Two weeks before death, Hawking submitted a paper on parallel universes • Hacker News Board

Re: Two weeks before death, Hawking submitted a paper on parallel universes

#11

Post by jfaucett » Mon, Mar 19, 2018, 8:24 AM UTC

epaga wrote: post #4

Something I've never understood and would greatly appreciate understanding: could someone ELI"5" how the concept of "parallel universes" will not always be a metaphysical instead of a scientific question? If there are truly separate "universes", then by definition wouldn't it be the case that there would be no way to test (or falsify) whether they exist or not, so would the question of their existence not be in the r…

> If there are truly separate "universes", then by definition wouldn't it be the case that there would be no way to test (or falsify) whether they exist or not.

Well, if the multiple universes theory provides falsifiable predictions about this universe and is the simplest explanatory model we have for this universe and said predictions / behavior, then the explanation would not be metaphysical at all. For example, if a multiple universe theory was a requisite basis to a universal theory of gravity and quantum mechanics then it would be perfectly within the realm of the physical sciences.

Re: Two weeks before death, Hawking submitted a paper on parallel universes

#12

Post by SaturateDK » Mon, Mar 19, 2018, 8:26 AM UTC

kgwgk wrote: post #6

SaturateDK wrote: post #5

Until it's published and reviews there isn't much to say. But it's exciting to me, hope I can read it soon.

As the article mentions, you can read it already: https://arxiv.org/abs/1707.07702v2

Oh, I was a bit too quick there it seems. Thanks! :-)

Re: Two weeks before death, Hawking submitted a paper on parallel universes

#13

Post by kijin » Mon, Mar 19, 2018, 8:26 AM UTC

epaga wrote: post #4

Something I've never understood and would greatly appreciate understanding: could someone ELI"5" how the concept of "parallel universes" will not always be a metaphysical instead of a scientific question? If there are truly separate "universes", then by definition wouldn't it be the case that there would be no way to test (or falsify) whether they exist or not, so would the question of their existence not be in the r…

I guess it depends on whether the "universes" are really separate as you say. If we could detect the existence of other universes, it would mean that there's some sort of relationship among universes. If we cannot detect them at all, either they don't exist or they're completely separate, and our inability to detect them won't tell us anything about which of the two scenarios is true.

When we're talking about "parallel universes", of course the word "universe" no longer means the sum of everything that exists. It has to be redefined as a suitable subset of existence, perhaps similar to the way we've learned to distinguish the "observable universe" with the universe proper. How we ought to redefine it will depend on what we find out (or not) about parallel universes (or lack thereof) in the coming decades and centuries.

Re: Two weeks before death, Hawking submitted a paper on parallel universes

#14

Post by blackflame7000 » Mon, Mar 19, 2018, 8:33 AM UTC

keithwhor wrote: post #2

Imagine the look on Stephen Hawking 1011156B's face when he finds out Stephen Hawking 7086C published the exact same paper that he did, died two weeks later, and the combination of those events compelled scientists in that Universe to eventually master interdimensional travel, when 1011156B only got laughed at.

This sounds like something Rick Sanchez would say

Re: Two weeks before death, Hawking submitted a paper on parallel universes

#15

Post by cperciva » Mon, Mar 19, 2018, 8:34 AM UTC

amelius wrote: post #7

epaga wrote: post #4

Something I've never understood and would greatly appreciate understanding: could someone ELI"5" how the concept of "parallel universes" will not always be a metaphysical instead of a scientific question? If there are truly separate "universes", then by definition wouldn't it be the case that there would be no way to test (or falsify) whether they exist or not, so would the question of their existence not be in the r…

I guess that if we can interact with (measure) a separate universe, then we should adjust our definition of "universe".

What if you can observe past interactions with it, but it is no longer possible to interact with it? Would you say it's still part of "our universe"?

Re: Two weeks before death, Hawking submitted a paper on parallel universes

#16

Post by nothrabannosir » Mon, Mar 19, 2018, 8:34 AM UTC

keithwhor wrote: post #2

Imagine the look on Stephen Hawking 1011156B's face when he finds out Stephen Hawking 7086C published the exact same paper that he did, died two weeks later, and the combination of those events compelled scientists in that Universe to eventually master interdimensional travel, when 1011156B only got laughed at.

Well, to be fair… if he suffers from the same ailment, I quite easily can imagine his look, actually.

Re: Two weeks before death, Hawking submitted a paper on parallel universes

#17

Post by ajuc » Mon, Mar 19, 2018, 8:38 AM UTC

hnarn wrote: post #8

epaga wrote: post #4

Something I've never understood and would greatly appreciate understanding: could someone ELI"5" how the concept of "parallel universes" will not always be a metaphysical instead of a scientific question? If there are truly separate "universes", then by definition wouldn't it be the case that there would be no way to test (or falsify) whether they exist or not, so would the question of their existence not be in the r…

>If there are truly separate "universes", then by definition wouldn't it be the case that there would be no way to test (or falsify) whether they exist or not This literally contradicts what the first paragraph of the article. It says that this paper "lays the theoretical groundwork for discovering a parallel universe". If you've discovered it, you've tested and proved that it exists. Furthermore, the article states…

There cannot be a mathematical proof of a physical fact. You can have infinite number of theories that are all mathematically correct, yet contradict each other.

You need data from experiments to falsify the wrong ones. And I think that's why the article means - paper shows what experiment needs to be done to falsify some theories that assume multiverse.

Re: Two weeks before death, Hawking submitted a paper on parallel universes

#18

Post by erric » Mon, Mar 19, 2018, 8:43 AM UTC

russdpale wrote: post #3

Truly amazing. Thank you Professor Hawking! RIP.

This statement is in the same domain as “thoughts and prayers”, which is the same as saying, ”I’m wishing at you really hard”.

Rest implies an awaking or movement at some point in the future, but for Hawking, he didn’t believe in that.

Maybe it’s just something to say, like acknowledging someone sneezing?

Re: Two weeks before death, Hawking submitted a paper on parallel universes

#19

Post by adrianN » Mon, Mar 19, 2018, 8:47 AM UTC

ajuc wrote: post #17

hnarn wrote: post #8

Earlier quoted context omitted.

>If there are truly separate "universes", then by definition wouldn't it be the case that there would be no way to test (or falsify) whether they exist or not This literally contradicts what the first paragraph of the article. It says that this paper "lays the theoretical groundwork for discovering a parallel universe". If you've discovered it, you've tested and proved that it exists. Furthermore, the article states…

There cannot be a mathematical proof of a physical fact. You can have infinite number of theories that are all mathematically correct, yet contradict each other. You need data from experiments to falsify the wrong ones. And I think that's why the article means - paper shows what experiment needs to be done to falsify some theories that assume multiverse.

Technically you might be able to do a proof by exclusion if you can show that only one of all the possible theories is sound and consistent.

Re: Two weeks before death, Hawking submitted a paper on parallel universes

#20

Post by nahumfarchi » Mon, Mar 19, 2018, 8:48 AM UTC

hnarn wrote: post #8

epaga wrote: post #4

Something I've never understood and would greatly appreciate understanding: could someone ELI"5" how the concept of "parallel universes" will not always be a metaphysical instead of a scientific question? If there are truly separate "universes", then by definition wouldn't it be the case that there would be no way to test (or falsify) whether they exist or not, so would the question of their existence not be in the r…

>If there are truly separate "universes", then by definition wouldn't it be the case that there would be no way to test (or falsify) whether they exist or not This literally contradicts what the first paragraph of the article. It says that this paper "lays the theoretical groundwork for discovering a parallel universe". If you've discovered it, you've tested and proved that it exists. Furthermore, the article states…

Isn't it the other way around? You start out with assumptions and a model (which usually involves some math), and then you show that you've made the correct assumptions by empirically testing it. You can't prove something in the mathematical sense about physical reality.