3 ms·

i'm a former physicist but yeah, a few stellar masses worth of energy is beyond (my) imagination 1. always wondered the same. i'd suspect that for most astrono

i'm a former physicist but yeah, a few stellar masses worth of energy is beyond (my) imagination 1. always wondered the same. i'd suspect that for most astronomical BH you would first need to worry of X/gamma rays. you could possibly hear a loud chirp since it is audio frequency. 2. the warping of space time here on earth is actually mostly a warping of time, which is even weirder. i means that the time at your feet is flowing slower that where you're head is. about one second on your entire life. that's actually WHY you feel earth gravity. 3. yes, more space is created out of nothing! because there's a vacuum energy density that inflate the local patch of universe. funnily why all of the above is hard to understand for our human brains, it all makes sense in the mathematics.. i highly recommend the YT channel PBS Space Time for more explanations

macspoofing 5y ago
>yes, more space is created out of nothing! because there's a vacuum energy density that inflate the local patch of universe. I don't think you can say that with that kind of certainty. We don't have a theory of quantum gravity, we don't know what dark matter is, and we don't know what 'dark energy' is, so we don't actually know what is driving the expansion of the universe, so saying that 'space is created out of nothing' is too strong. Even something like the theory of cosmological inflation, which has some explanatory power, hasn't been experimentally verified, but rather tuned to match the observations. It's something I've noticed in a lot of communicators of science (whether they have a background in science or not). They tend use terms that overstate our actual knowledge in some specific area of science.
- Iwan-Zotow 5y ago
  > I don't think you can say that with that kind of certainty. well, any classic (in SM sense) QFT will produce positive vacuum energy density which translates into negative pressure. P = -E
- immmmmm 5y ago
  you're absolutely correct, i was referring to models based on classical GR + QFT (standard cosmology + standard model). ofc those are wrong but yield the most accurate predictions any models has ever yielded. i'm almost certain (no proof tho) that space time itself is just an illusion (and that there is only "information "). in other term i know i know nothing (but still is able to give predictions up 10^-32 s after big bang)
lapetitejort 5y ago
> funnily why all of the above is hard to understand for our human brains, it all makes sense in the mathematics.. Of the four fundamental forces, the higher order aspects of gravity effect humans the least. Satellite operators may need to correct their clocks every once in a while, but other than that, we just can't reach the speeds or distance from earth to notice time dilation, nor can we collide masses large enough to detect gravitational waves. I was shocked in college when my General Relativity professor told me that very few scientists are studying GR, most likely because it's surprisingly more intuitive than quantum physics, and it's harder to experiment. I really wanted gravity to just be... cooler, I guess.
- treeman79 5y ago
  https://youtu.be/L2suMPiuog4 https://youtu.be/L2suMPiuog4 Perhaps quantum loop gravity will interest you.
- immmmmm 5y ago
  more intuitive??? for me both are far beyond my brain's intuition it's a quite active area of research even tho it's more than a 100 yo, check gr-qc on arxiv
  - lapetitejort 5y ago
    It's more intuitive in that it's deterministic. No rolling dice to figure out what happens. Yes, differential geometry is a beast and time being a spatial dimension is wacky, but at least things don't change when not observed.

macspoofing 5y ago

>yes, more space is created out of nothing! because there's a vacuum energy density that inflate the local patch of universe. I don't think you can say that with that kind of certainty. We don't have a theory of quantum gravity, we don't know what dark matter is, and we don't know what 'dark energy' is, so we don't actually know what is driving the expansion of the universe, so saying that 'space is created out of nothing' is too strong. Even something like the theory of cosmological inflation, which has some explanatory power, hasn't been experimentally verified, but rather tuned to match the observations. It's something I've noticed in a lot of communicators of science (whether they have a background in science or not). They tend use terms that overstate our actual knowledge in some specific area of science.

Iwan-Zotow 5y ago
> I don't think you can say that with that kind of certainty. well, any classic (in SM sense) QFT will produce positive vacuum energy density which translates into negative pressure. P = -E
immmmmm 5y ago
you're absolutely correct, i was referring to models based on classical GR + QFT (standard cosmology + standard model). ofc those are wrong but yield the most accurate predictions any models has ever yielded. i'm almost certain (no proof tho) that space time itself is just an illusion (and that there is only "information "). in other term i know i know nothing (but still is able to give predictions up 10^-32 s after big bang)

lapetitejort 5y ago

> funnily why all of the above is hard to understand for our human brains, it all makes sense in the mathematics.. Of the four fundamental forces, the higher order aspects of gravity effect humans the least. Satellite operators may need to correct their clocks every once in a while, but other than that, we just can't reach the speeds or distance from earth to notice time dilation, nor can we collide masses large enough to detect gravitational waves. I was shocked in college when my General Relativity professor told me that very few scientists are studying GR, most likely because it's surprisingly more intuitive than quantum physics, and it's harder to experiment. I really wanted gravity to just be... cooler, I guess.

treeman79 5y ago
https://youtu.be/L2suMPiuog4 https://youtu.be/L2suMPiuog4 Perhaps quantum loop gravity will interest you.
immmmmm 5y ago
more intuitive??? for me both are far beyond my brain's intuition it's a quite active area of research even tho it's more than a 100 yo, check gr-qc on arxiv
- lapetitejort 5y ago
  It's more intuitive in that it's deterministic. No rolling dice to figure out what happens. Yes, differential geometry is a beast and time being a spatial dimension is wacky, but at least things don't change when not observed.