Recent content by Sagittarius A-Star

Not really. The video "explains" the direction, into which the charged cat, moving with respect to the wire rest frame, is accelerated by the field. This "explanation" refers to the physical effect, that in electrostatics charges with same sign repel each other (and do not attract each other).

Maybe the following video makes it clear. In the wire's restframe, the cat must be repelled from the wire by it's magnetic field, because: In the cat's restframe, the cat is repelled by the wire's electric charge.

The sign of the electron-charge and the current-direction/sign are a matter of convention. This doesn't change physics. The (frame-dependent) magnetic components of the electromagnetic field-tensor are a relativistic effect. Lorentz-force: The 4-force on a charge is this charge divided by...

In addition to what others wrote, Spock doesn't shake hands. He uses the following salutation: Source: https://memory-alpha.fandom.com/de/wiki/Vulkanischer_Gru%C3%9F

A precondition that you can understand it is, that you first fully understand the relativistic calculation of the Sagnac-effect with respect to the rotating reference frame and the calculation of the Ehrenfest-"paradox". Links: http://www.physicsinsights.org/sagnac_1.html...

I think it depends on what the OP understands under "photon" between mirrors. If he means a standing EM-wave, then this wave has energy in the box's (including wave) center-of-momentum frame, that means it has mass.

Source: https://www.ed.ac.uk/news/2024/statement-on-the-death-of-professor-peter-higgs

There was a nice comment on PF:

The SI-definition of ##\mu_0## changed in 2019. Source: https://en.wikipedia.org/wiki/Vacuum_permeability Source: https://en.wikipedia.org/wiki/Vacuum_permeability#Ampere-defined_vacuum_permeability

According to the following paper, published shortly before April 1st, 2009, ##\pi## changes over time. https://arxiv.org/abs/0903.5321

That suggestion is wrong. As others mentioned, the value of ##c## is indirectly defined by the SI-definition of "1 meter": Source: https://en.wikipedia.org/wiki/Metre The constants ##\varepsilon_0## and ##\mu_0## contain a redundancy. You could for example remove ##\mu_0## from all physics...

For the following I assume, that the usable electric energy in the battery is neglectable small compared the the rest-energy of the rocket, so that the laser emission does not significantly change the velocity of the rocket. The rocket moved momentarily with ##v## in ##x##-direction and emits a...

I think this is a good idea. I like this text. However, please be aware, that Wolfgang Rindler used in the chapter about relativistic mechanics the "relativistic mass", which is today considered an out-dated terminology. Source...

Here is a good source: http://www.scholarpedia.org/article/Special_relativity

Such a measurement is not possible. For measuring time, you need a clock. For measuring distance, you need a ruler. Both have mass and therefore cannot move at the speed of light.