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Everything posted by MigL
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Are those the voters, or the Government officials, Dim ?
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The most populous species on the planet are insects, and a lsrge number of them are 'carnivores', subsisting on blood and innards of other species. Some of them even have 'herds' , like the 'farmer' ants with their aphid herds. ( you might wanna tell them aphid farming is bad for the environment )
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Seems to be the response of most Governments, not just American. They make up for their incompetent response by throwing the people's money at the problem.
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There is no question that, on a positively curved manifold, the circumference of a circle will be less than pi*D. Similarily, a triangle will have angles that add up to more than 180 deg. But this discussion originally started in another thread, where you claim the circumference of the Earth is less than pi times its diameter. Now we both know nobody has drilled a hole through the Earth's core to measure its diameter. The diameter is 'measured' against a co-ordinate system anchored on far-away points. This co-ordinate system will look like Janus' link from the other thread This co-ordinate system supplies us with x, y, z, and (-ict) co-ordinates which form the interval, S, that is the basis for the metric which determines the 'curvature' of this co-ordinate system we call space-time. It is also the model for gravity; and this model is what is curving. The surface of a sphere, like the Earth, is an actual physical thing, that can curve, and so, we can measure its curvature locally by comparing diameter to circumference. Space-time, on the other hand, is simply a volume evolving in time. It doesn't possess any property which can be curved, bent, warped, or twisted. Incidentally, the model which is GR, can be formulated in several ways, which are equivalent. It can be formulated in terms of varying distances and durations ( intervals ), or, in terms of the units themselves ( the rulers and clocks ) changing. ( this may be from Misner, Thorne, Wheeler Gravitation; but it's a big book, I can't find the reference right now )
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For the orbits of Jupiter and Saturn, Newtonian gravity gives essentially the same results as GR. The only anomaly is the procession of the orbit of Mercury, which is much deeper in the Sun's gravitational well, and subject to much greater 'curvature' on the time axis. Since GR essentially reduces to Newtonian gravity at the lo mass/lo energy limit, only a fool would attemt to solve the set of EFEs for outer planetary orbits when Newtonian gravity will suffice. Even NASA uses Newtonian gravity models to land rovers on Mars and 'sling-shot' Voyager around outer planets. What does that have to do with comprehending GR ?
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And is your measuring apparatus, rulers, clocks, etc. not also curved ? We use light to determine what is 'straight', yet light curves around massive objects. All we can do is measure the effects; we can't measure the underlying 'reality'. As members are fond of saying around here ... "The model is just the map, while 'reality' is the actual terrain"
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The above members have explained things to you in the clearest possible manner, yet you are either unable, or unwilling, to comprehend. The model we have of gravity tells us that gravity's behaviour is exactly the same as if space-time, the co-ordinate system, was curved. It is not a 'description' of reality, but rather, a predictive model. And your incredulity ( or incomprehension ) notwithstanding, it does an excellent job at those predictions.
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Our civilization lifespan as per Copernican Principle
MigL replied to Genady's topic in Applied Mathematics
If we don't agree on the meaning, or even if we are, a 'civilization, how can we establish that we are in the 5-95% of the Gaussian distribution ? Intelligence, or lack thereof, also tends to alter the distribution curve, as our 'evolution' is not solely controlled by environmental forcings, once we have the ability to control our environment ( to an ever increasing degree ). -
Our civilization lifespan as per Copernican Principle
MigL replied to Genady's topic in Applied Mathematics
That seems rather ambiguous/inexact, as there are no other civilizations for comparison. One could argue that we are not fully 'civilized', and may be at the 0.01 % of our civilization lifespan. One could also make the argument that intelligence will have an effect on civilization lifespan, for better or for worse. It may mke our civilization last forever, even expanding to other star systems, or, it may lead to our early demise. You need a definition of 'civilization' and 'intelligence', for comparison purposes; and there are none for comparison to. Statistical analysis with too many unknowns, such as with the Fermi Paradox, usually lead to invalid conclusions. -
You still don't get it. No one is questioning the fact that E=hf ( for massless particles ). We are questioning your mechanism for 'losing energy'. It simply cannot happen as you describe And we are saying light loses energy because the 'wave' is elongated as the space being traversed expands. Simply because the interactions you are considering are well understood, and cannot explain the 'red'shift. On the other hand, you can explain a 'red' shift by moving the source away from the observer. ( IOW, expanding the space between source and observer during transit time )
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The bison do !
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Absolutely not ! You can't measure the energy of light from its own rest frame, because, as yu correctly state it doesn't have a valid rest frame. As measured from any other frame, the measurement will be frame dependent.
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The explanation you've given for 'light losing energy' has been shown to be incorrect. It cannot happen as you describe. And, as Genady explained, energy is frame dependent. Instead of starting from the assumption that the universe is static, and then incorrectly applying physics to support that assumption, why not apply known/accepted physics to the actual observations, and see where that leads ?
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Powerless ? How so ? They have the power to eat what they choose, just like the rest of us. Or do you mean 'powerless' to dictate to the rest of us what we choose to eat ? What about the stress on the environment those uneaten cows, pigs, chickens and fish would cause ? Should we 'tell' all the other carnivores on the planet that they will help the environment by eating grass and leaves ?
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Merry Christmas.
Buon Natale.
Feliz Navidad.
Joyeux Noel....and stay safe ...
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Casimir effect is a local reduction of the vacuum energy ( relative to the global level ) . The Cosmological Constant is a global reduction of the vacuum energy, which is exchanged for the expansion force/acceleration. ( similar to exchange of potential for kinetic in a gravity field )
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"Gamma-ray bursts are thought to be highly focused explosions, with most of the explosion energy collimated into a narrow jet.[78][79] The approximate angular width of the jet (that is, the degree of spread of the beam) can be estimated directly by observing the achromatic "jet breaks" in afterglow light curves: a time after which the slowly decaying afterglow begins to fade rapidly as the jet slows and can no longer beam its radiation as effectively.[80][81] Observations suggest significant variation in the jet angle from between 2 and 20 degrees.[82] Because their energy is strongly focused, the gamma rays emitted by most bursts are expected to miss the Earth and never be detected. When a gamma-ray burst is pointed towards Earth, the focusing of its energy along a relatively narrow beam causes the burst to appear much brighter than it would have been were its energy emitted spherically. When this effect is taken into account, typical gamma-ray bursts are observed to have a true energy release of about 1044 J, or about 1/2000 of a Solar mass (M☉) energy equivalent[82] – which is still many times the mass-energy equivalent of the Earth (about 5.5 × 1041 J). This is comparable to the energy released in a bright type Ib/c supernova and within the range of theoretical models. Very bright supernovae have been observed to accompany several of the nearest GRBs.[36] Additional support for focusing of the output of GRBs has come from observations of strong asymmetries in the spectra of nearby type Ic supernova[83] and from radio observations taken long after bursts when their jets are no longer relativistic.[84] Short (time duration) GRBs appear to come from a lower-redshift (i.e. less distant) population and are less luminous than long GRBs.[85] The degree of beaming in short bursts has not been accurately measured, but as a population they are likely less collimated than long GRBs[86] or possibly not collimated at all in some cases.[87]" From Gamma-ray burst - Wikipedia
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My favorite were the 'Heisenberg compensators' of the transporters, that allowed for the exact reconstruction of a 'beamed' person without the effects of the HUP.
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There are two ways ( at least ) to look at it. One is as an uncertainty in the energy, where the wave function might 'briefly' have enough energy to surmount the potential barrier, to get to the other side in that 'brief' instant. The other, is that the extent , or position of the wave function allows for some finite probability of a part of it to be on the other side of the potential barrier, if the barrier is not very extensive. This latter is a re-interpretation of exchemist's previous post.
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There is another thread ( oddly, by the same name ) where I voice my objections to your preference 🙂 .
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I thought you were going to ask about the incident where Suarez bit Chellini ( Italian defender ). Suarez may be a good player , but he lacks ethics and sportsmanship.
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All observed Gamma ray bursts are directional in nature. That is because they are caused by the influx of rotating ionized material as supernovae clollapse into Black Holes or neutron stars. The polar jets are produced perpendicular to the plane of accretion. Other classes of Gamma ray bursts are produced from mergers of neutron stars, and are similarly directional, because of orbital motion. The Gamma ray burst from the end-of-life explosion/evaporation of a microscopic Black Hole would not be directional, as there is no rotating infalling ionized material to produce polar radiation. It would most likely be an omni-directional burst, and as far as I know, none of the sort have been observed.
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The problem is that Black Holes have entropy, and therefore a characteristic temperature and associated black body radiation, also known as Hawking radiation. Most Black Holes are greater than stellar size, and very cool. much less than the CMB radiation, but as they get smaller ( or start out much smaller, even microscopic ), their temperature increases dramatically, and the radiation emitted is more energetic. Eventually, when small enough, they don't have the mass to support an event horizon, and essentially de-collapse in a large explosion of highly energetic radiation. This Gamma ray burst would be the tell-tale of a microscopic Black Hole's final evaporation. If we know the size of a Black Hole, even primordial ones, we can compare to the CMB as it cooled, and we can estimate how long it would take for microscopic Black Holes to evaporate, and it turns out that primordial microscopic Black Holes would have evaporated by now. IOW, as we look out into the universe, and back in time, we should be seeing the tell-tale Gamma ray bursts that are the last gasps of these primordia; black holes that formed in the high energy densities shortly after the Big Bang. None have ever been recorded.