Skip to comments.Discovery that quasars don't show time dilation mystifies astronomers
Posted on 04/12/2010 8:40:43 PM PDT by Lorianne
The phenomenon of time dilation is a strange yet experimentally confirmed effect of relativity theory. One of its implications is that events occurring in distant parts of the universe should appear to occur more slowly than events located closer to us. For example, when observing supernovae, scientists have found that distant explosions seem to fade more slowly than the quickly-fading nearby supernovae.
The effect can be explained because (1) the speed of light is a constant (independent of how fast a light source is moving toward or away from an observer) and (2) the universe is expanding at an accelerating rate, which causes light from distant objects to redshift (i.e. the wavelengths to become longer) in relation to how far away the objects are from observers on Earth. In other words, as space expands, the interval between light pulses also lengthens. Since expansion occurs throughout the universe, it seems that time dilation should be a property of the universe that holds true everywhere, regardless of the specific object or event being observed. However, a new study has found that this doesnt seem to be the case - quasars, it seems, give off light pulses at the same rate no matter their distance from the Earth, without a hint of time dilation.
Astronomer Mike Hawkins from the Royal Observatory in Edinburgh came to this conclusion after looking at nearly 900 quasars over periods of up to 28 years. When comparing the light patterns of quasars located about 6 billion light years from us and those located 10 billion light years away, he was surprised to find that the light signatures of the two samples were exactly the same. If these quasars were like the previously observed supernovae, an observer would expect to see longer, stretched timescales for the distant, stretched high-redshift quasars. But even though the distant quasars were more strongly redshifted than the closer quasars, there was no difference in the time it took the light to reach Earth.
This quasar conundrum doesnt seem to have an obvious explanation, although Hawkins has a few ideas. For some background, quasars are extreme objects in many ways: they are the most luminous and energetic objects known in the universe, and also one of the most distant (and thus, oldest) known objects. Officially called quasi-stellar radio sources, quasars are dense regions surrounding the central supermassive black holes in the centers of massive galaxies. They feed off an accretion disc that surrounds each black hole, which powers the quasars extreme luminosity and makes them visible to Earth.
One of Hawkins possible explanations for quasars lack of time dilation is that light from the quasars is being bent by black holes scattered throughout the universe. These black holes, which may have formed shortly after the big bang, would have a gravitational distortion that affects the time dilation of distant quasars. However, this idea of gravitational microlensing is a controversial suggestion, as it requires that there be enough black holes to account for all of the universes dark matter. As Hawkins explains, most physicists predict that dark matter consists of undiscovered subatomic particles rather than primordial black holes.
Theres also a possibility that the explanation could be even more far-reaching, such as that the universe is not expanding and that the big bang theory is wrong. Or, quasars may not be located at the distances indicated by their redshifts, although this suggestion has previously been discredited. Although these explanations are controversial, Hawkins plans to continue investigating the quasar mystery, and maybe solve a few other problems along the way.
Hawkins paper will be published in an upcoming issue of the Monthly Notices of the Royal Astronomical Society.
More info: http://www3.interscience.wiley.com/journal/123345710/abstract?CRETRY=1&SRETRY=0
Please allow me to wax philosophical and a it theological.
God made a massive and unbelievably complex Universe with rules that are discoverable and consistent. He evolved within us, His Children, brains that can reach to that Universe, and attempt to identify, classify and in the end, harness that Universe and bend it to Man’s will.
But knowing there are rules and jotting them down takes some darn smart people.
This article puts me at the very edge of what I can understand scientifically. And, since I have acrophobia, I don’t want to look down at the cliff face I find myself backed into.
Thanks for posting this, Lorianne — it is of incredible substance.
>>This guy just proved the existence of G-d. Everywhere, all of the time and at the same time. Maybe these are just cracks through which we can peek at Heaven? <<
"One second is defined as 'the duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom'..."
Now imagine, instead of a vibrating 'caesium 133 atom', we have a beam of light bouncing back and forth between two mirrors within a vertical tube. Now let's say, for the sake of argument, that it takes precisely 'one second' for the light beam to reach the top mirror (tick), reflect off it, reverse and reach the bottom mirror (tock).
Now let's say the light tube, or 'light clock', is resting on a flatbed train car, and on the flatbed is an observer who we will call "Observer A". To Observer A, who is moving along with the train and is therefore 'at rest' with respect to it, the light beam simply travels from the bottom of the tube *vertically* to the top of the tube and then straight back down again. From the relationship, speed equals distance over time, we get time equals distance over speed. So this is then how Observer A defines time (t=distance/speed). Important to note here is that light travels at the SAME SPEED for ALL observers.
Now let's say there is an observer B standing on the embankment alongside the train watching it pass by. From this observer's point of view, or frame of reference, the light beam does NOT simply travel vertically up and down. Rather, it travels on a slanted or diagonal path since the train is in motion, let's say from left to right as Observer B sees it. Now since the light beam travels a diagonal path between tick and tock, again, from OB's stationary point of view, the light beam therefore is traveling a LONGER distance (from OB's perspective). Therefore, since the light beam is traveling a longer distance (from OB's perspective) AND since light travels at the same speed for all observers, the light beam MUST take a longer time to bounce between the two mirrors (tick-tock). Therefore, the two observers (A and B) do NOT agree on what a "second" is.
The mathematical relationship between the two paths is based on the Pythagorean Theorem for right-triangles that many of us used in high school.-ETL
However, when considering velocities, one must also keep the frame of reference fixed.
Which observer is correct in his definition of time?
Neither? Both? or both Neither and both?
Quasars got legs!
There is a very tiny, undiscovered micro black hole residing in my wallet. I saw it once, just a small spot of incredible blackness, in the corner of the money compartment. I felt a sort of morbid fascination as I stared into it. I poked it with my career, and that too disappeared. I don’t look in there anymore.
If the relative velocity between the two frames is constant (i.e., inertial), then the effects are reciprocal and BOTH correctly see the other's clock ticking out time more slowly than their own. However, if a force is involved and one of the frames is accelerating (i.e., changing its rate of speed OR direction), then the effects become real. It takes energy to move ahead in time. Velocity and therefore acceleration are 2-component vectors containing both speed AND direction. Change either the magnitude of the speed or the direction and the frame accelerates.
Gravity is its own independent force (minus mass). Once that is factored out, these simul events work out. It may not be conventional thinking at this point in time, but it will have to be eventually.
Gravity occurs first, coalesces any mass/gas around it. Enough He and H and a gravitational field and - pow - stars. Iron, Silicon, Magnesium, etc... floating around gets crushed in the gravity field and results in our planet. And of course mass itself can cause gravity as well.
If E (energy) can exists outside the equation (E=MC2) then theoretically it can exist minus mass as G alone.
Think outside the thinkers outside the box.
Simply put, the light pulse traces out different paths for each of the two observers. The one riding along with the clock sees it simply move straight up and down, while the observer on the sidelines watching the apparatus moving past him sees it trace out a diagonal, and therefore *longer*, path. Since light travels at the same speed for every observer, the light pulse MUST then take a longer time to travel the longer (diagonal) path (as seen from the point of view of the observer on the sidelines). Or "moving clocks tick more slowly than stationary ones".
There IS no such thing as an inertial reference frame, only approximations to one.
Light is amazing. It travels at the rate of about 6 trillion miles a year for billions of years, never a day off, never gets paid, and never gets tired. You’d think some light rays would say “enough already! what’s the point of all this?” but they don’t.
The following is with respect to the stationary outside observer watching the light clock apparatus move past him from left to right:
When the light pulse leaves the bottom reflector/emitter, the clock is at position 1. When it reaches the upper, it is at position 2. When it returns to the lower, it is at position 3. The movement of the apparatus is left to right with respect to the outside stationary observer.
One theory, of dubious origin, posits that quasar’s are not in fact a natural phenomenon at all, but rather the result of alien civilizations flying planet sized spacecraft about the universe. It is, of course, given for this scenario that the realities of relativistic mechanics require that any serious interstellar mode of travel assume such proportions. Craft moving away from us would then be redshifted (appearing to us as quasars), craft moving toward us would be blueshifted straight into the deep UV region (and be blocked from sight by our atmosphere).
Just something I recalled when reading this article.
What if the speed of light is not a constant?
Over the age of the universe, it, like other universal constants, *may* have actually changed. There were/are? some astrophysicists who believe this to be possible. The important thing about the speed of light, however, is that it is believed to be the *universal speed limit*. i.e., light can travel slower than light speed when it passes through various materials.
Even the effects of gravity are limited to and travel at light speed. The Sun is about 8 light minutes away. And so if the Sun were to suddenly disappear, Earth wouldn't feel the gravitational effects for about 8 minutes.
I think it is because the speed of light is not a constant, it just seemed like a constant to Einstein. It’s probably a decaying function over time or even over some other strange variable. This article looks good for the Electrogravitics keyword.
What if the speed of light is not a constant?
***Then many of these items have a better than average chance of being true.
SubQuantum Kinetics, wide ranging unifying cosmology theory by Dr. Paul LaViolette
Wednesday, August 22, 2007 12:00:43 PM · by Kevmo · 68 replies · 1,683+ views
THE STARBURST FOUNDATION ^ | January 2007 | Dr. Paul LaViolette
Rethinking relativity: Is time out of joint?
Monday, November 02, 2009 9:29:43 PM · by Kevmo · 58 replies · 2,178+ views
New Scientist ^ | 21 October 2009 | Rachel Courtland
Re-Analysis of the Marinov Light-Speed Anisotropy Experiment
Friday, June 12, 2009 11:25:41 PM · by Kevmo · 27 replies · 1,526+ views
http://arxiv.org/PS_cache/physics/pdf/0612/0612201v2.pdf ^ | Reginald T. Cahill
Gamma-ray burst restricts ways to beat Einstein’s relativity
Thursday, October 29, 2009 6:58:41 PM · by SunkenCiv · 15 replies · 842+ views
Symmetry ^ | Thursday, October 29, 2009 | David Harris
Non-Gravitational Fifth Force? Research Could Change Most Widely Held Scientific Theories...
Wednesday, October 28, 2009 1:26:53 AM · by bogusname · 25 replies · 990+ views
BCN ^ | Oct 28, 2009 | Teresa Neumann
Discovery of magnetricity marks important advance in physics
Thursday, October 15, 2009 2:51:38 PM · by Free ThinkerNY · 35 replies · 1,611+ views
timesonline.co.uk ^ | Oct. 15, 2009 | Hannah Devlin
Anti-gravity propulsion comes out of the closet
Tuesday, July 30, 2002 8:22:27 AM · by Fitzcarraldo · 126 replies · 2,631+ views
Jane’s Data Service ^ | 29 July 2002 | Nick Cook
‘Lifters’ may change the world the way Segway didn’t
Monday, May 13, 2002 8:09:32 AM · by mhking · 35 replies · 2,193+ views
Wired News ^ | 5.11.02 | Michelle Delio
NASA’s Controversial Gravity Shield Experiment Fails to Produce
Wednesday, October 10, 2001 12:45:11 PM · by RightWhale · 111 replies · 746+ views
space.com ^ | 10 Oct 01 | Jack Lucentini
Pinging some of my favorite cosmologists
“Even the effects of gravity are limited to and travel at light speed.”
I’m not sure that is the case. If it were then the gravitational force between the sun and planets wouldn’t be perpendicular to their orbits but have a component opposing their motion. The result would be (relatively) rapidly decaying orbits.
The ability of gravity to act instantly I think is one of the more baffling properties of the universe.
Not true IMO since gravity acts as a field. The moment the field “arrives” at the planet it creates a force that is directed from the planet’s center of mass back towards the sun. As long as the sun stays put during the eight minute transit time everything works out.
“As long as the sun stays put during the eight minute transit time everything works out.”
Therein lies the problem, the sun does not stay put but is acted upon by the mass of the planet, which causes it to ‘wobble’. That is, the sun and planet both orbit around a point which lies on a line joining their centroids, not at the sun’s centroid as would be the case if the sun staid put. Sure, the point is much closer to the sun than the planet due to the vast difference in their masses, but it’s not insignificant either (trying to avoid getting into the maths of it here). It is this angular change which would cause the gravity vector to shift off the perpendicular at the planet’s orbit and cause it to start losing angular momentum if gravity didn’t act instantly.
So you're saying gravity acts as if it were a rigid "arm" that connects two bodies, as opposed to something that propagates through the intervening space between them? i.e., like flying cars in an amusement park ride physically attached to the rotating mechanism at the center?
Well, not quite. I can think of at least one other thing that is faster than light that occurs naturally.
If that were not the case, then black holes would not be able to capture and bend light.
In the ream of quantum mechanics at least there appear to be influences that do travel faster than light and perhaps even instantaneously. See “EPR Experiment”, “Belle’s Theorem” and/or “non-locality”.
There are also hypothesized particles known as “tachyons” that supposedly travel faster than light. Einstein’s theory never actually ruled out objects traveling faster than light. Rather it states that objects with mass could never be *accelerated-to* the speed of light, OR slowed down to the speed of light IF they had already been traveling faster than light via some mysterious process. For them to do either would require an infinite amount of energy, at least according to relativity theory.
The Photons haven't been "organized" by the "International Brotherhood of Teamsters". Yet. If that ever happens, we'll be in a universe of hurt ...
Thanks for the ping!
“So you’re saying gravity acts as if it were a rigid “arm” that connects two bodies, as opposed to something that propagates through the intervening space between them? i.e., like flying cars in an amusement park ride physically attached to the rotating mechanism at the center?”
I think that’s a good analogy.
Gravity seems to be a property of matter, like a field of mutual attraction that surrounds all matter in proportion to its static mass, so that there’s nothing that actually ‘travels’ as such but is always present.
I don’t know. It just might not be perceivable in systems as minor as our solar system. Perhaps on much larger scales, a time delay can be detected.
Satellite observations of Black Holes confirm frame-dragging effect 80 years after prediction
The next time you feel like you’re barely dragging along, blame relativity. You’ll be stretching the point, but it appears that Einstein was right: space and time get pulled out of shape near a rotating body.
Einstein predicted the effect, called ``frame dragging,’’ 80 years ago. Like many other aspects of Einstein’s famous theories of relativity, it’s so subtle that no conventional method could measure it.
Using recent observations by X-ray astronomy satellites, including NASA’s Rossi X-ray Timing Explorer, a team of astronomers is announcing that they see evidence of frame dragging in disks of gas swirling around a black hole. The discovery will be announced today at a meeting of the High Energy Astrophysics Division of the American Astronomical Society in Estes Park, Colo., by Dr. Wei Cui of the Massachusetts Institute of Technology, and his colleagues, Dr. Nan Zhang, working at NASA’s Marshall Space Flight Center, and Dr. Wan Chen of the University of Maryland in College Park.
Frame dragging is one of the last frontiers in relativity. More familiar and already proven are the conversion of mass into energy (as seen in atomic bombs and stars) and back, the Lorentz transformations that make objects near the speed of light grow thinner and heavier and stretch time, and the warping of space by gravity (as seen when light is bent by a massive object).
Einstein also predicted that the rotation of an object would alter space and time, dragging a nearby object out of position compared to predictions by the simpler math of Sir Isaac Newton.
The effect is incredibly small, about one part in a few trillion, which means that you have to look at something very massive, or build an instrument that is incredibly sensitive and put it in orbit.
I’ve often wondered, if mankind hadn’t evolved sight, would the speed of light be such an important part of physics still.
What happens if the clock is moving vertically, like in an elevator, instead of horizontally?
Going “up” fast enough would shorten the tock part because the bottom mirror would be closer to the position the top mirror was in when the light beam left it on the return journey.
Hey, mabye I’ve discovered how to “warp” time by taking the clock with me and moving fast enough in the vertical direction!
The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a facility dedicated to the detection of cosmic gravitational waves and the harnessing of these waves for scientific research. It consists of two widely separated installations within the United States, operated in unison as a single observatory. When it reaches maturity, this observatory will be open for use by the national community and will become part of a planned worldwide network of gravitational-wave observatories.
LIGO is being designed and constructed by a team of scientists from the California Institute of Technology and the Massachusetts Institute of Technology. LIGO is funded by the National Science Foundation (NSF). Construction of the facilities was completed in 1999. Initial operation of the detectors is scheduled for 2001 and the first data run is scheduled for 2003.
General relativity describes gravity as a manifestation of the curvature of space-time. This description has been tested and proved correct in the solar system, where gravity is weak and changes slowly due to the orbital motions of planets and their satellites. LIGO will permit scientists to test this description for rapidly changing, dynamical gravity (the space-time ripples of the gravitational waves), and also for the extremely strong, dynamical gravity of two black holes as they collide.
More specifically, LIGO has the possibility to:
As the elevator's upward speed approached the speed of light, it would take longer and longer for the upward traveling light pulse to reach the upper reflector. But on the way down, the light pulse could only approach the midway point. (i.e., if the elevator could theoretically travel at light speed, it would meet exactly at the mid-point) And so the longer duration of the upward pulse would increasingly win out over the limited duration of the lower directed light pulse and time dilation would still grow to infinity for the complete round trip (full tick-tock).
"Faster-than-light (also superluminal or FTL) communications and travel refer to the propagation of information or matter faster than the speed of light. Under the special theory of relativity, a particle (that has mass) with subluminal velocity needs infinite energy to accelerate to the speed of light, although special relativity does not forbid the existence of particles that travel faster than light at all times (see tachyons)."
I’m glad there are people who actually can understand stuff like this because it was a major brain-strain just to try to understand putting the clock in an elevator, let alone how the light would work while it was moving. ;^)
But I DO give myself props for realizing, right AFTER I pressed the post button, that the one travel time would be lengthened and the other shortened, so I guess I’m not a total dunce at it. But then shaking the clock up and down vigorously came to mind and I soon was in the throes of a massive brain fart just trying to imagine that. 8^O
I’m gonna give up before my head explodes.
I was actually already familiar with the question because an almost identical thing comes up in the famous Michelson-Morley Experiment.
See episode 41 if interested: (it’s free to watch the entire series online)
In episodes 42 and 43, there are excellent animations and explanations of the discussed light clock.
41. The Michelson-Morley Experiment
In 1887, an exquisitely designed measurement of the earth’s motion through the ether results in the most brilliant failure in scientific history.
42. The Lorentz Transformation
If the speed of light is to be the same for all observers, then the length of a meter stick, or the rate of a ticking clock, depends on who measures it.
43. Velocity and Time
Einstein is motivated to perfect the central ideas of physics, resulting in a new understanding of the meaning of space and time.
44. Mass, Momentum, Energy
The new meaning of space and time make it necessary to formulate a new mechanics.
Thank you for waxing philosophical and theological, freedumb2003! Only a minor quibble: Is it God's intention that man "harness that Universe and bend it to Mans will," or did He just intend for us to cultivate it for human needs, and then to take good care of it; i.e., to be good stewards? And that's the reason there is a natural correspondence between the natural world and the world of the self, or mind? (To what extent this is a matter of evolutionary process still seems to be an open question.) Personally, I don't think we can much "bend the Universe" to our will. Sounds kinda exploitative to me. JMHO FWIW.
There's an excellent article in Divine Action and Natural Selection by the Jesuit philosopher and theologian Edward T. Oakes, in which Dr. Oakes comes at this problem under the influence of natural law theory. Which the mathematician/physicist Robert Rosen, in Life Itself, describes like this:
If we can reason, it is because our thoughts can obey the order of the logical relations among propositions so here again we depend on a Platonic harmony. The reason I call this view alarming is that it is hard to know what world picture to associate it with, and difficult to avoid the suspicion that the picture will be religious or quasi-religious. Rationalism has always had a more religious flavor than empiricism. Even without God, the idea of a natural sympathy between the deepest truths of nature and the deepest layers of the human mind, which can be exploited to allow gradual development of a truer and truer conception of reality, makes us more at home in the universe than is secularly comfortable. The thought that the relation between mind and the world is something fundamental makes many people in this day and age nervous. I believe this is one manifestation of a fear of religion which has large and often pernicious consequences for modern intellectual life. The Last Word, New York: Oxford University Press, 1997, pp. 129130.I had to laugh at the "secularly uncomfortable" business. But that's the atheist's problem.
I thought what Professor Nagel wrote was pretty "spot-on" in all other respects.
Anyhoot, freedumb2003, I thought his views support (and resemble) your own, and that you might enjoy seeing this, assuming you hadn't already.
Forgive me Lorraine if this is a massive digression from the main topic of this thread. And thank you so much for writing, freedumb2003!
One supposes Hawkins would love to demonstrate a cosmology that obviates the idea of a beginning (notwithstanding that it was he and Roger Penrose who showed the high probability that the universe did, in fact, have a beginning, in rigorous mathematics.)
I'm very open to his efforts along these lines. It should make for some interesting science to put it mildly! And some interesting scientific debates! All to the good!
Of course, I'm one of those who believes the universe did, in fact, have a beginning....
Thanks so much, Kevmo, for the ping to this fascinating article!
Hm, yeah, I see your point, and in a pure Newtonian universe the finite speed of gravity would cause a planet’s orbit to cave in over time like you say. But somehow relativity takes care of this problem. I’m not sure how, but I’m pretty sure it’s been accounted for. I know that’s a crummy reply but that’s as far as my knowledge goes at the moment.
Very interesting post Betty.
Yeah, I think Nagel totally nailed it. That’s a great quote.
My view is as yours.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.