Why not faster than light?

cuddlyrocket · Jul 12, 2005

Interesting thread. Lot of misconceptions. The practical question is: If I want to get somewhere through a vacuum, can I get there faster than a photon can? The answer is yes, although on the definition of causality accepted by most physicists you'd have to travel backwards in time to do so. The laws of physics don't prohibit time travel to the past, though it's a somewhat difficult engineering challenge.

Saiph · Jul 12, 2005

steve, einstein wasn't wrong. SR states the speed barrier, and says it applies within the realm of SR. However cosmological expansion is outside the realm of SR, and is dictated by the more general theory of general relativity. GR describes this process, and how it works. As such, Einstein's mroe general theory is correct...and thus he isn't wrong. His special case just doesn't apply. Cuddlyrocket: Actually physics as it stands now says you can't go back in time. I highly recommend Kip Thorne's "Black holes and Time Warps"...or similar title, that does a good job of explaining it all in pretty easy to understand terms. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

chew_on_this · Jul 13, 2005

Steve won't accept anything not spelled out for him in his wikepedia. Good luck!

MBA_UIU · Jul 13, 2005

Steve all I have to say is that Einstein did not win the Nobel Peace Prize for his work in relativity because it left to many openings for questions that even he could not answer. If you recall he hated the idea that nothing could travel faster than light so much that he was the one that invented wormholes. Read this then think on it for a while. http://www.omsriram.com/Helical%20Travel%20of%20Light.htm <div class="Discussion_UserSignature"> <img id="268587ce-7170-4b41-a87b-8cd443f9351a" src="http://sitelife.space.com/ver1.0/Content/images/store/6/8/268587ce-7170-4b41-a87b-8cd443f9351a.Large.jpg" alt="blog post photo" /> </div>

raghara2 · Jul 13, 2005

Speeds faster than light doesn't imply time travel, if you seen that, it could be an optical ilusion caused by finite speed of particles you are using to watch the effect. Actually it look interesting. You could seen a ship that splits in two moving in somewhat oposite direction, if you could seen them with help of signalizers propagating at speed of light. Of course it's somewhat likely that if you can detect superluminar effects, then you might have also device for superluminar transfer of informations. Basically people that are messing with deffinition of FTL, should try to define all events to some global reference frame. It looks like it could exist, if not naturally, then artifically. If you can define something towards a global reference frame, some misconceptions, and ilusions would simply go away. FTL simply means faster than could electromagnetical wave propagate in vacuum, it doesn't imply ANY time travel. An example object is at slice = 1 at d=1 2 2 3 3 if slice is 1/10 of second, then d = 1 light second. No time travel. slice and distance is increasing linearly, that could be verified by object moving 10 faster between start and finish, and interacting with first object, also by prepared devices along the path interacting with object, and by timer unaffected by behaviour of electromagnetical wave. I think there could be even better proofs, like that fleet of battleships that appeared above planets with information about bad fate of theirs ambasador, 20 times faster than light could propagate to theirs home system, so no preparation for return strike was properly done. ^_^ Faux pas I tried to do some equations with FTL effects, and they are nasty. Basically there is nothing like a free lunch, hopefully when FTL travel would be possible regulary it would be without accelerations, acording to them moving faster than c towards global refference

Saiph · Jul 13, 2005

well...it doesn't imply time travel...if you ignore Special and General Relativity and the velocity dependent time dilation effects. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

Saiph · Jul 13, 2005

<blockquote>In reply to:<hr />Interesting that they make no mention of relativity in all of this. Nor of the violation of the light speed barrier problem. But it seems rather interpreted, rather than a clear concensus of most astronomers. Do most agree with this interpretation of the data? Or is it a current working hypothesis? <hr /></blockquote> Pertaining to the Scientific American article: They do mention relativity...they say that the phenomena is a consequence of General Relativity, and is outside the realm of SR. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

toothferry · Jul 13, 2005

Sure, you can go faster than 300,000,000 kph (the speed of light), given you have a powerful enough rocket not yet engineered. Lets say you want to travel someplace that is 300,000,000,000 Kilometers away, well you can get there (according to your watch) in less than 1000 hours, which according to your calculations would be your maximum time given that you can't go faster than light speed (in Newton's world). Lets say you make it there in just 10hours though. That means you have a greater speed than the 300,000,000 kph you projected according to your calculation. 100X faster than max "possible", infact. But you didn't get there going faster than light. Even while you rusing towards your destination, advancing on it at 100X of your maximum predicted possible speed, light is advancing ahead of you still at the very same breakneck Constant speed of 300,000,000 KPH whenever you aim you laser rangefinder at your target destination. What gives, you ask? It's called time dialation. Everyone that was watching you travel, having not accelerated like you, has aged significantly more than 1000 hours. They are very old now while you are much younger than them. Its an Einstein world we REALLY live in, and this is really possible. But no, you can't ever go faster than light. You can never advance beyond C. It's against the very rules of nature. It's like asking, "can I go faster than infinitely fast?"

argosy · Jul 14, 2005

There are some indications about the possibility to travel faster than light even without breaking einsteins postulations. I belive the concept is called the alcubierre warp drive, and you should be able to find some web pages concerning the problem, just google...it involves stuff like negative energy density and negative mass, butt it seems it could work...check it out.

chew_on_this · Jul 14, 2005

you're obviously out of your league on this thread.

rickstine · Jul 14, 2005

People of the 13th centuary never belived the world was flat it's just a concept people of the modern era veiew people of the past,becauseeven the church blived it to be round also. I belive that the speed of light could be higher than once theroized .I accept it now for fact,until further proof can be proven as fact.It dose not seem possible that the galtic speed limite is 180,000.If the speed of light is fast then that means the distance between plants and stars outside our solar sstem is off. I throw away relatity and replace it with my own

kmarinas86 · Jul 14, 2005

If the speed of light is fast then that means the distance between plants and stars outside our solar sstem is off. um. no it isn't. If parallax is made smaller (or larger) due to the properties (e.g. geodesics) of the interstellar vacuum, then our estimates for the distances to the stars are probably off. The distance of more distant stars are determined by their relative brightness towards stars whose distance is "known" via parallax. Parallax is independent of the speed of light, as far as what scientists know today. The speed of light in interstellar space could be many times than we think, but that does not mean that the stars are closer. The distance is "determined" via parallax.

rickstine · Jul 14, 2005

It's just a thought not actual fact.

chew_on_this · Jul 14, 2005

steve blathers: "Nothing can exceed the speed of light. That is a theoretical as well s observational fact. If you believe it to be so, then show us the confirmed, published studies which show that to be true." Perhaps you missed Saiph's remark: steve, objects with a redshift of 1.5 or greater are receeding at superluminal velocities. http://tinyurl.com/98chu Like I said, you're out of your league.

MBA_UIU · Jul 14, 2005

I guess you don't as much as you think you do, it was not until the 50s that the Nobel Peace Prize was renamed to the Nobel Prize in [...]. Before then it was called the Nobel Peace Prize in [...] to emphasize that the nature of the award, and its winner, had peaceful intentions. Now than, I notice that you did not mention a thing about the site I posted, I wonder why? I should have realized that I was asking to much from someone who believes that comets cannot carry ice in space. <div class="Discussion_UserSignature"> <img id="268587ce-7170-4b41-a87b-8cd443f9351a" src="http://sitelife.space.com/ver1.0/Content/images/store/6/8/268587ce-7170-4b41-a87b-8cd443f9351a.Large.jpg" alt="blog post photo" /> </div>

MBA_UIU · Jul 14, 2005

Steve says, "observational fact". Steve show me one link to one paper where this experiment has been "observed"!! The last I knew the only place on earth that could move heavy atoms at anthying close to the speed of light was the Superconducting Supper Collider and they have not tried any FTL experiments and are not scheduled to try any until after upgrades are complete in 2010. <div class="Discussion_UserSignature"> <img id="268587ce-7170-4b41-a87b-8cd443f9351a" src="http://sitelife.space.com/ver1.0/Content/images/store/6/8/268587ce-7170-4b41-a87b-8cd443f9351a.Large.jpg" alt="blog post photo" /> </div>

chew_on_this · Jul 14, 2005

You made the statement "nothing can travel faster than the speed of light" well after Saiphs "fine report". My contribution is to correct your incorrect blanket statements.

Saiph · Jul 14, 2005

MBA Sorry...that's not what the Super collider is going to do. The current collider rings are quite capable of getting atoms (especially electrons) up to very high fractions of the speed of light (~90%+ IIRC), and those results completely support Special relativity. As such, no particle is ever expected to reach, let alone exceed, C by pumping in more energy (which is all supercolliders do). The super collider will merely get heavier atoms up to those same high speeds, and smack them into other things, and watch the particles spray out of the resulting high energy environment. Sorry, no FTL experiments. Steve: That article points out that significant portions of the observed universe are receeding at superluminal speeds due to cosmological expansion. <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

chew_on_this · Jul 14, 2005

Just an addendum to ftl chatter, carrying over from Black hole thread pertaining to quasars, jets from observed quasars appear to be exceeding c by many times.

chew_on_this · Jul 14, 2005

Quit whining. I've shown examples of FTL observations which is exactly on topic.

Saiph · Jul 14, 2005

The "superluminal jets" can easily be explained within SR (i.e. as sub-luminal velocities, even if highly relativistic) as a consequence of the jet being oriented at a shallow angle (nearly head on). <div class="Discussion_UserSignature"> --------------------SaiphMOD@gmail.com -------------------"This is my Timey Wimey Detector. Goes "bing" when there's stuff. It also fries eggs at 30 paces, wether you want it to or not actually. I've learned to stay away from hens: It's not pretty when they blow" -- The Tenth Doctor, "Blink" </div>

chew_on_this · Jul 14, 2005

Some can, not all.

MBA_UIU · Jul 14, 2005

In his book Faster than the Speed of Light (2003) Dr. Mageuijo, who is a professor of theoretical physics at the Imperial College, London, and studied at Oxford, Cambridge, the University of California, and Princeton, talks about using the superconducting supper collider to bolster his theories on light speed which includes FTL speeds. He hopes to carry out these experiments in 2010 after certain upgrades to the conductor in England are complete. <div class="Discussion_UserSignature"> <img id="268587ce-7170-4b41-a87b-8cd443f9351a" src="http://sitelife.space.com/ver1.0/Content/images/store/6/8/268587ce-7170-4b41-a87b-8cd443f9351a.Large.jpg" alt="blog post photo" /> </div>

MBA_UIU · Jul 14, 2005

Steve I am still await for a link to any published paper that shows where the speed of light is "observational fact" <div class="Discussion_UserSignature"> <img id="268587ce-7170-4b41-a87b-8cd443f9351a" src="http://sitelife.space.com/ver1.0/Content/images/store/6/8/268587ce-7170-4b41-a87b-8cd443f9351a.Large.jpg" alt="blog post photo" /> </div>

MBA_UIU · Jul 14, 2005

More indications of faster than light speeds done by USC at Berkleey Quantum Nonlocality in Two-Photon Experiments at Berkeley http://xxx.lanl.gov/PS_cache/quant-ph/pdf/9501/9501016.pdf MEASUREMENTS OF PHOTON TUNNELING TIMES Tunneling is one of the most striking consequences of quantum mechanics. The Josephson effect in solid state physics, fusion in nuclear physics, and instantons in high energy physics are all manifestations of this phenomenon. Every quantum mechanics text treats the calculation of the tunneling probability. And yet, the issue of how much time it takes a particle to tunnel through a barrier, a problem first addressed in the 1930s, remains controversial to the present day. The question arises because the momentum in the barrier region is imaginary. The first answer, the group delay (also known as the “phase time” because it describes the time of appearance of a wavepacket peak by using the stationary phase approximation), can in certain limits be paradoxically small, implying barrier traversal at a speed greater than that of light in vacuum [33,34]. This apparent violation of Einstein causality does not arise from the use of the nonrelativistic Schr¨odinger equation, since it also arises in solutions of Maxwell’s equations, which are fully relativistic. It has generally been assumed that such superluminal velocities cannot be physical [30], but in the case of tunneling, no resolution has been universally accepted. As a result of developments in solid state physics, such as tunneling in heterostructure devices, the issue has acquired a new sense of urgency since the 1980s, leading to much conflicting theoretical work [35–37]. Several experimental papers presenting more or less indirect measurements of barrier traversal times have appeared. Some seem to agree with the “semiclassical t <div class="Discussion_UserSignature"> <img id="268587ce-7170-4b41-a87b-8cd443f9351a" src="http://sitelife.space.com/ver1.0/Content/images/store/6/8/268587ce-7170-4b41-a87b-8cd443f9351a.Large.jpg" alt="blog post photo" /> </div>

Why not faster than light?

cuddlyrocket

Guest

Saiph

Guest

chew_on_this

Guest

MBA_UIU

Guest

raghara2

Guest

Saiph

Guest

Saiph

Guest

toothferry

Guest

argosy

Guest

chew_on_this

Guest

rickstine

Guest

kmarinas86

Guest

rickstine

Guest

chew_on_this

Guest

MBA_UIU

Guest

MBA_UIU

Guest

chew_on_this

Guest

Saiph

Guest

chew_on_this

Guest

chew_on_this

Guest

Saiph

Guest

chew_on_this

Guest

MBA_UIU

Guest

MBA_UIU

Guest

MBA_UIU

Guest

Similar threads

TRENDING THREADS

Latest posts

Share this page