Cosmobrain

If you said in your post that the wheel is made out of carbon nanotubes, the strongest material, you probably already knew that it was going to break.

finally, a soul!

people don't like clicking on unknown links.

Dude just hover over the link and you'll see it is a link to imgur. Unless of course you use internet explorer

...ANYONE?

if the universe is yours, then yes -you can

Many of you must be familiar with polandball comics. Well, I decided to make particleball comics, where balls represent the subatomic particles of the standard model

I've created two comics to get things going.

Upquark is sad

Tiny but heavy (it may be hard for some people to understand this one)

what do you think?

If the answer is all the stars, how does the gravity of all the stars (entities) accumulate, when there are huge distances among them?

 

 

For the same reason the gravity of planets and stars accumulate. They don't have to be touching one another. Each star has a small role in the whole gravity of the galaxy

3. We've spent all that money on New Horizons and now it won't even investigate a planet!!

 

 

I find this sad and hilarious at the same time

Instead of posting so many equations, can't you guys answer with a yes or no?

Intuition is like a brain fart

I have gathered some questions that have been bothering me for quite a good time.I hope you can ansswer them and help me out. An one paragraph long answer is good enough, no need to go so deep in each one. This can take some time but I hope you'll learn a lot too by answering it
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1. What if there IS a center of the Universe? By analyzing the cosmic microwave background, we can see microwaves that got redshifted due to the expansion of space, right? And the CMB forms like a sphere around the observable Universe, I assume. If we travelled billions of ly to any direction, the waves coming from that direction would be less redshifted than the ones on the other side, right? So can we find the center of the Universe that way?

2. The inflation theory is a complement of the Big Bang theory added to describe the similar temperatures at opposite sides of the Universe. If the Universe was at a single point and it was in contact, why is a theory of inflation needed?

3. Why is the Universe so asymetric? It would make much more sense to say that all galaxies are identical and are at the same distance away from each other, right?

4. What if the whole observable Universe is actually the whole Universe? Howcan we know that there is more light coming?
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That's it so far. I don't wanna flood you with questions. Thanks!

In order for gravitational information to flow, it requires space. Another universe wouldn't have space connecting itself with out universe, so I assumo gravity can't affect that other world

A possibility is that the two stars are orbiting very close to each other and the planet is much farther away from both, so its orbit could be pretty much stable

The only way to seriously look at it is to consider elementary particles like two electrons, They have equal masses and equal charges and since they are elementary, there is no 'empty space' in them. Gravity will tend to pull them together while their charge will tend to separate them. I haven't looked it up in along time, but off the top of my head, I seem to remember the separating force is 10^18 times stronger than the attractive force.

 

I.E. you will never form a black hole of similarily charged particles.

that makes sense. If you consider a single particle, the electromagnetic force will win

I've been thinking and I came to the conclusion (probably a wrong conclusion) that gravity isn't that weak. All the matter we see is made up of almost entirely of empty spaces. If you had a spoon of pure matter, it would be incredibly heavy and would have a very significant gravitational pull. The thing is that we don't have such material.

My question is, if you had pure matter, would the gravitational force be stronger than electromagnetism?

The Graviton is just a frustrated attempt to include gravity in the Standard Model

Their shapes wouldn't be possible if they weren't spinning

When I registered here, I didn't intend to be an active member, so I just came up with that dumb name. I want an admin to change it to Cosmobrain, please.

And sorry, there was no other place I could start this thread.

thanks

cb

Gravitons are today theoretical things and we should discuss them as such...

 

Gravitions are really objects in effective quantum general relativity, that is the closest thing to a quantum theory of gravity we have right now. The idea is, following standard methods of quantum field theory, to linearise the full theory and look at small fluctuations about some fixed configuration understood as the "vacuum" or "background". The classical part works fine here for GR, you construct gravitational waves. Then you apply standard path integral methods to these fluctuations and you see that the resulting theory does not quite work. This approach is the perturbative approach.

 

Technically the theory you end up with is full of infinities and you can't remove these using known methods of quantum field theory - the theory is non-renormalisable.

 

However, one can treat it as an effective theory and not a fundamental one. These infinities do not appear at tree level or one-loop level, so we can calculate scattering amplitudes for quantum general relativity to low orders with no real problems. We can discuss gravitons in this context perfectly consistently, remembering we have an effective theory.

 

So, what about the full theory? There is some evidence that quantum general relativity, or something close to it is asymptotically safe. Without any technical details, this means that the theory may be well defined, but not as a perturbative theory. That is we cannot understand the theory properly in terms of gravitons. It is quite possible that the full quantum theory of gravity is not a theory of gravitons at all!

When you think about it, pretty much everything has gravity. Even light. That means that photons of light can emit gravitons? Without changing its momentum? that doesn't make sense to me

The idea of Gravitions is just a frustrated way to include gravity in the Standard Model. There is no such thing. As far as we know, Einstein's GR is the best we've got to explain gravity

We have a theory called quantum chromodynamics (QCD) and this should explain all the phenomena of the strong force and the residual strong nuclear force. However, most of the very successful methods employed in quantum electrodynamics don't work so well for QCD. Either one can build phenomenological models of the residual strong force, which should come as a limit of the full theory of QCD or one can place QCD on a lattice and use computers to solve the equations.

 

Either way, people do have some handle on many aspects of QCD.

Yes, but that's a fallacy. You are basically explaining the strong force using the strong force. QCD is a theory, but it doesn't really explain the true nature of that force. Just like electromagnetism doesn't really explain how particles can attract or repel each other. But it's ok, no one can answer such questions anyway

what?

a photon is a photon an electron is an electron

Why do quarks have to exist in the first place? It just makes things more confusing than they already are. Why three? (or two, if it is a meson, but anyway...) What is the nature of the strong interaction?

I think that unfortunately I'll never be able to understand nature