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> a crazy theory that a universe existed before the big bang, and that the heat death of the universe starts a new big bang.

I realize this isn't what Penrose is saying, but is it really that crazy that random fluctuations will create the conditions for a new big bang in a universe at thermal equilibrium?




It's not useful to speculate about things that are unfalsifiable. That's why Penrose wants these things to be observable traces from before the big bang.


> It's not useful to speculate about things that are unfalsifiable.

I disagree. While such speculation obviously won't produce immediately useful data, where would we be today if noone had ever speculated about something which at the time could not be falsified? Case in point: the initial speculation on the existence of germs, which at the time was unfalsifiable.

(Edit: adding refs)

https://en.wikipedia.org/wiki/Germ_theory_of_disease

From the arcticle: "By the early nineteenth century, smallpox vaccination was commonplace in Europe, though doctors were unaware of how it worked or how to extend the principle to other diseases."

So doctors were saving lives even though they had no idea exactly how or why it worked. They could neither prove nor disprove why it seemed to work, it simply did. The fact that it was unfalsifiable had nothing to do with the truth of the matter - it still saved lives.


I think there's a difference between untestable in practice, right now, and unfalsifiable even in theory. The latter case can never hold any practical value.


I think the point dumpsterdiver is making is that determining what is falsifiable or not is context/time dependent. As our understanding of reality changes over time so does our definition of what can be falsifiable.


What's an example of something that's unfalsifiable in theory?


https://rationalwiki.org/wiki/The_Dragon_in_My_Garage

> "A fire-breathing dragon lives in my garage"

> "Show me," you say. I lead you to my garage. You look inside and see a ladder, empty paint cans, an old tricycle--but no dragon.

> "Where's the dragon?" you ask.

> "Oh, she's right here," I reply, waving vaguely. "I neglected to mention that she's an invisible dragon."

> You propose spreading flour on the floor of the garage to capture the dragon's footprints.

> "Good idea," I say, "but this dragon floats in the air."

> Then you'll use an infrared sensor to detect the invisible fire.

> "Good idea, but the invisible fire is also heatless."

> You'll spray-paint the dragon and make her visible.

> "Good idea, but she's an incorporeal dragon and the paint won't stick."

> And so on. I counter every physical test you propose with a special explanation of why it won't work.

> Now, what's the difference between an invisible, incorporeal, floating dragon who spits heatless fire and no dragon at all?

> If there's no way to disprove my contention, no conceivable experiment that would count against it, what does it mean to say that my dragon exists?

> Your inability to invalidate my hypothesis is not at all the same thing as proving it true.

> Claims that cannot be tested, assertions immune to disproof are veridically worthless, whatever value they may have in inspiring us or in exciting our sense of wonder.


Well, if the dragon exists it must have the characteristics of a dragon. Let's say it must be an animal with four legs and a tail. Currently it's unknown whether all animals are q-conscious[1]. Let's say it is discovered that all animals are q-conscious. Therefore the invisible dragon is q-conscious.

Currently we don't really understand qualia, but one mainstream theory is that qualia are a different kind of thing to anything else we know about (i.e. are non-physical).

Let's say this theory is true, and, further, that a method for detecting this different kind of thing is detected. That the dragon is invisible, floats, is heatless, is incorporeal, doesn't matter.

The theory that there is a dragon in the garage is falsifiable by the observation that a scan for qualia results negative.

You could say "ah, but this dragon is the dragon of any-test-you-can-come-up-with-doesn't-work, therefore you can't come up with any test which would work". But that would be begging the question.

[1]That is, all animals have qualia.


The existence of God.


Will be disproven by the existence of bablefish. Already has been in less backwards parts of the galaxy than ours.


Sorry didn’t understand the bablefish reference, why does that disprove the existence of god?

(I could define myself as an atheist anyway so this is really a non issue for me)


It is from the Hitchhikers Guide to the Galaxy. See https://www.youtube.com/watch?v=iuumnjJWFO4#t=2m07 for the TV version's rendition of this bit.

If you've not yet experienced H2G2 I suggest tracking down the original radio version before the books, TV, or more modern film - it is widely available to buy in various formats. It is justly recognized as a classic.


It's a reference to the Hitchhikers Guide to the Galaxy novels.


Well, the original radio series upon which the first two books were very closely based, to be pedantic!


Falsifiable by the observance that there is no God. If we get a view of the supernatural it might be clear that there is no God.


It seems not only has he made multiple predictions based on this theory, but he also is actively publishing research showing it may be true. Where do you get unfalsifiable from? There’s literally falsifiable claims being made.


There are a lot more books sold on speculative fiction than real astronomical insights. Clearly, such speculation serves a purpose and must therefore be considered useful.


A couple of theories regarding the ultimate fate of our universe are the Big Crunch (everything comes together) or the Big Freeze (everything drifts apart, forever). I agree that it's not hard to imagine that if a Big Crunch happened it could potentially create another Big Bang. That said, there's still no way to necessarily prove that.

https://en.wikipedia.org/wiki/Ultimate_fate_of_the_universe#...


It seems to be possible: https://en.wikipedia.org/wiki/Timeline_of_the_far_future

> 10^10^10^56: Time for quantum effects to generate a new Big Bang, resulting in a new universe.


I feel like this is a good time and place to bring up an idea that I sometimes like to entertain. It goes like this:

There is some number of dimensions that exist in total, which is a number higher than just the four dimensions that we are readily able to observe. Our universe exists within this higher dimension, alongside other universes.

Also, what we perceive as linear time within our universe might not be just a single dimension either. But even if it's not we can still treat it as though it was.

The laws that apply within each of these four dimensional universes as we might see them might or might not all be the same laws. I.e. all other universes might have the same laws as does ours, or some might be different, or all might be different. We can't know.

But the idea that I like to entertain is that these universes could serve some function within the higher dimensions.

For example, a set of many many parallel universes might each function analogously within the higher dimensions as to how cells function in our universe, and that analogously these parallel universes form a greater whole together as some sort of being that is made up of all of these.

Or another possibility might be that a universe could be able to develop within itself life that is able to sense the higher dimensions, and to break free of the universe within which it was created and to then continue existing in the higher dimensions beyond the end of the universe that created it. I imagine this not as human with more senses, but something very different. For example, the way it might come into existence in our universe could be through machinery that we create, with mechanical sensors that are able to pick up the other dimension(s), and with increased computational power the machines we create could in turn process all of the information available to it in order to construct something that somehow (yes, very vague sorry) is not limited by the reality of our universe itself.

But yeah, there is no scientific basis for said ideas. It's just something that I like to imagine.


It’s quite fun to speculate. If you’re into this sort of thing, you’d like lemmino on YouTube. Pick any one of his deep dives and you’ll end up listening to something pretty close to what you did here: speculation, in a tight straight jacket.

Part of the problem with dark energy is that so much of it is unfalsifiable in ways similar to these theories. Of course, the key difference is that we can measure the effect dark matter has on the universe, whereas thus far no more than 4 dimensions have ever been observed.

Sure makes drinking fun though. Take a sip and say a hypothesis. Like apples to apples but for physicists.




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