“Contrary to standard cosmological theories where the accelerated expansion of the universe is attributed to dark energy, our findings indicate that this expansion is due to the weakening forces of nature, not dark energy,” he continued.
Wildass hypothesis I just pulled out of my ass with an undergraduate degree in applied physics: maybe interaction with particles emerging from quantum vacuum?
Okay, that sounds like great technobabble. I’m going to watch star trek now ;)
It’s probably not that the light is losing energy it’s just that the distance it travels over time (the time we “know” is supposed to take for a given distance) appears compressed because of unknown/unseen gravitational forces.
Think of it like this: If there were only one star in the universe and it emits a particle of light we could calculate the distance it would travel over time. Yet we know that star will still have a gravitational effect on that light… No matter how far away it gets.
That’s what they mean by light “losing energy”. Is the energy actually “lost”? Not really. Is this slowing (aka appearance of lost energy) caused by dark energy/dark matter or something more fundamental like spacetime itself being stretched or compressed due to the gravity of astronomical objects we can see or “dark matter”/“dark energy” or… ? We don’t really know for certain yet!
It’s probably not that the light is losing energy it’s just that the distance it travels over time (the time we “know” is supposed to take for a given distance) appears compressed because of unknown/unseen gravitational forces.
This doesn’t seem to be at all what tired light proposes though. What you’re explaining sounds like red-shift due to an expanding universe. From what I can tell they claim it actually loses energy through interaction with “other things” in the universe.
This doesn’t answer the question in the context of this theory, but the current understanding is that light does lose energy as it travels through expanding space. As the space it’s in expands, the wavelength gets longer, and the energy goes down. It doesn’t go anywhere; energy just isn’t conserved in an expanding space-time.
If the light loses energy, then it must surely lose it to something? And if your last point that energy isn’t being conserved in our universe, in which case we are either in some deep shit with the first law of thermodynamics, or our universe isn’t an isolated system.
The thing about photons is that they redshift, losing energy as space expands. If we keep track of a certain fixed number of photons, the number stays constant while the energy per photon decreases, so the total energy decreases.
Ok. Smarter people probably thought of this, and probably found my hypothesis to be impossible. But what if… It is the the other way around. What if photons are losing energy because they are expanding spacetime. Like tiny little springs expanding out.
Further into the article he says that, "It would be irresponsible of me not to mention that plenty of experts in cosmology or GR would not put it in these terms. We all agree on the science; there are just divergent views on what words to attach to the science. In particular, a lot of folks would want to say “energy is conserved in general relativity, it’s just that you have to include the energy of the gravitational field along with the energy of matter and radiation and so on.” "
So energy is conserved on the whole, it’s just not conserved if you consider photons apart from their greater context.
The energy is actually not conserved across the universe in general relativity, as it is currently understood. Conversation of energy is due to the time symmetry, which the expansion of space breaks.
BTW, thanks! This comment sent me down a fascinating rabbit hole. It had simply never occurred to me that energy conversation didn’t apply in an expanding universe!
“Energy is conserved in general relativity, it’s just that you have to include the energy of the gravitational field along with the energy of matter and radiation and so on.”
IANAP, but isn’t universal expansion understood to be accelerating? How would “weakening forces of nature” account for that? Assuming this energy could be “lost” (breaking an even longer standing and well tested principle of physics), that loss wouldn’t accelerate anything. At best the speed would remain neutral.
The tired light theory is an alternative explanation to the red shift of distant light that says it’s not because distant objects are all moving away from us but instead that the light somehow loses energy as it travels, which lowers its frequency.
There was another alternate theory that suggested everything was shrinking instead of the universe expanding (thus wavelengths seem longer by the time they get to us).
Personally, I’m more “open to the idea” than “sold” for the idea of the universe’s accelerated expansion. I like theories that eliminate the need for dark matter or energy, especially given that the current ones requiring them assume that they make up 95% of everything. It just seems more likely that we don’t understand things as well as we do than to assume we’re right about everything we think but just need to add 19 times what’s already here to balance it all out.
The Covarying Coupling Constants theory posits that the fundamental constants of nature,[…], are not fixed but vary across the cosmos.
This undermines current fundamental axiom of science that laws of physics are constant across universe. Until we go there and measure them to be actually different. This hypothesis doesn’t have a leg to stand on.
I’m skeptical of this theory as well, but I’d point out that our observations show that at galaxy scales, gravity is much stronger in certain places than we’d predict using our current model of gravity and the matter we can otherwise detect, and at even larger scales the acceleration of the universe’s expansion is being driven by something we don’t understand.
Right now, the dominant theory in cosmology is that each of these observed phenomena are driven by dark matter and dark energy, but we don’t have any direct evidence of the existence of either, just indirect evidence that stuff doesn’t behave as we might expect.
So it’s a choice between theories that don’t make intuitive sense, and break some fundamental assumptions about physics.
Man, lots of people in this thread seem happy to accept any wild, physics-breaking idea rather than accept that there’s just a bunch of matter we can’t see.
I think it goes beyond not being able to “see” it and goes to we can’t detect it at all. Doesn’t dark matter just fill in the mathemagical holes with some numbers to make it all work?
We can detect its gravitational influence, as it interacts via gravity. The issue being that gravity is a weak force, and so there’s a lot of room for speculation.
But there is a lot of evidence backing up dark matter existing. But it’s not definitive yet.
I get that but it still sounds woo-woo since we can’t directly detect it. I’m not naysaying since I realize it’s the best we have and I’m not smart enough to come up with anything better.
I mean, I guess it depends on what you mean by “directly detect”. We measure neutrinos by having photoreceptors in huge tanks of very pure water deep under old salt mines… which hardly seems more direct than looking at where galaxies and stars are moving and calculating the gravitational pull and noticing that something is missing…
Dark matter is matter that we infir to exist only on its gravitational effects. We’ve observed its existence by the fact that it seems to clump up in the middle of two massive super-solar structures following a collision.
We can indirectly detect dark matter thru gravitational lensing. That is how NASA created this map showing the actual locations of dark matter in tinted blue.
Nope. No. Nuh-uh. Stop fucking up this planet, then we can talk. I’m drawing a line in the sand, I’m going to become an eco-terrorist if I see a fucking Coca-Cola ad when I look into the night sky.
All I think of is the movie, The Time Machine. Spoiler, the main character goes forward in time and sees the moon breaking apart, causing a collapse of civilisation.
On 20 April 2016, the Sky and Telescope website reported a sustained brightening since February 2015 from magnitude 10.5 to about 9.2. A similar event was reported in 1938, followed by another outburst in 1946.[20] By June 2018, the star had dimmed slightly but still remained at an unusually high level of activity. In March or April 2023, it dimmed to magnitude 12.3.[21] A similar dimming occurred in the year before the 1945 outburst, indicating that it will likely erupt between March and September 2024.
And if I’m interpreting some of the other content correctly, it’ll come and go in one night? Maybe someone who knows more about these can confirm or correct me.. See update below.
Also …
Even when at peak magnitude of 2.5, this recurrent nova is dimmer than about 120 stars in the night sky.
Once its brightness peaks, it should be visible to the unaided eye for several days and just over a week with binoculars before it dims again, possibly for another 80 years.
Reminds me of when Betelgeuse, the orange upper star of Orion, went dim in 2020. Lots of amateur reports on its brightness, 3x per night, for a few months waiting for it to go nova. It settled down a bit before disappearing behind the sun for the season and came back just fine. It was kinda fun to monitor, but soooo many false alarms from people trying to call it first
astronomy
Najstarsze
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