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> What proof does the physicist have for this theory he dubbed “conformal cyclic cosmology” (CCC) that goes against the current Big Bang dogma? It doesn't go a

> What proof does the physicist have for this theory he dubbed “conformal cyclic cosmology” (CCC) that goes against the current Big Bang dogma? It doesn't go against the current "dogma", as the Big Bang theory only covers history up until a fraction of a second after the big bang. Anything before that is basically fair game, even though some ideas are further out there than others. Penrose admits it's a "crazy idea of his", and that's fine. He's looking for evidence and not just speculating. It's much less out there than Hossenfelder's thoughts about FTL travel in her video from yesterday. And not even remotely comparable to Linus Paulings musings about vitamins.

JoelMcCracken 4y ago
What are you referring to re Linus Paulings?
- Arnavion 4y ago
  https://en.m.wikipedia.org/wiki/Linus_Pauling#Medical_research_and_vitamin_C_advocacy https://en.m.wikipedia.org/wiki/Linus_Pauling#Medical_resear...
- mr_mitm 4y ago
  Another user in this thread mentioned it and it's described in the wikipedia article about crazy nobel laureates linked elsewhere here. Basically, Pauling believed high doses of vitamin C could prolong the lives of cancer patients and cure schizophrenia, despite being out of his field of expertise and lack of evidence.
  - elashri 4y ago
    But Penrose's field of expertise is Cosmology. So I don't think I get the analogy? I understand that this is a speculation because it is very hard to collect evidence for that claim but it is still within the wide umbrella of what Penrose devoted his career.
    - slowmovintarget 4y ago
      That's the point. Penrose's ideas are worth taking seriously because they are directly in line with his field of expertise, and there are means supplied in his papers to rule the ideas out (predictions that should hold true on data we are able to measure). This was a contrast, not an analogy.
      - sangnoir 4y ago
        What data do we have from the time before the big bang?
        slowmovintarget 4y ago
        His papers present things to look for in the current cosmic microwave background that would be evidence. In other words, data we have access to. He's made some claims that these "circles" have been found, as some colleagues of his are working on making such observations. Those "circles" have not been independently verified, however, nor is it yet possible to rule out process error in the data, or the observations calculated from the data. The CMB should show cold spots from evaporated black holes that have expanded to several arc-seconds in diameter. It requires very sensitive survey data, though.
    - deleted 4y ago
      [deleted]
    - auntienomen 4y ago
      Penrose's expertise is general relativity. He's not at all expert in particle physics, which is an essential part of cosmology these days.
      - canadianfella 4y ago
        I’m pretty sure Mr. Penrose is at least somewhat of an expert in particle physics.
likeabbas 4y ago
> Hossenfelder's thoughts about FTL travel in her video from yesterday I didn't watch said video, but we have theories rooted in GR and Quantum Mechanics that would allow for FTL travel already using negative energy/pressure. We know there exists mechanisms to create negative pressure, like the Casimir effect. We know the universe is non-local, as per the Nobel prize awarded last year. And we are beginning to see experiments violate local causality. Who's to say we might not be able to engineer FTL travel at some point?
- throwaway290 4y ago
  What experiments violate causality?
  - likeabbas 4y ago
    https://phys.org/news/2017-04-physicists-violate-local-causality.html https://phys.org/news/2017-04-physicists-violate-local-causa... is one
    - throwaway290 4y ago
      It seems like a huge leap to use a violation of bilocal (not even local in general) causality as confirmation of even theoretical possibility of human FTL travel
    - GoblinSlayer 4y ago
      >If a Bell inequality is violated, then either locality or realism (or simply "local realism") has also been violated. In other words, it's a violation of classical realism, not a violation of locality.
      - aa-jv 4y ago
        Why not both? i.e. truly a violation.
        4y ago
LegitShady 4y ago
I had a hard time understanding the leap she made near the end of her video yesterday about co moving frames. She summarized the time travel theory/paradox as it has been known until now, and then she made some kind of reference to an co moving inertial frame observer ("moving at the same rate as the average of all of the stuff in the universe" paraphrased) she claimed would exist under general relativity. My understanding was that there was no such thing as inertial frame observers in GR, and that an observer in GR is actually something traveling on a world line in time with a future light cone and a post light cone. The observer portion in GR is literally the ability to observe with light, not a coordinate system as defined from within an inertial frame as in special relativity. Thats because in GR, because of the curvature of space, you could not extend a coordinate system across all of existence because you knew that in some areas curvature would cause that to be not accurate. You can sort of declare space effectively flat within a local region but not across the entire universe. It also wasn't clear what someone moving at an co-frame to the average of all the stuff in the universe has to do with faster than light travel - in a spacetime diagram a co-frame would be vertical with a horizontal constant offset, but faster than light travel would have to be in v > c zone not vertical. Maybe I'm too much of a layman to understand the logic she was using but none of it was very clear to me.
- mr_mitm 4y ago
  No, I have a PhD in physics and you are completely right. I had the same issue with her leap. She implies the co-moving frame is a privileged frame in SR, which is basically equivalent to saying: "SR is wrong and thus FTL travel is possible without time travel". Needless to say this is an extraordinary claim that she glosses over in two sentences of a short Youtube video. She's obviously a very smart and professional physicist, but this video that she published is bordering on crank territory and it makes me wonder if the social media fame has gotten to her somehow. It's truly baffling.
  - LegitShady 4y ago
    Maybe she'll post some kind of clarification video. I'm willing to give her the benefit of the doubt that she has an interesting idea that is not well communicated, rather than a bad idea. But until then I basically have no idea how she was trying to suggest that its possible that FTL could exist. I don't really get her logic.

JoelMcCracken 4y ago

What are you referring to re Linus Paulings?

Arnavion 4y ago
https://en.m.wikipedia.org/wiki/Linus_Pauling#Medical_research_and_vitamin_C_advocacy https://en.m.wikipedia.org/wiki/Linus_Pauling#Medical_resear...
mr_mitm 4y ago
Another user in this thread mentioned it and it's described in the wikipedia article about crazy nobel laureates linked elsewhere here. Basically, Pauling believed high doses of vitamin C could prolong the lives of cancer patients and cure schizophrenia, despite being out of his field of expertise and lack of evidence.
- elashri 4y ago
  But Penrose's field of expertise is Cosmology. So I don't think I get the analogy? I understand that this is a speculation because it is very hard to collect evidence for that claim but it is still within the wide umbrella of what Penrose devoted his career.
  - slowmovintarget 4y ago
    That's the point. Penrose's ideas are worth taking seriously because they are directly in line with his field of expertise, and there are means supplied in his papers to rule the ideas out (predictions that should hold true on data we are able to measure). This was a contrast, not an analogy.
    - sangnoir 4y ago
      What data do we have from the time before the big bang?
      - slowmovintarget 4y ago
        His papers present things to look for in the current cosmic microwave background that would be evidence. In other words, data we have access to. He's made some claims that these "circles" have been found, as some colleagues of his are working on making such observations. Those "circles" have not been independently verified, however, nor is it yet possible to rule out process error in the data, or the observations calculated from the data. The CMB should show cold spots from evaporated black holes that have expanded to several arc-seconds in diameter. It requires very sensitive survey data, though.
  - deleted 4y ago
    [deleted]
  - auntienomen 4y ago
    Penrose's expertise is general relativity. He's not at all expert in particle physics, which is an essential part of cosmology these days.
    - canadianfella 4y ago
      I’m pretty sure Mr. Penrose is at least somewhat of an expert in particle physics.

likeabbas 4y ago

> Hossenfelder's thoughts about FTL travel in her video from yesterday I didn't watch said video, but we have theories rooted in GR and Quantum Mechanics that would allow for FTL travel already using negative energy/pressure. We know there exists mechanisms to create negative pressure, like the Casimir effect. We know the universe is non-local, as per the Nobel prize awarded last year. And we are beginning to see experiments violate local causality. Who's to say we might not be able to engineer FTL travel at some point?

throwaway290 4y ago
What experiments violate causality?
- likeabbas 4y ago
  https://phys.org/news/2017-04-physicists-violate-local-causality.html https://phys.org/news/2017-04-physicists-violate-local-causa... is one
  - throwaway290 4y ago
    It seems like a huge leap to use a violation of bilocal (not even local in general) causality as confirmation of even theoretical possibility of human FTL travel
  - GoblinSlayer 4y ago
    >If a Bell inequality is violated, then either locality or realism (or simply "local realism") has also been violated. In other words, it's a violation of classical realism, not a violation of locality.
    - aa-jv 4y ago
      Why not both? i.e. truly a violation.
      - 4y ago

LegitShady 4y ago

I had a hard time understanding the leap she made near the end of her video yesterday about co moving frames. She summarized the time travel theory/paradox as it has been known until now, and then she made some kind of reference to an co moving inertial frame observer ("moving at the same rate as the average of all of the stuff in the universe" paraphrased) she claimed would exist under general relativity. My understanding was that there was no such thing as inertial frame observers in GR, and that an observer in GR is actually something traveling on a world line in time with a future light cone and a post light cone. The observer portion in GR is literally the ability to observe with light, not a coordinate system as defined from within an inertial frame as in special relativity. Thats because in GR, because of the curvature of space, you could not extend a coordinate system across all of existence because you knew that in some areas curvature would cause that to be not accurate. You can sort of declare space effectively flat within a local region but not across the entire universe. It also wasn't clear what someone moving at an co-frame to the average of all the stuff in the universe has to do with faster than light travel - in a spacetime diagram a co-frame would be vertical with a horizontal constant offset, but faster than light travel would have to be in v > c zone not vertical. Maybe I'm too much of a layman to understand the logic she was using but none of it was very clear to me.

mr_mitm 4y ago
No, I have a PhD in physics and you are completely right. I had the same issue with her leap. She implies the co-moving frame is a privileged frame in SR, which is basically equivalent to saying: "SR is wrong and thus FTL travel is possible without time travel". Needless to say this is an extraordinary claim that she glosses over in two sentences of a short Youtube video. She's obviously a very smart and professional physicist, but this video that she published is bordering on crank territory and it makes me wonder if the social media fame has gotten to her somehow. It's truly baffling.
- LegitShady 4y ago
  Maybe she'll post some kind of clarification video. I'm willing to give her the benefit of the doubt that she has an interesting idea that is not well communicated, rather than a bad idea. But until then I basically have no idea how she was trying to suggest that its possible that FTL could exist. I don't really get her logic.