Thread: More faster than light questions

I am basing this question from something I read from the thread speed of shadows ...

If something is moving at a FLT speed towards us ... it will appear to be moving away from us correct? Because the closer it gets the sooner we will observe it.

How would that effect blueshift? Would we still have blueshift even though the object is apparently ( from our viewpoint ) moving away from us or would there be redshift because of its apparent movement away from us?

Originally Posted by tom

If something is moving at a FLT speed towards us ... it will appear to be moving away from us correct?

No, we wouldn't see it coming at all, it will overtake the photons it emits towards us. We'd only see the image of it coming towards us after it has already passed us.
Just like you don't hear an object coming towards you at supersonic speed.

Originally Posted by tom

I am basing this question from something I read from the thread speed of shadows ...

If something is moving at a FLT speed towards us ... it will appear to be moving away from us correct? Because the closer it gets the sooner we will observe it.

How would that effect blueshift? Would we still have blueshift even though the object is apparently ( from our viewpoint ) moving away from us or would there be redshift because of its apparent movement away from us?

It is not possible for an object to move faster than light. A shadow is not an object so it can do that. But a shadow does not have red-blue shift in the same way that a moving object does.

Originally Posted by RayTomes

It is not possible for an object to move faster than light. A shadow is not an object so it can do that. But a shadow does not have red-blue shift in the same way that a moving object does.

I think we're in the speculative, tachyon-inhabited, universe on this one

I need to point out once again that there are no laws of physics that prevent objects from moving faster than light. The laws of physics only state that an object travelling at a speed slower than light would take an infinite amount of energy to accelerate to the speed of light. However, there are no laws that prevent objects either that start out travelling at the speed of light OR have been travelling at the speed of light since the beginning of the universe from existing.

Originally Posted by RayTomes

It is not possible for an object to move faster than light. A shadow is not an object so it can do that. But a shadow does not have red-blue shift in the same way that a moving object does.

Originally Posted by tom

However, there are no laws that prevent objects either that start out travelling at the speed of light OR have been travelling at the speed of light since the beginning of the universe from existing.

You're lucky you didn't put XOR since the two are really saying the same thing

Particles Found to Travel Faster than Speed of Light: Scientific AmericanAn Italian experiment has unveiled evidence that fundamental particles known asneutrinos can travel faster than light. Other researchers are cautious about the result, but if it stands further scrutiny, the finding would overturn the most fundamental rule of modern physics—that nothing travels faster than 299,792,458 meters per second.


The experiment is called OPERA (Oscillation Project with Emulsion-tRacking Apparatus), and lies 1,400 meters underground in the Gran Sasso National Laboratory in Italy. It is designed to study a beam of neutrinos coming from CERN, Europe's premier high-energy physics laboratory located 730 kilometers away near Geneva, Switzerland. Neutrinos are fundamental particles that are electrically neutral, rarely interact with other matter, and have a vanishingly small mass. But they are all around us—the sun produces so many neutrinos as a by-product of nuclear reactions that many billions pass through your eye every second. [Click here to read more about CERN's Large Hadron Collider]


The 1,800-tonne OPERA detector is a complex array of electronics and photographic emulsion plates, but the new result is simple—the neutrinos are arriving 60 nanoseconds faster than the speed of light allows. "We are shocked," says Antonio Ereditato, a physicist at the University of Bern in Switzerland and OPERA's spokesman.


Breaking the law


The idea that nothing can travel faster than light in a vacuum is the cornerstone of Albert Einstein's special theory of relativity, which itself forms the foundation of modern physics. If neutrinos are traveling faster than light speed, then one of the most fundamental assumptions of science—that the rules of physics are the same for all observers—would be invalidated. "If it's true, then it's truly extraordinary," says John Ellis, a theoretical physicist at CERN.


Ereditato says that he is confident enough in the new result to make it public. The researchers claim to have measured the 730-kilometer trip between CERN and its detector to within 20 centimeters. They can measure the time of the trip to within 10 nanoseconds, and they have seen the effect in more than 16,000 events measured over the past two years. Given all this, they believe the result has a significance of six-sigma—the physicists' way of saying it is certainly correct. The group will present their results September 23 at CERN, and a preprint of their results will be posted on the physics website ArXiv.org.


At least one other experiment has seen a similar effect before, albeit with a much lower confidence level. In 2007, the Main Injector Neutrino Oscillation Search (MINOS) experiment in Minnesota saw neutrinos from the particle-physics facility Fermilab in Illinois arriving slightly ahead of schedule. At the time, the MINOS team downplayed the result, in part because there was too much uncertainty in the detector's exact position to be sure of its significance, says Jenny Thomas, a spokeswoman for the experiment. Thomas says that MINOS was already planning more accurate follow-up experiments before the latest OPERA result. "I'm hoping that we could get that going and make a measurement in a year or two," she says.


Reasonable doubt


If MINOS were to confirm OPERA's find, the consequences would be enormous. "If you give up the speed of light, then the construction of special relativity falls down," says Antonino Zichichi, a theoretical physicist and emeritus professor at the University of Bologna, Italy. Zichichi speculates that the "superluminal" neutrinos detected by OPERA could be slipping through extra dimensions in space, as predicted by theories such as string theory.

I watched the live webcast from CERN, today (yesterday). Many scientists invited to put questions and suggestion, but none came up with anything that hadn't been thought of and ruled out, or compensated for.

Can you imagine the consternation of those conducting the experiments as the data began to show the effect - the early arrival of particles at the party.
"What the . . ." "Run it again!" "Check the detector" "Tighten those nuts" "Phone the speaking clock" "Are you sure we're on Summer Time?" "GET ME MORE MATHEMATICIANS!!!"

Would the travel time over distance of the Neutrinos be unaffected by expansion or contraction of local space/time.
(I'm concerned that I may be shrinking.)

Originally Posted by TaoZero5

Can you imagine the consternation of those conducting the experiments as the data began to show the effect - the early arrival of particles at the party.
"What the . . ." "Run it again!" "Check the detector" "Tighten those nuts" "Phone the speaking clock" "Are you sure we're on Summer Time?" "GET ME MORE MATHEMATICIANS!!!"

You've forgotten the most important: GET ME MORE COFFEE!!! NOW!!!!

Originally Posted by TaoZero5

(I'm concerned that I may be shrinking.)

According to an article in the Wall Street Journal last week you (we) are...