MigL

The driving force behind expansion is actually very weak. Once an area of space reaches a mass-energy density threshold, gravitational coupling of the mass-energy easily overcomes the expansion. It is only the very low density areas between galactic clusters, where space-time is nearly flat, that expansion is dominant. An area which contains a star would certainly not expand 100x.

That CO2 is a 'greenhouse' gas is undisputed. It can probably be verified by a simple lab experiment. The fact that atmospheric CO2 has increased during the last 100-150 yrs of coal and oil usage is also undisputed. And it can also be verified. Even if you weren't worried about climate change, these resources WILL run out. Why not start looking at alternative energy sources ( fusion research, solar, etc. ) which will provide a continued supply of energy well into the future, and do it without affecting our environment.

Ah, but as a chemical storage system it would be useful. We currently have a system where sometimes excess energy is produced, but it cannot be stored. Say a renewable source like solar panel generated electricity, which produces an excess in summer months ( at least in my part of the world ), uses some of this energy output to generate ethanol through this process, and then it is stored for use as fuel during the winter months. Aside from inefficiencies in the process ( and entropy ) there is no net release of greenhouse gases. It effectively steadies the supply of energy generated by renewable sources like solar, wind and other 'variable' sources.

And just to clarify, Imatfaal... Mig is a shortening of my last name. While L is my first initial.

I.E. a smaller BH is 'hotter' and will radiate more mass/energy, while a large one is 'cool' and will radiate very little mass/energy. So a large BH will persist for immeasurably long times, while a small one will radiate away in relatively few ( still billions ) of years. Or as a BH gets smaller its energy output increases and it evaporates faster and faster.

Hawking radiation is proportional to the BH's temperature and inversely proportional to its size.

This mechanism would be applicable for massless particles, i.e. EM radiation. But Hawking radiation can also consist ( to a small degree ) of massive particles. For massive pairs of virtual particles, the problem essentially reduces to an infinitely deep square well potential, for which ( as Swansont pointed out in another thread ) there are no tunneling solutions. ( This is because it would require infinite energy for massive particles to achieve escape velocity ) That is why I sometimes hesitate to use the tunneling model for Hawking radiation

The real question seems to be 'is there anything that can be considered solid at the quantum level ?'. And the answer would have to be NO. Even elementary particles 'smear' out at the energies needed to approach zero separation.

Although relativity has been successfully married to QM in some instances like QFT ( more specifically, with SR ), or Hawking radiation, the fact remains that GR ( or more specifically, the block-universe model ) remains classical/deterministic in nature. As such, I expect the block-universe model to be one of the first casualties of any viable Quantum Gravity theory. The probabilistic nature of QM cannot be reconciled with deterministic future events. I happen to like the term 'event', as it implies a time ( one of the co-ordinates ) and so makes perfect sense.

OK, OK... JC understood what I was trying to say. But Swansont is equally right, I could have been more clear.

I think minimum wage legislation is only a part solution. I know it sounds like protectionism, but if a company which sells $300 sneakers to a primarily North American market, decides to move their manufacturing to Bangladesh where manufacturing costs are reduced considerably, the differences in wages goes directly into the pockets of the company fat-cats/shareholders. This can be eliminated by smart consumerism ( which will never happen ) or legislation. The automotive industry already has a measure of this, with companies like Toyota and Honda establishing North American manufacturing plants. These companies provide some return to the North American economy by providing some good paying local jobs.

Yeah, but you guys voted to leave the EU. Obviously you guys don't know economics from a hole in the ground. How can we take you seriously ?

I don't think D. Trump himself thought he was going to win the nomination. He was just in it to stir up sh*t and get more publicity/exposure. He said whatever came into his head, whether it made sense or not, and had no platform to speak of ( he still doesn't ). He has, however succeeded in making Republicans look bad for backing him, Democrats look bad for getting in the 'mud' to fight him, and all of America look bad for taking him seriously.

Open to interpretation, unless it concerns money owed to me or a debt, as Studiot says. ( I'm gonna try that approach on my tax return ) Although if Studiot is going to criticize the OP's ambiguity, he shouldn't use the variable x as a multiplication operator. ( that's why I don't use LaTex; I'd make tons of similar mistakes )

So superstring equations are similar to computer code. And ??? A lot of computer code is comprised of equations. What exactly do superstring equations describe ? They could apply to a multitude of possible universes. They certainly aren't specific to this particular universe. And what if we were in a 'simulation', or the information describing our universe was encoded on a boundary surface ? Remember these are just models with which we attempt to describe reality, but how would it change the way you live your life ? So why stress out about it ?

Negative energy is simply an 'accounting' trick. The proper term is exotic matter. Consider two virtual particles on the edge of an event horizon. One of the pair escapes to infinity and becomes real, the other is 'captured by the BH. The mass-energy debt of these virtual particles must be re-paid, and so the captured particle, even though captured by the BH, actually causes it to lose mass-energy. It is termed exotic matter and can be considered to have negative energy so that the books balance. I don't know how one would ever 'harvest' exotic matter.

Must be difficult finding parts for the '27 T.

Some have made the argument that the Roman Empire never really ended until modern times. Rome was not changed by the 'barbarian' invasions, but rather the 'barbarians' took on Roman ways. The center of the Empire may have moved north, and classical knowledge lost during the so called 'dark ages', but the Habsburg monarchy of the Austro-Hungarian Empire rightfully referred to themselves as the Holy Roman Empire until 1918. ( Northern European emperors even referred to themselves as Caesar, i.e. Kaiser and Tsar )

Excellent Delta. The 'other side' isn't always stupid or ignorant for thinking the way they do. They simply have different priorities, which we may not even consider until we've 'walked a mile in their shoes'. And they have a right to a vote like all Americans. I may be embarrassed by how low this election has sunk, but democracy is still the best !

And before you ask... A compressed spring ( or a stretched spring ) also has more energy, and equivalent mass. Any energy added to a system increases its equivalent mass.

Agree with Arete's assessment. Can't wait for this month to end. Its like watching Michael Scott of Dunder-Miffland ; you cringe at some of the things said and are embarrassed for him. Incidentally, what old cars, Arete ?

Let me see if I can explain... Based on the visible mass composing the galaxy, centrally located to a large extent, and standard gravitational theory ( Newtonian will do ), the farthest stars should be rotating much slower than close-to-center stars. Just as Neptune rotates much slower around the Sun than Earth does. The spiral arms would rotate slower at their 'tips' compared to the central section, and get 'wound up'. This is not what is observed. The spiral arms don't rotate as 'strings' tied to a central hub, rather the whole galaxy rotates as a 'pinwheel', with the edges rotating at the same angular speed as the center. This would be the same as if Neptune was rotating around the Sun with the same period as the Earth. Clearly Neptune would then be moving faster than its escape velocity and be flung out of he solar system. But this does not happen with the stars on the edge of the galaxy. If we elect to keep standard gravitational theory, the only other explanation is that, as you move out from the center of the galaxy each successive shell has to have the same mass density as inner shells. This is, again, not what we see. This indicates that a lot of this mass density is 'hidden', in effect, it doesn't interact electromagnetically, just gravitationally. That is why it is called 'dark' matter. The other unknown cause for an anomalous effect, the accelerating expansion of the universe, is totally unrelated, and has been termed 'dark' energy, as its ( possibly ) related to vacuum energy, the resulting pressure nad expansion ( see Einstein's Cosmological Constant ).

Actually dark matter explains why we are NOT being flung outwards from the galactic center. It has nothing to do with expansion, accelerated or otherwise.

Very well forget about Bill. If Hillary is innocent of accusations because no charges were brought to bear for the deletion of classified e-mails, then until charges are filed against Donald is he also not innocent ? Or do you want to apply different standards to the two candidates because one is the better option ( or lesser of two evils ) ? Its only for traffic laws that 'you're guilty until you prove yourself innocent', not for criminal laws

Doesn't expand into anything. The separation between existing objects in the universe increases. ( with certain constraints imposed by gravity, of course )