Physics anyone?

[zerbaman]

I used to find stuff like this interesting, but frankly my brain got a bit mushed towards the end of my degree learning the advanced stuff and tbh it's just disinterests me completely now.

That sounds rough man. What're you gonna do next?

[LACE]

The original Big Bang postulate had two possibilities for the fate of the universe:
- Eventual contraction (ie Big Crunch) because there was sufficient mass in the universe to counteract the expansion rate, and so bring everything back together eventually.
- Infinite expansion because there was insufficient mass in the universe to counteract the expansion rate of the universe.
It was demonstrated in the 90s/00s that the second case was true. However, it was then shown a few years later that not only was the universe going to expand forever, the expansion rate was actually increasing.

As far as I am aware, most of the theories dealing with the accelerating expansion of the universe invoke something called Dark Energy. As a curious (perhaps coincidental) aside, it appears to match the Cosmological Constant which was a fudge factor that Einstein once incorporated into his equations dealing with the expansion rate of the universe, which he ultimately removed because it became apparent from experimental evidence back then that made the fudge no longer necessary. No one really has any conception as to what constitutes this Dark Energy, but the theories generally think that it is equivalent to an antigravitational effect that increases in strength as masses move further apart, or which only has significant effects in the regions of space containing very little matter (eg intergalactic space).

If dark energy is indeed effectively an unknown force, and if the theory of supersymmetry holds true, then it should have an equivalent particle (analagous to photons for electromagnetism). There have been suggestions that it may be possible to produce/detect these particles using the LHC. Some researchers have also claimed that the particle may have already been detected but this remains unconfirmed.

Some other possible mechanisms include:
- Previously unobserved spontaneous changes in particle masses. This may be happening in deep space, where the concentration of matter is very low.
- Mis-accounting of the amount of high energy particles zipping around in intergalactic space. Mapping these energy distributions is ongoing work.

So none of the postulates are really based directly on entropy or the big bang. They all do have to obey the 2nd law of thermodynamics though.

(LACE can probably correct me if I've oversimplified any of the above)

oversimplified haha..you're joking right.

besides all these questions can be easily googled.

http://map.gsfc.nasa.gov/universe/uni_fate.html

anybody got any theories or original ideas about the expansion of the universe, dark energy or spacetime? that'll peak my interest..

[kay]

I've been pondering one scenario. Will post it when I've thought it through a bit more.

[kay]

Horizon: How Small is the Universe (http://www.bbc.co.uk/i/b01mmrc0/) was rather good!

[alphacat]

http://phys.org/news/2013-02-spacetime- ... ciple.html

[eyes crossed]

[Phigure]

that's a pretty big "if" though lol

"we can work around the Heisenberg uncertainly principle.... If we can figure out time travel"

[eyeatus]

[EliteLennon117]

[garethom]

[zerbaman]

Why does the square accelerate & decelerate?

[garethom]

It doesn't, does it? Looks constant speed to me.

[zerbaman]

Question for our Resident Experts: I tried googling this, but you'll see why I found myself stumped...

This Week, we started the Quantum Physics Unit.

This morning, I had what I thought to be a small epiphany when thinking about particles having wavelengths which can be calculated by dividing Planck's number by their momentum(s). And with the understanding that waves are disturbances that travel through space and transfer energy while doing so, as well as the Energy-Mass Equivalence given by Einstein's theory of relativity, I found my self thinking that the reason particles can be treated as waves is due to the fact that when they're in motion, they're transporting energy.

While doing some light reading on a homework break, it dawned on me that this couldn't exactly be true because while Energy and mass are equivalent, they aren't exactly interchangeable like this are they? But part of me thinks it should still be right nonetheless.

Which brings me to what kept me from searching the web. This gave me the notion of something I can only describe as "energy potential" (which as you can imagine only results in "potential energy" when searched on the internet results in little more than web-links explaining the concept of Potential and Kinetic Energies). If this isn't perfectly clear, what I mean is that the capacity of energy a particle can theoretically move given the Energy-Mass equivalent. Which essentially leaves me with a particle as wave explanation, or theory of one at least.

Is there any truth to this?

[zerbaman]

It doesn't, does it? Looks constant speed to me.

If it was, the Oscilloscope would have linear transitions, not 'curved' ones wouldn't it?

[ascent]

the angular speed is constant which translates to variable linear speed

[Phigure]

Why does the square accelerate & decelerate?

because the 2nd derivative of the function is changing, in the middle it has the inflection point because that's where f''(x) changes sign

[mthrfnk]

I used to find stuff like this interesting, but frankly my brain got a bit mushed towards the end of my degree learning the advanced stuff and tbh it's just disinterests me completely now.

That sounds rough man. What're you gonna do next?

I got a job using what I specialised in during my degree, pile of shit tbh but it pays well - using it as a stop gap before moving on to something else

[hugh]

dafuck is going on on this page

[LACE]

Question for our Resident Experts: I tried googling this, but you'll see why I found myself stumped...

This Week, we started the Quantum Physics Unit.

This morning, I had what I thought to be a small epiphany when thinking about particles having wavelengths which can be calculated by dividing Planck's number by their momentum(s). And with the understanding that waves are disturbances that travel through space and transfer energy while doing so, as well as the Energy-Mass Equivalence given by Einstein's theory of relativity, I found my self thinking that the reason particles can be treated as waves is due to the fact that when they're in motion, they're transporting energy.

While doing some light reading on a homework break, it dawned on me that this couldn't exactly be true because while Energy and mass are equivalent, they aren't exactly interchangeable like this are they? But part of me thinks it should still be right nonetheless.

Which brings me to what kept me from searching the web. This gave me the notion of something I can only describe as "energy potential" (which as you can imagine only results in "potential energy" when searched on the internet results in little more than web-links explaining the concept of Potential and Kinetic Energies). If this isn't perfectly clear, what I mean is that the capacity of energy a particle can theoretically move given the Energy-Mass equivalent. Which essentially leaves me with a particle as wave explanation, or theory of one at least.

Is there any truth to this?

you're losing me here, i don't see it. i think this is because you're expressing yourself in a personal language without defining terms...um and it's planck's constant..not number, why are you defining it that way? but that's a nitpick..it's a widely appreciated fact that already in classical mechanics..like long before QM, there was a movement toward a more "optical" or "wavelike" approach to the motion of point particles. the real reason why the mathematics of classical particles can be treated as either particle or wave is much more advanced.. search for info on the hamilton-jacobi formulation.

[5910]

Question for our Resident Experts: I tried googling this, but you'll see why I found myself stumped...

This Week, we started the Quantum Physics Unit.

This morning, I had what I thought to be a small epiphany when thinking about particles having wavelengths which can be calculated by dividing Planck's number by their momentum(s). And with the understanding that waves are disturbances that travel through space and transfer energy while doing so, as well as the Energy-Mass Equivalence given by Einstein's theory of relativity, I found my self thinking that the reason particles can be treated as waves is due to the fact that when they're in motion, they're transporting energy.

While doing some light reading on a homework break, it dawned on me that this couldn't exactly be true because while Energy and mass are equivalent, they aren't exactly interchangeable like this are they? But part of me thinks it should still be right nonetheless.

Which brings me to what kept me from searching the web. This gave me the notion of something I can only describe as "energy potential" (which as you can imagine only results in "potential energy" when searched on the internet results in little more than web-links explaining the concept of Potential and Kinetic Energies). If this isn't perfectly clear, what I mean is that the capacity of energy a particle can theoretically move given the Energy-Mass equivalent. Which essentially leaves me with a particle as wave explanation, or theory of one at least.

Is there any truth to this?

you're losing me here, i don't see it. i think this is because you're expressing yourself in a personal language without defining terms...um and it's planck's constant..not number, why are you defining it that way? but that's a nitpick..it's a widely appreciated fact that already in classical mechanics..like long before QM, there was a movement toward a more "optical" or "wavelike" approach to the motion of point particles. the real reason why the mathematics of classical particles can be treated as either particle or wave is much more advanced.. search for info on the hamilton-jacobi formulation.

Well, I don't think it's a simply mathematical discussion.
Put simply I see it as follows:
Waves are disturbances in spacetime which acompany transfers of energy. And because energy and mass, at least seemed to be the same, any movement in spacetime is a disturbance and is also a transfer of energy.

[scspkr99]

Can someone explain where the matter for Lee Smolin's black hole universes come from?