Astronomy & Space Exploration

Revan

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many-worlders argue their case very well and give pretty straight-forward answers to most of the questions.

Regardless, the frame-work of quantum mechanics is ~100 years old. They added stuff and flushed it out, but its still rests on the same ideas. There are many things, that aren't figured out but there hasn't been a single observation in quantum mechanics, that wasn't predicted by the Schrödinger equation. In popular science QM ts often depicted as is this mystical idea, that nobody understands. All the (genuinely) amazing stuff, that is reported in slightly clickbaity articles, is always in agreement with the Schrödinger equation and the general frame-work. I would take any reasonable bet, that any observation/discovery in the next 40 years is also going to agree with this frame-work. It was well enough understood in the 60ies to predict what happens when we fire protons with incredible speed/energy at each other and it panned out exactly as expected, when the LHC detected the Higgs. Quantum mechanics nowadays is much more refined and advanced than it was back in the days. Just because its genuinely weird, doesn't mean that its not understood; there is always going to be a frontier towards smaller/higher-energy, because knowledge doesn't have any sensible limit.

Quantum effects could play a role when it comes to consciousness (just like they might play a role in photosynthesis), but it could also be entirely classical. Considering that we know very little about it at all, its hard to make any argument to begin with. One way or another, I don't think it changes all that much. It is certainly doesn't have anything to do with observers.
Yup, the nice thing of many-worlders is that it is quite straight-forward and it is totally based on Schrodinger's equation. While in other interpretations (including Copenhagen) when the wave collapses, you have to dismiss the other states of Schrodinger's equation, in many-world interpretation you always keep the entire equation. Interestingly, the many-world interpretation seems to be quite similar to the concept of landscape in string theory. Leonard Susskind says that they are actually the same in his 'The Cosmic Landscape' book.

I don't think it is that nobody understands quantum mechanics, but that it is extremely hard to understand it on an intuitive level, and have good interpretations for it (this is what the likes of Bohr and Feynman meant by it). It is actually one of the most exact theories right there, and awesome at predicting and measuring things (every prediction made by quantum mechanics that eventually was put to an experiment, ended in the exact same way as the theoretical predictions), and is actually useful in technology (the concept of tunneling is massively used). The question is if quantum mechanics is all that is there and it describes the world (in which case, general relativity is wrong, but quantum mechanics is hopeless at explaining the gravity), or it is just a theory that is useful to measure things, but it is not the real cause (aka, there are hidden variables which we do not observe, and quantum mechanics is an approximation for them). I don't think that anyone really knows it and who knows if we will ever know it.

Finally, has anything fundamentally novel (in quantum mechanics) has happened since the standard model and the unification of the weak force with the electromagnetism? I am not talking about experiments that confirmed predictions (Higgs boson) or observing gravitational waves. More like, theoretically speaking, I don't know if there are massive blocks that have been added to it, I think everything is still based on Schrodinger's equation.
 
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Balljy

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The question is if quantum mechanics is all that is there and it describes the world (in which case, general relativity is wrong, but quantum mechanics is hopeless at explaining the gravity)
There's a really interesting experiment going on which may help unite theories of gravity and quantum mechanics (basically the effect QM may have on gravity). It's a few years away from getting results but is a field of research which could have major repercussions in our understanding of gravity. To be fair nothing has been found yet, but they think they have a way of measuring the interaction.

https://arstechnica.com/science/2020/06/tiny-pendulum-may-reveal-gravitys-secrets/
 

Revan

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There's a really interesting experiment going on which may help unite theories of gravity and quantum mechanics (basically the effect QM may have on gravity). It's a few years away from getting results but is a field of research which could have major repercussions in our understanding of gravity. To be fair nothing has been found yet, but they think they have a way of measuring the interaction.

https://arstechnica.com/science/2020/06/tiny-pendulum-may-reveal-gravitys-secrets/
Interesting. There is actually the entire field of quantum gravity, that tries to study gravity in the quantum level (surprisingly, the force of gravity becomes extremely strong in near-Planck distances). However, I think that there has not been much progress in the field. If I am not mistaken, Feynman said that quantum gravity won't be cracked for many centuries.

The hope is that one of the superstring theories might actually unite them, and both of them to essentially be 'right' on their current domain, while in general being non-complete. Someone like Sean Carroll seems to think that quantum mechanics is actually the reality, there are no hidden variables there, this is what it is. Who knows, let's hope there will be progress.
 

Revan

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@PedroMendez did you read 'The Cosmic Landscape' from Susskind? Finished it yesterday and it was amazing, I think that I liked it even more than The Black Hole War.

In fact, the chapter here on The Black Hole War finally helped me understand that book. Or well, understand it a bit better than before (a lot of stuff I don't get). Like the other book, it is quite heavy though, especially when it goes to string theory (and here it is mostly about it), in many places I totally don't understand what is going on. I still felt that I left learning much more than I knew before. But the universes popping into existence all the time is still something I find hard to fully understand.
 

PedroMendez

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@PedroMendez did you read 'The Cosmic Landscape' from Susskind? Finished it yesterday and it was amazing, I think that I liked it even more than The Black Hole War.

In fact, the chapter here on The Black Hole War finally helped me understand that book. Or well, understand it a bit better than before (a lot of stuff I don't get). Like the other book, it is quite heavy though, especially when it goes to string theory (and here it is mostly about it), in many places I totally don't understand what is going on. I still felt that I left learning much more than I knew before. But the universes popping into existence all the time is still something I find hard to fully understand.

no, I always wanted to read it, but didn't get to it. I am turning more and more into a slouch when it comes to reading books. :nervous:
 

Buster15

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@PedroMendez did you read 'The Cosmic Landscape' from Susskind? Finished it yesterday and it was amazing, I think that I liked it even more than The Black Hole War.

In fact, the chapter here on The Black Hole War finally helped me understand that book. Or well, understand it a bit better than before (a lot of stuff I don't get). Like the other book, it is quite heavy though, especially when it goes to string theory (and here it is mostly about it), in many places I totally don't understand what is going on. I still felt that I left learning much more than I knew before. But the universes popping into existence all the time is still something I find hard to fully understand.
Just briefly, what was the explanation for universes popping into existence.
Reason is that I have read about eternal inflation which really does challenge the brain.
 

PedroMendez

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So what are these beams of light that are being seen coming out of black holes?
any specific article you are referring to?

The matter that is spiraling into the black hole accelerates and "bumps into each other". In this process it heats up and emits radiation (=light). The light is not coming out of the black hole, but out of the gas-disc, that can form around them. A bit like a space-shuttle entering the atmosphere; it needs a heat shield or it would just burn.
 
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golden_blunder

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any specific article you are referring to?

The matter that is spiraling into the black hole accelerates and "bumps into each other". In this process it heats up and emits radiation (=light). The light is not coming out of the black hole, but out of the gas-disc, that can be form them. A bit like a space-shuttle entering the atmosphere; it needs a heat shield or it would just burn.
Something I read on FB yesterday, sorry I can’t find the article now. I think you’re right it did say something about stuff bumping together to form a light coming from within the black hole.

but I choose to believe that it’s them coming
 

0le

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Man I wish I did theoretical physics. I'd probably have been awful at it, but its so cool thinking about all these things.
 

Buster15

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Man I wish I did theoretical physics. I'd probably have been awful at it, but its so cool thinking about all these things.
Only if you are a highly competent at mathematics. Because essentially, that is the main thing they need to do.
 

Buster15

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Best intro (almost a cartoon, so not sure you can call it intro) on quantum field theory for a laymen: https://www.ribbonfarm.com/2015/08/20/qft/

Really nicely done.
That helped me visualise what a scalar field is. I have struggled to comprehend that but at least the description cleared up a few things.

The reason I was interested is because I have read that the energy fluctuations in a scalar field could give rise to the cosmic inflation that it is believed to have happened at the beginning of our universe.
 

Revan

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Just briefly, what was the explanation for universes popping into existence.
Reason is that I have read about eternal inflation which really does challenge the brain.
Honestly, that was the hardest part. They just seem to pop into existence (or a part of the universe might change the constants/rules and then become a new universe). So mostly it is him speculating (with good reasons), but no one really knows.
Man I wish I did theoretical physics. I'd probably have been awful at it, but its so cool thinking about all these things.
It is really, really hard. You essentially need to be really good at math, and that might not even be enough. It is fascinating though, I would have loved to do it too.

It needs to be said, that modern theoretical physics has probably surpassed the possible experiments (at least on the short term). This could mean that the entire work of the top physicists on the end has been for nothing, cause it might be totally wrong. For example, Ed Witten, largely considered as the top physicist in the world for the last 3 decades, might be totally wrong on his approach. If string theory is fundamentally flawed (or it might not be flawed at all, it is incredibly consistent, but just not describe our universe) then not only his work did not help us understand the universe better, but his brilliance essentially dragged another smart scientist ongoing into a wrong path.

It is beautiful though. And incredibly weird. I mean, the theory with the highest prediction power (quantum field theory) essentially says that everything is created from fields. The particles, everything you see and believe it exists, it actually just made of fields. Particles do not exist, we are actually just oscillation of fields. And the information for this is probably stored somewhere else, not in what we think as space (hologram theory).
 

Revan

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Interesting and makes sense. I always struggled to understand the vacuum energy, but if you start thinking in terms that everything is a field, then quantum fluctuation, vacuum energy and 'particles' popping into existence and getting destroyed make perfect sense. Of course, measuring it is a bit different, but quantum mechanics and quantum field theory's predictions have always been proven true when the experiments were able to be done.
 

Charles Miller

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Interesting and makes sense. I always struggled to understand the vacuum energy, but if you start thinking in terms that everything is a field, then quantum fluctuation, vacuum energy and 'particles' popping into existence and getting destroyed make perfect sense. Of course, measuring it is a bit different, but quantum mechanics and quantum field theory's predictions have always been proven true when the experiments were able to be done.
Yes the quantum noise is very real. In fact it can create a problem for the progress of technology very soon, because our transistors are so small now, that they are reaching a limit where quantum effects will become relevant and parts of the transistor can just go away via quantum tunneling. A way to avoid it is colling things down, but it would not be practical and is very expensive.
 

Revan

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Yes the quantum noise is very real. In fact it can create a problem for the progress of technology very soon, because our transistors are so small now, that they are reaching a limit where quantum effects will become relevant and parts of the transistor can just go away via quantum tunneling. A way to avoid it is colling things down, but it would not be praticle and is very expensive.
Interesting, and never thought about it. Transistors now are reaching sizes as small as 10nm which is still quite bigger than the atoms, but it is getting close to those sizes where quantum noise can essentially wipe them away (in theory, it can wipe anything out) via tunneling. IT, why my computer is not working? Sorry, part of it has gone away, have you tried on waiting an infinite number of years and then try it again?
 

luke511

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Not really astronomy per say but...

https://getpocket.com/explore/item/...robiologist-explains?utm_source=pocket-newtab
Could Invisible Aliens Really Exist Among Us? An Astrobiologist Explains
The Earth may be crawling with undiscovered creatures with a biochemistry that differs from life as we know it.
I'll try avoid turning this into a UFO discussion, but this is interesting footage from 2004 that relates to that idea, that alien life/technology could be incredibly unconventional. This is police helicopter footage using an infared camera, it shows the thing deposit some sort of liquid, they look like round orbs almost. At 2:20 you can see it begin to shoot off, then at 2:46 when there's cloud in the background for reference, you can see the crazy speed of it. I've seen a handful of UFO clips that are hard to explain (I've watched a hell of a lot of shit cases to find the good ones mind), they all share common traits that they seem almost alive in the way they move and behave in the sky.

 

Charles Miller

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Interesting, and never thought about it. Transistors now are reaching sizes as small as 10nm which is still quite bigger than the atoms, but it is getting close to those sizes where quantum noise can essentially wipe them away (in theory, it can wipe anything out) via tunneling. IT, why my computer is not working? Sorry, part of it has gone away, have you tried on waiting an infinite number of years and then try it again?
:D
Dont want to sound conspiranoic, but there is another aspect of it. If turns out that its impossible to find a solution for this problem, i bet that only big corporation and very rich individuals are going to have access/afford quantum computers and futuristic technologies. The rest of us are going be stuck in the caves.
 

Revan

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:D
Dont want to sound conspiranoic, but there is another aspect of it. If turns out that its impossible to find a solution for this problem, i bet that only big corporation and very rich individuals are going to have access/afford quantum computers and futuristic technologies. The rest of us are going be stuck in the caves.
I don't see anything conspirative about it, and I don't see any problem with it. Obviously, most people won't have access to quantum computers, same as how most people right now don't have access to supercomputers or clusters with thousands of GPUs. I don't see what is wrong with that, most people don't need a supercomputer, as they won't need a quantum computer.
 

Charles Miller

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I don't see anything conspirative about it, and I don't see any problem with it. Obviously, most people won't have access to quantum computers, same as how most people right now don't have access to supercomputers or clusters with thousands of GPUs. I don't see what is wrong with that, most people don't need a supercomputer, as they won't need a quantum computer.
No, no. A quantum computer are not projected to replace supercomputers. It can do it of course, but the whole idea is to create a quantum pc. Otherwise why so many public funds invested on it? And this is not like you having a pc and Google having a supercomputer. We are talking about a technology that would make any information of criminal activities of certain groups impossible to access, and in the other hand would allow corporations/governments to know and control every aspect of your life. One can think this is not a problem, due to ideological motivations, bu its such a colossal difference in terms of technology, that would create a second class type of mankind, for those with no access to it.
 

Revan

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No, no. A quantum computer are not projected to replace supercomputers. It can do it of course, but the whole idea is to create a quantum pc. Otherwise why so many public funds invested on it? And this is not like you having a pc and Google having a supercomputer. We are talking about a technology that would make any information of criminal activities of certain groups impossible to access, and in the other hand would allow corporations/governments to know and control every aspect of your life. One can think this is not a problem, due to ideological motivations, bu its such a colossal difference in terms of technology, that would create a second class type of mankind, for those with no access to it.
I'll admit that I don't have much knowledge of the full effects of quantum computing (and also have no idea when it will be really ready, not the IBM demos that they make on normal computers emulating quantum computing). However, I struggle to see why it will be needed for everyone. I see it more like a replacement for supercomputers/clusters, and even that is gonna be a very slow gradual shift considering that the algorithms won't necessarily work for quantum computers, so there will be needed novel algorithms.

Actually, I was planning to study the basics of it (an introductory course of it) for a couple of years now but still didn't.
 

PedroMendez

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I don't think quantum computers are going to replace classical system; super computers are still going to be needed. They are specialized and have advantages in very specific/narrow areas, but for most tasks, quantum computers are in principle equal to classical computers. The two big ones are simulating quantum system itself (=>applied material science; chemistry) and number/group theory (=cryptography; e.g. Shor's algorithm). I think once quantum computers with sufficient q-bits are available for research, material science would really benefit, but thats extremely positive.
The issue of cryptography is a bit scary, but also imo fairly solvable. Cryptography on classical computers can be designed in different ways, that can't be easily cracked via quantum computation. If thats necessary, it will be done.

Overall, its all pretty far away. Currently quantum computers have less than 100 q-bits with massive investment. Its unclear if/to what extend the current concepts can scale at all and quantum computers, that are useful outside of research about quantum computing, probably need at least 1000/10.000 times more q-bits. If anything, I'd be worried that quantum computers needing much more time than expected.
 

Buster15

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I have often wondered whether there has to be a reason for the/our universe to be there.
I fully acknowledge that this is a very 'human' or 'phyilosophical' thought, and of course it is highly probable that it/they just exist and have no obvious purpose.
I am not a religious believer by the way.

But if you just ponder the fantastic scale and form and function of it all, it seems so incredible for it/them just to happen to be there.

All of that energy in whatever form, all of that matter in whatever form, all of those galaxies with all of those stars and planets and moons.
And all of those laws of physics in whatever form that defines them.
Did it all just happen??
 

antsmithmk

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Good news. We dont have a good record with Mars missions.
Recent missions have been a little more successful. The last to land, Insight, is still having mole trouble however. I'm not counting any chickens, but at least Perseverance lands exactly like Curiosity did so we have a decent benchmark.
 

Revan

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@PedroMendez I am reading ‘Something Deeply Hidden’ from Carroll and enjoying it so much. It is actually quite introductory Quantum Mechanics book, though focused on Many World Interpretation. I am at around half of it and while I don’t think I learnt much new, it is a very good reinforcement exercise and just delicious to read. Recommended if you have time for it.