Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Wed Mar 19, 2014 6:02 pm
by Anthony Barreiro
DavidLeodis wrote:... Why is the Big Bang so called, as it is said that noise cannot be heard in Space so surely the bang would not also! Perhaps it should be called the 'Big but silent Bang'!
The mid-20th century British polymath Fred Hoyle helped discover that chemical elements could be synthesized in stars. This gave him a lot of credibility in scientific circles. Hoyle was also convinced that the universe must have existed in its current conditions for an infinitely long time, the "steady state" theory of cosmology. Hoyle found the idea that the universe could have originated as a tiny point at a particular moment in time absurd. In 1950 he argued that the universe could not possibly have begun in a "big bang!"
"This instantaneous creation of the universe is like a party girl jumping out of a birthday cake, it's ridiculous. I call it the big bang." — Fred Hoyle
The name stuck. In 1963 Arno Penzias and Robert Wilson of Bell Laboratories accidentally discovered microwaves still radiating from this ridiculous "big bang."
I wonder which current theories are where the steady state theory was in 1950: held by the majority of experts in the field and supported by a preponderance of available evidence -- and which currently ridiculous ideas will turn out to be prescient big bangs. Time will tell.
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Wed Mar 19, 2014 7:55 pm
by neufer
neufer wrote:
Chris Peterson wrote:
neufer wrote:
Spin-2 gravitons have two polarizations:
. right handed & left handed.
Assuming they exist.
They left their fingerprints
Chris Peterson wrote:
No, they didn't. Gravitational waves left their fingerprints.
That gravitational waves are propagated by gravitons remains a largely untested theory.
<<In the paper, "Using cosmology to establish the quantization of gravity," published in Physical Review D (Feb. 20, 2014), Lawrence Krauss a cosmologist at Arizona State University, and Frank Wilczek a Nobel-prize winning physicist with MIT and ASU, have proposed that measuring minute changes in the cosmic background radiation of the universe could be a pathway of detecting the telltale effects of gravitons.
"This may provide, if Freeman Dyson is correct about the fact that terrestrial detectors cannot detect gravitons, the only direct empirical verification of the existence of gravitons," Krauss said. "Moreover, what we find most remarkable is that the universe acts like a detector that is precisely the type that is impossible or impractical to build on Earth."
It is generally believed that in the first fraction of a second after the Big Bang the universe underwent rapid and dramatic growth during a period called "inflation." If gravitons exist, they would be generated as 'quantum fluctuations' during inflation. Ultimately... this would affect how electromagnetic radiation in the cosmic microwave background (CMB) radiation left behind by the Big Bang, is produced causing it to become polarized. Researchers analyzing results from the European Space Agency's Planck satellite are searching for this "imprint" of inflation in the polarization of the CMB.
Krauss said his and Wilczek's paper combines what already is known with some new wrinkles: "While the realization that gravitational waves are produced by inflation is not new, and the fact that we can calculate their intensity and that this background might be measured in future polarization measurements of the microwave background is not new, an explicit argument that such a measurement will provide, in principle, an unambiguous and direct confirmation that the gravitational field is quantized is new. Indeed, it is perhaps the only empirical verification of this very important assumption that we might get in the foreseeable future."
This implies that finding the fingerprint of gravitational waves in the polarization of CMB will provide evidence that gravitons exist and it is just a matter of time (and instrument sensitivity) to finding their imprint.
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Wed Mar 19, 2014 8:22 pm
by neufer
Anthony Barreiro wrote:
DavidLeodis wrote:
Why is the Big Bang so called, as it is said that noise cannot be heard in Space
so surely the bang would not also! Perhaps it should be called the 'Big but silent Bang'!
The mid-20th century British polymath Fred Hoyle helped discover that chemical elements could be synthesized in stars. This gave him a lot of credibility in scientific circles. Hoyle was also convinced that the universe must have existed in its current conditions for an infinitely long time, the "steady state" theory of cosmology. Hoyle found the idea that the universe could have originated as a tiny point at a particular moment in time absurd. In 1950 he argued that the universe could not possibly have begun in a "big bang!"
"This instantaneous creation of the universe is like a party girl jumping out of a birthday cake,
it's ridiculous. I call it the big bang." — Fred Hoyle
<<Franklin Hall is a Canadian physicist [Rob?] involved in an experiment in a private research facility in the Canadian Rockies. A mistake in Hall's calculations causes graviton particles to merge with his own molecules, and Hall later discovers that he can mentally control gravity. Hall at first tries to hide his newfound ability, but becomes tempted by the potential power, and donning a costume adopts the alias "Graviton." Graviton was among the villains recruited by Mister Bitterhorn into Mephisto's Legion Accursed. They were used in part of a plot to kill the Beyonder with Mephisto's Beyondersbane weapon, but were delayed by the Thing until the weapon melted down.
Graviton describes himself as becoming a "living black hole" [Orin?] and morphs into a 50-foot humanoid. Graviton is then attacked until he loses concentration, and then apparently implodes and is considered dead. Graviton is eventually able to reform his body, and decides to seek a bride. Elevating a Bloomingdale's store into the sky, he takes several women hostage until tricked by Thor.
By decreasing the pull of gravity beneath him, then manipulating its direction of effect, he could fly at any speed or height at which he could still breathe. However, by using his force field generation capabilities he could also breathe in space. By increasing the pull of gravity beneath his opponents, he could pin them to the ground, having made them too heavy to move, or cause sufficient gravitational stress to impair the normal functioning of the human cardiovascular system. With time and training, his powers further advanced, even to the extent of levitating an island miles above ground level, exerting his power even while sleeping, somewhat reshaping mountains on the Moon, and demonstrating the ability to lift a small stone in China while residing in L.A., then depositing it in Australia through a victim[Nitpicker]'s head just to see if he could do so.
Hall's single most ambitious display of power was when he held almost every Marvel hero in stasis, including the Fantastic Four, some of the X-Men and such physical powerhouses as Thor, Hercules, the Hulk and Namor, and began using his powers to try reshaping the Earth in his image. Aside from his powers to manipulate gravity, Hall had a PhD in Physics and was intellectually brilliant, with expertise in advanced physics, including teleportation. His greatest limitation was that he was emotionally and mentally very disturbed.>>
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Wed Mar 19, 2014 9:20 pm
by chuckster
Isn't inflation supposedly something that initially spread out faster than light ?
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Wed Mar 19, 2014 9:28 pm
by Anthony Barreiro
chuckster wrote:Isn't inflation supposedly something that initially spread out faster than light ?
Yes. Einstein's special theory of relativity says that nothing can move through space faster than the speed of light. But during the moment of inflation space seems to have expanded faster than the light that was traveling through it. That's why the universe is bigger than we can observe, because light from beyond our visible horizon hasn't had time to get here yet.
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Wed Mar 19, 2014 9:29 pm
by neufer
chuckster wrote:
Isn't inflation supposedly something that initially spread out faster than light ?
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Wed Mar 19, 2014 9:32 pm
by Anthony Barreiro
neufer wrote:
http://en.wikipedia.org/wiki/Graviton_%28comics%29 wrote:... Aside from his powers to manipulate gravity, Hall had a PhD in Physics and was intellectually brilliant, with expertise in advanced physics, including teleportation. His greatest limitation was that he was emotionally and mentally very disturbed.>> (Art?)
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Wed Mar 19, 2014 9:38 pm
by neufer
Anthony Barreiro wrote:
neufer wrote:
http://en.wikipedia.org/wiki/Graviton_%28comics%29 wrote:
... Aside from his powers to manipulate gravity, Hall had a PhD in Physics and was intellectually brilliant, with expertise in advanced physics, including teleportation. His greatest limitation was that he was emotionally and mentally very disturbed. (Art?)
No...I never got my PhD in Physics.
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Thu Mar 20, 2014 3:04 am
by BillBixby
Was this link posted somewhere and I missed it. I am posting the YouTube link from The Kim Komando Show of Must See Videos. She appears to be posting from YouTube what the Stanford University News Service has posted.
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Thu Mar 20, 2014 3:06 am
by geckzilla
BillBixby wrote:Was this link posted somewhere and I missed it. I am posting the YouTube link from The Kim Komando Show of Must See Videos. She appears to be posting from YouTube what the Stanford University News Service has posted.
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Thu Mar 20, 2014 5:50 am
by chuckster
Anthony Barreiro wrote:
chuckster wrote:Isn't inflation supposedly something that initially spread out faster than light ?
Yes. Einstein's special theory of relativity says that nothing can move through space faster than the speed of light. But during the moment of inflation space seems to have expanded faster than the light that was traveling through it. That's why the universe is bigger than we can observe, because light from beyond our visible horizon hasn't had time to get here yet.
OK - now how about entanglement ? Wasn't it demonstrated in a lab on one of the Canary Islands ? I'm trying to enumerate things that are generally known to travel faster than light. What do they know that we don't know ?
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Thu Mar 20, 2014 12:59 pm
by MargaritaMc
chuckster wrote:
Anthony Barreiro wrote:
chuckster wrote:Isn't inflation supposedly something that initially spread out faster than light ?
Yes. Einstein's special theory of relativity says that nothing can move through space faster than the speed of light. But during the moment of inflation space seems to have expanded faster than the light that was traveling through it. That's why the universe is bigger than we can observe, because light from beyond our visible horizon hasn't had time to get here yet.
OK - now how about entanglement ? Wasn't it demonstrated in a lab on one of the Canary Islands ? I'm trying to enumerate things that are generally known to travel faster than light. What do they know that we don't know ?
I hadn't heard of this, although it happened in my back yard
DENVER — The reach of the spooky quantum link called entanglement keeps getting longer. A team has transmitted entangled photons some 144 kilometers (89 miles) between La Palma and Tenerife, two of Spain's Canary Islands off the coast of Morocco. Physicist Anton Zeilinger of the University of Vienna, the group's leader, presented the results to his colleagues this week at the American Physical Society conference.
The distance achieved is 10 times farther than entangled photons have ever flown through the air. When two photons or other particles are in this state, what happens to one determines the fate of the other, no matter how far apart they are. Zeilinger compares the phenomenon with throwing a pair of dice that land on matching numbers every time.
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Thu Mar 20, 2014 1:28 pm
by Chris Peterson
chuckster wrote:OK - now how about entanglement ? Wasn't it demonstrated in a lab on one of the Canary Islands ? I'm trying to enumerate things that are generally known to travel faster than light. What do they know that we don't know ?
Wikipedia has a good list. The important point about quantum entanglement, and the other cases, is that no information is transmitted faster than c, which is the apparent limitation of nature on the matter. Most of the Universe is moving faster than light with respect to us, but since we can't observe that material, there is no violation. A body can't be accelerated to faster than c, since that would require infinite energy. But it can be carried to any speed at all by the framework of spacetime it's embedded in.
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Thu Mar 20, 2014 5:01 pm
by BillBixby
geckzilla wrote:
BillBixby wrote:Was this link posted somewhere and I missed it. I am posting the YouTube link from The Kim Komando Show of Must See Videos. She appears to be posting from YouTube what the Stanford University News Service has posted.
Those were good comments. Another wonderful link shared, to me.
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Thu Mar 20, 2014 6:07 pm
by chuckster
Chris Peterson wrote:
chuckster wrote:OK - now how about entanglement ? Wasn't it demonstrated in a lab on one of the Canary Islands ? I'm trying to enumerate things that are generally known to travel faster than light. What do they know that we don't know ?
Wikipedia has a good list. The important point about quantum entanglement, and the other cases, is that no information is transmitted faster than c, which is the apparent limitation of nature on the matter. Most of the Universe is moving faster than light with respect to us, but since we can't observe that material, there is no violation. A body can't be accelerated to faster than c, since that would require infinite energy. But it can be carried to any speed at all by the framework of spacetime it's embedded in.
Great link ! I bookmarked it for perusal later. I get a lot of help from discussing topics like this on forums like this, because I can pose a question to myself and bark up the wrong trees for answers, sometimes.
My next candidate for FTL phenomena was going to be the 'searchlight' beams of energy flying out of the poles of rapidly-spinning pulsars and magnetars, etc. One pulsar has been clocked at 716 revolutions per second. Somewhere along the length of its energy stream, and from there outward, it is sweeping through space at a speed greater than light, isn't it ?
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Thu Mar 20, 2014 6:13 pm
by Chris Peterson
chuckster wrote:My next candidate for FTL phenomena was going to be the 'searchlight' beams of energy flying out of the poles of rapidly-spinning pulsars and magnetars, etc. One pulsar has been clocked at 716 revolutions per second. Somewhere along the length of its energy stream, and from there outward, it is sweeping through space at a speed greater than light, isn't it ?
An "energy stream" isn't a thing. All you have is a stream of photons being emitted by a rotating source. If you traced out the virtual rays, however, they'd be curved. Stand on your lawn and spin with a hose. Any individual molecule of water is moving in a straight line away from you once it exits the hose, but the water stream (again, not a physical thing) appears curved. And not moving faster with radial distance.
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Thu Mar 20, 2014 6:33 pm
by chuckster
Chris Peterson wrote:
chuckster wrote:My next candidate for FTL phenomena was going to be the 'searchlight' beams of energy flying out of the poles of rapidly-spinning pulsars and magnetars, etc. One pulsar has been clocked at 716 revolutions per second. Somewhere along the length of its energy stream, and from there outward, it is sweeping through space at a speed greater than light, isn't it ?
An "energy stream" isn't a thing. All you have is a stream of photons being emitted by a rotating source. If you traced out the virtual rays, however, they'd be curved. Stand on your lawn and spin with a hose. Any individual molecule of water is moving in a straight line away from you once it exits the hose, but the water stream (again, not a physical thing) appears curved. And not moving faster with radial distance.
OK I can see that. I guess it's the same idea as a headlight on a spaceship traveling near the speed of light doesn't put out light that is traveling at a speed equal to the speed of light plus the speed of the spaceship. Light is light - it gets emitted and then does its usual thing, regardless of the motion of the emitter. I kept thinking of the photons in the pulsar stream as having an outward vector of speed c, and a sideways vector of something more than c. I just got through reading the "Light Spots and Shadows" section in the link you posted, regarding 'apparent' FTL effects. Thanks !
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Thu Mar 20, 2014 6:51 pm
by Anthony Barreiro
chuckster wrote:
Chris Peterson wrote:
chuckster wrote:OK - now how about entanglement ? Wasn't it demonstrated in a lab on one of the Canary Islands ? I'm trying to enumerate things that are generally known to travel faster than light. What do they know that we don't know ?
Wikipedia has a good list. The important point about quantum entanglement, and the other cases, is that no information is transmitted faster than c, which is the apparent limitation of nature on the matter. Most of the Universe is moving faster than light with respect to us, but since we can't observe that material, there is no violation. A body can't be accelerated to faster than c, since that would require infinite energy. But it can be carried to any speed at all by the framework of spacetime it's embedded in.
Great link ! I bookmarked it for perusal later. I get a lot of help from discussing topics like this on forums like this, because I can pose a question to myself and bark up the wrong trees for answers, sometimes.
My next candidate for FTL phenomena was going to be the 'searchlight' beams of energy flying out of the poles of rapidly-spinning pulsars and magnetars, etc. One pulsar has been clocked at 716 revolutions per second. Somewhere along the length of its energy stream, and from there outward, it is sweeping through space at a speed greater than light, isn't it ?
While now slightly dated, I find the book Coming of Age in the Milky Way by Timothy Ferris to be a very clear explanation of how relativity and quantum mechanics can help us understand our place in the universe. Ferris is an excellent writer with a clear grasp of the fundamental science, a very humane perspective on the history of science, a healthy skepticism regarding both reductionistic determinism and unwarranted flights of fancy, and an exceptional ability to explain things in layperson's terms without dumbing down the subtleties and contradictions.
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Sun Mar 23, 2014 6:21 am
by Ann
I'm still mulling over the meaning of this. Specifically, I'm mulling over the difference between the Big Bang and inflation.
When I was young, I was told that astronomer Edwin Hubble discovered that all galaxies are moving away from each other (except galaxies that are gravitationally bound to each other), and that this proves that the universe is expanding. I was also told that since the galaxies are now moving away from each other, they must have been much closer to one another in the beginning. Indeed, in the very beginning they must have been so close that they were crowded together in a single point. (Bear with me; I'm using the the extremely imprecise terms that I learned more than forty years ago.)
Okay. So I was told, in extremely imprecise terms, that in the beginning all the galaxies (I know: all the energy of the universe, the energy that was going to become dark and baryonic matter and dark energy) were gathered together in a single point, and because they have moved apart since then, our universe must have started out with a huge, incredible explosion, which made all the galaxies fly apart. (I know: the Big Bang was not an explosion.)
And Fred Hoyle, the British astronomer, didn't like this idea, so he called it, derisively, the Big Bang. The term stuck, and to most people, the Big Bang is the explosion that started the universe.
But now that astronomers have found strong evidence of the era of inflation that happened some 10-35 seconds after the Big Bang itself. But wait a moment, now. (Please wait a little more than 10-35 seconds, if you'll pardon this feeble joke.)
Are inflation and the Big Bang separate events? Should we use another term for the Big Bang, and perhaps indicate a tiny, tiny, tiny spacetime bubble suddenly appearing either in "nothingness" or somehow being born from but immediately separated from a pre-existing spacetime? And was it inflation that blew this inconceivably tiny bubble of spacetime into such proportions that it could grow into a universe?
So, in other words, did Edwin Hubble discover the effects of inflation rather than the effects of the Big Bang when he discovered that galaxies are moving away from one another?
So again, are the Big Bang and inflation separate events, or should they be regarded as different stages of a two-stage rocket?
Ann
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Sun Mar 23, 2014 2:11 pm
by Chris Peterson
Ann wrote:I'm still mulling over the meaning of this. Specifically, I'm mulling over the difference between the Big Bang and inflation.
The Big Bang is the name given to the entire cosmological model, which describes the evolution of the Universe from t=0 to the present (see this, for example). It isn't uncommon for the actual moment of creation to be called the "Big Bang", but that's not really accurate.
Inflation (or the inflationary period) is merely one component of that cosmology. What Hubble discovered was a relationship between redshift and distance, and that's all. The Big Bang had already been proposed as a theory in the 1920s, and analyzed using Einstein's new general relativity. So Hubble discovered neither the BB nor the inflationary period, but provided the first observational evidence supporting a Big Bang cosmology (then, quite primitive compared with the modern lambda cold dark matter model).
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Sun Mar 23, 2014 7:19 pm
by neufer
Chris Peterson wrote:
Ann wrote:
I'm still mulling over the meaning of this. Specifically, I'm mulling over the difference between the Big Bang and inflation.
The Big Bang is the name given to the entire cosmological model,
which describes the evolution of the Universe from t=0 to the present
(see this, for example):
<<The inflationary epoch was the period in the evolution of the early universe thought to have been triggered by the phase transition that marked the end of the preceding grand unification epoch at approximately 10−36 seconds after the Big Bang. One of the theoretical products of this phase transition was a scalar field called the inflaton field. As this field settled into its lowest energy state throughout the universe, it generated a repulsive force that led to a rapid expansion of the fabric of space-time. This expansion explains various properties of the current universe that are difficult to account for without such an inflationary epoch. It is not known exactly when the inflationary epoch ended, but it is thought to have been between 10−33 and 10−32 seconds after the Big Bang. This rapid expansion [period] increased the linear dimensions of the early universe by a factor of at least 1026 (and possibly a much larger factor), and so increased its volume by a factor of at least 1078. The rapid expansion of space meant that elementary particles remaining from the grand unification epoch were now distributed very thinly across the universe. However, the huge potential energy of the inflation field was released at the end of the inflationary epoch, repopulating the universe with a dense, hot mixture of quarks, anti-quarks[, blueberry juice] and gluons as it entered the electroweak epoch.>>
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
In fact, the Big Bang describes the entire process, to present. We call all of these models "Big Bang cosmologies" (currently dominated by LCDM, but there are others). As I noted, the term refers to both the initial event, and the entire model.
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
It is the most pertinent answer as regards to Ann's specific question:
Ann wrote:
I'm mulling over the difference between the Big Bang and inflation.
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Sun Mar 23, 2014 8:27 pm
by Chris Peterson
neufer wrote:
Chris Peterson wrote:Not wrong, but not an inclusive answer.
It is the most pertinent answer as regards to Ann's specific question:
Ann wrote:
I'm mulling over the difference between the Big Bang and inflation.
Actually, I think not. The most pertinent answer is that the Big Bang is the theory describing the formation and evolution of the Universe, and inflation is one of the processes it describes.
Re: APOD: Cosmic Microwave Map Swirls Indicate... (2014 Mar
Posted: Sun Mar 30, 2014 6:21 pm
by Ron-Astro Pharmacist
Chris Peterson wrote:
Ron-Astro Pharmacist wrote:Doesn't it seem unusual that much of our science is only evidenced statistically via anomalies in physical measurements?
I don't think that statement is accurate. In fact, I'm not sure what it means. Our science is evidenced by physical measurements.
“Anomalies” was a poor choice of words. The concept I was trying to portray was more similar to the defunct idea of the ether. This days APOD exemplifies one way scientists are trying to examine the large scale universe. Could there still be an unseeable dimension (possibly based on size) that exerts effects on our seeable universe that we might investigate with a different experiment than Michelson–Morley employed to eliminate ether as light’s medium? My point was more along the lines to substitute a concept such as a “dimensional ether” as a simile for the ether that was once hypothesized as a substance to describe the transmission of electro-magnetic waves.
My real question is, “Are there still investigations that attempt to use an “unseen medium” as a theory or basis for describing some of the mysteries in our observable universe?” Has the astronomic ether disappeared as did the medical variety with the advent of new and different theories?