Starship Asterisk*

RJN wrote:
After midnight when the APOD appeared, I showed a person I know hoping to get a "Cool!" response. But this APOD made that person sad. The dead cartoon cat made them remember a recently deceased real cat of which they were fond. Apparently the thought of a dead cat -- and possibly killing a cat -- even a virtual cat -- weighs heavily on people's minds. Oops. And so maybe the tie-in to Schrodinger was less appealing than I thought.

https://en.wikipedia.org/wiki/Wigner%27s_friend wrote:
<<Wigner's friend is a thought experiment proposed by the physicist Eugene Wigner; it is an extension of the Schrödinger's cat experiment. The thought experiment posits a friend of Wigner who performs the Schrödinger's cat experiment after Wigner leaves the laboratory. Only when he returns does Wigner learn the result of the experiment from his friend, that is, whether the cat is alive or dead. The question is raised: was the state of the system a superposition of "dead cat/sad friend" and "live cat/happy friend," only determined when Wigner learned the result of the experiment, or was it determined at some previous point?>>

https://www.mersenne.org/primes/?press=M74207281 wrote:
GIMPS Project Discovers
Largest Known Prime Number: 2^74,207,281-1

<<On January 7, 2016, at 22:30 UTC, the Great Internet Mersenne Prime Search (GIMPS) celebrated its 20th anniversary with the math discovery of the new largest known prime number, 2^74,207,281-1, having 22,338,618 digits, on a university computer volunteered by Curtis Cooper for the project. The primality proof took 31 days of non-stop computing on a PC with an Intel I7-4790 CPU. This is the fourth record GIMPS project prime for Dr. Cooper and the University of Central Missouri. Dr. Cooper's computer reported the prime in GIMPS on September 17, 2015 but it remained unnoticed until routine maintenance data-mined it. The official discovery date is the day a human took note of the result. This is in keeping with tradition as M₄₂₅₃ is considered never to have been the largest known prime number because Hurwitz in 1961 read his computer printout backwards and saw M4423 was prime seconds before seeing that M₄₂₅₃ was also prime.>>

BDanielMayfield wrote:

Chris Peterson wrote:

Bruce wrote:Wouldn't that mean that the overall energy of the whole Universe is unchanged due to cooling?

I don't think it's normally suggested that the overall energy of the Universe is changing.

My worldview is substantially less rocked, so thanks. But that's not counting Dark Energy, right?

Chris Peterson wrote:

Bruce wrote:Wouldn't that mean that the overall energy of the whole Universe is unchanged due to cooling?

I don't think it's normally suggested that the overall energy of the Universe is changing.

Guest wrote:

Chris Peterson wrote:Keep in mind that photons are not really massless. They have energy, and therefore a mass equivalent. They also have momentum, which means a mass equivalent. The confusion likely comes from the understanding that a photon has zero rest mass. But that's a theoretical concept, given that a photon is never at rest.

While Art is correct that the kinetic energy of CMB photons is decreasing (because of redshift), this does not violate the law of conservation of energy, because kinetic energy is an observer dependent property- the kinetic energy we measure depends upon our frame of reference.

Can you blame us non scientists for thinking that conservation of energy is a law when scientists commonly call it such? (Just an amusing irony :wink: )

The frame of reference energy dependence is interesting. Would it be correct to then assume that the energy of these CMB photons hasn't really decreased, it's just that they look that way due to the expansion of the universe?

Wouldn't that mean that the overall energy of the whole Universe is unchanged due to cooling?

Chris Peterson wrote:Keep in mind that photons are not really massless. They have energy, and therefore a mass equivalent. They also have momentum, which means a mass equivalent. The confusion likely comes from the understanding that a photon has zero rest mass. But that's a theoretical concept, given that a photon is never at rest.

While Art is correct that the kinetic energy of CMB photons is decreasing (because of redshift), this does not violate the law of conservation of energy, because kinetic energy is an observer dependent property- the kinetic energy we measure depends upon our frame of reference.

Chris Peterson wrote:

BDanielMayfield wrote:As mass is involved in Kinetic energy I don't understand how it relates to massless photons. I would like to though.

Keep in mind that photons are not really massless. They have energy, and therefore a mass equivalent. They also have momentum, which means a mass equivalent. The confusion likely comes from the understanding that a photon has zero rest mass. But that's a theoretical concept, given that a photon is never at rest.

While Art is correct that the kinetic energy of CMB photons is decreasing (because of redshift), this does not violate the law of conservation of energy, because kinetic energy is an observer dependent property- the kinetic energy we measure depends upon our frame of reference.

BDanielMayfield wrote:

neufer wrote:

Chris Peterson wrote: ...conservation of energy is more of an observed principle than it is something with strong theoretical underpinnings.

Dark Energy is constantly increasing.

Kinetic energies of unbound particles (e.g., CMBR photons) are constantly decreasing.

As mass is involved in Kinetic energy I don't understand how it relates to massless photons. I would like to though.

neufer wrote:

Chris Peterson wrote:
...conservation of energy is more of an observed principle than it is something with strong theoretical underpinnings.

Dark Energy is constantly increasing.

Kinetic energies of unbound particles (e.g., CMBR photons) are constantly decreasing.

Chris Peterson wrote:
...conservation of energy is more of an observed principle than it is something with strong theoretical underpinnings.

Chris Peterson wrote:

geckzilla wrote:What is this world coming to? Chris just used a bona fide emoticon.

It was not my intent. I have emoticons disabled on my system, so any that I use are good old-fashioned ascii constructs. I guess the system must convert them for those who have them enabled.

geckzilla wrote:What is this world coming to? Chris just used a bona fide emoticon.

BDanielMayfield wrote:

Chris Peterson wrote:Maybe. But to be sure, these are philosophical assertions, not scientific ones.

I'll take the "maybe" Chris. Philosophical assertions can be correct if they are based on reality.

And yet, in a physical sense, i is entirely real, an essential element in a large number of equations that appear to accurately describe the workings of the universe in which we live. That is, it is only imaginary in the mathematical sense of the word, which is quite different than the everyday use, in which things like unicorns are imaginary.

Yes I was aware that there are real and necessary uses for i. Does my use of it fit here? If not, let's create a new term; lowercase italicized u, short for unicornian.

Chris Peterson wrote:

BDanielMayfield wrote:

neufer wrote: Where in GR, in the macro world, are those multiple copies?

Nowhere. They don't exist in real spacetime. The supposed other universes are purely imaginary. We all live in the one real universe which we all effect by our actions as far as our individual spheres of influence extend.

We live in the real U, which is the sum of all paths actually taken by all mater and energy inside it, both animate and inanimate. The paths not taken are iUx, which are infinite but not real.

Maybe. But to be sure, these are philosophical assertions, not scientific ones.

(To the non math heads out there i is the imaginary number, the square root of negative one. As you cannot take the square root of a negative number the result isn't real, its imaginary. Imagine that.)

And yet, in a physical sense, i is entirely real, an essential element in a large number of equations that appear to accurately describe the workings of the universe in which we live. That is, it is only imaginary in the mathematical sense of the word, which is quite different than the everyday use, in which things like unicorns are imaginary.

BDanielMayfield wrote:

neufer wrote:

BDanielMayfield wrote: Where in GR, in the macro world, is energy conservation violated?

Where in GR, in the macro world, are those multiple copies?

Nowhere. They don't exist in real spacetime. The supposed other universes are purely imaginary. We all live in the one real universe which we all effect by our actions as far as our individual spheres of influence extend.

We live in the real U, which is the sum of all paths actually taken by all mater and energy inside it, both animate and inanimate. The paths not taken are iUx, which are infinite but not real.

(To the non math heads out there i is the imaginary number, the square root of negative one. As you cannot take the square root of a negative number the result isn't real, its imaginary. Imagine that.)

neufer wrote:

BDanielMayfield wrote:
Where in GR, in the macro world, is energy conservation violated?

Where in GR, in the macro world, are those multiple copies?

BDanielMayfield wrote:

Chris Peterson wrote:

BDanielMayfield wrote:I don't know why this didn't occur to me sooner, but the notion that the choices we make can actually "split the universe" into multiple copies can not be true because it violates conservation of energy.

Conservation of energy is an empirical principle, not a well defined law of nature. It is probably violated in a number of general relativity cases, and possibly some quantum mechanical cases, as well. Violating conservation of energy is not necessarily a good argument against something. The situation is further complicated by the fact that it applies to closed systems, and when we're talking about the Universe, we do not know if or how it is closed. Alternatively, the condition may be satisfied so long as each individual universe which exists after a decision has itself conserved energy. After all, the law may only apply within any given universe; creating a new one is a different situation.

Wow. I've always heard the declaration, (like it was carved in stone or something), that Energy can neither be created or destroyed. Thus I've always thought that it is a fundamental truth of physics. Where in GR, in the macro world, is energy conservation violated?

BDanielMayfield wrote:
Where in GR, in the macro world, is energy conservation violated?

Chris Peterson wrote:

BDanielMayfield wrote:
I don't know why this didn't occur to me sooner, but the notion that the choices we make can actually "split the universe" into multiple copies can not be true because it violates conservation of energy.

Conservation of energy is an empirical principle, not a well defined law of nature. It is probably violated in a number of general relativity cases, and possibly some quantum mechanical cases, as well. Violating conservation of energy is not necessarily a good argument against something. The situation is further complicated by the fact that it applies to closed systems, and when we're talking about the Universe, we do not know if or how it is closed. Alternatively, the condition may be satisfied so long as each individual universe which exists after a decision has itself conserved energy. After all, the law may only apply within any given universe; creating a new one is a different situation.

Chris Peterson wrote:

BDanielMayfield wrote:I don't know why this didn't occur to me sooner, but the notion that the choices we make can actually "split the universe" into multiple copies can not be true because it violates conservation of energy.

Conservation of energy is an empirical principle, not a well defined law of nature. It is probably violated in a number of general relativity cases, and possibly some quantum mechanical cases, as well. Violating conservation of energy is not necessarily a good argument against something. The situation is further complicated by the fact that it applies to closed systems, and when we're talking about the Universe, we do not know if or how it is closed. Alternatively, the condition may be satisfied so long as each individual universe which exists after a decision has itself conserved energy. After all, the law may only apply within any given universe; creating a new one is a different situation.

BDanielMayfield wrote:I don't know why this didn't occur to me sooner, but the notion that the choices we make can actually "split the universe" into multiple copies can not be true because it violates conservation of energy.

BDanielMayfield wrote:
Having just watched the above video my thinking bifurcates. Much of it went over my head of course, but it otoh it kinda spoke to my heartfelt love of math and science. The other side of my thoughts go like, "you stepped in whaaaat?"

• At times an electron can be both a particle and a wave, carry on conversations.
  At other times, the particle half took over completely.
  The electron was NEVER all wave, but it was often only particle.

Psycho (1960) wrote:

Click to play embedded YouTube video.

Dr. Fred Richmond: Now to understand it the way I understood it, hearing it from the mother... that is, from the mother half of Norman's mind... you have to go back ten years, to the time when Norman murdered his mother and her lover. Now he was already dangerously disturbed, had been ever since his father died. His mother was a clinging, demanding woman, and for years the two of them lived as if there was no one else in the world. Then she met a man... and it seemed to Norman that she 'threw him over' for this man. Now that pushed him over the line and he killed 'em both. Matricide is probably the most unbearable crime of all... most unbearable to the son who commits it. So he had to erase the crime, at least in his own mind. He stole her corpse. A weighted coffin was buried. He hid the body in the fruit cellar. Even treated it to keep it as well as it would keep. And that still wasn't enough. She was there! But she was a corpse. So he began to think and speak for her, give her half his life, so to speak. At times he could be both personalities, carry on conversations. At other times, the mother half took over completely. Now he was never all Norman, but he was often only mother.