[Physics]Negative Mass

its not that antimatter has negative mass but if it were to come in contact with a 'normal' particle it would cancel it out.

i.e. a positron + electron = nothing

In positron electron annhilation you wouldn't get nothing. Depending on the energy (how fast they were moving), you could get a few photons (if low energy) or you could create a higher mass particle anti-particle pair (if high energy) with the extra energy leading to the rest mass of the particles. You could even create force particles for the weak force (we call them Z, W- and W+) from an electron positron pair.
 
as said by other people both matter and antimatter have positive mass, or mass as its called.

i remember reading an article about 10 years ago that postulated that negative mass existed as a way of explaining how mass was seemingly created out of nothing at the big bang - an equal amount of negative mass was created, the positive and negative separated and so whole galaxies and clusters would be made from negative mass somewhere in the universe - it was interesting but i don't think the theory took off.
 
After hours of doing Schrödinger work for electron probabilities, I've grown to hate physics to the point, that I want to stab the next physicist I see in the face :(
 
After hours of doing Schrödinger work for electron probabilities, I've grown to hate physics to the point, that I want to stab the next physicist I see in the face :(

If you try and stab me in the face I'll put you in an infinite potential well (and make it a classical one so you can't get out!).*


*Apologises for sad physics reference
 
Last edited:
Now, perhaps the most interesting idea is that alone, all these particles would be massless. No mass at all. The Higgs-Boson particle is believed to give them all their mass. However, this is the only particle predicted by the standard model of particle physics which hasn't been observed. We expect to know whether or not it exists within the next few years though as there are some rather large experiments going on these days.

Anyway, I really should get on and do something now.

Technically in order for the higgs to exist the Hierarchy Problem means there would either need to be a plethora of hitherto-undetected super-symmetric particles or a number of compactified extra dimensions causing gravitational 'dilution'. Also in the simplest supersymmetric model (MSSM) there are several different higgs particles, some with charge.

With that in mind it's probably unsafe to say it is the only unobserved particle. (even though neither of these thories are standard model, the Higgs doesn't really work in Sm as it is anyway!)
 
I can only understand a fraction of what the physicists in this thread are saying but I'm oddly fascinated - carry on guys :D

I particularly like this sentence
Minto said:
Technically in order for the higgs to exist the Hierarchy Problem means there would either need to be a plethora of hitherto-undetected super-symmetric particles or a number of compactified extra dimensions causing gravitational 'dilution'.

I'm going to memorise it and repeat in front of people sometime (hopefully none of them will be physicists) and watch the expressions on their faces :p
 
When watching the program i thought:So,a pair of particels form, 1 anti matter and 1 matter and usaully pair up then sorta cancle out. But near a black hole the antimatter goes in to the black hole and the matter particle goes off in to space as radiation. At a certain point the black hole can not take any more antimatter and sorta collapses. Also that in a black hole time is changed.

So what i want to know is: Presuming the antimatter particle that went in to the black hole is emitted when the black hole collapses, if the antimatter particle caught up with its matter counter part what would happen? Would they react as normal and pair up and cancle or would they react differently as the antimatter particle has a different time than its matter counter part, due to the antimatter being in the black hole? for example the matter particle has spent 100 years in our normal time but the antimatter particle has only spent 50, the other 50 lost due to there being a different time in the black hole.:confused: I hope you understand what i mean as i was pretty lost myself writting this.
 
So what i want to know is: Presuming the antimatter particle that went in to the black hole is emitted when the black hole collapses, if the antimatter particle caught up with its matter counter part what would happen? Would they react as normal and pair up and cancle or would they react differently as the antimatter particle has a different time than its matter counter part, due to the antimatter being in the black hole? for example the matter particle has spent 100 years in our normal time but the antimatter particle has only spent 50, the other 50 lost due to there being a different time in the black hole.:confused: I hope you understand what i mean as i was pretty lost myself writting this.


How does a particle that has been consumed get emitted?

Assuming that it does, How will the same particle ever catch up with its paired one? Why would time delay between creation and anihilation make a difference?
 
Just to add to puzzlement, has anybody read up on un-mavity yet ? Supposed to be a replacement theory for dark matter, very intresting but confusing stuff.
 
When watching the program i thought:So,a pair of particels form, 1 anti matter and 1 matter and usaully pair up then sorta cancle out. But near a black hole the antimatter goes in to the black hole and the matter particle goes off in to space as radiation. At a certain point the black hole can not take any more antimatter and sorta collapses. Also that in a black hole time is changed.

So what i want to know is: Presuming the antimatter particle that went in to the black hole is emitted when the black hole collapses, if the antimatter particle caught up with its matter counter part what would happen? Would they react as normal and pair up and cancle or would they react differently as the antimatter particle has a different time than its matter counter part, due to the antimatter being in the black hole? for example the matter particle has spent 100 years in our normal time but the antimatter particle has only spent 50, the other 50 lost due to there being a different time in the black hole.:confused: I hope you understand what i mean as i was pretty lost myself writting this.
A few points that might clear it up a bit.
1) Either the particle or the antiparticle can be captured by the black hole. On average an equal number of each (excluding cp violation) will be emitted.
2)Any particle in the universe meeting any of the same antiparticle (eg electron meets any positron) will annihilate (ie go to a photon or heavy particle/resonance)
3)The same applies for an antiparticle meeting a particle.

This means that given the liberation of (anti)particles from a black hole (if we allow this), or from anywhere, they will annihilate if they, at any time, meet any instance of their partner particle.

Just to add to puzzlement, has anybody read up on un-mavity yet ? Supposed to be a replacement theory for dark matter, very intresting but confusing stuff.

Einstein postulated the 'lambda' cosmological constant as a 'fudge' for general relativity in order so that his ideal of a steady state universe could be possible in the theory. Though he later called this his greatest mistake, it turns out that there may in fact be a similar destabilizing force acting on cosmological scales, causing the expansion of the universe to accelerate. Modern astronomy has suggested that this 'dark energy' could be attributed to the vacuum energy of space, which comes from the potential of empty space to pair produce. (Same effect as at event horizon!)
This approach hasn't yielded any results even near what we observe yet, but there could be other factors influencing the acceleration that we haven't accounted for yet.
 
Just to add to what Minto said - a black hole doesn't collapse because it can't take anymore mass. When the gravitational attraction forces in a large mass (which act to compress the mass) are greater than the radiation/pressure forces (which act to expel the mass or increase the volume) then the mass collapses into a black hole.
Imagine having a sphere in a steady state. Forces acting outwards and inwards are balanced. Now apply more and more pressure from the outside and eventually you will overcome the forces maintaining its structure and crush it. Similar story with black holes, except that when you do eventually crush it you're going to let go whereas in a black hole, that results in the crushing force becoming even larger so crushing it further making it extremely dense.
 
In positron electron annhilation you wouldn't get nothing. Depending on the energy (how fast they were moving), you could get a few photons (if low energy) or you could create a higher mass particle anti-particle pair (if high energy) with the extra energy leading to the rest mass of the particles. You could even create force particles for the weak force (we call them Z, W- and W+) from an electron positron pair.

Obviously you don’t get nothing, i meant mass. I was assuming a lower understanding of the physics in this thread but it seems to have become quite intellectual
 
Some great info there. Knew OcUK wouldn't let me down :)

I struggle following some of the advanced theoretical stuff but at least I can get my head around what the prog was (badly) describing.
 
Neil out of the series known as the Young Ones sang about this....He called the song "A hole in my shoe" even then it was very radical thinking for him and he seemed to really know what he was talking about, no conjecture whats so eva. Check the lyrics out the similarities are astounding!

neil_holeb.jpg


HOLE IN MY SHOE

Traffic - 1967
Neil -1984


I looked in the sky where an elephant's eye
Was looking at me from a bubblegum tree
And all that I knew was the hole in my shoe
Which was letting in water (letting in water)
(letting in water)

I walked through a field that just wasn't real
With one hundred tin soldiers which stood at my shoulder
And all that I knew was the hole in my shoe
Which was letting in water (letting in water)
(letting in water)

(Narration: I climbed on the back of a giant albatross
What flew through a crack in the cloud
To a place where happiness reigned all year round
And music played ever so loudly)

I started to fall and suddenly woke
And the dew on the grass had soaked through my coat
And all that I knew was the hole in my shoe
Which was letting in water (letting in water)
(letting in water)
 
Last edited:
I always thought hawkins radiation (if that is what the program was referring to) was just x-ray particles that are ever-so-just outside the EH, and zipping around near the speed of light, occasionally collide - sending one flying free, and the other flying into.
 
I always thought hawkins radiation (if that is what the program was referring to) was just x-ray particles that are ever-so-just outside the EH, and zipping around near the speed of light, occasionally collide - sending one flying free, and the other flying into.

Xray's do travel at the speed of light.... They are 'Light' but at a much higher frequency and shorter wavelength
 
Back
Top Bottom