# Tag Info

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This is the plot you are looking for. This a solar model taken from the Padova evolutionary tracks by Bertelli et al. (2008). It shows the (log) solar luminosity in terms of the current solar luminosity, as a function of age in years. From this plot we see that the Sun reaches 100 times its present luminosity at an age of 12.50 Gyr (that is 12.50-4.57=7.43 ...

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If this site is to be believed, it will only happen for a relatively brief period during the Sun's red giant phase, 7.5 billion years from now (give or take): Around the year 7.1 billion AD, the Sun will begin evolving so rapidly that it will cease to be a main-sequence star. Its position on the H-R diagram will begin to shift from where it is now, near ...

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The three possibilities that you talked about are very different from each other... To do research about black holes in high school is pretty much impossible because you need to have background in GR and QFT. I don't know what you mean exactly by "doing research about wave/particle duality". You have to be more specific. Same comment for Newton's Laws of ...

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The first underlying question is "what is a fluid", and in which condition we can consider we have one. At the time the Feynam courses were written (i.e. days of manual calculus with few digits ;-) ), it was considered that you need the space and time of 100 collisions, i.e. 100 mean free path. less than this you are in the mecanics of collision between ...

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There are a few problems with this question, but also the potential to answer some parts. The short answer is that reduced gravity (in relation to an observer who is far removed, as you mentioned frequently) will allow time to appear to pass more quickly (once again, relative to us, as the other answer said.) This would not mean that time would be observed ...

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"Local" time is invariant. It does not respond to gravity, or speed, or anything else. All you can ever experience is Time. You can't travel faster than light or time. An object sitting on top of Mt. Everest will experience time as being unchanged, but us folk at sea level will perceive it as ticking very slightly faster. So there is no such thing as "our ...

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A top's precession is caused by torque from the point not being aligned with the center of gravity, this tends to try to get the top to rotate away from the stable axis. In the case of Earth, the oblateness interacts with the sun's, moon's, and Jupiter's gravity to try to align the axis of rotation perpendicular to orbital plane. This is a torque that tries ...

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A Little History You ask a very good and relevant question. In fact, back in 1958 H.E. Petschek wrote an interesting paper on "Aerodynamic Dissipation". In that paper, he hypothesized that one could, in theory, produce a shock wave in a collisionless medium (like most plasmas in space). This was highly controversial, since the very concept of a shock ...

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This is assuming the earths magnetosphere is the minimum required to shield an object from cosmic rays which is, in fact, incorrect. Here is the what you need to figure out to calculate a satellite system to do what your proposing .. 1-what is the required minimum strength of a magnetic field so that it deflects virtually all cosmic rays and ...

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Space isn't empty, as I'm sure you've heard before. There's always something between different bodies, such as the interstellar medium. There are also denser regions of space, including molecular clouds and H I/H II regions. Shockwaves can form in any of these places, and propagate through them. There are several different common sources of these shock waves ...

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Not sure about overall EM radiation from colliding singularities, but one part is almost possible to answer: the Hawking Radiation (HR). As singularities approached, the amount of radiation emitted would reduce slightly in certain directions. HR emitted by Black Hole and 2 (S1 and S2) should be absorbed by the other. Assuming S1 and S2 then have a ...

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First, the video which the question links to augments real data with artistic interpretation. I am sure that the OP and other posters know that, but I just wanted to make sure there was no misunderstanding. I was part of the research group that created the data shown in the video. We worked with a scientific visualization specialist/artist to create the ...

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Typical ballpark figure for the diameter of a pulsar is 10km. Therefore circumference is Pi multiplied by the diameter, which is about 30km. If it is rotating at (say) 1000 revolutions per second (for a millisecond pulsar) we get a velocity of 30,000 km/s or about 10% the speed of light

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I've read that the Earth's magnetic field is produced by a dynamo effect, whereby convection currents in the electrically conducting magma of the Earth's outer core create electric currents that produce a magnetic field. There's more than one way to skin Schrödinger's cat. See where we were talking about the Einstein-de Haas effect here. A bar magnet is ...

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I think there is a better way to think about it. To a small factor, you are essentially saying the planet is on the photosphere of the star. The star will fill almost half the solid angle. Therefore the flux (power per unit area) from the star at the substellar point on the planet is $$f \simeq \pi \int B_{\nu}\ d\nu =\sigma T^{4} = 1.5\times 10^{11}\ ... 0 The precise happenings cannot be predicted. However, let's try using the basics of radiation heat transfer to suppose what will happen. As we know, the radiation emitted by a body is directly proportional to T^4, where T represents the temperature of the body. Thus, the increase in emission of radiation increases very rapidly with an increase in ... 2 What will be destroyed? The Moon or the Death Star? Both. You are ignoring length contraction. At a "mere" 0.90 c, the 385000 km between the Earth and the Moon is length contracted to 168000 km. The perceived distance grows ever smaller with increased speed: 54000 km at 0.99 c, 17000 km at 0.999 c, 5450 km at 0.9999 c. You are also ignoring human ... 0 This answer possibly isn't at the level that you would like, but I'm inclined to write it anyway because it's a good introductory answer. In the event that that this question does merge as duplicate, I'll probably just move my answer over there (as this is slightly different than the posted answers). First, watch this Minute Physics video as it provides a ... 1 The Roche limit is a tidal effect. It is due to the fact the Sun pulls more strongly on the near side of the Earth than on the far side. Suppose the Earth is at some distance d from the Sun, by which we mean that the distance from the centre of the Sun to the centre of the Earth is d. The acceleration due to the Sun's gravity is then just given by ... 2 OK. Here we go. I turns out that the above integration can't be solved analytically. There is a HUGE body of science devoted to the subject, enough for a couple of Ph. Ds. Some people have tried to create a generalization of the formula (see http://adsabs.harvard.edu/abs/1987A%26A...175....1M) but I found these approximation lacked the detail needed for ... 2 Some theories posit that a neutron star's magnetic field is residual, left over from the remnant's creation. Strong arguments are given for this in Flowers & Ruderman (1977)1: Dynamo mechanisms, which are responsible for the magnetic fields of many celestial bodies, cannot exist in mature neutron stars, because damping of fluid motion would have ... 5 I) In this answer we will only discuss the equilibrium shape. Recall that when we discussed the shape of Earth in this Phys.SE post, the gravitational quadrupole moment was important. Unlike the Earth, from a surface perspective, it is a very good approximation to assume that all the mass of the Sun sits in the center, cf. below graph. Moreover, the ... 5 Altair, Vega, and Regulus A are perhaps the most famous examples of stars that have been "flattened" by rapid rotation. Some studies (mentioned in Yoon et al. (2010) suggest that Vega is rotating at 70-90% percent of the speed at which it would break up (its rotational velocity is about 20 km/s). Regulus is even closer to this breakup speed: If its ... 59 The symmetry of the Sun has got very little to do with any symmetry in its formation. The Sun has had plenty of time to reach an equilibrium between its self gravity and its internal pressure gradient. Any departure from symmetry would imply a difference in pressure in regions at a similar radius but different polar or azimuthal angles. The resultant ... 7 There is a great deal of effort to try an answer this question in an observational way. Or let be more precise: there is lots of effort to establish what the peculiar velocity field is in our "neighbourhood". The peculiar velocity v_p is the velocity that an object has in addition to the velocity we expect to see because the object is part of the "Hubble ... 5 The question of considering every macroscopic body in the universe is formidable, mostly because on smaller scales (~sub-galactic) you need to worry about more than just gravity. Also, are you only interested in the velocity distribution at the present epoch? The universe is far from static and so it is natural to consider a time dependent distribution. ... 4 It seems strange to me that no one mentioned the Hubble Law. Basically, all galaxies are receding from us with "velocity" proportional to the proper distance.$$v=H_0 D Where $H_0$ is the Hubble constant and the "velocity" is the derivative of the proper distance with respect to cosmological time. There are some subtleties with this definition of ...

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Extremely bright light caused by "running into" a higher number than normal photons, Depends on the warp drive, for the Alcubierre drive that's what you might see, but also blue shifted, but also quantum effects could be important. Note that you can start at a star that is 10,000 light years away and accelerate at a finite acceleration and ...

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My answer is a Reader's Digest version of various Wikipedia articles based around your question. I was thinking about how the sun outputs bajillions of neutrinos (about 7 x 10^7 per second per cm^2) and how their mass is extremely small and their speed extremely close to the speed of light. ... I have no intuition for how that product works out. Is the ...

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