One For The People Of Northern Ireland
ChatterBank2 mins ago
Sub-atomic particles
If an atom comprises mostly of space, then it follows that our bodies, constructed of atoms, are not solid and are mostly made up of space too. If the particles within the atoms were somehow combined, what would be their total volume ? I have read somewhere 'about the size of a pinhead'! Is this true? If not, what would the combined volume be ? and would it weigh as much as we do ?
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Well the only place that this "empty space" has actually been remove is in a neutron star.
My favourite statistic on this is that a teaspoon of such material would weigh more than 100 million elephants.
Working back from this I would imagine that making the atoms in your body that dense would move you much smaller than a pinhead.
Would you weigh the same - now that's a much trickier question.
It rather depends on how this mythical transformation is supposed to have occured.
In such a situation the strong nuclear force becomes important and there are interactions between the nucleons. A large nucleus like Uranium has more matter than the sum of it's parts. It is this matter that is converted to energy when it splits.
So there might be some variation depending on whether there was any binding energy involved in this transformation
My favourite statistic on this is that a teaspoon of such material would weigh more than 100 million elephants.
Working back from this I would imagine that making the atoms in your body that dense would move you much smaller than a pinhead.
Would you weigh the same - now that's a much trickier question.
It rather depends on how this mythical transformation is supposed to have occured.
In such a situation the strong nuclear force becomes important and there are interactions between the nucleons. A large nucleus like Uranium has more matter than the sum of it's parts. It is this matter that is converted to energy when it splits.
So there might be some variation depending on whether there was any binding energy involved in this transformation
I’ve done some quick calculations and I’m sure someone will point out if I’ve gone wrong anywhere.
I believe the radius of a typical atom here on earth is about 100,000 times that of the nucleus. This means the volume of the entire atom (including the empty space) is very roughly 4 million billion (four followed by fifteen noughts) times the volume of the “solid” bits.
A 75kg (12 stone) man has a volume of about 80 litres 80,000cc, or 80 million cubic millimetres. Using the ratio above, if all the space in his atoms were eliminated I calculate that about 50 million of him would occupy a space slightly less than one cubic millimetre! Or put another way, the entire population of the UK would fit into a cube of one millimetre.
It’s very rough and ready but I think it is correct. And it’s astounding!
I believe the radius of a typical atom here on earth is about 100,000 times that of the nucleus. This means the volume of the entire atom (including the empty space) is very roughly 4 million billion (four followed by fifteen noughts) times the volume of the “solid” bits.
A 75kg (12 stone) man has a volume of about 80 litres 80,000cc, or 80 million cubic millimetres. Using the ratio above, if all the space in his atoms were eliminated I calculate that about 50 million of him would occupy a space slightly less than one cubic millimetre! Or put another way, the entire population of the UK would fit into a cube of one millimetre.
It’s very rough and ready but I think it is correct. And it’s astounding!
That really is astounding Judge! Furthermore some skeptics say these Higgs Bosun guys are up the creek, and particles have no substance other than 'waves' , If this is so, and it probably isn't (?), then matter has no real substance at all. To cap it all, the main protagonists in this week's BBC 'Horizon' program claimed that all reality is a hologram ! This is all 'doin' me hed in'.
Thanks NJ didn't have time to do the calculaton but though a pin head sounded too big!
No Knahdro the wave thing is pretty solid science infact some of the electronics in your computer rely on it. - it's not really in conflict with the Higgs idea.
This is quite a long, but fascinating story. It started with a punchup between Newton and Huygens - Newton could start a fight in an empty room - so no surprise there!) as to whether light was a wave or a particle. Then it really got interesting with the discovery of the electron about 100 years ago. Electrons behaved as if they were little billard balls in some experiments but also as if they were waves in others - very confusing.
People had got their heads around light by then - little wave packets acting as particles, photons they had momentum (despite having no mass) but of course they could form interference patterns as if waves.
Then a French physicist Louis de Broglie (strangely from French aristocracy - he's the only Noble Nobel I know) said that if waves can act like particles particles can be waves.
This is known as wave particle duality it's well established and used in a number of applications not least electron microscopes.
No Knahdro the wave thing is pretty solid science infact some of the electronics in your computer rely on it. - it's not really in conflict with the Higgs idea.
This is quite a long, but fascinating story. It started with a punchup between Newton and Huygens - Newton could start a fight in an empty room - so no surprise there!) as to whether light was a wave or a particle. Then it really got interesting with the discovery of the electron about 100 years ago. Electrons behaved as if they were little billard balls in some experiments but also as if they were waves in others - very confusing.
People had got their heads around light by then - little wave packets acting as particles, photons they had momentum (despite having no mass) but of course they could form interference patterns as if waves.
Then a French physicist Louis de Broglie (strangely from French aristocracy - he's the only Noble Nobel I know) said that if waves can act like particles particles can be waves.
This is known as wave particle duality it's well established and used in a number of applications not least electron microscopes.
Thanks Jake, - you really know your stuff! Deviating just slightly from what you say I have just finished reading a biography of Leonardo. Everyone has thrown a stone into a pond and watched the ripples spread out across the surface, but he seems to have been the first (including the Greeks and Romans) to have thrown 2 stones simultaneously and some distance apart, observing the effect, - which is indescribably beautiful. What is happening here? Please go figure!
What is happening here is the classic intereference pattern.
Where one wave is reinforced by another you get 2 wave peaks making a double height one and where a peak meets a trough they cancel each other out.
You can do it with light or electrons passing them through slits that are close together and you gata pattern like this:
http://www.mtbaker.we...ectronIntPattern2.gif
It's the classic demonstration of electrons behaving like waves
Where one wave is reinforced by another you get 2 wave peaks making a double height one and where a peak meets a trough they cancel each other out.
You can do it with light or electrons passing them through slits that are close together and you gata pattern like this:
http://www.mtbaker.we...ectronIntPattern2.gif
It's the classic demonstration of electrons behaving like waves
Well I guess it would be less as there would be binding energy involved that would need to come from somewhere.
However it's a bit of a moot point because nucleii over a few hundred aren't stable so you're condensed person wouldn't be stable either.
Lets put it this way - if you took some hydrogen nucleii from a person and started sticking them together to make a bigger and bigger "nucleus" at first you'd get energy out until you got to about 56. Then you'd have to find more and more energy to stick them together which presumably you'd have to supply by changing more of that matter to energy. Eventually it would all keep falling apart
However it's a bit of a moot point because nucleii over a few hundred aren't stable so you're condensed person wouldn't be stable either.
Lets put it this way - if you took some hydrogen nucleii from a person and started sticking them together to make a bigger and bigger "nucleus" at first you'd get energy out until you got to about 56. Then you'd have to find more and more energy to stick them together which presumably you'd have to supply by changing more of that matter to energy. Eventually it would all keep falling apart
That's the "missing mass" problem - dark matter
If you add up the amount of matter we can see it doesn't come close to the amount of gravity that we can account for.
It's been a problem for at least 30 years but slowly some of the suspects are coming out of the shadows:
Seems likely there are several answers to this. Firstly it was discoverred that at the rate galaxies were rotating stars ought to be flying out of them - there wasn't enough gravity from what we could see to hold them together.
We now know that at the heart of spiral galaxies are super massive black holes - and when I say super massive I'm not kidding! We're talking up to a billion times the mass of the sun!
But even these are not enough
Three possible candidates Machos, neutrinos and Wimps
Machos are Massive astrophisical compact halo objects - these are things like dead stars that have run out of fuel so we don't see them. we know such things exist and make a contribution to this but it doesn't look as if it's enough.
Neutinos are massless particles that interact so slightly with matter that they could travel through a light year of lead without noticing - It was thought though that perhaps they did have some mass perhaps so little that nobody had yet measured it.
Would that make a difference? - perhaps there are a lot of neutrinos! - every photon from every star produces one!
Not the space here to go into the details but it was recently shown that yes they must have mass just too little for us to be able to measure it. Until we can measure it we don't know if they are the answer.
Finally WIMP or weakly interacting massive particles. Theoretical undiscoverred particles rather like neutrinos but as yet undiscovered.
Although as yet undiscoverred, if the Higgs particle is discoverred and has certain properties it would indicate that the
If you add up the amount of matter we can see it doesn't come close to the amount of gravity that we can account for.
It's been a problem for at least 30 years but slowly some of the suspects are coming out of the shadows:
Seems likely there are several answers to this. Firstly it was discoverred that at the rate galaxies were rotating stars ought to be flying out of them - there wasn't enough gravity from what we could see to hold them together.
We now know that at the heart of spiral galaxies are super massive black holes - and when I say super massive I'm not kidding! We're talking up to a billion times the mass of the sun!
But even these are not enough
Three possible candidates Machos, neutrinos and Wimps
Machos are Massive astrophisical compact halo objects - these are things like dead stars that have run out of fuel so we don't see them. we know such things exist and make a contribution to this but it doesn't look as if it's enough.
Neutinos are massless particles that interact so slightly with matter that they could travel through a light year of lead without noticing - It was thought though that perhaps they did have some mass perhaps so little that nobody had yet measured it.
Would that make a difference? - perhaps there are a lot of neutrinos! - every photon from every star produces one!
Not the space here to go into the details but it was recently shown that yes they must have mass just too little for us to be able to measure it. Until we can measure it we don't know if they are the answer.
Finally WIMP or weakly interacting massive particles. Theoretical undiscoverred particles rather like neutrinos but as yet undiscovered.
Although as yet undiscoverred, if the Higgs particle is discoverred and has certain properties it would indicate that the
It doesn't really work like that - you're still thinking billiard balls.
When two particles come close to each other there is a probability of their interaction depending on how close they come.
These are fundamental particles. a neutrino is a point - no size that we can determine. sampe goes for the quarks that make up nucleons
Neutinos have a very very small probability of interaction (this is what is meant by weakly interacting in Wimps).
Your typical neutrino "telescope" is a swimming pool in a mine deep underground totally lined with detectors.
http://en.wikipedia.org/wiki/Super-Kamiokande
Though some now use Ice at the South pole or are using the Sea off of France
With all the neutrinos flooding out of the sun you may get only a few hundred detections a day.
When two particles come close to each other there is a probability of their interaction depending on how close they come.
These are fundamental particles. a neutrino is a point - no size that we can determine. sampe goes for the quarks that make up nucleons
Neutinos have a very very small probability of interaction (this is what is meant by weakly interacting in Wimps).
Your typical neutrino "telescope" is a swimming pool in a mine deep underground totally lined with detectors.
http://en.wikipedia.org/wiki/Super-Kamiokande
Though some now use Ice at the South pole or are using the Sea off of France
With all the neutrinos flooding out of the sun you may get only a few hundred detections a day.
If all space between the constituents of all the atoms in every human being being alive today were to be removed, we would all "theoretically" fit inside a matchbox. However you wouldn't be able to see the matchbox as it would be safely tucked away inside an event horizon surrounding the mass of the matchbox's contents.
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