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Another answer to stress that the expansion of the universe a) is happening at every point in space by all points receding from all points b)it is a very weak effective "force", which means it is observable between clusters of galaxies receding from each other. The gravitational energy of galaxies, as well of all their stars and planets allows them to ...


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Age of universe is roughly 13.8 billion years, so anything with longest traveling record can only travel 13.8 billion light years at most (in any direction; not necessarily to Earth) because nothing can travel faster than light. Now, we are at the center of the observable universe (which is spherical with visible radius 13.8 billion years), so longest ...


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A community Wiki answer recording someone else's (Ben Crowell's) comment that I think is worthy of being a permanent answer. The proper length is zero, because the photon's path is lightlike. If you want to define the photon's "odometer," you can't do it in the photon's frame, because a photon doesn't have a rest frame. The 13.7Gyr is measured on a clock ...


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The other answers address mainly the solar system's motion relative to our galaxy. To answer the question in your (time varying) title at the time I saw it: Does our solar system rotate parallel or perpendicular to the direction of the expansion of the universe? The answer is neither. There is no "direction" to the universe's expansion. In technical ...


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Assuming our solar system is at a 60degree angle in respect to the galactic plane, the planets would still not trail behind the sun like they do in the video. The theory of relativity(as well as our observation of the planets in our solar system) show that the sun's gravity acting on the planets are enough to form a flat plane. If you want to know why things ...


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Does our solar system rotate parallel or perpendicular to the galactic disc? Neither. You have created a false dilemma. There are lots and lots of other possibilities; in fact, there are an uncountably infinite number of other possibilities. The ecliptic plane is inclined at about a 60 degree angle with respect to the galactic plane. With the possible ...


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The cosmological principle is that the universe is both homogeneous and isotropic on large scales -the last meaning that it looks the same in every direction. This principle has been extensively tested and holds up pretty well (there are some debatable anomalies in the cosmic microwave background that are suggested anisotropies, but they are small). ...


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Light always travels at the speed of light when in a vacuum. Space is a pretty good vacuum. So if it's been travelling for 13.7 billion years, then it has travelled 13.7 billion light years. There is no contradiction here. Yes, those galaxies are now 46 billion light years light years away, but this is because the universe has expanded. You can find lots ...


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Generally speaking they refer to the distances from us when the light as emitted. No correction is usually made to say how far away the object is from us now, because this correction would be very small and inconsequential compared to the uncertainty in the original distance measurement. For instance, taking the Andromeda M31 galaxy as an example. Riess et ...


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Here is the scenario from wikipedia According to inflation theory, the inflaton is a scalar field that is responsible for cosmic inflation in the very early universe. A quantized particle for this field is expected, similar to other quantum fields, called an inflaton. The field provides a mechanism by which a period of rapid expansion from 10^−35 to ...


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Which scientists have called dark matter and dark energy forces? Dark matter is a form of matter that doesn't feel any force other than gravity (so far as we have observed). It's true that dark matter bends light because it has mass and it makes up about $5/6$ of all the mass in the universe. The gravity from this mass is what bends light through ...


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Answer to this question is only by understanding and not proof. If the Universe is expanding then I say Yes, to that the Matter is also expanding. Explanation for this is, all the Matter is expanding means, even the scale to measure the Matter is also expanding. Consider a small Example: A rectangular wooden block is expanding, Measure the initial ...



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