured warm water over the area until it heated up enough to free him.

     

  19. 17 hours ago, tmdarkmatter said:

    I am sorry, but even in the "highly simplified" image of Wikipedia it does not seem that the light passes close to the black hole of the "lens galaxy":

    https://en.wikipedia.org/wiki/Einstein_ring

    The only distances that matter are the distances between source, lense, and observer.

    It seem highly improbable that it is the light passing closest to the black hole that we see in the Einstein ring. If you watch the Andromeda galaxie, you can see that the center of the galaxy seems not to be transparent from a distance. Rather this light seems to be passing by the galaxy. If you analyze the sun, it is made of trillions of atoms. The same happens with galaxies, they are made of billions of stars, but work together to create the effect.

    The actual amount of bending of the light path passing by the galaxy is very, very, very tiny.  To see this Einstein ring . we need to be the correct distance from that galaxy in order for the  bent light to converge where we are.   For example, we could use the Sun as a gravitational lens, but to do so, we would need to be 542 AU from the Sun, because light grazing the sun deflects light by just 1.7 seconds of an arc.

    Now consider that the galaxy bending the light is billions of ly away, and keeping in mind that just 1 light year is ~117 times longer than 543 AU. Just how much do you think the light passing the galaxy would need to converge on us?  Magnitudes less than it does passing the Sun.

    Secondly, Astronomers, astrophysicists, etc. are well aware of the Relativistic effects that exist, and how to calculate them.  If they were a significant issue, they would be factoring them in already.

  20. 49 minutes ago, tmdarkmatter said:

    The question is, if time passes by slower close to heavy masses, what effect does that have on light passing by a heavy object (black hole). According to Einstein, all processes take place slower and, although light keeps travelling at the speed of light, we (from our point of view) should see that this light should pass by slower. In the intergalactic space, however, the total opposite should happen. As time goes by faster and the light there also passes by at the speed of light, from our point of view we should see this light travelling faster than the speed of light as we know it. If this is real, the galaxies we see, should actually be slightly farther away from us, because the light was travelling faster than we think, a light year would be a bigger distance in the intergalactic space. And if we watch the center of our milky way, it should be somewhat closer to us, because the light was travelling slower. A light year would be a smaller distance.

    Please tell me what you think.

    This is the difference between "proper" light speed (that measured locally), and the  "coordinate" speed of light,( the speed of light at some distant point, measured by our local units of time and space). 

    So yes, light passing say, by the surface of the Sun, would appear to be moving just a tad slower than c, as measured by us further out (Though someone at the surface would measure it as moving at c).

    How would this effect our measurements of interstellar or intergalactic distances?  Insignificantly.  The very slight difference this might make in any distance measurement is completely overridden by other factors that lower the accuracy of our distance measurements.  In other words we don't claim that our distance measurements are accurate enough in the first place to worry about it. For example, take the star Betelgeuse. It is given a distance of 548 ly with an error of +90 to -49 ly.    This potential error range is magnitudes larger than any  due to a difference between proper and coordinate light speed.

     

  21. 1 hour ago, MigL said:

    I would not rule out an errant Ukrainian S-300, but it would have to be nearly 180o off course to hit areas of Poland. Russia fired more than 100 missiles, also S-300, yesterday, mostly targetting power generation infrastructure. The S-300 is not very modern to begin with, and as most have been 're-commissioned' with washing machine parts, I don't imagine they are very reliable. I still believe it originated from one of the Russian firing positions, until evidence proves otherwise.

    This might give NATO the excuse needed to establish a 'no-fly' zone over areas of western Ukraine that border NATO countries, so as to prevent further incidents.
    Just as Russia needs to protect itself from those Nazi Ukrainians by invading them, so should NATO be able to protect itself from the Russian 'special operation'

    For the very reason that it gives NATO an reason to increase air presence in the region is why I have my doubts as to this being Russia.  They are having trouble enough with Ukraine, why would they take an action that would only make things worse for them?

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