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Thalita Luna
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Hi guys! Is there a simple explanation to describe why light owns the faster speed at the universe ?
Yes. It has 0 mass. Nothing is faster because nothing has less than 0 mass.Thalita Luna said:Hi guys! Is there a simple explanation to describe why light owns the faster speed at the universe ?
I would say yes or no, depending on exactly what question you want answering.Thalita Luna said:Hi guys! Is there a simple explanation to describe why light owns the faster speed at the universe ?
I expect that most, possibly all, of the people who are OK with that are taking the position that any solution of the EFE that allows for signalling into the past is unphysical.Vanadium 50 said:This is usually regarded as a fatal problem, although GR suffers from the same problem (Tipler cylinders) and people are OK with that.
Well, it is easy to have tachyons that never allow CTCs or tachyon anti-telephone, in SR. Just posit that there exists a preferred inertial frame in which all tachyon trajectories must move forward in (coordinate) time. Many people (me included) reject this on the grounds that a preferred frame is at odds with the principle of relativity.Vanadium 50 said:And techyons signaling into the past might require a set of unphysical initial conditions. We don;t know, and with no observation and no real theory we are unlikely to.
I am working on a paper now. I don't want to discuss the details before it is published,, but I can tell you it is possible to cook up a model without CTCs and that these tachyons have a signature that has not really been looked for - a dedicated experiment can push the limits way, way down. Stay tuned.
Actually, the causality violations in tachyon models do not involve CTCs, because tachyon worldlines are spacelike. The causality violations come from allowing causal connections to occur along spacelike curves as well as timelike or null curves. That is really the root problem.PAllen said:tachyons that never allow CTCs
Ah, yes. What you have are closed causal curves (e.g. two spacelike sides and a timelike side forming a causal loop). And the preferred frame restriction prevents such a construction from occurring.PeterDonis said:Actually, the causality violations in tachyon models do not involve CTCs, because tachyon worldlines are spacelike. The causality violations come from allowing causal connections to occur along spacelike curves as well as timelike or null curves. That is really the root problem.
Have in mind that tachyon fields (as opposed to tachyon point particles) do not propagate faster than light. See the paper https://journals.aps.org/prd/abstract/10.1103/PhysRevD.18.3610Vanadium 50 said:I am working on a paper now.
Yes, that's called tachyon condensation. https://en.wikipedia.org/wiki/Tachyon_condensationvanhees71 said:Then you rather get massive particles as excitations around a minimum of the effective (quantum) action with a non-vanishing VEV of the field.
Well, some physicists call it tachyon condensation.vanhees71 said:This is not Tachyon condensation but just the usual case of a massive particle, described by a field with a non-vanishing vacuum expectation value.
The speed of light is considered to be the fastest possible speed because it is the maximum speed at which energy, information, or matter can travel in the universe. This is due to the fundamental laws of physics, specifically Einstein's theory of relativity, which states that nothing can travel faster than the speed of light.
Based on our current understanding of physics, nothing can travel faster than the speed of light. The speed of light is considered to be a universal speed limit, and any object that approaches or exceeds this speed would require infinite energy, which is impossible.
As mentioned before, the speed of light is considered to be a universal speed limit because of the laws of physics. According to Einstein's theory of relativity, as an object approaches the speed of light, its mass increases infinitely, making it impossible to accelerate any further.
Yes, there is a significant amount of evidence that supports the idea of nothing being faster than light. One of the most famous examples is the Michelson-Morley experiment, which showed that the speed of light is constant in all directions. Additionally, many other experiments and observations in physics have consistently shown that the speed of light is the maximum speed in the universe.
There are currently no known exceptions to the rule that nothing can travel faster than light. However, there are some phenomena, such as quantum entanglement, that may appear to violate this rule. Still, they do not involve the actual transfer of information or matter faster than the speed of light. Scientists continue to study and explore the laws of physics to understand the universe better and potentially discover any exceptions to this rule.