MarkE

Are you saying it's not certain yet that they will merge to form one big galaxy?

In about 4 billion years, these two spiral galaxies will merge together to form one big, much more massive, elliptical galaxy. How will other galaxies in the universe react to this (gravitationally)? Are there any other big collisions scheduled to occur?

Thanks @studiot. When, in your example, "the kinetic energy will be transferred to potential energy", where did the energy exactly go? Is it still measurable, but in another field? By the way, thanks for your recommendation of that book on thermodynamics. Next on my schedule is the TTC lecture on thermodynamics, so we'll see about that (if I still have questions afterwards)

There were multiple Big Bangs?

If that is the case, than I don't understand want Strange meant by this: Everywhere outside galaxies?

If you state that the Big Bang happened in our galaxy, than why isn't it possible to be more specific about where it happened within that galaxy? 'Everywhere' within a galaxy as well? I'm not allowed to conclude that it therefore must have happened in all organisms, agree, but is there a possibility to more specific than just stating 'in the Milky Way'? Do you mean that all the stuff that galaxies are made of were already present (only closer) at the Big Bang?

But...the big bang happened only once, right? So there must have been one location for it. Or, if the Big Bang happened everywhere, then what about people on earth? Did the Big Bang happen in all of us at the same time as well? (Or does this 'everywhere' only account for galaxies, not planets/organisms?)

If we know the distances between stars and galaxies, than why aren't we able to calculate which galaxy in space emerged first, in order to find out chronologically what the universe's family tree looks like, and where the location of the big bang must have been?

It was my misinterpretation, somebody else explained it to me this way, a wrong way now it seems, that made it look like heat energy could actually reside somewhere, unmoving, in this 'field', which can't be seen/detected/measured because it's magically 'hiding' in this field. So thanks again for explaining to me that this is not the case. I know that the quantum world is a strange world, but this would be a little bit too strange! Every particle has a field, but, have they ever been proven to exist outside of theoretical/mathematical models? Does nature actually creates these fields? The fact that a photon's energy is equal to mass, but at the same time it's the Higgs boson that gives mass to all particles in the Higgs field, is still very hard for me to understand.

Thanks! It's important to set the different terminologies and concepts themselves right first, @studiot. If I understand correctly, energy doesn't just 'disappear' into a field (of course!) because energy is always being conserved, which can be proven by measuring the binding energy, and heat that has been 'lost'. There's no 'hidden field' in QFD whatsoever (fortunately!), and everything is perfectly measurable. This binding energy can be high or low, if differs from the bond itself, one bond can be stronger than the other. That makes perfect sense. An electron bound to a proton (a hydrogen atom) has slightly less mass than a free electron and a free proton. When the electron becomes bound to the proton, a photon is emitted, and the hydrogen atom becomes more massive because of this photon. But… a photon has no mass. So how can this photon itself be responsible for the mass change, according to E=mc2?

@studiot Thanks for your answer, well, everybody thanks for your explanations, but I'm concentrating only on your reaction here, because otherwise it's too much at once. You're saying something about 'packing fraction'. I understand now that because of this, sometimes fusion can release energy, and sometimes fission instead (after Iron-56). In our sun, 4 protons are turned into 1 Helium atom + energy. This Helium atom has less mass than those 4 protons together because there's less total binding energy involved in Helium. This difference is exactly the energy that has been released (gamma rays, positron and neutrino). Does this by the way mean that our sun is becoming lighter and lighter? I have a pretty hard time understanding this 'electrostatic energy'. How can heat energy be static? 'Energy', sure, gravitational potential energy, but 'heat energy'? Heat, radiation, is constantly moving, that's why it's called heat, because a particle is moving, the faster the hotter, so how could heat energy be static (not moving), and reside anywhere in the first place? Gravitational energy it's the path that 'stuff' can fall to increase its own movement, like a ball falling from a hill, but empty space (like the space in between the ball and the floor) could never be heat by itself, right? That wouldn't make sense. The space between a hill and a ball on top of it has no energy by itself, only the ball has mass, and therefore energy, because it's made of 'stuff'. But the way I (wrongfully, I hope) understand molecules like glucose, alkanes or ATP is that heat can be stored in a field, poof, gone, and than can be called up (like a genie in a bottle) to show up out of this 'field' where it was hidden from reality. I mean, a ball has to stay a physical ball in order to ever roll down. I have a really hard time understanding a quantum field if it would imply that, at the quantum level, this somehow is totally different from a ball on a hill, because somehow a quantum ball could actually disappear, into a field, where it 'resides', and still be heat energy. it doesn't make any sense (to me). Or is it just that, in these molecules, electrons are in a different shell that explains the difference? I really hope that, concerning these three molecule examples I just gave, just like in the sun, measuring the difference in binding energy explains where the heat went, just by rearranging itself, without disappearing from the real world or something like that. I really hope that the quantum world is understandable

The answer should be 'YES' then?

I think that the answer should be 'NO'. This is my explanation: The arrangement of atoms in a molecule can store energy. The same atoms, arranged differently, may hold less energy. It takes energy to hold a bond together, so by breaking it, you’re releasing the energy that held it together. Heat/fire therefore is the breaking of a formation and/or bond, just like glucose, oil (alkanes), ATP, they’re all ‘balls on top of a hill’ so to speak. (Why THIS arrangement has that feature, and not some other arrangement, is also quite interesting to me). The sun releases energy in the form of gamma rays by fusing hydrogen atoms together. Does this mean that the element hydrogen conserves energy, just like glucose, oil, or ATP? That would mean that the arrangement ‘hydrogen’ is potential energy by itself? (I’m referring to ‘hydrogen’, not just to a ‘proton’, because it’s not just the protons that, by fusing together, create gamma rays, but also the electrons, that cancel out with the positrons together release gamma rays). Hydrogen is of course a 'bond' of 2 subatomic particles, a proton and an electron, but protons tend to repel each other, because they are charged +1, so fusing them together can’t be a natural reaction, it doesn't seem to be in accordance with the thermodynamic law of entropy. Radioactive decay on earth take place by neutrons becoming protons, without any external input, that releases stored energy, right? This reactions happens naturally, obeying the law of entropy, because (subatomic) arrangements can’t become more organised just by themselves, they tend to become less organised instead. The sun is changing its hydrogen atoms into combinations of proton-neutron elements (first deuterium, later higher elements numbers), and by doing that release energy. But how? This can't be stored potential energy, right? If this is an opposite reaction (compared to radioactive decay on earth), you would need an energetic input to make those protons fuse together, but... where does this input come from?

Thanks @swansont and @Strange! Is this also the reason why there is no center of the universe?

It's known that all galaxies are moving away faster from each other, due to dark energy. The further away these galaxies are from each other, the faster their movement is. Newton's law of motion (which is about gravity of course, not dark energy) states that, on earth, a falling object will accelerate, but, after a while this acceleration stops, due to its mass, and a steady falling speed remains without any further acceleration. Again, this is gravity, not dark energy, so why this example? Well, I'm wondering if it has yet been detected that galaxies far away from us (outside our Local Group, to exclude a gravitationally bound galaxy like Andromeda) have decreased their acceleration speed to a steady acceleration, just like a falling object on earth. If not, than I guess it must have been detected that all galaxies are continuously increasing their acceleration speed at the same rate, no matter what their location in space is, NOT like a falling object on earth would behave. Is this true?

Are we to conclude then that the force carriers of the weak interaction originate only from within both quarks and leptons?

So the source could still be a quark then?

That's not what swansont said:

Summarizing our discussion so far: If I understand this correctly, the weak interaction also occurs in mesons, and because their 2nd and 3rd generation family members don't consist of any quarks we can therefore conclude with certainty that the source for the force carriers of the weak force (W-, W+ and Z bosons) can't possibly come from within a quark. If this is the case, than what are our remained options? The weak nuclear force is a force between sub-atomic particles, so it has to originate from somewhere inside an atom, right?

Could you please explain to me what you mean by that?

The term for interactions between sub-atomic particles regarding the weak nuclear force

OK, thanks for pointing that out. So 'nuclear force' means 'interaction between nucleons'. What then is the correct scientific term for 'interaction between sub-atomic particles'?

In particle physics, the weak interaction (the weak force or weak nuclear force) is the mechanism of interaction between sub-atomic particles that causes radioactive decay. -> https://en.wikipedia.org/wiki/Weak_interaction "The interaction between sub-atomic particles". If I understand you correctly, this does NOT mean that it's taking place inside an atom? And if you are referring to radiation, yes, that's happening outside the atom, but that doesn't mean that the source for this radiation is not coming from inside the atom.

Do you mean that the term 'nuclear force' is not right?

Not 'derive from' then, but 'take place inside' an atom (since it's a subatomic force). Sorry for not using the correct verb there