"Special relativity is based on the observation that the speed of light is always the same, independently of who measures it, or how fast the source of the light is moving with respect to the observer. Einstein demonstrated that as an immediate consequence, space and time can no longer be independent, but should rather be considered a new joint entity called "spacetime."
https://www.bowdoin.edu/news/2015/04/physics-professor-baumgarte-describes-100-years-of-gravity.html
So if spacetime is "doomed", the underlying premise, Einstein's 1905 constant-speed-of-light postulate, is doomed as well, no? Not in Einstein's schizophrenic world. Theoretical physicists repudiate spacetime but worship the constancy of the speed of light:
Nima Arkani-Hamed: "Almost all of us believe that spacetime doesn't really exist, spacetime is doomed and has to be replaced."
https://youtu.be/U47kyV4TMnE?t=369
"We've known for decades that space-time is doomed," says Arkani-Hamed. "We know it is not there in the next version of physics."
https://www.discovermagazine.com/the-sciences/amplituhedron-may-shape-the-future-of-physics
"Einstein introduced a new notion of time, more radical than even he at first realized. In fact, the view of time that Einstein adopted was first articulated by his onetime math teacher in a famous lecture delivered one century ago. That lecture, by the German mathematician Hermann Minkowski, established a new arena for the presentation of physics, a new vision of the nature of reality redefining the mathematics of existence. The lecture was titled Space and Time, and it introduced to the world the marriage of the two, now known as spacetime. It was a good marriage, but lately physicists passion for spacetime has begun to diminish. And some are starting to whisper about possible grounds for divorce."
https://www.sciencenews.org/article/its-likely-times-are-changing
"Was Einstein wrong? Do we have to kill off the theory of space and time to make sense of the universe?"
https://space.com/end-of-einstein-space-time
"Bye bye space-time: is it time to free physics from Einstein's legacy?"
https://www.newscientist.com/article/mg24332472-900-bye-bye-space-time-is-it-time-to-free-physics-from-einsteins-legacy/
Philip Ball: "And by making the clock's tick relative - what happens simultaneously for one observer might seem sequential to another - Einstein's theory of special relativity not only destroyed any notion of absolute time but made time equivalent to a dimension in space: the future is already out there waiting for us; we just can't see it until we get there. This view is a logical and metaphysical dead end, says [Lee] Smolin."
http://www.guardian.co.uk/books/2013/jun/10/time-reborn-farewell-reality-review
"Was Einstein wrong? At least in his understanding of time, [Lee] Smolin argues, the great theorist of relativity was dead wrong. What is worse, by firmly enshrining his error in scientific orthodoxy, Einstein trapped his successors in insoluble dilemmas."
http://leesmolin.com/time-reborn-2/reviews/
"Rethinking Einstein: The end of space-time...Horava, who is at the University of California, Berkeley, wants to rip this fabric apart and set time and space free from one another..."
https://www.newscientist.com/article/mg20727721-200-rethinking-einstein-the-end-of-space-time/
What scientific idea is ready for retirement? Steve Giddings: "Spacetime. Physics has always been regarded as playing out on an underlying stage of space and time. Special relativity joined these into spacetime...The apparent need to retire classical spacetime as a fundamental concept is profound..."
https://www.edge.org/response-detail/25477
"...says John Norton, a philosopher based at the University of Pittsburgh, Pennsylvania. Norton is hesitant to express it, but his instinct - and the consensus in physics - seems to be that space and time exist on their own. The trouble with this idea, though, is that it doesn't sit well with relativity, which describes space-time as a malleable fabric whose geometry can be changed by the gravity of stars, planets and matter."
https://www.newscientist.com/article/mg20026831.500-what-makes-the-universe-tick
Nobel Laureate David Gross observed, "Everyone in string theory is convinced...that spacetime is doomed. But we don't know what it's replaced by."
https://www.edge.org/response-detail/26563
Pentcho Valev
https://twitter.com/pentcho_valev