What if light speed wasn't the limit?

Click For Summary

Discussion Overview

The discussion revolves around the implications of light speed not being the ultimate limit, particularly in light of recent reports from CERN suggesting the possibility of faster-than-light (FTL) neutrinos. Participants explore theoretical consequences for black hole formation, astronomical events, and the impact on existing theories regarding the speed of light as a fundamental limit.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants note that CERN's report on FTL neutrinos is uncertain and may stem from statistical or measurement errors, emphasizing that light speed remains unbroken as far as current understanding goes.
  • Others propose that if light speed were not a limit, it could fundamentally alter our understanding of phenomena like black hole formation and other astronomical events.
  • One participant stresses the importance of considering the speed of light (c) not just as a limit but as the speed at which massless particles travel, while massive particles approach c with increasing energy.
  • Some argue that the phase velocities of massive quanta can exceed c, suggesting that the concept of c as a speed limit may not apply universally.
  • A participant references a statement from a physicist indicating that if the CERN results are validated, it could lead to significant advancements in unifying gravity and quantum mechanics.
  • Concerns are raised about the validity of statistical claims until all underlying assumptions are confirmed, indicating ongoing uncertainty in the interpretation of the CERN results.
  • Another participant clarifies that while phase velocities can exceed c under certain conditions, this does not imply superluminal information transfer.

Areas of Agreement / Disagreement

Participants express a mix of skepticism and curiosity regarding the CERN findings, with no consensus on the implications of potentially breaking the light speed limit. The discussion remains unresolved, with competing views on the validity and significance of the reported results.

Contextual Notes

Participants highlight limitations in the current understanding of the implications of FTL phenomena, including unresolved statistical issues and the need for further validation of the CERN results.

narrator
Messages
241
Reaction score
17
I saw the recent report where CERN was able to measure something that traveled a tiny bit faster than light. It made me think that only in exceptional circumstances can that speed limit be passed. But it did prompt other questions.

If light speed wasn't the limit, how would that affect things like BH formation?
What other astronomical events might be affected by having no such limit?
And how has the CERN event affected theories based on this limit?
 
Astronomy news on Phys.org
The CERN team reported the possibility of FTL by neutrino's, however it is far from certain that the results are correct. Many many people believe it is either a statistical or measurement error. As far as we know currently light speed is unable to be broken.

As for your what if questions, how can we answer them if they break the laws of nature? Anything is possible if we do that.
 
Also I might stress it important to consider c not just as the speed of light, but at the speed which all particles with 0 mass travel. Bosons travel at c. Fermions travel <c and require increasing energy to approach c.
 
Drakkith said:
The CERN team reported the possibility of FTL by neutrino's, however it is far from certain that the results are correct. Many many people believe it is either a statistical or measurement error. As far as we know currently light speed is unable to be broken.

As for your what if questions, how can we answer them if they break the laws of nature? Anything is possible if we do that.

As I read it, they took a long time to publish, to be as certain as is possible that it wasn't a statistical or measurement error.

If the scale of possibility on the left end measured as being "far from certain" and on the right end as "as close to certain as we can get", this one sounds closer to the right side of the scale than the left.
 
c isn't the speed limit of much of anything. All massive quanta have phase velocities greater than c. Real quanta light has a phase velocity of c in atificial laboratory conditions but is variable in general. What is limited to less than c?
 
narrator said:
As I read it, they took a long time to publish, to be as certain as is possible that it wasn't a statistical or measurement error.

If the scale of possibility on the left end measured as being "far from certain" and on the right end as "as close to certain as we can get", this one sounds closer to the right side of the scale than the left.

Perhaps. I have not kept up with the 1000+ posts on the issue here on PF.

Phrak said:
c isn't the speed limit of much of anything. All massive quanta have phase velocities greater than c. Real quanta light has a phase velocity of c in atificial laboratory conditions but is variable in general. What is limited to less than c?

Signal velocity?
 
Phrak said:
c isn't the speed limit of much of anything. All massive quanta have phase velocities greater than c. Real quanta light has a phase velocity of c in atificial laboratory conditions but is variable in general. What is limited to less than c?

Keeping it simple for boffins like me and quoting from http://www.guardian.co.uk/science/2011/sep/22/faster-than-light-particles-neutrinos" :

The trip would take a beam of light 2.4 milliseconds to complete, but after running the experiment for three years and timing the arrival of 15,000 neutrinos, the scientists discovered that the particles arrived at Gran Sasso sixty billionths of a second earlier, with an error margin of plus or minus 10 billionths of a second.

The result is so unlikely that even the research team is being cautious with its interpretation. Physicists said they would be sceptical of the finding until other laboratories confirmed the result...

Subir Sarkar, head of particle theory at Oxford University, said: "If this is proved to be true it would be a massive, massive event. It is something nobody was expecting.

"The constancy of the speed of light essentially underpins our understanding of space and time and causality, which is the fact that cause comes before effect."

The key point underlying causality is that the laws of physics as we know them dictate that information cannot be communicated faster than the speed of light in a vacuum, added Sarkar...

Despite the marginal increase on the speed of light observed by Ereditato's team, the result is intriguing because its statistical significance, the measure by which particle physics discoveries stand and fall, is so strong.

Physicists can claim a discovery if the chances of their result being a fluke of statistics are greater than five standard deviations, or less than one in a few million. The Gran Sasso team's result is six standard deviations...

Neutrinos are mysterious particles. They have a minuscule mass, no electric charge, and pass through almost any material as though it was not there.

Kostelecky said that if the result was verified – a big if – it might pave the way to a grand theory that marries gravity with quantum mechanics, a puzzle that has defied physicists for nearly a century.

"If this is confirmed, this is the first evidence for a crack in the structure of physics as we know it that could provide a clue to constructing such a unified theory," Kostelecky said.[/B]​

The above and other articles I've read suggest that CERN have done everything by the book (statistically and measurement) but are remaining conservative until validated by others. What is interesting is where Kostelecky suggests that the benchmark may shift from light speed to neutrino speed. If so, then "the laws of nature" don't break. And the discovery could aid in the work towards a unified theory.
 
Last edited by a moderator:
Statistics are not valid until all assumptions have been validated. That appears to still be an issue.
 
Chronos said:
Statistics are not valid until all assumptions have been validated. That appears to still be an issue.

yes.. the usual process still needs going through
 
  • #10
c is the limit of information transmission speed.

The phase velocity of electromagnetic radiation may – under certain circumstances (for example anomalous dispersion) – exceed the speed of light in a vacuum, but this does not indicate any superluminal information or energy transfer.

http://en.wikipedia.org/wiki/Phase_velocity
 

Similar threads

Stargazing Inquiry Regarding Hypothetical Faster-Than-Light Travel Scenario
  • · Replies 2 ·
Replies
2
Views
2K
High School Why Does the Speed of Light Max Out at 186,282 Miles Per Second?
  • · Replies 120 ·
5
Replies
120
Views
9K
High School How fast do space-time changes propagate?
  • · Replies 4 ·
Replies
4
Views
2K
Why can’t we observe all regions of the universe?
  • · Replies 3 ·
Replies
3
Views
717
Graduate Black Holes, Light & Photons: Mass & Speed
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Conventionality of the One-Way Speed of Light
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Ships passing each other at near light speed
  • · Replies 5 ·
Replies
5
Views
684
High School Could There Be a Cosmic Speed Limit Higher Than the Speed of Light?
  • · Replies 7 ·
Replies
7
Views
2K
High School Is light breaking its own speed limit when cornering?
  • · Replies 25 ·
Replies
25
Views
2K
Undergrad Does time dilation occur due to the speed limit of light or c?
  • · Replies 47 ·
2
Replies
47
Views
6K