Discovery that quasars don't show time dilation mystifies astronomers

Physorg ^ | 09 March 2010 | Lisa Zyga

[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 doesn’t 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 doesn’t 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 universe’s dark matter. As Hawkins explains, most physicists predict that dark matter consists of undiscovered subatomic particles rather than primordial black holes.

There’s 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

[ETL]

There really isn't anything particularly special about light in this regard, other than the fact that its speed is limited to the apparent speed limit of the universe: 186,000 miles per second or "light speed". Supposedly, any massless object travels at light speed. And it's only the "speed limit" in the sense that no object with mass can be accelerated-to the speed of light, OR slowed downed to it IF already traveling faster.

______________________________________

"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)."

http://en.wikipedia.org/wiki/Faster-than-light

[hadit2here]

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.

[Captain Beyond]

bflr

[ETL]

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.

http://www.learner.org/resources/series42.html

[betty boop]

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.

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 Man’s 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:

In his article, Dr. Oakes cites the secular atheist philosopher Thomas Nagle on matters regarding our present concern:

“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. 129–130.

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!

[betty boop]

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 universe’s dark matter. As Hawkins explains, most physicists predict that dark matter consists of undiscovered subatomic particles rather than primordial black holes.

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!

[Yardstick]

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.

[Lorianne]

Very interesting post Betty.
Thanks.

[Yardstick]

Yeah, I think Nagel totally nailed it. That’s a great quote.

[Quix]

INDEED.

My view is as yours.

Thx.

[betty boop]

That’s a great quote.

I really liked it, too! Thanks for writing Yardstick!

[Swordmaker]

Traditional Cosmologists again surprised by something... PING!

If you want on or off the Electric Universe Ping List, Freepmail me.

[zeugma]

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 read something a while back that would argue that case. Seems that devices that can detect gravitational effects show the sun where it actually is as opposed to where we see it (8 minutes in the past). I may have bookmarked the article. If I can find it I'll post the link to this thread.

AmP

[zeugma]

I knew I should have read further on this thread. This was exactly what I was talking about in my previous post.

[raygun]

ping

[onedoug]

M-Theory

[valkyry1]

//Traditional Cosmologists again surprised by something//

I am not surprised! LOL

[ETL]

I knew I should have read further on this thread. This was exactly what I was talking about in my previous post.

Also see post 39:
LIGO: "Test general relativity's prediction that these [gravitational] waves propagate at the same speed as light, and that the graviton (the fundamental particle that accompanies these waves) has zero rest mass."

http://www.freerepublic.com/focus/chat/2491839/posts?page=39#39

[betty boop]

Thank you Lorianne! (So sorry to have misspelled your name before. I need an eye exam....)

As you are the host of this thread, may I ask your permission to correct something I said before, for the record?

I described the late Robert Rosen as a "mathematician and physicist." I think it would be more truthful and correct to say: He was a world-class mathematician, and theoretical biologist. Though I'm sure he had a pretty good grip on physics, as well.

I find him one of the most interesting biological theorists I've come across lately. He definitely "thinks outside the box."

Thank you so much for your hospitality!

[LeGrande]

The gravitational field effects are instantaneous for all practical purposes. If they weren’t the planets would have spiraled into the sun a long time ago. Newtonian physics works just fine for non relativistic acceleration.