u/DiagnosingTUniverse

My question is whether dark energy is the only plausible explanation for the observed acceleration of the universe.

Have alternative interpretations been seriously explored and ruled out?

My concern isn’t that the observations are wrong, but that we may be misunderstanding what we’re observing. For example, could this fit with some form of black-hole cosmology? Suppose matter/energy crossing a black-hole horizon doesn’t ultimately terminate at a singularity, but undergoes a transition inscale, re-emerging as an expanding spacetime at a lower scale.

From inside that descendant universe, could this scale transition appear as cosmological expansion or even contribute to the apparent acceleration?
I’m aware that “the universe is inside a black hole” isn’t a new idea. What I’m interested in is whether this explanation has been ruled out observationally, and if so, what observations have ruled it out? Also we know black holes grow and expand over time, which seems to be some kind of correlation?

Thanks!

Hi guys, I wanted to run something by you.

Im a 40 year old doctor, studied math and physics to A- level but then went to med school. I’ve always been fascinated by physics. In reality I probably should have gone on ti study this at university, that being said medicine given me an amazing career that im very happy with.

Im at a crossroads, call it a midlife crisis if you will, where i’m seriously considering going back to university to study a degree in physics. My motivation is purely academic and interest. I can also carry on working as a doc on the side to pay the mortgage/ bills etc.

- Thoughts on mature students going back? Any physicists have experience of this?
- Distant learning vs in person
- Its a fairly big financial and time commitment so just wanted to sanity check it. Like if a 40 year old was thinking of restudying medicine i’d have some very candid advice for them.

Thanks!

This is just a conceptual question from a curious armchair physicist who reads about quantum mechanics and relativity in his spare time so please don’t take this as me claiming to have solved the universe but I’m genuinely interested if this ideas git any conceptual merit or if its falls directly onto its a*s.

Okay, here goes. We usually say light exhibits wave-particle duality. It propagates like a wave, yet interacts in discrete quanta. But what if the “particle” isn’t fundamental? Suppose reality is one continuous underlying structure. In that picture, light would always be a propagating disturbance of that structure, never literally a tiny particle flying through empty space.
Then the obvious question becomes: where does the discreteness come from?
Could it instead arise from the receiving system?
Matter is already highly organized and stable. Perhaps atoms don’t absorb arbitrary amounts of energy because only certain structural transitions are allowed. The wave remains continuous throughout propagation, but interactions with stable matter are necessarily discrete.
So instead of:
wave + particle
could it be:
continuous propagation + quantized interaction?

Cheers

My understanding is that gravitational waves are ripples in spacetime that travel at the speed of light, while electromagnetic waves are oscillations of the electromagnetic field that also travel at the speed of light. Both carry energy, both have wavelengths and frequencies, and both propagate as waves.

From a more ontological pov, a wave is a mechanism for transferring energy. So why regard gravitational and electromagnetic waves as fundamentally different rather than different?

Is there experimental evidence that rules out the possibility that they’re different expressions of the same underlying structure? To put it another way, if gravitational and electromagnetic waves can both travel at the speed of light, have wavelengths and frequencies, and carry energy, what experimental or theoretical evidence tells us they are not actually the same thing, ripples in the fabric of spacetime of different wavelengths and frequencies…

II’ve been reading quite a bit about General Relativity, cosmology, and some of the recent ideas around emergent spacetime, and I’d like to sanity-check a thought with people who know this subject better than I do.
In the standard cosmological picture, all of the matter and energy we observe today originated from an extremely hot, dense early universe. If that’s correct, then everything we see today was once part of a single primordial state. That raises a question for me: what does it actually mean for things to be “separate”?
When we look at distant galaxies, stars, planets, or even ourselves, we naturally think of them as distinct objects occupying different regions of space. But is that separateness fundamentally real, or is it an emergent feature of how we perceive reality?
I’ve been wondering whether matter and spacetime might be better thought of not as fundamentally different entities, but as different configurations of some deeper underlying structure. In that picture, what we call “objects” would simply be localized patterns, excitations or regions of differing organization within a single connected reality, rather than genuinely independent things.
Take quantum entanglement. I understand that entanglement does not allow faster-than-light communication, but it seems to suggest that our intuitive notion of separateness may not be a given when examinign quantum systems.
Are there existing areas of research that explore this kind of idea? Could “separation” not be fundamental.
I’d be very interested to know where current physics stands on the question.
Thanks

Aware this is a subjective and loaded question, but what audiobook would you recommend as your all time favourite in the literary/ speculative/ philosophical genre. Not really into horror/ thrillers. One of my favourites has been the alchemist with Jeremy Irons narrating. Read the books years ago and was wonderful revisiting it as audiobook.

Thanks!

I’ve read quite a lot about General Relativity from a layman’s perspective, and I keep returning to gravitational time dilation.

Experimentally, the result is obvs clear: clocks deeper in a gravitational well accumulate less time than clocks farther out.

I’ve been thinking about it like this and wondered if this had any merit conceptually?

An atomic clock is just a physical process:

oscillations/ transitions

Could it be accurate conceptually to say: physical processes evolve more slowly in regions where the underlying structure of spacetime is more densely organized?

In other words: regions near mass correspond to greater structural depth/resolution, while regions farther away are more stretched.

So a clock deeper in the well simply exists in a region where each tick corresponds to traversing more underlying structure thus it takes longer.

The observable result remains identical: fewer accumulated ticks relative to clocks farther out.

The mathematics of GR would remain unchanged obviously I am not in anyway disputing that. The shift would be interpretive: geometry and time behavior emerging from deeper structural variation rather than being fundamental themselves.

Apologies if this idea is somewhat ridiculous. Just wanted to hear some experts thoughts on this concept and whether its been explored before/ has any merit.

Thanks