<story><title>I think faster than light travel is possible [video]</title><url>http://backreaction.blogspot.com/2023/04/i-think-faster-than-light-travel-is.html</url></story><parent_chain><item><author>cyberax</author><text>I&amp;#x27;ve seen this video a couple of days ago, and basically it can be summarized as:&lt;p&gt;1. Special relativity disallows FTL because it requires moving faster than light.&lt;p&gt;2. Which is impossible, because you&amp;#x27;d need an infinite amount of energy to do that.&lt;p&gt;3. However, from the past experience with physics, we know that mathematical infinities or singularities are often just an evidence of the theory breaking down. So perhaps it&amp;#x27;s the case here, and a more complete theory will allow to work around the infinity somehow.&lt;p&gt;4. The other problem is that moving faster than light will result in causality paradoxes in the Special Relativity.&lt;p&gt;5. However, if there exists a privileged reference frame, then this can be worked around.&lt;p&gt;I somewhat agree with the arguments given in the first part of the video. We do know that the relativity theory is incompatible with QM, so it&amp;#x27;s not impossible that there is a way to work around this.&lt;p&gt;I&amp;#x27;m much more skeptical of her example of a privileged frame solving the time-travel paradox. It would require some pretty un-physical behavior, like not being able to move in certain directions if you receive an FTL message.</text></item></parent_chain><comment><author>est31</author><text>I would also add point 3.5 which explains that there has been a historic transition (Electroweak Symmetry Breaking) where particles which were massless and travelling at the speed of light before, slowed down and attained mass due to the Higgs field condensing. As the energy that was released back then due to this transition had to be finite, the Lorentz factor argument about infinite energy can&amp;#x27;t be entirely accurate: if the transition works in one way without involving infinite energy, it should surely work in the other way too (otherwise energy conservation would be violated).</text></comment>
<story><title>I think faster than light travel is possible [video]</title><url>http://backreaction.blogspot.com/2023/04/i-think-faster-than-light-travel-is.html</url></story><parent_chain><item><author>cyberax</author><text>I&amp;#x27;ve seen this video a couple of days ago, and basically it can be summarized as:&lt;p&gt;1. Special relativity disallows FTL because it requires moving faster than light.&lt;p&gt;2. Which is impossible, because you&amp;#x27;d need an infinite amount of energy to do that.&lt;p&gt;3. However, from the past experience with physics, we know that mathematical infinities or singularities are often just an evidence of the theory breaking down. So perhaps it&amp;#x27;s the case here, and a more complete theory will allow to work around the infinity somehow.&lt;p&gt;4. The other problem is that moving faster than light will result in causality paradoxes in the Special Relativity.&lt;p&gt;5. However, if there exists a privileged reference frame, then this can be worked around.&lt;p&gt;I somewhat agree with the arguments given in the first part of the video. We do know that the relativity theory is incompatible with QM, so it&amp;#x27;s not impossible that there is a way to work around this.&lt;p&gt;I&amp;#x27;m much more skeptical of her example of a privileged frame solving the time-travel paradox. It would require some pretty un-physical behavior, like not being able to move in certain directions if you receive an FTL message.</text></item></parent_chain><comment><author>peteradio</author><text>I can&amp;#x27;t tell if I&amp;#x27;m misreading point 1, barely rephrasing:&lt;p&gt;Special relativity disallows faster than light travel because it requires moving faster than light.&lt;p&gt;I can&amp;#x27;t gain a lot of insight from that point.</text></comment>