Janus

Gravitons would be quanta of gravitational radiation( gravitational waves). You would not "find them" anywhere in the nucleus. They would be produced under the type of conditions that generate gravitational waves, in the same way that photons are produced by the generation of electromagnetic radiation ( radio waves, light, etc)

The Big bang was not an explosion in space and time, it was an explosion of space and time. It happened everywhere in the universe, as it involved the entirety of all space.

"Worse" and "better" are subjective and depends on the circumstances. The other factor to keep in mind is that evolution acts on populations, not individuals or single family lines. So for example, If you have a population of animals, there is going to be a variation in genetic characteristics within that population. These variations will tend to cluster around an "average" or "norm". If we examine a trait like length or thickness of fur, you will find that it varies around a median. Individuals can have longer than normal or shorter than normal fur. As long as this variation isn't too great everything is hunky dory. Now occasionally an offspring will be born that has fur that is a bit too short or too long for the present climate. They won't do as well and will be less likely to survive to produce offspring. This will end up being a pretty stable scenario as long as environmental conditions remain constant. But, if the climate begins to change, the "ideal" fur length also changes. If the temp goes up on average, offspring which, up until then, would have been born with too short of fur, will fare much better, and those that had been born with long fur but still within an acceptable range will find themselves faring much worse. The change in conditions will lead to slightly The climate change will drive the population towards shorter fur. "Survival of the fittest" means a higher chance of survival( and thus produce offspring) for those that have characteristics that are the best "fit" for the present circumstances. If circumstances change, then the characteristics that "fit" best also change. With your robot example, for it to be more in line with evolution you have to start with a large number of robots at the beginning. Thus while the odds of any individual robot at the start having surviving descendants after 100,000 generations might be low, if you start with a large enough population of robots to begin with, enough of those lines will still be around after 100,000 generations to maintain a robust population.

Rotation has nothing to do with the space-time curvature that results in gravity*. The curvature is caused by the presence of mass. "Mass tells space-time how to curve, and space-time tells mass how to move." -John Wheeler *Except for causing frame-dragging, which is a very weak effect, hard to detect, and for most practical purposes, can be ignored.

WavePad(NCH software) is a downloadable sound editor that is compatible with a number of formats, including mp3 and wav. ( you could even upload in one format and save as another*) It has a "reverse" feature as well as other editing options. It has a free unlicensed version for personal home use and a licensed commercial version. * Some of the "save as" options, such as mpeg-4, are limited to the commercial version. You can upload mpeg-4 files, you just have to save the edited file as something else.

He comparing two frames in relative motion with respect to each other. There is assumption that one is in motion and other still other than for convenience sake. You could repeat the experiment with four lightning strikes. One pair ( strikes A and B) occur simultaneously in the embankment frame, while the other pair ( strikes C and D), occur simultaneously according the the train frame. Thus according to the embankment, strikes A and B occurred simultaneously, but strikes C and D did not occur simultaneously, while according to the train, Strikes A and B did not occur simultaneously, but strikes C and D did.

This inclination puts it well within the range of Kuiper belt objects ( of which it is likely one of) Eris has an inclination of 44 degrees. The Kuiper belt is considered to be made up of material left over from the formation of the Solar system, and I don't expect that Pluto is any different. Even the main core of the asteroid belts contains objects with inclinations up to 20 degrees.

Those links are in his "signature", which means that they show up at the bottom of every post he makes, regardless of the subject of the post. So they were not meant to be part of hs response in this thread.

The actual thermal equilibrium temp of the Earth is -18 degrees C. In other words, without the Greenhouse effect of the CO2 in the atmosphere, The average temp of the Earth would remain below freezing. In addition, an ice ball earth would reflect more Sunlight back into space, reducing the effectiveness of solar heating. Your "evidence" is fatally flawed, as it is based on the false assumption that the Sun alone would provide enough heating at the Earth's present distance from the Sun to keep it above freezing.

670,616,629 mph is just a tad over c, so you can't go from "0" to that speed ( relative to your starting position) The solar system is not traveling through space at "some speed". It's not a matter of it having some real set speed with respect to "space" that we haven't yet been able to determine. It's that it's meaningless to say that the solar system has an absolute motion at all. There are no "stationary objects", as there is no absolute frame of rest for them to be stationary with respect to. You can only measure speeds relative to a chosen reference frame ( which doesn't have to have a physical object associated with it). No single reference frame has any priority over any other, so we are free to choose which ever one is the most convenient for our purposes. So for example, if we were to reduce that 670,616,629 mph just a bit to below c, then if you where to "jump" to this near c speed, someone who remained at your original velocity, would indeed measure you as having undergone a length contraction and see you as "flattened". However, from your reference frame, they are the ones moving at near c speeds, have undergone length contraction, and are "flattened" When it is said that the speed of light is constant, it means that no matter what reference frame you chose, if you are at rest with that reference frame, you would measure light as moving at c relative to yourself. So for example, if you are in a space ship and produce a flash of light, you will measure the flash expanding outward from you at c in all directions. If you were moving past someone moving at 0.5c relative to them when you produced the light, and they produced their own flash of light as you passed them, they would measure that flash as expanding outward at c from themselves in all directions. But not only that, but both of you would measure the same thing for the flash produced by the other person. Each of you would measure both flashes expanding outward from themselves neck and neck. The point being is that the you can never catch the light you produce. Neither can can anybody else, regardless how fast you are moving with respect to them, see you catch that light. But these observers have to measure the light as moving at c relative to themselves. If you never catch the light, this means that you are always are traveling at less than c with respect to them. ( In fact, even for you, in the the space ship, no matter how many times your increase your speed or by how much, you will never be able to measure the speed between you and me as being even equal to c, let alone greater than it. ) This is a result of our living in a Relativistic universe rather than a Newtonian one.

They only moved in the frame in which the distance between A and B was 1 light month. As measured from that frame is took just a tad over 10 month for them to cross the distance while their clock ran slow and only accumulates 10 sec. From their perspective, A and B are moving at nearly light speed relative to them and thus the distance between them is only 10 light sec. Thus it only takes a little over 10 sec from the moment A is next to them until B reaches them. If then then change velocity to match that of B, the distance between A and B will expand to 1 light month. A couple of other things to take into consideration: If we put a clock at A and B and synchronize them to each other in the rest frame of A and B, then in that frame, they will leave A when both clocks read the same time, and arrive at B when both clocks read 1 month later. However if we consider events by the spaceship's frame: The occupants will agree that the clock at A reads the same time when they leave A as A does, however, they will not say the same for the clock at B. They will instead say that the clock at B already reads only about 38 microseconds short of 1 month later than What A's clock reads. During the 10 sec the ship measures until it and B are next to each other, the clocks at A and B will run slow compared to the ship's clock and advance about 38 microseconds. At the moment B reaches the ship, the clock at B will read just that tad over 1 month past the time A's clock read when the ship left A. The clock at A will have accumulated just 38 microseconds. If the ship were to now match speeds with B and A( while remaining next to B), not only would the distance between A and B increase to 1 light month, but the clock at A would rapidly advance ( according to the ship) until it matched the reading of the clock at B.

You are confusing two different things, visual magnitude and angular resolution. Visual magnitude is a measure of how much light coming from an object reaches our eyes. The naked eye can detect things as dim as a magnitude of 6. Uranus at its brightest has a magnitude of 5.7 (the more positive the magnitude, the dimmer the object. A full Moon has a magnitude of -12.6, and the Sun of -26.7) This puts it just in the naked eye viewable range under good viewing conditions. Angular resolution is a measure of how large something has to be in our field of vision before we our eyes can resolve it as anything else than a point of light. Just because something has an angular size less than the resolution ability of our eyes doesn't mean that we can't see it it at all, just that we can only resolve it as a point. Uranus reflects enough sunlight back to our eyes to trigger the receptors on the retina, But we can't distinguish between light coming from different parts of its surface. Thus we simply see it as a single point of light. In other words, it's the amount of light we get from Uranus, and not how big it looks, that determines whether or not is is naked-eye visible. It is very easy to work out how bright Uranus should look to the naked eye. We know how far is is from the Sun and how bright the Sun is, so we know how much sunlight hits it. We know how much of that light is reflected off of Uranus' surface. We also know how far away the Earth is from Uranus and thus can calculate how much of that reflected light reaches the Earth and would enter the eye of an observer. We also know how sensitive the eye is to light. Thus using all that information we can work out whether or not we should be able to see Uranus just based on reflected Sun light. The answer you would get lines up with what we actually see. So the reason we are able to see Uranus is already perfectly understood without have to introduce any other mechanism like gravitational lensing. That would only be needed if Uranus was brighter than it should be, which it isn't.

Issac Asimov wrote an article about this called The Relativity of Wrong We once thought the world was round, and then we corrected that to it being a sphere. That was further corrected to being an oblate spheroid, and later, further refinements were made. The point is that this represents a series of refinements, each step being a smaller adjustment to the previous. When it comes to the Earth's shape, we will never again see such a large shift as between flat Earth and round Earth. Just because we once thought it was flat and now believe it to be round doesn't mean that some day we will conclude that is is shaped like a tetrahedron. Likewise, any correction to Relativity would still need to fit our present observations of the universe, which do indicate that c is a natural speed limit built into the universe. While we can never absolutely be sure that there might not be a way around this, there is no reason to believe that this will ever be the case. It is entirely possible( maybe even likely) that c is an insurmountable barrier. It is important not to let what you would prefer to be true to influence what you believe to the be true. As pleased as I would be if it turned out that the universe was populated with advanced civilizations and that FTL travel between star systems was practical, I can't bring myself to believe it to be true given the lack of any credible evidence for it.

The problem is that you can't assume that all those that riot are there "for the cause". Protests, no matter how peaceful those who organize them intend them to be often attract those who are only there to cause trouble and want to use the peaceful protesters as cover. Then there can be people from the other side of the issue that show up just to stir up trouble; The hope being that by doing so, they can get people to focus on that rather than the issue. There was a post above about looting of a store in Portland. But there was also a very peaceful protest here a day or so later*. Which do you think made the news? It's a bit of a Catch 22, Peaceful protests attract no attention, while violent ones attract the wrong attention. *As an example of one of the points I made above, there were also reports of a group of "Proud Boys" that were planning to march to meet the protesters. Since I never heard of any problems, I assume that the two groups were kept apart.

In addition, any black hole more massive than the Moon is taking in more energy from just the cosmic background radiation than it is emitting via Hawking radiation.

While we don't know it to 100% absolute certainty, ( experiments have only been able to set an upper limit for photon mass), It is consistent with our understanding of the universe. Relativity, which has passed every test thrown at it so far, Says that anything that has zero rest mass must travel at c and only c (in a vacuum). If something has even the slightest bit of rest mass, it can travel at any speed from 0 up to, but not including, c. So, if a photon had any rest mass at all, we should be able to find at least some photons traveling at speeds well below c. So far this has not been the case. So both theory and observation seem to indicate that photons are indeed massless, and unless something crops up to cast doubt on this, it's the way to bet.

That timer on the screen is just showing the time according to the frame of the camera that recorded the image, and there is nothing unique or special about that choice of frame. You could have also had cameras attached to the individual players, each with its own timer. The recordings made by these cameras would be just as valid as the stadium camera. While the stadium recording might show that two events at different ends of the field occurred at the same moment, a player camera may show that they did not. And there is no reason t accept the stadium camera's determination over that of the player's camera. So the fact that anyone watching the recording sees the same events occurring at the same time mark of the digital time stamp, just means that they all agree that this was what was recorded from the reference frame of the camera, not that this represents any kind of universal absolute time.

It is not just that the train observer "sees" the lightning strikes at different times, for him, the strikes occurred at different times. So for the embankment observer, the strikes actually hit the front and back train simultaneously, while for anyone riding in the train, they they do not strike the ends of the train simultaneously. What Einstein is saying is the the very notion of "simultaneous" is frame dependent and is not absolute.

Just to expand a bit on my last post: If you look at this diagram, you can see how to orient Mercury's orbit. https://en.wikipedia.org/wiki/Longitude_of_the_periapsis#/media/File:Orbit1.svg For Mercury, the reference direction is the vernal equinox. It is a point on the celestial equator, just a bit South of Pegasus. For this line, you would measure the longitude of the ascending node. For the epoch starting on J2000 ( astronomy uses Julian years), for Mercury, this is 48.33076593 degrees. Using this as a reference, you tilt the the orbit by the inclination ( 7.000497902 degrees). Then you measure out the longitude of periapsis ( longitude of perihelion for Mercury: 77.45779628 degrees) A line passing through this point and the Sun follows the line of apsides ( which passes through both foci). Now, as already mentioned, the values given are not constant. So for any given date, you will have to take into account that the inclination changes by -0.00594749 deg/century, the longitude of the ascending node by -0.12534081 deg/cen, and the longitude of perihelion by 0.16047689 deg/cen. And even these values are only good for the interval of 1800 AD-2050 AD

Orbital velocity can be expressed as the tangential velocity for a circular orbit. The magnitude of the escape velocity is independent of direction. (technically it is escape speed). An escape velocity trajectory will follow a parabola. So, if you are already in an orbit, it is most efficient to achieve escape velocity by boosting your speed in the direction of your current orbital velocity. In fact, the equations for circular orbital velocity and escape velocity only differ from each other by a numerical factor.

I think you've succumbed to a common misconception about gravitational waves ( the term "gravity wave" actually refers to something like ocean waves, which are affected by gravity) Gravitational waves are not the source of, nor the means by which the "force" of gravity is mediated. Gravity is a field. Gravitational waves just carry information about changes in the field. The gravitational attraction between masses would exist even in a situation where no gravitational waves were present.

There are a number of elements that are used to fully describe a planet's orbit.: The semi-major axis of the orbit (average orbital radius) The eccentricity ( how elliptical the orbit is) The orbital inclination The longitude of perihelion The longitude of the ascending node. The last three are measured with respect to the Earth's orbit around the Sun. The imaginary plane which passes through the Earth's orbit is the ecliptic. The orbital inclination is how much the planet's orbit is tilted relative to this plane.* The longitude of perihelion is measured relative to the Vernal equinox. (draw a line from the Sun that passes through the Earth's orbit where the Earth would be on the date of the spring equinox.) If you draw a line between planet and Sun when the planet is at perihelion ( the closest point of its orbit around the Sun, the angle between this line and the line above will give you the longitude of perhelion. (which also gives you how the major axis of the orbit is aligned). The longitude of the ascending node gives you where the plane of the planet's orbit and the ecliptic cross each other. *Because the Earth is subject to various gravitational disturbance from other planets, this plane can change. To keep things simple, the ecliptic is defined as the plane of the Earth orbit on the starting date of the epoch we are presently in. That way, we aren't always adjusting the inclinations of the other orbits due to the Earth own orbital changes.) All of these elements are subject to change over time due to being perturbed by other bodies in the solar system. The Horizons web site can give the these values and the position of a planet for any date: https://ssd.jpl.nasa.gov/horizons.cgi#top

For long distances, there is a hypothetical means of travel known as the "gravity train". Basic concept is this: You start by digging a tunnel with a downward slope. You keep digging in a straight line. Since the Earth's surface is curved, your straight line tunnel will end up coming out at some other point of the Earth's surface. The midpoint of the tunnel will be closer to the center of the Earth and thus lower than the ends. You seal and evacuate the tunnel of air and put a mag-lev train in it. If you start the train at on end, it will slide down the tunnel picking up speed until it reaches the mid point, and then will climb back up the other side, coming to a stop at the other end. Now here's the kicker: No matter how far apart the ends of the tunnel are from each other, the trip will take a bit over 42 min. Of course, you would never be able to eliminate all friction and losses, so you would have to add a bit of energy to get the train to reach all the way to the other end. Also, the further apart the ends, the deeper the depth of the midpoint, so there would be practical limits on just how long you could make the tunnel. It's a neat idea, even if it never becomes practical.

In the equation, r is measured from the center of the Earth. It seems that you just plugged 424 in for r. The answer you got would have been the GPE for the spaceship if it were sitting on the surface of a world with the mass of the Earth, and just 424 m in radius. For one, you have to convert km to meters, and for the other, you are looking for the difference in GPE between sitting at the surface of the Earth and being 424 km above it, not just the GPE for some point.

Pangaea is just the last of a series of super-continents that existed in the past. The land masses had collided and separated in ages prior to its formation. As far as an imbalance is concerned; The entire mass of the Earth's crust is 2.77e22 kg, which is just 1/72 the mass of the Earth. In addition, continental crust is actually less dense than oceanic crust. So while the crust is thicker under the continents, it doesn't weigh that much different per square mile than oceanic crust. Thirdly, even if there were a slight shift in the mass of the Earth, it wouldn't cause an " imbalance". The axis of rotation would just shift to pass through the new center of mass. It isn't like a washing machine drum which starts to shake the whole machine if the load is unbalanced. In this situation, the axis of rotation is fixed relative to the washing machine and can't shift in response to the center of mass change. Thus the whole washing machine moves in response. The Earth rotates freely in space and is not connected to something else like the drum is connected to the washing machine.