stefan r

Could poachers hack into the tracking collar network?

https://arxiv.org/pdf/0704.0908.pdf https://arxiv.org/pdf/1405.1566.pdf Light is redshifted when it is climbing out of a gravity well. Going into a void is the same thing. The cosmic microwave background is redshifted in areas that have large voids. Because the universe expanded while the light was crossing the void the trip out of the void did not blueshift the light back. No. This is wrong. Light gets emitted by hydrogen and travels across a vacuum. It does not matter what temperature the hydrogen is at when the light gets to the observer. The light is only effected by the temperature at the time of emission. The wavelength of light is stretched as the universe expands. Also wavelengths are stretched if light is catching up with a moving target. When they list the temperature of the CMB it just means the frequency of light is proportional to the frequency emitted by gas at that temperature. Alternatively a black body at 2.7K will be in equilibrium with the CMB and will adsorb and radiate an equal flux.

The stars form in clouds of gas. We observe open clusters now. The stars we see in the open cluster are moving away from a location that would make them dense. The stars are close to the same age as the time it would take to get from that location to their current location. Protostars grow in size as gas and dust fall in. When anythings falls into a gravity well it releases energy. A lot of mass falling will become extremely hot. Radiation from a hot object will blow gas away. That slows down the rate that gas falls into a particular protostar. The gas cloud continues to collapse but it forms multiple stars instead of collapsing into one. When fusion starts stars will blow gas away in a stellar wind. Three or more similar mass objects usually form unstable orbits. So individual stars get catapulted away. Stars are much denser than interstellar clouds so an ejected star does not experience much drag force.

There may be a lot of Dyson spheres. But N6946-BH1 does not look like a Dyson sphere. It got brighter from 2009 to 2015. Constructing Dyson sphere should be lowering the visible radiation. Then it went dark in 2015 and lacks infra-red. A Dyson sphere in construction would increase the infra-red output of a star. N6946-BH1 has a some infra-red emission but it is less than the star had in 2009. There could be hundreds, or millions of Dyson spheres in galaxy NGC6946 but N6946-BH1 is not likely to be one of them.

You say to look at stars between 1 and 2 solar masses. Yes these are more obviously massive than the sun. They will also be hotter because their cores are burning hydrogen. Heat causes expansion which lowers density. If you look nearby stars 0.5 to 1 solar mass they are less massive. They are also more dense. There is a consistent trend among most stars. The sun's properties fit with the main sequence. A star with a white dwarf core will blow out into a red giant. You could argue that red giants are a white dwarfs with a mostly hydrogen atmosphere. No, that is just gravity. Jupiter does something similar. So does our atmosphere. A white dwarf has a density closer to 106 x density of water. A white dwarf cannot be surrounded by a atmosphere of hot hydrogen. The heat and pressure would ignite hydrogen fusion and blow it away from the surface. This is the mechanism behind novas. We can also demonstrate fusion in labs on earth. Gas can orbit around a star the same way that planets stay around a star. Orbiting gas will form an accretion disk. Gas molecules orbiting perpendicular (or at high angles) will collide with the disk. So in 1917 the sun had 37% of the current luminosity? In 17 A.D. the Romans would have seen a sun with 2.7 x 10-9 the luminosity we see? The Roman sun would have been less bright than a sliver of crescent moon is today? Socrates saw Sirius as brighter than the sun? Please post a reference to an article that backs this up with data.

If the "very accurate scale" is a balance scale then it will read the same anywhere on earth, on the moon, or on Jupiter. Changes in gravity effect both sides of the balance. A spring scale changes measurement when gravitational force changes. All objects with mass have a gravitational effect. They do not need to be in our solar system. It gets smaller with distance. Distance from earth to moon: 384,399 km (average) Mass of moon: 7.342×1022 kg G = 6.67408(31)×10−11 m3⋅kg−1⋅s−2 F = G m1m2r-2 Force is equal to the gravitational constant multiplied by mass #1 mass #2 and divided by radius squared. F = 6.674×10−11 m3⋅kg−1⋅s−2 x 7.342×1022 kg x 1 kg / (384,399,000m)2 F = 3.316 x 10-5 kg⋅m⋅s-2 So near the equator the scale will increase and decrease around +/- 3.3 x 10-5 newtons with the lunar cycle. Sun 1.496x 1011 m (average) 1.989x 1030 kg F = 6.674×10−11 m3⋅kg−1⋅s−2 x 1.989×1030 kg x 1 kg / (1.496x 1011m)2 F = 0.00593 kg⋅m⋅s-2 F is in units of Newtons. So the "weight" of one kilogram is 9.8 newtons, 9.8 kg⋅m⋅s-2. Rotation of earth has a centripetal force so a kg exerts less force on the spring. Near the poles the gravity from the moon and sun are close to perpendicular.

"Star" is not a measurement of mass. "Solar mass" is a unit of mass equal to the mass of the sun, 1.99 x 1030 kg. When supernovas create a black hole its mass is more than one solar mass. Neutron stars are also more than one solar mass. The primary star that explodes is larger than the black hole or neutron star remnant. Stars smaller than around 8 solar mass will form white dwarfs without exploding as supernovas.