“To convince someone of the truth, it is not enough to state it, but rather one must find the path from error to truth.”
— Ludwig Wittgenstein, Philosophical Occasions, 1912-1951 (via philosophybits)
On this day, 23 March 1894, revolutionary writer and advocate for women’s rights, Salvadora Carmen Medina Onrubia was born in La Plata, Buenos Aires. She started a relationship with a Uruguayan journalist called Natalio Félix Botana in 1915, and when he later became a powerful newspaper mogul, Salvadora used her new-found wealth to help the anarchist movement, working to free political prisoners, getting jobs for unemployed militants and distributing goods to poor women from her Rolls-Royce. She attempted to break famed anarchist assassin Simon Radowitzky out of prison, but after this failed she was able to use her influence to secure his release from the President. During the Spanish civil war she helped anti-fascist exiles and sent money to Republican orphans in Spain. More info in this short biography: https://ift.tt/2uBCAaohttps://ift.tt/2UNW076
March 23, 1931: Martyrdom of comrade Bhagat Singh, a young communist revolutionary leader of India/Pakistan.
Singh and two comrades, Rajguru and Sukhdev, were executed by the British colonialist regime.
Born in the Punjab region of colonial India (now part of Pakistan), Singh is a legendary revolutionary role model throughout South Asia and the world. Like Che Guevara, he has become a symbol of resistance for revolutionary youth.
In 2018, a trio of researchers at Columbia University proposed that sound waves—just … ordinary sound waves—might generate negative gravity. That theory, covered in phys.org, has to do with something called a “phonon.” The phonon (not photon) is a concept from quantum mechanics that represents an elementary unit of vibrational motion. In terms that would surely drive a quantum physicist to distraction, it might be thought of as the smallest possible “particle of sound.”
As with photons and light waves, sound waves (or any “excitation”) within matter may display both wave-like and particle-like behaviors. And as with all things quantum, there are fixed scales at which things not only do, but can, occur. But while phonons may be “particle-like” physicists have generally treated this behavior as a kind of convenience for dealing with how sound interacts with other forces. It hasn’t been treated like a “real particle.”
But the Columbia researchers did the math on what it would mean if a phonon was more than just particle-like, and out of the math from that theory sprang a prediction that phonons would interact with gravitational fields to produce negative-mass and negative-gravity. Unfortunately, the predicted phenomenon would be very difficult to detect using current technology. Except … as the March edition of Physics reports, the three researchers have extended their math, and found that the theory applies to sound waves traveling through materials like liquids and solids, which means it potentially can be detected. …
