u/DiagnosingTUniverse

Trying to age the universe or assign it an arbitrary birthday has always seemed like a very human and somewhat meaningless task. We commonly say the universe is approximately 13.8 billion years old, counting from the Big Bang. But what precisely does that age mean when elapsed time depends on the observer?
For example, someone remaining close to a black hole could experience much less time than someone far away. Their clocks would record different durations between comparable stages of the universe’s evolution. So whose elapsed time are we referring to when we assign the universe a single age? The early universe was incredibly dense, on a level that males black holes seem like a piñata so might that imply strong time dilation. I suspect I’m incorrectly applying the analogy of a black hole within surrounding space to the universe as a whole. Would “time ran more slowly back then” even mean anything without an external clock to compare it with? Peace

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I’m working on an early-stage tech concept that I think has the potential to become very large. I realise every founder probably thinks that about their idea, and I’m under no illusion about the reality of getting from an idea to an actual functioning company. Right now I’m at the very beginning and have developed most of the concept fairly independently.
But there’s a bigger question I’ve been thinking about, and I’d be interested to hear from people who have actually built companies.
If this ever became successful, I don’t particularly want to follow the conventional path of building a company whose ultimate purpose is generating returns for shareholders.
I’d like to explore whether it’s possible to build something closer to a self-sustaining economic engine for public good.
The company would still operate commercially. It would compete, generate revenue, pay its employees very well, attract excellent people and reinvest heavily in its own growth.
But beyond what is required to operate, remain resilient and continue growing, the surplus wouldn’t ultimately exist to enrich shareholders or founders. It would be directed towards tackling large-scale problems like climate change, ecological restoration, poverty, public health, scientific research, or whatever areas could produce the greatest measurable benefit.
In other words, rather than:
company- profit- shareholders
something more like:
company- profit- reinvestment- employees - reserves for public-good projects.
And ideally those projects wouldn’t simply be donations. Over time the company could build and fund its own teams and organisations to work directly on problems.
I’m aware this raises a huge number of practical questions: ownership, governance, raising capital, attracting early employees, founder control, incentives, taxation, succession and preventing the mission being diluted or captured decades later.
I’m also aware that talking about the eventual structure of a massive company before you’ve even built the small one is putting the cart several miles before the horse but I think the destination matters because some early decisions around ownership and investment could make that destination difficult later.

My questions are:
Has anyone here tried to build something along these lines?
What corporate/ownership structures would actually make sense?
Would avoiding conventional VC make something like this dramatically harder to scale?
How would you attract exceptional early employees when equity doesn’t have the same eventual purpose?
And perhaps most importantly: if you were at the very beginning, with the concept mostly developed but wanting to protect both the idea and the eventual mission, what would you do next?
Itd be great to hear from founders who have built and scaled technology companies, social enterprises, cooperatives, public-benefit companies etc

Cheers guys x

I have a question about what we actually mean when we say something is billions of light-years away.
For example, Andromeda is about 2.5 million light-years away, while some of the earliest galaxies observed by JWST are seen as they existed more than 13 billion years ago.
My questions are:
How do we actually determine those distances? Obviously we can’t measure them directly in the ordinary sense so what observations and assumptions allow us to say that a galaxy is a particular distance away?
More speculatively, how confident are we that relativistic and cosmological effects couldn’t cause us to substantially misinterpret those distances or travel times?
For instance, JWST has found surprisingly mature galaxies very early in cosmic history. Could there conceivably be something wrong with our interpretation of the relationship between redshift, distance and elapsed time? In other words, could light that we interpret as having travelled for billions of years actually have travelled for a radically different amount of time because our model of spacetime between us and the source is incomplete?
I’m not suggesting that the answer is yes but trying to understand what makes the distance scale robust enough that we can rule out possibilities like this. We can measure the light arriving here, but we obviously can’t put a ruler between ourselves and a galaxy 13 billion light-years away, so what ultimately anchors the inference?

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