For Questions That Don't Merit Their Own Thread

[Terwin]

1 hour ago, Gargamel said:

But what if we are the last?

Counting from the formation of the earth to when the sun expands to engulf the current earth orbit, we are less than half way along.

To ensure that no life will evolve after a sterilizing event before the end of this epoch, would likely require the earth no longer be a planet in the goldilocks zone.(or any other 'zone' that turns out it can support the development of life)

As such, hopefully we will have enough time to become multi-planetary before whatever comes and either turns the earth into an asteroid field or changes the orbit enough that it an never again sustain life.

Edited February 13, 2023 by Terwin

[kerbiloid]

The Sun is expanding, the Earth is warming.

Estimated end of an organic life due to the ocean evaporation and the common temperature was ~500 My.

The more or less developed species will get extinct in ~50..250 My.

So, 80%+ has passed.

[steve9728]

1 hour ago, Gargamel said:

But what if we are the last?

If to be serious, I would have already been part of the ocean waters by that time: let our descendants worry about this, and I'm sure they can made it.

If don't to be serious, "Goodbye Solar System!"

Spoiler

This film offers three ways of continuing human civilisation:

1. Get in and live in the city underground beneath the planetary engines that propel Earth to Proxima
2. Become an astronaut and go the space station
3. Upload your personality to the server and engrave it into the chip, thereby gaining immortality in the cyber world

Spoiler

Just to be clear, I'm Earthist

Edited February 13, 2023 by steve9728

[kerbiloid]

Btw, how far are the interstellar debris with dinosaur times DNA thrown away by the Chicxulub?

P.S.
And does everyone see this burning meteoroid crossing the screen if google "Chicxulub"?

(At least in Opera.)

[Gargamel]

3 hours ago, Terwin said:

ensure that no life will evolve

That’s not what I said.   In the context of “if a tree falls in the woods”, what if there’s nobody left to observe and name the eons? 

[magnemoe]

1 hour ago, Gargamel said:

That’s not what I said.   In the context of “if a tree falls in the woods”, what if there’s nobody left to observe and name the eons? 

Well that would be true for all time but less than  200 hundred as I don't bother googling it. Obviously modern humans fell trees way earlier than 30K years ago, humanoids. 
But the  idea of an billion year old earth is younger than Darwin so any geological dating system outside of before Noah is modern. 
And we are a couple of hundred years away from surwing without Earth. So Musk's occupy  Mars is unrealistic, make access to space in the magnitude of long haul military freight, else leave it to your grand kids or radical life extension I say later option is much better. 

[JoeSchmuckatelli]

4 hours ago, Gargamel said:

That’s not what I said.   In the context of “if a tree falls in the woods”, what if there’s nobody left to observe and name the eons? 

Fine, Captain-Philosopher-Pants, ignore my 'second evolutionary observer' comment - and yeah, if we are gone and there's noone left to care, there will be no further epochs.  I doubt very much that Mars cares what we name its parts, nor Betelgeuse that we worried about it a couple of years ago.  That isn't to say that the current epoch won't continue to be subject to natural processes... just that in your 'frinstance, nothing* will be named anything.

 

*and anything and everything will also not be named.

[kerbiloid]

The humans climbed down from the trees.

Until that, they were falling together.

[sh1pman]

19 hours ago, kerbiloid said:

The more or less developed species will get extinct in ~50..250 My.

Mass extinctions happen every ~100 My, but complex life always survives and manages to repopulate Earth. It'll adapt to the changing conditions next time too, as it always did.

[kerbiloid]

6 minutes ago, sh1pman said:

Mass extinctions happen every ~100 My, but complex life always survives and manages to repopulate Earth.

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

https://ru.wikipedia.org/wiki/Временная_шкала_далёкого_будущего

(The text differs a little)

And from other sources.

P.S.
Btw, we should make a note to not forget to do that.

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

Edited February 14, 2023 by kerbiloid

[sevenperforce]

News now coming out that the last UFO to be destroyed, the one over Lake Huron, survived the first missile shot at it because the pilot of the F-16 selected a heat-seeking missile....

https://www.foxnews.com/us/us-military-first-shot-unknown-octagonal-object-lake-huron-missed

[DDE]

2 hours ago, sevenperforce said:

News now coming out that the last UFO to be destroyed, the one over Lake Huron, survived the first missile shot at it because the pilot of the F-16 selected a heat-seeking missile....

https://www.foxnews.com/us/us-military-first-shot-unknown-octagonal-object-lake-huron-missed

The first balloon was shot down by an AIM-9X. Missile selection clearly wasn't the problem.

Also, if we're back to balloons, guess who else joins the contest!

https://www.pravda.com.ua/eng/news/2023/02/14/7389304/index.amp

The launch appears to have successfully simulated a Shahed/Geranium raid, jusdging by the alert that went out that night.

Edited February 14, 2023 by DDE

[JoeSchmuckatelli]

2 hours ago, sevenperforce said:

News now coming out that the last UFO to be destroyed, the one over Lake Huron, survived the first missile shot at it because the pilot of the F-16 selected a heat-seeking missile....

https://www.foxnews.com/us/us-military-first-shot-unknown-octagonal-object-lake-huron-missed

Air National Guard 

[DDE]

 

Got tone?

[StrandedonEarth]

1 hour ago, DDE said:

Got tone?

Oh, it looks like it’ll be getting plenty hot in that basket…

[kerbiloid]

Spoiler

 

Edited February 15, 2023 by kerbiloid

[kerbiloid]

8 hours ago, DDE said:

who else joins the contest!

https://www.pravda.com.ua/eng/news/2023/02/14/7389304/index.amp

The launch appears to have successfully simulated a Shahed/Geranium raid, jusdging by the alert that went out that night.

Spoiler

 

[DDE]

US and China: "Is it aliens?" "We can neither confirm nor deny"

Russia and Ukraine: "So this UFO in my backyard has a Romanian cola bottle as ballast, go figure"

Spoiler

 

[kerbiloid]

26 minutes ago, DDE said:

Russia and Ukraine: "So this UFO in my backyard has a Romanian cola bottle as ballast, go figure"

Cyrillic. Moldavian.

[magnemoe]

37 minutes ago, kerbiloid said:

Cyrillic. Moldavian.

And it looks like payload is an radar reflector. 

[kerbiloid]

1 hour ago, magnemoe said:

And it looks like payload is an radar reflector. 

A promo-action of Coca-Cola.

Spoiler

[Nuke]

On 2/13/2023 at 7:12 AM, kerbiloid said:

Btw, how far are the interstellar debris with dinosaur times DNA thrown away by the Chicxulub?

P.S.
And does everyone see this burning meteoroid crossing the screen if google "Chicxulub"?

(At least in Opera.)

thats a cool little easter egg. more elaborate than recursion that's for sure. 

Edited February 16, 2023 by Nuke

[kerbiloid]

Quote

but this is the first observational paper where we're not adding anything new to the universe as a source for dark energy: black holes in Einstein's theory of gravity are the dark energy.

 The black hole is a dark energy.
Sounds reasonable, black is dark.

Do the gravitons exist?
Do they have a mass?
Do they produce gravitation (i.e. more gravitons)?
Does it mean that the gravitons lose energy?
Tired gravity? https://en.wikipedia.org/wiki/Tired_light
GM*exp(-r) /r² instead of just /r²?
And the closer to the dark lamp, the darker is the dark spot.  A gravity halo around every mass, making more gravity?
Especially around the massive black holes, making them be heavier than they actually are?
"Dark matter" as gravity of gravity?
Maybe a tired photon loses its energy also as gravitons?
Wait... Then maybe the tired light is also tired?
The JWST strange pictures...

[K^2]

15 hours ago, kerbiloid said:

[...]

Anything to do with gravity has an "as far as we know," kind of qualifier, but keeping in mind that modern theory of Gravity is tightly intertwined with modern field theory, and is, in fact, a type of it. So if we're completely wrong about it, we're basically wrong about all of physics, cosmology, most of chemistry, and big chunk of biochemistry as a consequence, leaving very little of actual good science behind. Except thermodynamics, I guess. Thermodynamics can still be right by the same virtue of being accidentally such a good theory that it works with completely different underlying mechanics simply statistically.

But with all of that in mind...

Do the gravitons exist? - Yes, even if we're wrong about how the underlying field works, so long as any other fields are particles, so is gravity. But, of course, we lack ability to detect it, so it remains theoretical, and I don't see that changing any time soon.

Do they have a mass? - Not as far as we can tell, but it's also something we cannot measure directly. They could, but that would require a mechanism similar to a Higgs mechanism, implying existence of yet more particles, more fields associated with these, and an entire family of gravity-mediating particles, some of which would likely still be massless. This is by analogy with photons, W and Z bosons. The U(1)xSU(2) symmetry by itself makes all of these massless, and it's the interaction with the Higgs field that breaks the symmetry and generates the mass. The "photons" are basically just a component of that soup that remains massless.

Do they produce gravitation (i.e. more gravitons)? - Yes. Gravity self-interacts. There is no real reason to doubt that.

Does it mean that the gravitons lose energy? - They can. A gravity wave departing a massive object will lose energy. But interaction bosons are virtual, so they can have a net zero energy, or even negative energy. You can think of virtual particles as just being an artifact of the math we use to describe the fields, but this is what people talk about when they say that electrons interact by exchanging photons. This is the same thing.

Tired gravity? - Only if they have mass. A massless particle cannot age. This is a consequence of the Special Theory of Relativity, and would require our understanding of space-time to be completely wrong. But if space-time is more complex and gravitons do gain mass through some sort of interaction with a yet another degree of freedom, that can result in graviton aging, and can be responsible for many of the effects both attributed to dark matter and dark energy. It is an active avenue of investigation.

GM*exp(-r) /r2 instead of just /r2? - The field equations we have for gravity come from symmetries. So unless we're wrong about the symmetries, we can't be wrong about the gravity. Simply plugging in different formulas for interaction at a distance won't give us better results than what we have. If there is some sort of a discrepancy, it's going to be more subtle than that, and we'll need different ways of finding it. Like, finding these extra particles that'd have to exist.

And the closer to the dark lamp, the darker is the dark spot.  A gravity halo around every mass, making more gravity? - Yes, but we're accounting for that. You can think of MG/R² being incorrect near massive bodies because of this. If there are additional interactions, like if we're dealing with massive gravitons, the effect could be stronger, and we might need to correct for it, but our measurements on neutron star binaries agree with theory to eleven or twelve decimal places, so if there is an additional effect, it's very subtle. Such that as not to effect the rate at which two neutron stars spiral into each other by more than one part in a trillion.

Especially around the massive black holes, making them be heavier than they actually are? - While the gravity near a supermassive black hole is stronger because of that effect, far away from it, as in the distance at which we're looking at stars orbiting a galactic nucleus, gravity still behaves in a normal MG/R² way. The real reason is "math works out that way," but if it helps you think of it, you can think of it as stronger gravity having to fight the gravity to get out, perfectly canceling the self-interaction effect. Bottom line is, no, this isn't a factor in dark energy/dark matter. Our measurements of black hole - neutron star merger events agree with the prediction that the final gravitational mass of the newly formed black hole is a combined sum of initial masses less energy released in gravitational waves.

"Dark matter" as gravity of gravity? - There's awful lot of it. We'd have to be missing something big. Not impossible, but existing cosmological models suggest otherwise.

Maybe a tired photon loses its energy also as gravitons? - Tired light disagrees with modern observations. While tired gravity is on the table, light has nothing to do with it. There is a search for a heavy photon, which is a separate class of boson, but so far it came up blank both theoretically and experimentally.

The JWST strange pictures... - So far, nothing detected by JWST is outside of the standard cosmological models. We've seen a few signals that look suspiciously old, but they can be just on the threshold of plausible, or indicate a fairly minor effect we're not considering during early expansion of the universe.

 

On the net, good questions to ask, but that's why they've been asked decades ago and much smarter people than any of us have spent lifetimes working out these possibilities. General Relativity is still the best we've got, and still the framework in which we're most likely to find the answers. Even if it involves discovery of the new fields. I mean, Higgs bosons took a while to actually confirm, despite the fact that nearly everyone was convinced that they have to be there, and whatever might be messing with gravity would be even trickier to detect.

[kerbiloid]

 

A little notice.
  

7 hours ago, K^2 said:

modern theory of Gravity is tightly intertwined with modern field theory, and is, in fact, a type of it. So if we're completely wrong about it, we're basically wrong about all of physics, cosmology, most of chemistry, and big chunk of biochemistry as a consequence

The gravity is not a significant actor on such short distances which 99% of the human science deals with.
All it needs to know about gravity, is "g = 9.81 m/s²".

Looking back, the XVII..early XX experiments required such primitive equipment, that it could be produced even in an early Bronze Age neolithic village, if they knew in which direction they should think.
Including the primitive particle accelerators and X-rays.

And most part of chemistry didn't relate to a field theory until early XX.
In the early XX they were thinking that atom is an amorphous pudding with electrons as raisins. 
A little later the scattering experiments ensured them that some of the electrons are orbiting around a pudding nucleus, which consists of protons and other electrons.

Only in 1932 they discovered the neutron and got the idea that the nucleus consists of protons and neutrons. Also they realized that there can be isotopes and discovered deuterium.
Only in 1934 they discovered tritium and its radioactive decay, and finally came to the idea of a primitive full-hydrogen fusion bomb (of then-future RDS-6t style).
Only in 1938..40 they finally discovered the uranium fission and came to the idea of a fission bomb, and thus how to ignite the full-hydrogen fusion bomb. And only a decade later they came to the idea of a (then-ont very well understood) radiation implosion.
In 1940s the primitive V-2 had no analogs anywhere in the world, and the German chemistry as well.
In 1950s they were laughing at the continent drift, and in 1980s they were teaching in schools the false geosinclinal theory instead.

In early XX they were still sure that the Galaxy is the whole Universe, so the whole Universe can be colonized in observable future.
Almost till the mid XX they were seriously thinking that Mars and Venus are full of life.

The relativity theory and the quantum physics were treated as nonsense by the opposite theory adepts, and both at once as more conservative scientists.

So, the field theory, and especially the gravitation played a very little role in the modern science building until last several decades.
And even if it got reveled that the Earth is flat and covered with a crystal dome, 99% of science would not be affected at all.