u/Wise-Veterinarian-97

From the last section ("Gravity and relativity") of the The Theory of Gravitation piece of Six easy pieces:

>One feature of this new law which is quite easy to understand is this: In the Einstein relativity theory, anything which has energy has mass -- mass in the sense that it is attracted gravitationally. Even light, which has an energy, has a "mass." When a light beam, which has energy in it, comes past the sun there is an attraction on it by the sun. Thus the light does not go straight, but is deflected.

I always thought that light has no mass and that its energy derives from momentum, according to the extended version of Einstein's mass-energy equivalence, and that light is "attracted" by celestial bodies because the energy of massive objects warps spacetime; and so, from the light's perspective, its traveling in a straight line, but in reality, the spatial geometry that is going thru is curved. Why does Feynman explain it that way? Wasn't he a leading expert on general relativity?

Edit:
Thanks for the replies; my confusion mainly arised from the translation of the text, which omits quotation marks and phrases things much more ambiguously. (i took the quote above from a random free pdf online)

allora volevo sapere fra i due atenei avesse il miglior corso di laurea triennale di matematica. siccome mi immagino già che pisa verrà descritta come l'inferno sceso in terra, dove i professori banchettano con il sangue di bambini appena nati e gli esami chiedono di risolvere tutti e 7 i problemi del millennio, volevo sapere se a Firenze fosse decente ed in generale la difficoltà di esso rispetto all'altro.

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https://i.redd.it/gnzj8z2vsn4h1.gif

So, since you're bordighists, you're also pretty much leninists, so you believe in vanguardism while still not being marxist-leninist. But couldn't the political, administrative, and bureaucratic degeneration of most failed communist projects, that brough most of them to the point of state capitalism, be attributed to state power being directly centralized in the party? Both in the USSR and in Maoist China, there existed people's administrative bodies that were supposed to safeguard the existence of the dictatorship of the proletariat (the soviets and the National People's Congress, respectively), but these completely lost all functionality while the party gained absolute power.

I want to know your opinion