- #1
windy miller
- 303
- 25
Carol Rovelli recently claimed :
"in physics there is nothing that corresponds to the notion of the ‘now’. Compare ‘now’ with ‘here’. ‘Here’ designates the place where a speaker is. For two different people, ‘here’ points to two different places. Consequently ‘here’ is a word whose meaning depends on where it is spoken. The technical term for this kind of utterance is ‘indexical’. ‘Now’ also points to the instant in which the word is uttered and is also classed as indexical."
https://aeon.co/ideas/what-s-the-time-just-ask-a-black-hole
i think this is normal relativity. But I was recently reading a philosopher saying Rovelli has it wrong:
"When scientists say that the universe is around 14 billion years old, they are not talking just in Earth-time. They don’t mean relative to our reference frame. Rather, this cosmic time parameter is independent of space. It is independent of spatial coordinates. Therefore, cosmic time is the same for every hypothetical observer in the universe regardless of his state of motion. In other words, cosmic time is a kind of reinstatement of Newton’s absolute time. It measures the duration of the universe in a frame-independent way."
Read more: http://www.reasonablefaith.org/black-holes-and-the-arrow-of-time#ixzz4fdKYoUIz
My suspicion is that Rovelli know more about relativity than this philosopher but perhaps someone can elaborate on what is going on, is Rovelli wrong? if not, is it false to say the cosmic time is measure the same by all observers?
"in physics there is nothing that corresponds to the notion of the ‘now’. Compare ‘now’ with ‘here’. ‘Here’ designates the place where a speaker is. For two different people, ‘here’ points to two different places. Consequently ‘here’ is a word whose meaning depends on where it is spoken. The technical term for this kind of utterance is ‘indexical’. ‘Now’ also points to the instant in which the word is uttered and is also classed as indexical."
https://aeon.co/ideas/what-s-the-time-just-ask-a-black-hole
i think this is normal relativity. But I was recently reading a philosopher saying Rovelli has it wrong:
"When scientists say that the universe is around 14 billion years old, they are not talking just in Earth-time. They don’t mean relative to our reference frame. Rather, this cosmic time parameter is independent of space. It is independent of spatial coordinates. Therefore, cosmic time is the same for every hypothetical observer in the universe regardless of his state of motion. In other words, cosmic time is a kind of reinstatement of Newton’s absolute time. It measures the duration of the universe in a frame-independent way."
Read more: http://www.reasonablefaith.org/black-holes-and-the-arrow-of-time#ixzz4fdKYoUIz
My suspicion is that Rovelli know more about relativity than this philosopher but perhaps someone can elaborate on what is going on, is Rovelli wrong? if not, is it false to say the cosmic time is measure the same by all observers?