View Full Version : Parallel universes exist - study
"Parallel universes really do exist, according to a mathematical discovery by Oxford scientists described by one expert as "one of the most important developments in the history of science".
The parallel universe theory, first proposed in 1950 by the US physicist Hugh Everett, helps explain mysteries of quantum mechanics that have baffled scientists for decades, it is claimed.
In Everett's "many worlds" universe, every time a new physical possibility is explored, the universe splits. Given a number of possible alternative outcomes, each one is played out - in its own universe.
A motorist who has a near miss, for instance, might feel relieved at his lucky escape. But in a parallel universe, another version of the same driver will have been killed. Yet another universe will see the motorist recover after treatment in hospital. The number of alternative scenarios is endless.
It is a bizarre idea which has been dismissed as fanciful by many experts. But the new research from Oxford shows that it offers a mathematical answer to quantum conundrums that cannot be dismissed lightly - and suggests that Dr Everett, who was a Phd student at Princeton University when he came up with the theory, was on the right track.
The Oxford team, led by Dr David Deutsch, showed mathematically that the bush-like branching structure created by the universe splitting into parallel versions of itself can explain the probabilistic nature of quantum outcomes."
http://www.breitbart.com/article.php?id=paUniverse_sun14_parallel_universes&show_article=1&cat=0
tinmenace
24-09-2007, 10:37 PM
Yes, this is a fascinating subject. It would explain where atoms disappear to when they go missing.
tejas
24-09-2007, 10:50 PM
Yes, this is a fascinating subject. It would explain where atoms disappear to when they go missing.
:D you mean where electrons disapear to. The atoms remain intact :D
tinmenace
24-09-2007, 10:54 PM
:D you mean where electrons disapear to. The atoms remain intact :D
ROFL! Yeah, them electronomic thangs. Thanks for the correction ;)
phoebe
25-09-2007, 02:42 PM
Each one of us is a parallel universe.
revolutionary_jam
25-09-2007, 03:53 PM
i don't believe there is a universe for every possibility, it becomes ridiculous
there would be infinite universes where you're currently gangbanging an elephant and a giraffe
thoth
25-09-2007, 05:42 PM
Each one of us is a parallel universe.
Yes you are right! Absolutely! Each time we think about a decision or choice, those decisions exist in a multiverse, so to speak. We literally pull them from a higher dimensional plane, beyond space and time. When we chose, for this reality we close down the quantum potential for the other realities and the wave function collaspes on the one choice, in this dimension. But, energy cannot be created or destroyed, those decisions have to be played out in parallel universes!
thoth
25-09-2007, 05:49 PM
:D you mean where electrons disapear to. The atoms remain intact :D
There are really no electrons, merely waves. Those waves extend into all space and time, places where our 3d tuned brains cannot handle. So we see the waves collasped to a single point, a single awareness. The atoms and other particles are just waves of ether chasing itself in a torodial shape funnel. Kind of like light eating itself. This creates standing waves and a source of ether that can feed itself indefinitely.
uchiha
25-09-2007, 11:53 PM
ummm yeah its called the 5th dimension
in short we create everything that can be but experience only that what we want to experience, and all the choices we make we make them subconciously.
so simple but so brilliant. nature of reality is really interesting :)
thoth
26-09-2007, 04:06 AM
ummm yeah its called the 5th dimension
:D:cool:
freedomnonfighter
27-09-2007, 07:08 AM
Each one of us is a parallel universe.
http://img130.imageshack.us/img130/6962/thumbs20upoe4.gif
guyblokeman
27-09-2007, 02:55 PM
I dont buy it and would envoke Occambs Razor on this model.
The whole universe splitting every time the slightest chemical reaction takes place?
Nah....
Theres only one UNIverse, with a possibly infinite frequency range.
This model is the Atheists dream.
mr_moon
27-09-2007, 03:06 PM
If reality only exists NOW, in this moment, then:
Do not wait to be happy because the only time you can EVER be happy… is now.
Do not wait to be free because the only time you can ever experience freedom… is now.
If you are angry then it will only go away if you express it now.
If you are feeling sad the only way to stop is to cry now.
FEAR exists in the illusion that is the Future…it never exists in this moment where you are now. Fear is worry and worry is based on an event that hasn’t even happened!
If you want to do something… do it now. Make the effort to do whatever you choose because you only ever have a choice in this moment. You can’t base a choice on an event that may happen or hasn’t happened yet because it is yet to be created and you make that decision.
Realise that every miniscule action and thought you have- is your choice.
You are making a difference to your life and you are making a difference to the UNIVERSE with every choice you make and it is constantly affecting EVERYTHING in this moment...
... or may i be wrong?
Bad Astronomy and Universe Today Forum > Space and Astronomy > Against the Mainstream (http://www.bautforum.com/against-mainstream/65972-alternative-2-time-dimension.html)
Alternative 2 time dimension Today, 02:31 PM
bigsplit
Senior Member
Alternative 2 time dimension
--------------------------------------------------------------------------------
I was considering that perhaps a 2 time dimension model is not such a grossly negligent approach, but I will see what I can do about that.
I don't want to add a new time dimension, so where does that leave me? I suppose the only thing to do is divide the one we have now into two.
The one we have now is so complex and confusing. What time is it here, there or anywhere often causes struggle. GR and SR are there to save the day for those disciplined enough to understand or brazen enough to claim understanding.
Standard 4D Spacetime can be divided into=T1 and T2 Spacetime
This generates 2 3D spacetimes.
T1 spacetime is universal time. It is a single bodied system of three D space-time flowing at c.
T2 spacetime is "local" time. It is a hyper-plural bodied system imbedded within the T1.
T1 exists eternally while T2 began at the BB "moment".
The flow of T1 only interacts directly with the time dimesion of the T1 continuuim. The flow of the T1 cotinuum represents a constant. The disturbances that generate T2 can be represented as point like reductions in the T1 energy constant. The T1 flow rushes in to fill this "voiding" and its interaction with these disturbances give rise to both gravity and charge.
I will stop here. Please if you see an unanswered response please allow me to reply before I get completely swamped with responses.
Thanks,
Johnny
If reality only exists NOW, in this moment, then:
.
.
Realise that every miniscule action and thought you have- is your choice.
You are making a difference to your life and you are making a difference to the UNIVERSE with every choice you make and it is constantly affecting EVERYTHING in this moment...
... or may i be wrong? Bad Astronomy and Universe Today Forum > Space and Astronomy > Against the Mainstream (http://www.bautforum.com/against-mainstream/34150-time-dilation.html)
Time Dilation
25-October-2005, 03:23 AM
Time Dilation
--------------------------------------------------------------------------------
i've started this thread as a carry on from another thread.
it entailed a short exchange between myself and Tim Thompson on the subject of time dilation and lorentzian contractions/rotations.
in that discussion Tim stated that the twins paradox was not an example of time dilation.
regardless of that opinion/position, the twins paradox was formulated many years ago as an example of time dilation...which had previously been expressed as the clock paradox by einstein.
and although Tim wishes not to call it time dilation....still the same parameters are involved and the same results obtained eg: 2 clocks (or twins) with 2 separate and distinct spacetime lines that are at odds with each other...hence the paradox.
so i've started this thread to again address the concern i have with these relativistic effects.
this is unrelated to mathematics...focusing on what i believe is a crucial problem.
ie: "how the data is applied".
i propose that these relativistic exercises should never devolve into paradoxes...at least not to the extent that they cause conflict with real spacetime....and that they are simply optical illusions...and should be treated as such....nothing more or less.
in the following sections i put forward an argument as to why i think there is no real paradox involved in time dilation...and also comment on a few associated points.
************************************************** *************
************************************************** *************
************************************************** *************
************************************************** *************
to achieve time dilation, we need data...which is supplied by light, travelling at velocity c.
we also require an observer (or detector if it's gps) to receive the light/data....and something to observe (say "the observee", who will transmit the light/data).
************************************************** ******
nb: light takes time to travel..the further the distance, the longer the time.
if the distance is further increased between observer and observee, then the light signal becomes further delayed as well, simply because it has further to travel from the emission point to the detection point.
at relativistic speeds (which produce great distances) the delay can become substantial.
nbesp: this is the reason why the following exercise in "spacetime paradox" can occur...and also why it takes a particular formularisation involving time.
************************************************** ******
in the twins paradox, one twin is stationary and the other travels away at a relativistic speed.
the observer (for this example) is the stationary twin, who observes the travelling twin.
and to actually do this, the observer must receive data from the observee...which again is provided via the "light signal" (the rarely mentioned mechanism for the act of observance).
so what is the natural product of this scenario?
due to the increasing distance between the twins (approaching several light years over time)...the light signal sent from the travelling twin becomes increasingly delayed...simply because it is emitted at increasingly further distances and therefore takes "longer and longer" to travel to the stationary twin, as time goes by.
....so eventually the stationary twin can find himself receiving data that is years out of date....and therefore be able to experience a paradox involving time.
in the twins paradox this is applied to the concept of age difference displayed by the 2 sets of data held by the observer..ie: his own age and the age of the travelling twin seen in the received data.
the data conflicts of course...the travelling twin looks like he has aged less than the stationary twin....but this is just because the data is old....so is this acknowledged?
no.
************************************************** ******
the observer and data are bundled together under the term "reference frame"...SR predisposes our decision processes to accept any reference frame in the exercise (with whatever data it holds) as valid...so the fact that the data held by the observer is old, is forgotten...and that data is plugged straight into spacetime theory immediately causing an aberrant space-timeline (projected for the travelling twin...by the stationary twin).
the same conditions (and pre-disposition) also relate to the travelling twin, resulting in the same product type.
************************************************** ******
************************************************** ******
the pre-disposition relates back to SR
SR is based on the "inertial reference frame" (IRF).
the aspect of the IRF that makes it "special" is the aquisition of a state of uncertainty.
uncertainty as to time/place/velocity etc relative to other IRFs.
therefore in this state...all IRFs may seem valid...but this is a very special state, that can only be achieved if there are no clues to help you out of the predicament.
in time dilation we do have clues....we know the signal has been delayed and we know the reason why....just like we know that the sun's image is really 8 minutes old...and precisely why it is "observed to be that way".
we do not have to suspend reason and demand illusions to be temporal facts....just like we don't demand that the true age of the sun is exactly the age we observe it to be.
************************************************** *********************
************************************************** *********************
both time dilation and lorentzian contractions/rotations are dependent on travel time of light...from observee to observer.
these exercises cannot function without these parameters.
time dilation is the result of imposing out of date data upon the universe
lorentzian contractions are the result of imposing 2d motion blur upon the universe
lorentzian rotations are the result of imposing 3d motion/fov distortions upon the universe
they are all observer based illusions that are allowed to bypass reality checks and run amok on reality.
************************************************** *********************
************************************************** *********************
************************************************** *********************
************************************************** *********************
also...since time dilation and lorentzian contractions/rotations are solely observer based illusions...they therefore cannot be measured in-situ.
any variance in rates of eg: atomic clocks flown on planes in comparison to stationary clocks...is a separate physical process totally unrelated to time dilation.
combining this effect with time dilation only confuses the issue...generating an inappropriately derived "proof"....and promulgating an incorrect belief that time dilation produces real physical alterations.
it does not...and cannot. (Tim in fact stressed this point in the other thread too).
************************************************** *********************
************************************************** *********************
the same for muons.
muon half-lifes only last for 2.2 microseconds when the muons are kept at rest or at a very low speed.
muons travelling at relativistic speeds in an accelerator ring (or through the atmosphere) last a lot longer.
http://www.er.doe.gov/Sub/Newsroom/N...IN_PARADOX.htm
"At rest, or moving very slowly compared with the speed of light, the muon decays into an electron and two other particles, known as neutrinos, typically in 2.2 microseconds."
how far might these types of muons travel then?
"2.2 microseconds multiplied by 300,000 km/second = 0.66 km"
(nb: the above is a quote from the article...but it implies a conflicting situation of having a muon "at rest", yet travelling at speed c so we can measure it's travel distance vs halflife...this is really a fantasy extrapolation applied to an unnatural muon state (ie: kept at rest) and is also the root of the incorrect prescription that muons need time dilation to travel through our atmosphere)
"Muons are created in the upper atmosphere, roughly 10 kilometers above the surface of the Earth, when cosmic rays collide with the atoms in the atmosphere. Muons can subsequently be detected at the surface of the Earth, or even as much as 1 kilometer below the surface."
"Muons can be produced in the laboratory through the same types of collision as take place in the upper atmosphere. Because they are charged, we can steer them into circular storage rings, and keep them going round and round at speeds exceedingly close to the speed of light, say 0.995 c. In experiments at laboratories in both Europe and the United States, such muons have been found to survive typically for 30 times the 2.2 microsecond lifetime before decaying"
************************************************** ****
muons need to travel at least 11 kms to get from the atmosphere to 1km below the surface of the earth...is this possible?
30 * 0.66km = 19.8km
yes...when created and/or maintained in their natural state (travelling at velocities close to c) their lifetimes are longer...so they can get from the atmosphere to the earth with kms to spare.
************************************************** **
one set of data points to a halflife of 2.2 microseconds for muons (when at rest or low speeds).
2 sets of data point to a halflife of upwards of 66 microseconds for muons (when travelling at relativistic speeds in an accelerator ring..or through the atmosphere).
muons therefore do not appear to require time dilation to travel from the atmosphere to the earth.
even if time dilation were applied (to an "at rest" type muon...allowed to travel at c....but retaining it's 2.2 microsecond life), the observer would still only see the muon travel 0.66km...but take upwards of 66 microseconds to do it.
and really...to even be able to achieve this as a "time stretching" would require the muon to travel away from the observer...otherwise there can be no paradoxical "stretching of time", which is reliant on the "light travel time to the observer" getting longer...a parameter that is directly effected by "distance".
muons approaching the observer would be time-condensed and have shorter lives...or "age faster"...just like a travelling twin on the return leg of his relativistic trip...seems to the observer.
for time dilation to come anywhere near being an explanation for why muons can travel from the atmosphere to the ground would first require an observer sitting up in the atmosphere directly above the creation point of the muon...so they can watch it travel directly away from them and towards the earth....and still it wouldn't work because the muon will still only travel 0.66km....regardless of how long it seems to take for the observer.
************************************************** *******************
************************************************** *******************
another point in regards to this business of muons needing time dilation to reach earth.
where are all the observers that are required to achieve this?
who is watching this illusion?
if a muon is created in the atmosphere and there is no observer to time dilate it..does it still not reach the earth?
25-October-2005, 08:07 AM
captain swoop
Senior Member Join Date: Feb 2003
Location: Yorkshire
Posts: 3,659
--------------------------------------------------------------------------------
ISn't time dilation taken into account by GPS?
__________________
'The eye can only see what the mind is prepared to accept'
#3 (permalink) 25-October-2005, 09:00 AM
Thanatos
Senior Member Join Date: Dec 2004
Location: midwest
Posts: 872
--------------------------------------------------------------------------------
Particle physicists observe this 'illusion' on a daily basis. Particles at rest in a lab facility decay in less time [according to clocks in the same inertial rest frame] than their accelerated brethren. This has been experimentally confirmed on a daily basis for decades.
#4 (permalink) 25-October-2005, 09:31 AM
tusenfem
Senior Member Join Date: Aug 2002
Location: Graz, Austria
Posts: 1,215
--------------------------------------------------------------------------------
Maybe it would be better if madman would order his message a little and describe what he does not like about time dilation.
And naturally the problem with a paradox is that it is a paradox.
__________________
************************************************** *************************
Optimism does not change the laws of physics. (T'Pol)
A good scientist has freed himself of concepts and keeps his mind open to what is. (Dao De Jing 27)
************************************************** *************************
Martin ( http://www.geocities.com/DrMartinV )
#5 (permalink) 25-October-2005, 11:19 AM
swansont
Senior Member Join Date: Sep 2003
Location: Washington, DC USA
Posts: 1,364
--------------------------------------------------------------------------------
Quote:
Originally Posted by captain swoop
ISn't time dilation taken into account by GPS?
Yes. It's not a separate mechanical/physical process. Note that there is a combination of gravitational and kinetic effects.
I've read that when the first GPS-related satellite was flown, there was some doubt (among the beancounters, presumably, and not the physicists) that any correction would be necessary, so the clocks were synchronized on the gotund, with the ability to tune an oscillator onboard. The satellite was launched, lo and behold, it was running at the wrong rate. The synthesizer frequency was changes to the preset value, and the clock output was then correct to 1%.
__________________
"I have a cunning plan that cannot fail."
S. Baldrick
#6 (permalink) 26-October-2005, 05:07 AM
Tim Thompson
Senior Member Join Date: Oct 2001
Location: Los Angeles
Posts: 1,812
proper time & coordinate time
--------------------------------------------------------------------------------
The reason I don't like the usual time dilation explanations is that they make it too easy to confuse coordinate time with proper time. Coordinate time is the time coordinate, that goes along with the space coordinates, to make up the spacetime coordinates for an event (x,y,z,t). The coordinate time depends on the observer, as do all of the spacetime coordinates for any event. So, for any given event, there are as many different coordinate times associated with it as there are observers.
But there is only one proper time for a given event, and that is the time ticked off by a clock in the rest frame of the event. That time, as observed by an observer at rest with respect to the clock, never dilates, whatever anyone else might see or think.
We see the muons falling through the atmosphere, and we see "time dilation", the muon lives longer in our reference frame. But the muon does not see it that way. It's too easy to think of time dilation as "real", not in the sense that we see it, but that it somehow means more than what any other observer would see. I call it an illusion, because it is entirely dependent on the observer reference frame, which is not the case for proper time.
[/QUOTE]
26-October-2005, 02:36 PM (http://www.bautforum.com/against-mainstream/34150-time-dilation.html)
madman
Tim
(...)you mention "proper time of a frame"...and the ability of another frame to be at rest in regards to it..and therefore experience no time dilation effect from the first frame.
again i agree.
also i can agree that similar time speeds can be achieved by similar entities/bodies in similar energetic environments.....so that eg: 2 atomic clocks will tick at the same rate under the same conditions.
but any frame at rest with respect to another frame is still separated by distance....so whatever one frame can know about another frame still relies on the travel time of light between them.
Who can solve this? Confused Geometer (http://www.godlikeproductions.com/bbs/message.php?messageid=450931&mpage=1&showdate=10/17/07&forum=1) Look at this at explain where to me where the extra square comes from.
Is it a legitimate math problem or is it just a mind trick/illusion?
[link to www.wonderfulinfo.com (http://www.wonderfulinfo.com/illusions/optical_illusion_021.JPG)] http://www.wonderfulinfo.com/illusions/optical_illusion_021.JPGNothing is the same:D
Parallels ex(g)sists not, but...only in a moment(u-o)s of thinking/thoughts
ps. geometry might be a prove how math is just a generalising ( but.. use-full) tool
as..
Bending Light 'Wrong' Way http://www.sciencedaily.com/images/2007/10/071014163634.jpg
-- Exciting Application Potential
www.sciencedaily.com (http://www.sciencedaily.com/releases/2007/10/071014163634.htm)
..Right?
The arrow of time
Why does time apparently fly one way, when the laws of physics are actually time-symmetrical?
Quantum mechanics may be applied to the entire universe in the manner discussed by Hartle and Hawking (1983), by taking the wave function of the universe to be a sum over all possible cosmic histories and geometries. The question of how to interpret such a wave function has been much discussed, but the consensus seems to be that only the so-called many universes interpretation makes sense. That is, one supposes that every branch of the cosmic wave function describes a really existing universe, and that this infinity of universes co-exist in parallel (Everett 1957, Deutsch 1996). So this is one variety of a theory of all possible worlds.
The implications are easiest to understand if we restrict to the wave function for all possible recontracting universes only. These are universes that start out with a big bang and end with a big crunch.
http://xs320.xs.to/xs320/07424/icketing.gif (http://xs.to)
The gross dynamical behaviour is thus symmetric in time, on average. However, in individual universes (i.e. branches of the wave function) the entropy will not follow the cosmic scale factor by rising and falling again. Rather, it will most probably start out low and end up high, or vice versa.
Any inhabitants of these universes would by definition label the low-entropy end "the big bang" and the high-entropy end "the big crunch", so from their point of view it doesn't matter which way round it is for any particular branch of the wave function (i.e. universe). The key thing is that for the assemblage of universes as a whole the situation remains time symmetric. (In technical parlance, the wave function is unitary.) So we embed special universes with time asymmetry in an overall time-symmetric ensemble. Note that in very rare cases (since the wave function of the universe contains all possible recontracting universes) the entropy will rise and then fall again, allowing the arrow of time to reverse (sometimes mis-stated as "time running backwards"). But the probability of our inhabiting such a universe is infinitesimal.
It seems to me that this is the best we can do to both have our cake and eat it. It accounts for the existence of an arrow of time without imposing one via ad hoc special laws, and without making undue appeal to anthropic selection. Its weakness lies with the fact that applying quantum mechanics to the entire universe remains a highly speculative exercise, and interpreting the wave function in the manner I have described is far from generally accepted.
The arrow of time
Why does time apparently fly one way, when the laws of physics are actually time-symmetrical?
Quantum mechanics may be applied to the entire universe in the manner discussed by Hartle and Hawking (1983), by taking the wave function of the universe to be a sum over all possible cosmic histories and geometries. The question of how to interpret such a wave function has been much discussed, but..
http://xs320.xs.to/xs320/07424/icketing.gif (http://xs.to)
.. ---------- At that star, turn left!
Our bodies contain proteins that are made of smaller molecules that can be either left- or right-handed, depending upon their structure. Regardless of which hand we use to write, however, all human beings are `left-handed` at the molecular level. Life on Earth uses the left-handed variety and no... view more (http://www.brightsurf.com/news/headlines/13884/At_that_star_turn_left.html) (2002-10-17)
How left-handed amino acids got ahead: a demonstration of the evolution of biological homochirality in the lab
A chemical reaction that demonstrates how key molecules in the biological world might have come to be predominately left or right handed has been reported by scientists at Imperial College London. Ever since discovering that the building blocks of the biological world, such as amino acids and...
view more (http://www.brightsurf.com/news/headlines/9752/How_left-handed_amino_acids_got_ahead_a_demonstration_of_th e_evolution_of_biological_homochirality_in_the_lab .html) (2004-06-21)
Amino_Acid_Sequence (http://64.233.183.104/search?q=cache:UEoVfB5MjZgJ:www.brightsurf.com/search/r-a/Amino_Acid_Sequence/1/Amino_Acid_Sequence_news.html+human+dna+left-handed+amino+acids&hl=nl&ct=clnk&cd=2&gl=nl)
www.fourwinds10.com
El Morya: Message In Response To Questions About His Race, The White Dragons (http://www.fourwinds10.com/siterun_data/spiritual/specific_channelings/el_morya/news.php?q=d6f4f16ef47cfedb053f1538569a617e)http://news.nationalgeographic.com/news/bigphotos/25875389.html
[sixe="1 (http://news.nationalgeographic.com/news/bigphotos/images/071017-black-hole_big.jpg)]Most Massive Stellar Black Hole Found in Binary Systemnews.nationalgeographic (http://news.nationalgeographic.com/news/2007/10/071017-black-hole.html) Don't let anyone rob you of your imagination, your creativity, or your curiosity.
http://www.crystalinks.com/oct17jemisonquote.jpg
It's your place in the world; it's your life. Go on and do all you can with it,
and make it the life you want to live. [/size (http://www.crystalinks.com/sacoverartsm.jpg)]
Mae Jemison [crystalinks-ezine[IMG]Quotes ] (http://www.crystalinks.com/ezine.html) http://news.nationalgeographic.com/news/images/thumbs/071017-black-hole_170.jpg
seanx
18-10-2007, 11:44 PM
Thoth wrote:
Yes you are right! Absolutely! Each time we think about a decision or choice, those decisions exist in a multiverse, so to speak. We literally pull them from a higher dimensional plane, beyond space and time. When we chose, for this reality we close down the quantum potential for the other realities and the wave function collaspes on the one choice, in this dimension. But, energy cannot be created or destroyed, those decisions have to be played out in parallel universes!
Are all these 'other' realites 'real' realities or 'potential' realities?
For example, do we have an overriding consciousness, that
based on our feelings at any one moment selects one
particular version of reality - and at that moment, all the
other potentially infinite realities collaspe? - until the next choice we
make and all this is happening moment-by moment?
Or are all these realities 'equal' and all happening at the same time
- and if so, does this mean free will is an illusion as we have no choice
but have to experience everything anyway?
YouTube - Broadcast Yourself.
http://news.nationalgeographic.com/news/images/thumbs/071017-black-hole_170.jpg
There is currently a clear discrepancy in the proper motions measured on different angular scales in the approaching radio jets of the black hole X-ray binary GRS 1915+105. Lower velocities were measured with the Very Large Array (VLA) prior to 1996 than were subsequently found from higher resolution observations made with the Very Long Baseline Array and the Multi-Element Radio Linked Interferometer Network. We initiated an observing campaign to use all three arrays to attempt to track the motion of the jet knots from the 2006 February outburst of the source, giving us unprecedented simultaneous coverage of all angular scales, from milliarcsecond scales out to arcsecond scales. The derived proper motion, which was dominated by the VLA measurements, was found to be 17.0 mas d-1, demonstrating that there has been no significant permanent change in the properties of the jets since 1994. We find no conclusive evidence for deceleration of the jet knots, unless this occurs within 70 mas of the core. We discuss possible causes for the varying proper motions recorded in the literature.
Since they were first observed by Mirabel & Rodríguez (1994), the radio jets in the black hole X-ray binary GRS 1915+105 have been the focus of intensive study. The ejecta have been observed at milliarcsecond scales with the Very Long Baseline Array (VLBA) (Dhawan, Mirabel & Rodríguez 2000) and the Multi-Element Radio Linked Interferometer Network (MERLIN) (Fender et al. 1999; Miller-Jones et al. 2005), and at arcsecond scales with the Very Large Array (VLA) (Mirabel & Rodríguez 1994; Rodríguez & Mirabel 1999). Rodríguez & Mirabel (1998) and Kaiser et al. (2004) have also searched on arcminute scales for potential impact sites of the jets on the interstellar medium (ISM), although at present the evidence is inconclusive.
The proper motions initially measured by Mirabel & Rodríguez (1994) with the VLA were μapp = 17.6 ± 0.4 mas d-1 for the approaching (southeastern) jet and μrec = 9.0 ± 0.1 mas d-1 for the receding (northwestern) counterjet. Rodríguez & Mirabel (1999) used the VLA to measure proper motions for other ejection events, and found fairly consistent values, with no evidence for deceleration of the jets, which were in all cases found to move ballistically outwards from the core. However, MERLIN observations of a 1997 ejection event (Fender et al. 1999) measured a significantly higher set of proper motions, μapp = 23.6 ± 0.5 mas d-1 and μrec = 10.0 ± 0.5 mas d-1, albeit on smaller angular scales. Again, the jet knots were observed to move ballistically. Such high proper motions were also confirmed by VLBA observations (Dhawan et al. 2000) and further MERLIN observations (Miller-Jones et al. 2005). In no case was there ever any evidence for deceleration. Fig. 1 shows all the published proper motions for the jets in this system as a function of time, and highlights the stark discrepancy between observations prior to 1997 made with the VLA and those made later with higher resolution arrays. The actual data are listed in Table 1.
Several possibilities have been put forward to explain this apparent discrepancy in the motion of the jet knots between milliarcsecond angular scales, as measured with MERLIN and the VLBA, and those seen on arcsecond scales with the VLA. Fender et al. (1999) found that the discrepancy could not be explained away by a simple change in the angle to the line of sight of an otherwise physically identical jet (i.e. ruling out precession). They suggested two possible explanations; either the jet velocities were intrinsically different or resolution effects were at work between the two arrays. This latter would lead to a blending of components, and would explain the proper motion discrepancy if there was a sequence of ejecta which decreased sequentially more rapidly in flux density with increasing distance from the core (such that each ejected knot decayed more slowly than its predecessors). This effect was originally highlighted by Hjellming & Rupen (1995) for the case of GRO J 1655−40. Observing the same outburst sequence with both the VLBA and the VLA, they found a similar reduction in the fitted proper motion from 54 to 40 mas d-1 on moving from VLBA to VLA angular scales. They suggested that a combination of the flux density fading with time and spatial averaging of underlying structures led to the discrepancy.
A further possibility is that the knots could be decelerating as they moved outwards (which would imply that they could not be highly relativistic after the deceleration, since the Lorentz factor Γ must be of the order of 2 to see discernible changes in the proper motion), although the ballistic motions of the observed knots would tend to argue against this. Alternatively, as pointed out by Miller-Jones et al. (2005), there could have been an intrinsic change in the system between the time when the VLA observations were taken (all between 1994 and 1995) and the time when the higher resolution observations were made (between 1997 and 2001). Since the source was not detected until 1992 (Castro-Tirado, Brandt & Lund 1992), despite the existing X-ray satellites prior to that time having the sensitivity to detect it, the system might only have emerged from quiescence at that time. Indeed, Truss & Done (2006) suggested that the system has been in a continuous outburst phase since 1992, and may soon switch off again, moving back into quiescence. In this case, the powerful jets might since 1992 have evacuated a cavity through which the ejecta could propagate, such that they could coast for longer during later outbursts, giving rise to the higher proper motions measured with the VLBA and MERLIN. As suggested by Heinz (2002), this would explain the location of the system within a region of very low ISM density, although in that case the jet would have needed to have been active for a time-scale of the order of 103 yr, rather than only since 1992.
To try to discern the cause of this proper motion discrepancy, we proposed to track the motion of the ejecta in GRS 1915+105 over all available angular scales, using the VLBA, MERLIN and also the VLA. In Section 2, we detail our observations, in Section 3 we discuss our results and in Section 4 we draw our conclusions.
See here ~ Evidence for deceleration in the radio jets of GRS1915+105? (http://www.speedyshare.com/230810239.html)
http://www.oal.ul.pt/oobservatorio/vol8/n1/phot-31a-01-normal.jpg