New on // foss.events: Electromagnetic Field by Electromagnetic Field Ltd.
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New on // foss.events: Electromagnetic Field by Electromagnetic Field Ltd. on 16-19 July 2026 in Eastnor Castle Deer Park in #Eastnor, #United Kingdom
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https://foss.events/2026/07-16-electromagnetic-field.htmlFollow the official account: @emf
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undefined andypiper@macaw.social shared this topic on
Gli ultimi otto messaggi ricevuti dalla Federazione
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What's the best accessory for a night out?
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Is it easy to migrate from Firefox and keep saved bookmarks and login passwords ?
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I worry everything is getting stupider
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@jon No AI is based.
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Is the Theory of Special Relativity Wrong?
There’s an adage coined by [Ian Betteridge] that any headline ending in a question mark can be answered by the word “No”. However, Lorentz invariance – the theory that the same rules of physics apply in the same way in all frames of reference, and an essential component of special relativity – has been questioned for some time by researchers trying to unify general relativity and quantum field theory into a theory of quantum gravity. Many theories of quantum gravity break Lorentz invariance by giving photons with different energy levels very slightly different speeds of light – a prediction which now looks less likely since researchers recently analyzed gamma ray data from pulsed astronomical sources, and found no evidence of speed variation (open-access paper).
The researchers specifically looked for the invariance violations predicted by the Standard-Model Extension (SME), an effective field theory that unifies special relativity with the Standard Model. The variations in light speed which it predicts are too small to measure directly, so instead, the researchers analyzed gamma ray flare data collected from pulsars, active galactic nuclei, and gamma-ray bursts (only sources that emitted gamma rays in simultaneous pulses could be used). Over such great distances as these photons had traveled, even slight differences in speed between photons with different energy levels should have added up to a detectable delay between photons, but none was found.
This work doesn’t disprove the SME, but it does place stricter bounds on the Lorentz invariance violations it allows, about one and a half orders of magnitude stricter than those previously found. This study also provides a method for new experimental data to be more easily integrated into the SME. Fair warning to anyone reading the paper: the authors call their work “straightforward,” from which we can only conclude that the word takes on a new meaning after a few years studying mathematics.
If you want to catch up on relativity and Lorentz invariance, check out this quick refresher, or this somewhat mind-bending explanation. For an amateur, it’s easier to prove general relativity than special relativity.
Top image: Crab Pulsar, one of the gamma ray sources analysed. (Credit: J. Hester et al., NASA/HST/ASU/J)
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Brescia: giornata di azioni antisfratto promosse da “diritti per tutti”
@anarchia
Lotta per la casa. Giornata di mobilitazione contro gli sfratti il 15 gennaio 2026 con attiviste e attivisti dell’Associazione Diritti per tutti di Brescia impegnati in tre azioni https://www.rivoluzioneanarchica.it/brescia-giornata-di-azioni-antisfratto-promosse-da-diritti-per-tutti/
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Signal, the private messaging app.
Curious to see what the uptake is on Fedi.
#poll #signalApp
