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Blogger Mark Wyman wrote on Jul. 14, 2010 @ 16:06 GMT
One of the fastest moving fields in contemporary astronomy involves getting some new tricks out of the oldest light in the Universe. The cosmic microwave background radiation, or CMB for short, is the light left over from the hot plasma that filled the Universe after the Big Bang. This glow fills all of space and encodes the state of the Universe at the early time when it was released. This information has been and is still being mined by space telescopes, the now long-in-the-tooth Wilkinson Microwave Anisotropy Probe and the newer Planck satellite. The data that we have gained from these experiments already have revolutionized our understanding of early-Universe cosmology.
In addition to teaching us about the Universe’s earliest moments, it turns out the CMB can be used for other purposes. One of these is the finding and counting up of galaxy clusters that live between our observers and the distant screen it establishes on the boundaries of the sky. As a background, the CMB acts as a backlight to every object that formed or exists in the time since its creation. These CMB photons can thus be affected by the objects through and by which they pass.
Galaxy clusters are a perfect example of this. Galaxy clusters are the largest collections of matter in the Universe -- the gathering place of dozens to hundreds of galaxies and huge amounts of hot gas. There are actually two ways that clusters affect CMB photons. The more subtle is a phenomenon known as the Integrated Sachs-Wolfe (ISW) effect. As photons pass through a galaxy cluster, they are blue shifted as the “drop” into the well of the cluster’s gravitational attraction, then red shifted as they climb out to escape. In a static or matter-dominated Universe, these shifts exactly cancel. But in our Universe, which has been accelerating in its expansion for the past few billion years, the red and blue shifts don’t cancel out, leaving a characteristic effect on photons that flow through clusters. This effect has been detected and provides striking independent evidence for the Universe’s accelerating expansion.
As nifty as the ISW effect is, the Sunyaev-Zeldovich effect may prove to be an even richer vein for observers to mine. This effect comes about from the direct interaction of the hot gas that lives in clusters with the CMB photons. Essentially, the CMB is “heated up” by interacting with the hot gas in a way that telescopes on Earth can detect. Because this effect is acting on CMB photons, it is one of very few observations that doesn’t discriminate against clusters that are very distant from us -- a cluster so distant that its stars can’t be seen directly can still be found by searching for this effect in the CMB light.
This is why the SZ effect has astronomers and cosmologists heated up themselves. For a start, clusters are extremely interesting objects on their own, but they are difficult to search for directly using either optical or X-ray methods, which are the traditional tools. In the optical, it’s a lot of work to definitively prove that a grouping of galaxies are truly bound together by gravity, since galaxies that sit next to each other on the sky can be millions of light-years apart in the direction along our line of sight. The hot gas in cluster centers is a smoking gun for clusters, but X-ray telescopes can’t easily scan the sky searching for clusters we haven’t found through other means. Hence the ability for CMB observations to catalog cluster locations could make individual cluster finding a much more straightforward process.
In addition, cosmologists have long known that the number and sizes of clusters are an independent source of information about the Universe’s laws and initial conditions. As the largest objects in the Universe, clusters probe the tail of the probability distribution for density fluctuations -- regions with so much extra stuff relative to the background are very rare events. Hence, an exhaustive catalog of these rarest events can tell us a lot about the nature of the probability distribution for cluster formation, much as super-tall NBA centers give us a notion of what nations and racial backgrounds have a genetic propensity for tallness. This, in turn, gives us a handle on what kind of physics was at play when that probability distribution was formed in the very first moments of the Universe’s existence.
Right now, two major experiments to hunt for SZ clusters are underway: the South Pole Telescope (SPT), located, surprisingly enough, at the South Pole; and the Atacama Cosmology Telescope (ACT), located in Chile’s high, dry Atacama desert, where it almost never rains, keeping the sky crystal clear for observing most of the year. Unlike the all-sky space telescopes used to look at the CMB before, these telescopes are designed for high-resolution work. This is because the primordial fluctuations in the CMB are from so early on in the Universe’s history that they have been spread out by the Universe’s expansion into large and easy to resolve shapes, even using the a small telescopes that can be carried into space. Clusters, however, are diminutive in comparison, requiring the larger collecting areas that ground-based telescopes can provide. These telescopes have already gathered and released their first data, confirming the promise of SZ observing by finding at least a few clusters that had never before been seen in any other way. However, there has also been a disappointing surprise: the telescopes have seen far fewer clusters than expected. This is still something of a mystery, but the most likely explanation is that the computer models used to calculate the size of the effect have, hitherto, inadvertently overestimated it. In any event, though, this field is expanding quickly, and will be teaching us a lot about clusters and many other things in the coming months and years.
this post has been edited by the author since its original submission
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Anonymous wrote on Jul. 14, 2010 @ 16:44 GMT
A four dimensional space really can only be 3 dimensional. It is understood as stretched and compacted. in fact, this flattened space can be understood as subdivided in 6 dimensions, 2 dimensions, and 4 dimensions -- all at the same time -- with the average being 4.
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Lawrence B. Crowell wrote on Jul. 14, 2010 @ 23:34 GMT
I read last year an article on the history of the Sunyaev-Zeldovich effect, and the troubles Zeldovich had in promoting the idea. It was a huge problem, for the SZ effect appears at first blush to violate the laws of thermodynamics. Zeldovich was clever enough to see there might be local gravity pockets, similar to the physics of the ISW, where there is this heating up effect. Zeldovich faced formidable opposition, again in the Soviet Union which was good at making life Kafka-esque, from the Landau school of thought
This image is the first release from the Planck spacecraft. One of the hopes is to detect B-modes in the CMB. Detecting B-modes is crucial. This will tell us much about inflationary cosmology and anisotropy. Further, these B-modes are CMB detection of an analogue of the CMB that involved gravitons. Prior to the inflationary period the universe was quantum gravity dominated. The decoupling of gravitons from the other fields and its transition to classical behavior is the source of these gravity waves. These B-modes are induced by huge gravity waves that were produced in a sort of black body radiation of gravitons. The gravitons were stretched into classical gravity waves which are now stretched to nearly the length of the cosmological horizon. These should have a footprint in the CMB. It is interesting to think that the CMB is a sort of gravity wave detector, and we are now trying to detect the reading of that detector.
Cheers LC
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Eckard Blumschein wrote on Jul. 15, 2010 @ 05:05 GMT
To me, Mark Wyman's blog provides a lot of serious results. However, I am missing a clear distinction between used methods, reached results and related problems on one side and more or less speculative hypotheses like temporal and spatial finiteness of the object under study on the other side. Aren't Big Bang and accelerated expansion still hypotheses to be confirmed by means of as diverse as possible observations including CMB? Well, the FQXi community seems to predominantly include pure theorists like LC rather than leading experts of microwave measurement.
The picture of measured CMB reminds me of the difficulty to correctly interpret ground penetrating radar pictures where the indications of buried land mines to be found are superimposed by numerous artifacts.
Eckard
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Steve Dufourny wrote on Jul. 15, 2010 @ 17:11 GMT
In perpetual search of our origins, we watch and analyze our environment.
We want to know everything as impatients.
We can imagine and extrapolate, indeed, to these universal truths.
But we are young biological masses moving,evoluing in this physicality towards a harmony.Can we see all ? Can we understand all ? ....it's always this wall, or Should I say the walls around us,in us, suround us....which are so far of us.
Like this hypothetic BB, the CMB is an approximation so difficult to perceive correctly......indeed the rays are so weaks 0.3mm to 1.....we must insert the point of reference with a kind of lagrangian indeed but the center seems a problem if we insert the evolutive rotations more the increase of mass and the relations of volumes between spheres.
In my line of reasoning, the distribution of energy is correlated with the black body in an isotropic system.....if the spatial fluctuations and rotations more the different centers, that becomes very difficult,and still I forget the parameters of superimposings implying problems.
That said the distribution is like the law of Black Body, it's logic in a thermodynamical point of vue.
I insist about the real distribution of energy via the rotating spheers,quantics or cosmologics........there we can correlate for the main center, thus the main central volume, this ultim coded sphere.....now of course we must insert the correct serie of evolution around the main center,in the 2 senses, if not ....
Furthermore with age of the universe it's also possible to see the real distribution of energy , matter.The law of Hubble interpreted like a Doppler Fizeau effect with all these rotations with the age can give us the correct topology.And thus we shall know where we are and where we go....The density decreases logically towards the center thus this Hypothetical BB.
iF WE KNOW THAT? WE CAN SORT THE SYSTEM OF WAVES AND THEIR AGES .
The expansion is just a step and has its specif osillation of evolution.We can made generalities abbout this expansion.The space in dilatation is just a step of evolution and when the number is ok, the densityn and mass makes the rest towards the main center...the oscillation becomes a contraction , of course the line time constant in its locality must be respected, thus we can see where we are and how we turn around this center,also this BB.
Regards
Steve
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Lawrence B. Crowell wrote on Jul. 15, 2010 @ 19:45 GMT
Eckard,
The SZ effect is an inverse Compton scattering with photons in the CMB and KeV energy electrons. This can happen before or after the onset of the matter dominated period of the universe. So a distant galaxy may have jets and the like which interact with CMB photons and increase their energy. This will introduce local non-blackbody distributions in the microwave radiation detected.
Cheers LC
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Eckard Blumschein wrote on Jul. 15, 2010 @ 21:20 GMT
Lawrence, As a layman I would like to learn whether the path of earth around the sun has already been used like a huge phased array.
The main reason for me to distrust is the tacit denial of any possible alternative to some putative facts like creation of universe. When I was five years old and far from my relatives for health reasons in Binz at Baltic sea, a nurse told to me and many older children a poem: Stalin, you are the light of the world.
Incidentally, I appreciate your hint to the word naturalized units. I was already aware that physicists prefer c=h_bar=1. However, I considered this a sloppy disregard of the metric system SI just for convenience. Your hint caused me to search for "naturalized units". Yahoo returned almost nothing matching. Why? Our basic units meter and second are arbitrarily chosen ones like the year of Christ's birth. Shouldn't we look for a natural system of units instead of arbitrary ones? My suggestion to accept the very moment as the natural zero of time is perhaps even more uncommon. What quantity is the most basic one? Time? Or Energy? Or length? Or what else?
Eckard
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Lawrence B. Crowell replied on Jul. 15, 2010 @ 23:40 GMT
Units are fairly arbitrary, and one can reset the scaling arbitrarily. There are some cut-offs, such as the Planck units. There are also pure numbers such as the fine structure constant.
Cheers LC
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Eckard Blumschein replied on Jul. 16, 2010 @ 05:46 GMT
Isn't CMB alone a shaky ground? While it yields just one picture of reality that may of may not confirm theories the more reliably the more obviously redundant features will be found in combination with other methods, redundancy due to arbitrarily chosen units should be eliminated. One does not need Siemens because it is just the reciprocal of Ohm. One does not need Ohm because it equals Volt divided by Ampere, etc. Natural cut-offs and zeros may help to further naturalize physics. I do not see conclusive evidence for limitation of time and space in CMB.
Let me reiterate and specify my so far implicit question concerning interpretation: What causes the bright horizontal line in the middle? Is it an artifact? Don't the "poles" look red-shifted? Why? Is the distance of the blue-shifted structures available?
Eckard
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Georgina Parry replied on Jul. 19, 2010 @ 11:54 GMT
Eckard,
Energy. IMO change in spatial position. It is something natural that happens. Whether any measurement using distance and time are made.
Length and time are scales used to make comparisons. Within the space-time construct they are not fixed scales but are flexible, as there can be time dilation and length contraction. Also as Lawrence says "Units are fairly arbitrary, and one can reset the scaling arbitrarily."
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Eckard Blumschein replied on Jul. 20, 2010 @ 12:30 GMT
Georgina and LC: ""Units are fairly arbitrary, and one can reset the scaling arbitrarily." ? This is definitely true for physics or more strictly speaking for unrealistic physics but not for reality.
Eckard
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Don Limuti (zenophysics.com) wrote on Jul. 16, 2010 @ 02:17 GMT
Care should be used in interpreting the Integrated Sachs-Wolfe (ISW) effect. It may be due to the acceleration of the expanding universe as postulated OR it may be due to light traveling at slightly different speeds at different wavelengths as indicated by results from the Magic Gamma Ray Telescope.
"A very special possibility was offered by observation of a short outburst of the blazar Markarian 501. which seems to show some energy dependence of gamma arrival times" From: http://magic.mpp.mpg.de/
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Lawrence B. Crowell replied on Jul. 16, 2010 @ 03:02 GMT
The Fermi spacecraft (GLAST) discounted speed deoendency with frequency.
Cheers LC
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Don Limuti (zenophysics.com) replied on Jul. 16, 2010 @ 06:28 GMT
Lawrence,
That is true. But the Magic gamma ray people are standing by their results, for now.
The future will tell.
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Lawrence B. Crowell replied on Jul. 16, 2010 @ 13:25 GMT
I suspect something is wrong here. The system is also based on the ground, which makes me ponder whether there is some media effect due to the atmosphere. The universe makes less sense if there is a frequency dependency with the speed of light. In fact you could parametrically amplify photons in a way which permits a temporal communication of information.
Cheers LC
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Don Limuti replied on Jul. 17, 2010 @ 05:23 GMT
Hi Lawrence,
Again I am going to have to agree with you, but with a caveat. Indeed the speed of light not being a constant would be a "monkey wrench' into physics as we know it. And before we even consider it we want hard experimental evidence.
However, the edifice of physics as it stands is protected by physicists who act like the Inquisition defending Christianity. I will give just one example, the declaration that the speed of light is a fixed constant.
This is from (http://www.nist.gov/mel/ped/museum-timeline.cfm) On October 20, 1983 the meter was redefined again. The definition states that the meter is the length of the path traveled by light in vacuum during a time interval of 1/299,792,458 of a second. The speed of light is c = 299,792,458 m/s
This expresses the attitude that we "really" know what is going on and further refinement on the speed of light is unwarranted. I believe this is religion and not science and NIST should register itself as a church.
I should mention the reason why I am so into "nit picking", I have a theory that produces a result that the speed of light varies as the wavelength of the light and that the expansion of the universe is not accelerating. This work was first presented in the last FQXi essay contest as "Gravity from the Ground UP" (finalist). I have updated this work as Digital Wave Theory (DWT) and it can be found on my webpage: http://www.zenophysics.com/DWT/Table_of_Contents.html
Sincere
ly, I would love to get your thoughts on DWT, and I do not think you would pull any punches.
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Lawrence B. Crowell replied on Jul. 17, 2010 @ 12:33 GMT
The problem with a frequency variability in the speed of light is it raises some serious problems. Suppose I had a photons with a frequency f and it is parametrically down shifted to two photons with frequencies f’ and f”. Then if the photon with frequency f’ travels faster than the photon with f”. it would be possible to violate aspects of causality. By shifting to a frame based on a Lorentz boost using the c’ for the f’ frequency of light an ambiguity can exist as to the ordering of initial and final (state preparation and detection, of the photon f”. This could also lead to some no-signaling violations with quantum nonlocality, for these entangled photons would nonlocally propagate information on a spatial direction according to a certain frame or boost using the speed of light c’.
The problem is that without pretty clear experimental evidence I am not sure I am prepared to go there.
Cheers LC
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Eckard Blumschein replied on Jul. 17, 2010 @ 21:19 GMT
To me it looks as if results from CMB and MAGIC are difficult to agree with each other and with already existing theories. MAGIC challenges the theorist´s to explain some of the striking details. CMB lets much room for wild guesses and "confirmation" of guesswork.
What can we conclude? I reiterate my experience: Only a variety of essentially different experimental methods provides sufficient redundancy. I do not expect "pretty clear experimental evidence" available from just one measurement. A puzzle consists of many exactly matching elements. The fallacies behind Nimtz-type evidence must be revealed and excluded.
In all: I suspect, theoretical physics should change its focus from a rather sophisticated but speculative approach to careful dealing with truly foundational issues of non-arbitrariness including a systematic unbiased search for possible mistakes even in the most fiercely defended tenets.
I mentioned a poem on Stalin that early sparked my distrust. To my gut feeling e.g. G. Cantor was also too much idolized as to be trustworthy. As a result of my careful effort I found mounting evidence confirming my suspicion.
Eckard
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Lawrence B. Crowell replied on Jul. 18, 2010 @ 04:11 GMT
The problem experimentally is with the Fermi (GLAST) spacecraft. This found no different in the time of arrival from a bust 10 billion light years away.
Cheers LC
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Don Limuti (zenophysics.com) replied on Jul. 18, 2010 @ 07:14 GMT
Hi Lawrence,
1. It seems to me that both the Magic and Fermi gamma ray measurements are single data points based upon a new phenomena of "Blazers" which may not be very controlled sources of light. More data will be coming, hopefully.
2. If you know as a fact that nothing moves faster than the speed of light you have a causality problem when something moves faster than light. A different wavelength of light moving faster than another wavelength of light does not cause any violation of causality. You may not believe that it is true, but that is a matter for experiment.
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Jason Wolfe replied on Jul. 18, 2010 @ 08:19 GMT
Don,
GR physicists are stuck on the idea that FTL will create causality violations. When in fact it is light itself that carries causality with it. FTL does not result in time travel; there simply is no other time to travel to. Traveling faster than light just causes you to get somewhere before light gets there. You could watch the light from your own spaceship show up just after you arrive; but you wouldn't be able to violate any causality relationships.
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Lawrence B. Crowell replied on Jul. 18, 2010 @ 14:17 GMT
Light which travels at different speeds is due to one of three possible sources. The first is an index of refraction. This is of course trivial to understand. The other is the photon has some tiny mass. So the wave equation |∂_iψ|^2 + m^2ψ^2 = 0 gives a propagator ~ (k^2 + m^2 –iε) that exhibits a dispersion when summed over k. The photon’s mass is zero to within one part in 10^{-50}ev, so this is ruled out FAPP. The third way is the structure of spacetime itself has a null structure or a projective algebraic structure which depends upon frequency. In other words the equivalence principle is violated in some ways, or Einstein got it wrong ultimately. This is the point where you get these problems with causality. If there are different light cone structures for different frequencies, which can include quantum fluctuations of the metric, there are then difficulties with being able to get a signaling of nonlocal entanglements and causality issue. Roger Penrose advanced twistor theory as a way to understand quantum gravity without these problems. Here the light cone direction is absolute, but the location of a null direction is uncertain. While twistor theory has fallen into a very secondary position I think it has structure that is likely to find its way into a complete quantum gravity theory.
Jason, we have been through this numerous times. Any causal propagation of information on a spacelike path, even if this involves some nontrivial connected topology (leaving the universe and reentering, wormhole handles etc) you simply can’t avoid the problem of time order ambiguities.
Cheers LC
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Don Limuti (zenophysics.com) replied on Jul. 19, 2010 @ 06:49 GMT
Lawrence,
Thanks for the thoughtful reply.
Your first listed reason for light changing speeds is that it is going thru a substance that has an index of refraction. That is what I believe is happening in free space. If we think of free space as a medium like a subtle glass (and not as nothing) we can assign it an index of refraction. In glass the index of refraction is a function of wavelength. This can also be true for free space and then the speed of light in free space may not be constant. I believe that as the wavelength of light becomes very long its speed approaches "c" the maximum speed of space-time.
We have never looked at light this way because historically Maxwell found "c" as a single number. Maxwell measured Permittivity and Permeability with magnetic and electric fields that were static. He never considered that Permittivity and Permeability could be functions of velocity. Maxwells equations were a magnificent breakthrough in physics. This does not mean that they should never be reconsidered.
Now, I am not saying that light moves at different speeds is a fact, but it something that could be investigated. When NIST makes the speed of light a fixed constant by fiat, it effectively stops the investigations of questions like these.
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Jason Mark Wolfe wrote on Jul. 18, 2010 @ 19:37 GMT
Lawrence,
Would there have been time ordered ambiguities withing the jet stream that was belched forth out of the super-massive black hole at the center of Messier 87? The jet stream was clocked at 4 to 6 times the speed of light. If this is somehow a trick if light or of angles, then why don't we see this sporadically for low energy cosmological events, as well.
When a super-massive black hole spits out of jet stream that is 5000 light years long, when it appears to violate the laws of physics, a reasonable person has to suspect that stability conditions for the laws of physics have been exceeded.
What ever time order of events you are talking about, there is a super-massive black hole out there that seems to disagree with you.
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Lawrence B. Crowell replied on Jul. 19, 2010 @ 01:05 GMT
Jason,
These apparent superluminal velocities of jets are similar to shining a light on a wall an moving the spot faster than light.
LC
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Eckard Blumschein replied on Jul. 19, 2010 @ 05:37 GMT
Yes LC, I uttered this argument in a discussion with Peter Jackson and did not face any compelling refutation. I do not yet see a reason to either question the method of MAGIC or further boost speculative theories. Even if the twin paradox seems to demand the admission of the opposite of time dilation too, I see the limit to the velocity of speed anchored in electromagnetic properties.
Incidentally in Magdeburg and with my grandson, I visited again a nice but ten years old exhibition on the history of science and found mentioned that there are a few galaxies, if I recall correctly less than ten. The recent discovery of much more does not suggest the world being a closed system as claimed by monotheists, Hilbert, Hawking, Schulman, etc. At least, I cannot see an ultimate border while on the other hand, constant c and MP3 go on proving very reasonable.
Eckard
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Jason Wolfe replied on Jul. 20, 2010 @ 02:20 GMT
Lawrence,
So a supermassive black hole can belch forth a jet of energy and create a light on a wall effect? I don't see how that seems likely.
As for trying to beat relativity using angles and shadows, I don't think you can because that is considered "signaling" or tranmitting information. But if a supermassive black hole appears to spit out energy that is clocked at 4 to 6c, and I've looked at the pictures, I just don't see how a trick of light can explain that.
Eckard,
Do you know anything about this "trick of light" that only super massive black holes can accomplish?
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Lawrence B. Crowell replied on Jul. 20, 2010 @ 13:22 GMT
The physics of
superluminal jets is now well understood. This is fairly elementary to understand.
LC
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Jason Mark Wolfe replied on Jul. 20, 2010 @ 17:44 GMT
I looked over the superluminal jet article. If line of sight is 19 degrees or less, then the superluminal effect is just an optical illusion. However, in the case of M87, the line if sight is at 43 degrees.
I can't think of a more significant challenge to relativity than the superluminal motion of jets. This is not something that physicists can dismiss readily without appearing to be dismissing a significant challenge to relativity.
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Lawrence B. Crowell replied on Jul. 20, 2010 @ 20:35 GMT
Jason,
As the Wiki article indicates this has been modelled and fits with the data. There has been no great trumpet blast proclaiming FTL in the unvierse or the lab. Believe me if this happens we will all know about it.
Cheers LC
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Jason Wolfe replied on Jul. 20, 2010 @ 21:07 GMT
Lawrence,
Would you personally be excited if FTL really existed in the universe? I need to know that you are not deeply motivated to conceal such a possibility. If I knew that you would delighted by a scientifically verified FTL phenomena, I would no longer need to debate M87.
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Lawrence B. Crowell replied on Jul. 20, 2010 @ 22:59 GMT
If FTL were found in the universe my reactions would vary some. To be honest I think that faster than light propagation of information would mean that a whole set of bases for physics would collapse. This would involve causality and frankly logic as well might be in trouble. Causality goes back to Thales of Miletus in 580BCE. I think that my first reaction would be shock and frankly despair. I would then have to wait or maybe work on how physics might recover these basic principle with FTL. Yet to be honest FTL might simply mean that the universe can’t really be understood in any complete manner, even as an effective field theory.
I am not terribly worried that something like this will happen.
Cheers LC
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Jason Wolfe replied on Jul. 21, 2010 @ 00:14 GMT
Lawrence,
That's a reasonable answer. I don't know if you're a critic of my interpretation of physics. I believe that everything, GR & QM, is implemented with virtual photons; more accurately, with building blocks of the form exp^i(kx-wt) which tranmit causality at the speed of light. I hold this idea as absolute. It has paid off very well by giving me some great ideas.
One of those ideas is shift-photons as objects that transmit a gravity-like force. Each photon transmits a force equal to,
I am looking at Phase Modulation and Frequency Modulation equipment trying to find what I need to run the experiment. The idea is to generate a lot of these photons.
What if the experiment worked. Is it then possible, with enough money and power availability, to build an Alcubierre drive? It would also be similar to a wormhole. I would build lots of high power tractor beams around the mouth of a cylinder. On the inside, I would build lots of repulsor beams.
Question: do you think with enough terawatts of power, I could build an Alcubierre drive/wormhole? Why or why not?
If not? Then what would go wrong?
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Jason Wolfe replied on Jul. 21, 2010 @ 02:06 GMT
Lawrence,
I hope you understand that I do not wish despair upon anyone. I am only trying to pursue a possibiliity because I believe it will lead to new physics. New physics means new technology. New technology means new jobs.
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Lawrence B. Crowell replied on Jul. 21, 2010 @ 03:31 GMT
Jason: If you want to do some blog archeology I have addressed this issue in some of the FQXI pages here. The number of problem are large, ranging from violations of energy conditions, lack of boundedness conditions in quantum states and fields, and so forth.
Cheers LC
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Jason Wolfe replied on Jul. 21, 2010 @ 04:37 GMT
Lawrence,
I really wish it was easier to locate blog entries on this website. Just like you, I have limited time too.
Energy conservation won't be a problem. Everything that I do is with due consideration of conservation of energy.
Lack of boundedness? Just because the mathematical physics can't be worked out for want of boundedness, it doesn't mean that the phenomena can't happen. I have no idea what the probability is that some girl will wink at me in a store. There really is no mathematical way to describe such an event. But such things do happen.
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Lawrence B. Crowell replied on Jul. 21, 2010 @ 12:58 GMT
Jason,
The upshot is this. Spacetimes which permit information to propagate from one point to another faster than light violate the weak energy condition T^{00} >= 0. I am not going to get into hair splitting issues over configurations of spacetimes which have this violation. There is no proof as yet of the chronology protection or cosmic censorship hypothesis, but so far spacetimes with this FTL property violate T^{00} >= 0. The quantum field which acts as the source of this curvature then has no minimum energy eigenvalue. As a result these sources of curvature generate a huge quantity of radiation, which also perturbs the spacetime enormously. This reason and with others means that the universe fails to really make much sense.
Ford, Romans and others have pretty carefully examined these pathologies. FTL by all means studied so far, which implies time ordering ambiguity or closed timelike loops, represents a complete disaster for physics. This is in spite of the fact FTL makes for nice science fiction. Such configurations in nature may only take place in quantum gravity near or at the string energy (Hagedorn temperature), but this would not mean it can realistically exist on a macroscopic scale.
Cheers LC
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Jason Wolfe replied on Jul. 21, 2010 @ 18:53 GMT
Lawrence,
I suppose it does make sense that if FTL were possible, the T^{00} >= 0 condition would be violated. As an example, if I had a spaceship of mass m that could travel at a velocity of v = 10c, it's kinetic energy would be
K = 1/2(m)(v)^2 = 1/2(m)(10c)^2 = 50mc^2. This is of course an insanely huge amount of energy.
However, if superluminal travel is ever to be achieved, then the existence of a hyper-space is mandatory. Could there be a coexisting hyperspace that we don't even know about? Nobody knows for sure.
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Steve Dufourny replied on Jul. 21, 2010 @ 19:11 GMT
1/2 mv² = mgh .....impossible Jason!
Impossible also for hyperdimensions they don't exist...we have only a 3D space Jason really.
On the other side, we have a pure topology in rotations around the center of our universe, the evolution makes the rest........the the velocity is important of course but it's the toplogy the essential and the decrease of spaces between cosmological spheres....and quant.spheres....
your ideas are very interestings but irrealistics, if you focus on foundamentals you shall improve a space ship...you know the biology, the shield, the sphere of motion, the lattices between quantum spheresz and the universal link of cosmological spheres...the spaces between spheers is the same, only the velocities of rot change.......
Regards
Steve
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Jason Wolfe replied on Jul. 21, 2010 @ 21:12 GMT
Steve,
"1/2 mv² = mgh .....impossible Jason!" What are you talking about? I didn't say that. But this equation is correct.
Some people say that FTL is impossible. I'm looking at the details of how it's impossible. Lawrence says that FTL results in a violation of T^{00} >= 0; that means that FTL requires negative energy. I'm looking at that.
First things first.
Step 1: test red/blue shift yields artificial gravity (acceleration field). If tests show that this will work, we have to perfect this technology.
Step 2: Build a wormhole device. The force generators will be built (bolted down) to the mouth of a cylinder/tunnel. Those force generators will be tractor (attraction) devices. Inside of the tunnel there will be more force generators that are bolted down. Bolting down these force generators fixes boundary conditions.
Fixes boundary conditions.
Fixes boundary conditions.
The force generators inside of the tunnel are repulsive and aimed away from the mouth to the other end of the tunnel.
If the supplied power is high enough, we might be able to induce a wormhole with...
fixed boundary conditions...
fixed boundary conditions...
...
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Jason Mark Wolfe replied on Jul. 22, 2010 @ 01:35 GMT
Lawrence,
I've been thinking about wormholes. Let's say I build a wormhole simulator within and around a concrete cylinder. At the mouth of entrance, there are strong attractive forces. Inside and at the output of the cylinder, there are strong repulsive forces. If something gets too close to the mouth of the wormhole simulator, it gets pulled in. It falls through the cylinder and gets catapulted out the back end.
That is how a typical wormhole would work, right?
If I am using gravitational energy, then I have a problem. My potential energy, between the mouth and the output, is discontinuous. Is that what you meant by boundary conditions?
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Steve Dufourny replied on Jul. 22, 2010 @ 11:17 GMT
Jason,
I know my equations, like you I am passionated by the equations.
Thus thanks to say me it's correct, fortunally I know 1/2mv²=mgh...like I know m1v1=m2v2....like U=RI...AND THIS AND THAT AND THERE .....the mechjanics, the motions, etc etc it's our laws jason and we must accept these foundamentals.
First the whole is false ...why ....the whormholes do not exist, like a BH ...in fact a BH is a sphere jason and has a rule in the galaxy and inside the universal sphere...it's not a door or others.....Second you need an big energy , negative, it's not possible.
But I like read your extrapolations,be sure.
A whormhole is simply an error.They don't exist in my humble opinion.
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Jason Wolfe replied on Jul. 22, 2010 @ 17:33 GMT
Dear Steve,
Do you know what a wormhole is used for?
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Steve Dufourny replied on Jul. 22, 2010 @ 17:44 GMT
Dear Jason,
No,I am not a specialist of wormholes .
Could you elaborate,please?
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Jason Wolfe replied on Jul. 22, 2010 @ 17:44 GMT
Let me tell you Steve,
If my tractor/repulsor beam works, if red/blue shift really does induce an acceleration field, I am going to build an amusement park ride. I am going to construct a long tube about 300 meters long. I am going to build tractor beams at the mouth of the tube. I am going to build tractor/repulsor beams all the way down the length of the tube. Parents are going to take there kids there. The kid will "fall" into the wormhole. They will accelerate really fast. At about the middle of the wormhole/tube/ride, the falling/acceleration will change polarities which will slow the child down. When they reach the other side of the ride, they will just "fall out" onto the mat.
For the sake of my personal amusement, once a day I will NOT change the polarity. The kid will fall faster and faster. By the time they reach the outflow of the ride, the kid will be spit out at about a 100mph.
I'll call it the "Evil Wormhole".
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Jason Wolfe replied on Jul. 22, 2010 @ 17:46 GMT
I know Lawrence doesn't read my posts. But if he did, maybe he could explain why the laws of physics prevent me from building such a wormhole.
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Steev Dufourny replied on Jul. 22, 2010 @ 18:04 GMT
Thanks, it's interesting.
Good luck in your researhs and works.
Regards
Steve
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Jason Wolfe replied on Jul. 22, 2010 @ 18:10 GMT
But do you understand what I did? OK, maybe wormholes that extend millions of light years require insane amounts of energy. However, in principle, I can build a wormhole that is a couple hundred meters long.
For it to be a real wormhole, does the acceleration at the mouth have to exceed the speed of light (like a black hole)?
When will the physics community talk about what IS possible?
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Dr. Cosmic Ray replied on Jul. 22, 2010 @ 18:16 GMT
Dear Jason,
An evil wormhole? You will need an ER and an underwear souvenir shop nearby, and a bunch of lawyers.
Dear Steve,
Are Florida women beautiful? I don't know your taste in women, and I am admittedly biased, but YES!
Have Fun!
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Jason Wolfe replied on Jul. 22, 2010 @ 18:52 GMT
Dear Dr. Ray,
OK, I was making a joke. But do you get my point? It might be possible to build a wormhole. It would have to be very short because of energy costs. I have yet to see any PhD's in General Relativity to contradict me. They don't seem to be responsive to either logic or rudeness. Ok, maybe the rude comments are not helping. But still, physicists who think that wormholes cannot exist are full of it.
I Double Dog Dare anybody in the physics community to challenge me on this point! My point is that wormholes CAN exist. They have to be little ones; and No Time Travel.
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Steve Dufourny replied on Jul. 23, 2010 @ 09:49 GMT
Hi Ray ,
I took the airplane,I am on the beach with a girl , at the sphere beach, I try the surf.
Steve
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SteveDufourny wrote on Jul. 19, 2010 @ 16:20 GMT
Why so many violations of our constants, of our equivalence principle......
why to search these roads of violations ....that has no sense......
We must differenciate the perceptions and the reality, it's that the relativity,
It doesn't exist any road of violation which explains the quantum gravity .....
An illusionary causality do not explain nothing.......
Never the fluctuations can be used in these roads of confusions where the foundamentals aren't respected.
Best Regards
Steve
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Steve Dufourny wrote on Jul. 20, 2010 @ 16:42 GMT
All that seems just an optical perception due to superimposings of evolution and parameters.
The special relativity is essential for all locality and its intrinsic parameters of evolution, thus why these perceptions.
The radioastronomy must be realistic and objective respecting our referential.
When we correlate the quazars for example, we see the links with NGAs.
These nuclei , actives are in a specific dance of evolution where the superimposings of time are numerous.
The distribution of energy is specific also and the special relativity is necessary for all good correlations.
The spectral cosmologic displacable seems a cause of confusions.
In conclusion, the BH is at the center and is the cause, gravitational of the galaxy dynamic, the rule is not to eject these superluminal things,on the other if that exists, few probable, the decrease towards the respect of special rerlativity ,thus c will be.....
A jet of quazars is due to photons of the cosmological scale boosted by relativistic electron if my memmory is good,we know thus the intensity of this cosmological effect and thje energy of the BH.....for PROOF, see the CHANDRA results of ejections of this BH, the X rays of course.
OR THE IDEA OF THE DAY,the special relativity is only for a perception of a star system ....there the DFM from Peter seems very relevant about the informations and the evolution......that seems relevant there also about the velocities linears and spinals and orbitals of all spheres the sense implying the difference between mass and light, the time makes the rest.
Best Regards
Steve
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songjoong sdfsd df wrote on Dec. 27, 2017 @ 07:20 GMT
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