MigL

That link was posted by me on January 21. Doesn't anybody read my posts ?☹️

Yeah ! Never mind the transgendered; why can JC ( and I ) post the same opinions and get treated 'respectfully', while poor Curious Layman was accused of having a hidden agenda, and pilloried ? Is this evidence of noob discrimination, as the rest of us have been around for 10 years or more ? Can we not be more inclusive ? 😀

Thanks for the clarification, Beecee.

We have a fairly good idea of the separation between objects in our observable universe, and we also know that separation between them is increasing ( expansion ). With this information, we can 'wind back' the clock, such that 4 Billion years ago those same objects were separated by half the present amount. Assuming a cnstant rate of expansion, 4 Billion years before that, they were separated by half the amount again. And the separation was reduced by half the previous 4 Billion years. A scaling factor that sounds a lot like Zeno's paradox. However, we know that expansion seems to be currently accelerating, and the universe may have undergone an exponential 'growth spurt' shortly after its 'origin'. This scaling factor is happening throughout the observable universe, such that there is no 'outside' that the expansion is moving into, and, the effect looks the same from every vantage point ( ie. there is no center ).

I find it amusing that people who readily give their opinion as fact, without evidence, then demand evidence from those who disagree with them. Actually, no; I find it extremely annoying.

Two different constraints in play here. Measuring anything to an arbitrary precision is known as the 'measurement problem', which, as Swansont explained, is due to the limited precision of our measuring equipment/experiments,is the first constraint. New technology and fresh ideas help kick this can down the road until we hit the next roadblock.. The other constraint is inherent in quantum systems, and represnted by Heisenberg's uncertainty Principle. It states that certain aspects of reality itself cannot be measured to arbitrary precision, and that is a propertty of the system, having nothing to do with the method of measurement

No ! post science and we can discuss/confirm/refute it. Post quotes from the Bible ( on a science forum ) and you will be ignored ( or shut down ).

Cows produce methane by the action of methanogenic microbes in their ore-stomach. These microbes break down coarse plants and produce methane as part of pre-digestion. Feeding the cows something that obstructs the methane producing microbial action, results in incomplete digestion. So you either need to feed them more food, or more easily digested food. There is no 'free lunch'; even for cows.

To be fair Zap, John usually is not, but Dim is always ambiguous ... 😁😁

IIRC, that happens when a test mass is counter-rotatng wrt the BH, within the ergosphere, and by what is called the Penrose process, that mass can split in two, one half falling through the EH and gaining negative energy, while the other half has more energy than the original. This energy comes from the rotational energy of the BH, and slows its rotation down. Usually, the accretion disk is rotating with the BH ( due to frame dragging effects ) and actually add to its rotational momentum.

If anmyone doesn't want their Astra-Zeneca, send them to Canada. Our only hope for large scale vaccination is if J Biden is right, saying that all Americans who want a vaccine will have it by the end of May; then ( maybe ) Moderna and Pfizer will send us some.

I would think that R-N and Schwarzschild BHs are highly unrealistic. A R-N BH with any charge will be highly 'selective of the ionized plasma in its accretion disk, and quickly rid itself of that excess charge. While any collapsing body, with even the smallest hint of rotation, will see it amplified tremendously by the 'ice-skater drawing in her arms' effect. That makes Kerr BHs the only realistic solution. Hawking radation is only a 'tacked-on' QM effect, due to having assigned entropy to the surface of the EH, and therefore, a 'temperature' to the BH. Glad this conversation is ongoing.

You are one of the people I've learned a lot about GR from, on this Forum, and a previous one. You were always appreciated, and while sad to see you go, you gotta do what makes you happy. Good luck; hope to hear from you again, whenever you can.

Today I learned that a 17 year old girl will marry a 93 year old widower. https://www.yahoo.com/huffpost/civil-war-veteran-widow-helen-jackson-030518406.html Thanks Zap.

No, it was M Grossmann, an expert in differential geometry and tensor calculus, and a former classmate of A Einstein at the ETH, who helped Einstein with the non-Euclidian geometry of GR. Meanwhile N Tesla was feeding birds in the park , and going broke with unworkable schemes. Did I mention he was nuts ?

And why do you keep bringing up N Tesla ? You realize he was half-nuts ? ( its a fine line between genius and madman )

They may be fellow countrymen, but I don't think Studiot is as 'quirky' as P A M Dirac is reputed to have been. What do you think ?

What 'time' are you referring to ? Proper time is necessarily linear, as the clock moves along your wordline. "In relativity, proper time along a timelike world line is defined as the time as measured by a clock following that line. It is thus independent of coordinates, and is a Lorentz scalar.[1] The proper time interval between two events on a world line is the change in proper time." Co-ordinate time is not necessarily linear. "Coordinate time is the time between two events as measured by an observer using that observer's own method of assigning a time to an event. In the special case of an inertial observer in special relativity, the time is measured using the observer's clock and the observer's definition of simultaneity." Quotes from Proper time - Wikipedia

It was also, IIRC, derived from experimental data, not first principles. I could, however, be wrong; it has been a while since I read that. And it was P Dirac, I believe, who showed that E Shrodinger's wavelike differential approach, and W Heisenberg's matrix mechanics were equivalent.

Frankly, I haven't a clue what you're referring to, half the time. I gave an example of a classical wave which demonstrates uncertainty. And you started talking about 'collapse'. What 'collapse' are you talking about here ? Or is it simply nonsense, as usual ?

Didn't have time to read all your post. The first part, which deals with the fact that vision ( used by most predators at long distance ) can be asily fooled by evolved 'countermeasures', is not evidence for your assertions. It is simply that as evolution ( adaptive survival of the species ) has evolved sharper eyesight in predators, it has also evolved camuflage in their prey.

Noahs flood has been proposed as ancient memories of the Zanclean flood, of 5 million years ago, that flooded the Mediterranean basin. I find it hard to believe that our ancestors of 5 million years ago ( Australopythecus, I believe ), could preserve such 'memories' through story-telling, since Homo Sapiens only emerged ( in Africa ) about 300 000 years ago.

I predict that, when AI gains 'imagination', and starts believing it has a 'soul', we'll be close. Of course, by then, it will have ALL human failings, and send Terminators back in time to kill me.

What do you mean by a classical wave 'collapse' ?

I know what you mean ... I was thinking about it overnight, and almost ready to give in to Halc and md65536 PoV, thinking that maybe I had made some incorrect assumption. Then Markus posted, and now I'm not sure either. It seems to be a scale problem, with differing scenarios, and gruesome calculations. But I did enjoy th discussion 🙂 .