Posts by 'zilla

Nice idea. Unfortunately I didn't pay enough attention to the words, so I didn't immerse myself fully in the scene.

I saw a dark silhouette against the fog, no features visible. Apparently wearing a coat. Male, lean, like a mysterious agent in a detective story. Probably caucasian if I had kept imagining, but possibly asian because of connotations to anime. I did not hear the voice at all, I only knew that he had spoken.

If I think about it a bit, the person is probably a "template" individual slightly similar to myself but more similar to the ideals of society as I have perceived it through media. Then I add layers that the scene reminds me of, like the detective stories, anime, even some Mickey Mouse comics. I can also mention that I am not that good at picturing scenes in books, they often stay very vague in my mind.

To your last question - yes!

I haven't read Stewart's books myself, but they seem interesting. Personally, I stay away from the higher level math, it simply does not speak to me. I do have a university degree in Physics, and that helps, but I find it much more fun to get the essence of something, even if it is mathematics, without having to understand the equations. My point is that if you get stuck with the maths, don't let that deter your curiosity. But yes, if you got the math, you got the power to play with the universe.

Frank Wilczek writes about deep physics without equations, I liked his recent book A Beautiful Question. Sean Carrol, Robert Oerter and maybe Roger Penrose have written books giving very deep insights without requiring too much math.

I can add two relevant points of interest:

Atomic orbitals
The electron was much debated once the atom's shape was discovered. If the electromagnetic force functioned in the same way for atoms as for larger things, then the orbiting electron would be always accelerating (changing direction to stay in orbit). Doing so would make it emit photons (not sure why) and it would lose energy and spiral inwards in no time at all.

As a digression, I believe this is true for planets as well. The orbiting Earth emits gravitational waves. Imagine it like the Earth and Sun are floating in water and the Earth moves around. The energy in these waves, however, are so tiny that we can never hope to detect them*. It's a whole different story for the much stronger electromagnetic force.

The agreed solution to this paradox was that the electron does not move at all. It is now regarded as a standing wave in 3 dimensions. This is basically what you get inside of a violin case when it is played, as it resonates with the tone. If you search for pictures of atomic orbitals, you'll see our modern visualizations of the electron:

Of course, further progress could one day show that this is not the most fundamental way to picture the electron.

Chaos and Emergence
Really amazing subjects that cannot be done justice by me, but I can give some hints. They are related to your wonderings about statistical behavior at different scales.

When a large number of small things act together, this can lead to entirely new behaviors. That is emergence, and it describes how complexity can create new phenomena from simple ingredients like atoms.

My favorite example is gases. We can manipulate their pressure and temperature very well. We find that they follow the laws of thermodynamics, which coincidentally state that the universe will some day end. But there is no hint of this in the behavior of the atoms making up the gases! There is even no concept of temperature for atoms. Temperature is the amount of disorder in the motion of individual atoms. It is simply kinetic energy which is not acting collectively.

Temperature is a measure of chaos. We have simple gas laws we can use only if the temperature is low enough. When it is, all the atoms will more or less act as one, and you get the gas laws from statistics of great numbers. But the higher the chaos, the more erronous the laws are, and the lower the predictability.

Chaos in fact defeats emergence, and you have to start considering the individual atoms again. This is much more demanding. That is why, when simulating atomic bombs or the hot plasma of the sun, we need vast supercomputers. Interestingly, we also need them for the quantum fluctuations inside of protons. That is also a high-energy mess!

You'll find chaos and emergence everywhere, on all scales. Weather is sonewhat chaotic yet predictable. Climate is more certain for the reasons you describe. Consider birds or fish moving in great flocks, or humans moving in traffic or along streets. We have physics for this. Consider the interplay of animal populations deriving from biology and brains. Equations exist. So too for the stock market. That one has a higher portion of chaos. Some would say that free will exists in such a void of chaos. Consciousness might even be quantum.

So as you move across scales, uncertainty may fall and rise and fall again, and the governing equations will be correspondingly demanding. Our surroundings are astoundingly predictable and simple to calculate compared to the quantum realm. But perhaps deep down, the quantum is again an emergent phenomenon?

* for the Earth, that is. We did detect then for black holes orbiting each other, and predictably, they did spiral inwards and merge as they lost energy to their gravitational waves!
The Dirac Sea
I just read about this and it blew my mind again.

First: The Dirac Sea is most likely just one way to interpret the vacuum. This interpretation might have no physical reality, but whether or not it is real makes no difference for the end result. It might be that all of our interpretations are equally irrelevant for the true nature of the universe.

The idea is that the universe is basically teeming with energy, but at such a constant level that we cannot measure it. All we can measure is the deviation from this level. That is our particles. And not just the normal particles. Because if you are able to take energy away from the Dirac sea, making the energy lower, that is also measurable. This is what antiparticles are, and this is how Paul Dirac predicted antiparticles in 1930.

What this implies is that antiparticles are not really particles at all, but they are holes in the vast continuum of the Dirac sea. Despite this, there is nothing about antiparticles to say that they are not a type of particle, too. And that's actually not weird..

The Physics of Holes
In some branches of physics, holes are absences of particles. This is really important when you deal with electricity. In a computer chip, or in a solar cell, holes are just as important charge carriers as the electrons themselves. But they are really just bubbles where there is one electron less than there could be. As an electron moves to fill in that slot, the hole will move over to where the electron used to be. The holes are therefore stable and move around just like electrons do, except they have opposite electrical charge! What's more, they have all of the properties that a particle can have, which is why physicists can easily treat them just like particles. Even though they are really not.

So how can we be sure that any particle is really a particle, and not a hole in a sea of particles? This also means it makes sense to think about the Dirac sea.

Great idea! I'm not very good at telling a genre, but I guess we'll just have to try and post something sufficiently different.

The genre I'm posting is a modernisation of yoik. Yoik refers to the ancient singing style of the Sami people, whose history is bound to the Eurasian Arctic steppes. Mari Boine is Sami and has used used her musical talent and fame to shed light on the mistreatment that her people have been put through. This mesmerizing song is my favorite among her works so far.

Mari Boine - Vuoi Vuoi Mu

I have the original! I even have this battery-powered contraption that wraps around it with external lights! It even magnifies the screen, so it's like I gave my GBA the nerdiest glasses ever.

Mostly I never went for SP because I'm so cheap that I would never buy another device when I had a working model. Now that nostalgy kicks in, I of course love the original more. It was also my first Game Boy, and ironically the first game I played on it was Pokémon Yellow, which is not a GBA title. I had the game before I even got the device to play it on, so getting the GBA was a great moment of my life!

Balancé - Stopped Time

Jurassic Park, Godzilla and Gremlins were high in my esteem in those days.

I have seven books on my desk, I might and might not read them all.

Fashion, Faith and Fantasy in the New Physics of the Universe, by Roger Penrose
A brilliant scientist, he has worked with Stephen Hawking previously. This book deals with string theory, quantum mechanics and cosmology, and what we might be forgetting or doing wrong in these fields. Coincidentally, he visited Oslo yesterday to promote the same book, and I got to ask him a question and got my book signed.

The Particle at the End of the Universe, by Sean Carrol
It's going into the deep implications of the Higgs particle and how it affects our understanding of reality.

Surely You're Joking, Mr. Feynman!, by Richard Feynman
A bunch of funny life stories from a legendary rascal physicist.

The Wisdom of Insecurity, by Alan Watts
A great thinker trying to explain how he sees the absurdity of modern human life and how to get to terms with such a strange existence, speaking from the 1940s. I like the way he writes.

Thinking Fast and Slow, by Daniel Kahneman
Supposedly a famous book about two different ways we think. I've yet to read to a part of the book that doesn't seem obvious.

Burning Country, by Robin Yassin-Kassar and Leila Al-shami
The most important book I'm reading. It's laying out the story of the Syrian revolution and consequent civil war, prodding only lightly into historical triggers and focusing on the civil society trapped beneath the chaos of warfare, a people who were just starting to grasp their unity and freedom when the bullets and the bombs came.

Olav H. Hauge's most beautiful poems
This is a collection of Norwegian poems from the last half of the 20th century.

All of the classics. They are forever on my bucket list.

I also want to read more fantasy by Ursula LeGuin and Diana Wynne Jones. Some eerie perspectives on human culture by Daniel Quinn. Some philosophy by Alan Watts (just received The Wisdom of Insecurity, a 1951 print). And Frank Wilczek's book The Lightness of Being, which is about fundamental particle physics.

I did have an old 2nd gen Kindle, the one with a keyboard. It broke after about two years, and I bought a Kindle Keyboard 3rd gen used. Then I lost that one rushing to switch trains, and I've been without one since.

I really liked having one, but I'm not a fan of flimsy products made to last until the next launch. I've ended up getting most of my books used or from the library instead. I might grab a new reader if I find a used one dirt cheap though.

I'm holding in a fart because I'm in bed and I don't want to pollute the local atmosphere

I'm actually impressed. After the Wii U, and the way traditional consoles are losing market to mobile, and the vague rumours going around, I didn't expect much. But this – I feel I want one. And I haven't bought any console since the Wii.

I like how this even builds on the flexibility of the wiimote. You can play with a classic pad (though I think that one looks silly), a piece in each hand like a wiimote and nunchuk, or either of the two small pieces. That means you got 2-player right out of the box!

They are increasing the difference to the competitors, but that is a good thing – Nintendo does best when they go their own way, as long as they can carve out something there. And this thing, I think it's hype-worthy.

I'd rather the console have poor specs, so that it can be cheaper. If I have to shell out loads for every single piece of this, it's not that appealing. So long as it beats Gamecube, I'm game.

Quote from Silent Lion

The uncertainty principle is meant to mean that there is true randomness in the universe. But I don't see how that can be verified, without rewinding the universe and seeing if the results repeat. I have yet to find a compelling argument (or be qualified enough to understand a compelling argument) that the universe is not deterministic. The uncertainty principle is supported by Godel's incompleteness theorems, which say that the universe is an incomplete, non-trivial computational system and therefore not all values and formulae can be deduced from any particular point within the system. But, more colloquially, all that means is that not everything can be deduced, referring to human knowledge. That's not quite the same as saying it isn't predetermined. It could well be, only that we are incapable of deducing it. So, the uncertainty principle holds, for now, as a practical experimental concept, but is it really some fundamental truth about the universe?

Great questions! It's very interesting how you combine this with Gödel's theorem. That basically ties in to the debate of hidden variables.

Basically, a hidden variable means that there is some underlying system, and when we do quantum mechanics we only see the surface, the result. The pilot wave theory, I believe includes hidden variables. But many physicists, especially those working in the quantum field, deny hidden variables and accept the uncertainty principle as a fundamental truth of the universe. Weird experiments seem to indicate that there is no actual physicality at the most basic level, only abstract superpositions of potential futures. See this video from PBS Space Time, for example:

There's also another way to see the uncertainty principle which I only found today. The principle is actually a wave phenomenon, rather than a purely quantum one. The link further down explains it best, but I'll give it a shot. Location and velocity are two properties that cannot be known at the same time due to the uncertainty principle. Well, in terms of quantum waves, position is encoded in the amplitude of the wave, whereas velocity is encoded in its wavelength:

A perfect sine wave, like the one pictured above, has a very easy wavelength, but it has the same amplitude an infinite number of times! Therefore its velocity can be known, but its position cannot. Now to illustrate a more general quantum, see the following animation:

This illustrates superposition, which is adding many simple waves to make up one actual particle state. As this is done, one peak dominates while its wavelength starts to vary a lot. This means its position is known well, but its velocity is very uncertain.
Source: http://physics.stackexchange.com/questions/2871…ainty-principle

So the uncertainty principle isn't actually that weird. You can say the same for a wave on the ocean: where is the wave really? You can see many peaks and troughs, so its position is not exact, but spread out. What is really weird, is how this wave will collapse into behaving as a point particle. The randomness is encoded here, and the indeterminacy of the universe lies in what happens to the wave.

Heisenberg, one of the founders of quantum theory, made the philosophical point that our universe is causal, but not deterministic. We know the reaction to every action, but that reaction is a predictable range of possibilities. Note that a computer simulation can have the same characteristics, albeit with a pseudo-random nature. Numerical simulations start with initial conditions and equations that strictly govern change. You cannot calculate the result without letting it actually happen. In that sense, is the simulation predetermined or not?

In short: in quantum theory, which is our most successful theory ever in terms of predicting experimental results, the uncertainty principle is a fundamental truth of the universe. There could still be an underlying theory that has greater determinacy. And as you said, even though there is, we might never know for sure!

The weak force has two distinct charges, like the

This is a thread for discussing and learning awesome things about the universe.

For earlier topics, see these links to the "Learn stuff + share it" thread:
Dark Energy
Electroweak Symmetry Breaking

Gravitomagnetism
I don't know many details about this, but it blew my mind when I realized that it exists.

Gravitomagnetism is not magnetism. But it is to "regular" gravity what magnetism is to electricity!

When electric current moves through a wire, a magnetic field appears around it, going round and round the wire. Basically, the magnetic field is the electric field's buddy, doing something in those remaining dimensions of space that the electric field isn't acting on. There's a super tight coupling between the electric and magnetic fields, because they are really just two sides of the same force, the electromagnetic force.

It turns out that gravity has such secondary effects too. They are usually too weak to make a difference, but they are very real. One effect is seen through a special motion in Mercury's orbit. Because the Sun is rotating, and because Mercury is very close to the Sun, Mercury's orbit is slowly being pushed around, like an uneven pebble pushed by an ant. This is called frame-dragging and it is a gravitomagnetic effect. Gravity as we think of it just attracts, but Mercury is being pushed sideways as well! So there is a gravitomagnetic field pointing around the Sun, just like there is a magnetic field pointing around an electric wire. (Einstein knew all of this and it's part of relativity.)

What really blows my mind, though, is that this behavior seems to be something all forces do!

In the 1860s, there was a breakthrough in our understanding of electric and magnetic fields, and the equations found are considered some of the most elegant laws of nature. When you see gravitomagnetic effects, though, the exact same equations can be used there too!

What this means is that the equations don't really have anything to do with the electromagnetic force at all. They describe how any force will act inside of our three-dimensional space, whether it be gravity or electromagnetism or even the last two, the strong and the weak force. There are magnetic-like parts to everything. It's not just electromagnetism that is weird!

When we talk of soulmates, we kind of know and agree what that is. But I think the reason why we get disappointed, is that as we meet someone interesting, we are forced to flesh out that definition. We either stretch it to define the person we met, or the definition breaks down because of an unmet expectation. I think there are problems with both of those end results.

I prefer a more complex system of illusions about my bonds with other people. For a significant other, I see several possible roles that that person might share with me. Lover, guardian, partner, receiver, etc, each with its own personal definition. The receiver is someone who accepts to be the target of your infatuation. A guardian helps you stay who you are, while a partner helps you develop. So basically, the roles are made out of actions, and none of them cover a whole personality.

I define a soulmate as someone who understands your identity and makes an effort for it to thrive. Additionally, a soulfriend is someone who agrees with a whole lot of your tastes, values and interests, so that your souls resonate in this manner. I have found these roles to be separate.

You could say I don't believe that soulmates are "out there", waiting to me found. However, there are several people who are able to be these roles for you, and that is a matter of effort and chance as well as compatibility. And no matter how deep that connection is, it only involves part of a person. They will have sides which are completely independent of your wishes, unknowns that you never foresaw. And that is what you embrace to create real love, because that makes that person real. In fact, too much connection can stifle love, because what you are so excited about is not the other person at all; it is yourself.

--

I've been and felt the roles of soulmate, as I see it, a couple of times. Each time a different degree and different flavor. I no longer have those connections, but even so, through them, I have become a stronger and happier person. It is as if others can build you like a puzzle, piece by piece. You cannot do it yourself. What is more important, however, is that you have that power for others as well. And the more you learn about that, the easier it is to find a soulmate.

All that is easier said than done, however, and only makes sense in retrospect. We are somewhat powerless in life, sometimes lost. I spent nearly a decade searching/waiting for missing pieces of myself, for a soulmate, for confidence. What saved me then was chance. It might also have been the fact that I kept trying new things, going new places, joining new events, etc. I exchanged to a different country and thereby moved out of all social norms that had suppressed me and kept me stuck to the same patterns. This freedom made me excited, and I reached a mental state which apparently made me attractive and interesting. I met a girl who was full of positive energy, and I felt that she could sustain that mental state in me. Without her, I would eventually have recollapsed into apathy. We enhanced each other, we were good for each other, because we shared similar beliefs and values in the world. I'd never met anyone exactly like her, someone who actually seemed to desire my company openly. She thus earned my trust and gave me the confidence to steal her heart. I was positively shocked and thrilled to be defying my own illusory tragedy.

That relationship ended, but I am now somewhat cured of my past inability to reach out to others. Before her, the soulmate I dreamed of was an impossibility, and I knew it. She was not it, but rather she delightfully proved me wrong. Now, a soulmate to me is easier to find, because they do not need to be so divinely insightful as to tear down a wall of isolation. Also, I have learnt even more of the complexity of relationships, and instead of the redeeming white light of a vague soulmate, I see also the ubiquitous warmth of heart in so many people out there.

One can never ramble too much about the mysteries of the universe!

Quote from Silent Lion

Particle/wave duality, for example, always eludes me. I mean, I've read about it, and I get the basic premise and its power to explain observations. But my brain just isn't equipped to truly grasp the concept.

This is a conundrum and I don't grasp it either – I keep wanting to have something to compare it to. There might be something, though. Take a look at the experiments in this video:

There is also something called solitons. Solitons are not particles, but special waves that can appear in the ocean. They are extraordinary because they do not spread out, instead they keep their shape even if they move really far. That, in essence, is what a particle is, too. Namely, a self-sustaining pattern that can move around, without "spilling over", falling down or fading out. The oceans where the particles exist, is so-called fields.

This brings you into the subject of Quantum Field Theory, which does away with a lot of past confusion and simply states that pretty much everything in the universe is interacting fields. All that matters is which fields are connected and how strongly. What I'm currently trying to understand, is what it means for a field to form a particle, and whether the fields can interact directly with each other, without the detour through a particle.

Quote from Silent Lion

And it ties in to the forces, because in Brief History, gravity stars as a particle (a graviton), and objects are only afftected by gravity when struck by gravitons. But, at the same time, it's a wave and so is present everywhere within its particular field. But you can't be 'struck' by something that is everywhere at once (or everywhere within a range). Similarly put, something that has a locational range rather than a fixed location could not have speed, because speed is defined as a change of location (movement). If a wave/particle occupies a range of positions at the same time, then it already occupies the position it is moving towards, rendering the idea of motion meaningless.

The clue is this: a wave collapses into a particle. The duality states that what we know as a particle, IS also a wave, but it actually isn't both at the same time. It becomes a wave between interactions, but every time it interacts, it has to reveal itself as a particle. This instantaneous collapse of a wave into a particle is a great unsolved problem in physics.

Basically, when you are "struck" by a quantum wave, it is as if a cloud sails above your head, and each spot under that cloud has a certain chance to be hit by a raindrop. There will only be one raindrop, though, and it will drop at random, with a higher chance of falling where the cloud is denser. And, once the drop has hit the ground, the cloud is gone.

So basically, a moving quantum wave is a moving, evolving pattern. The trunk of a car also moves in the direction of the front seat, so this is valid. Like a car, a wave has structure that enables you to tell the front from the back. (In the mathematical calculations, of course, you can never look at one. In the mainstream theories, quantum waves are not considered to be physically manifest.)

Quote from Silent Lion

And another thing! If an object travels at very high speeds, less time passes for that object than for a stationary observer. But speed is measured as distance over time. So, if you travelled across my vision at the speed of light, every second you experience should be an infinite length of time for me. So, if it's taking you an infinite amount of time to do anything (from my perspective), then you aren't travelling very fast at all.

Well spotted. But this is actually not a problem. It is only the internal time that changes. If I run past you really fast, I will appear not to move my body, but I will still speed past you. Why? Because my moving past you is part of your experience of time.

In my perspective, I didn't move very far at all. How does that make sense? Because the entire universe in front of me is compressed, and distances are much shorter in that direction. Even you were practically flat until I ran past you. Then you got really long.

Quote from Silent Lion

Unless you invert the problem, and then it's fixed. If you are travelling at the speed of light, and time is not passing for you, then you must be (from your perspective) taking zero time to reach your destination. From your perspective, you are travelling with infinite speed, and so you occupy every position on your journey at once. It is only from the observational perspective of a slower/stationary observer that you appear to change from one position to another. This is Star Trek fixed. Do you remember the old problem: "Even if you could travel at the speed of light, it would take you millions of years to reach the nearest planet! You would never survive the trip!" Well, perhaps if you were travelling at the speed of light, then it would take you no time at all. It is only the universe that would age around you as you 'blink' to a different section of spacetime.

Exactly! Neat, isn't it? :D Photons, being the particles of light, can have no idea of the concept of distance.

We could always make a separate thread for this.

I bought the player about two years ago. Sandisk is the manufacturer. I'm quite sure the originals are out of production, but this one has some underground popularity.

I tried using my phone, but the native music app is useless. Haven't heard of any good app for non-streaming