Download Discovering the Nucleus of the Indivisible

DISCOVERING THE NUCLEUS
OF THE INDIVISIBLE
BLUEPRINT FOR

THE LEGACY OF FUNDAMENTAL PHYSICS
Tristan Hübsch
Howard University, Washington DC
University of Central Florida, Orlando FL
& Faculty of Natural Sciences, Novi Sad
http://homepage.mac.com/thubsch/
Monday, November 7, 11
Briefly:
Pan
Rutherford’s discovery
?
x
o
b
s
’
a
r
o
d
First: e– & “plum pudding” model
Test: using !++-rays and Rutherford’s formula
Planetary model of the atoma …and quantum physics
Collision experiments
Nuclei have a structure; consist of nucleons
Nucleons have a structure, consist of quarks
Quarks and leptons have no structure, as best as we know.
So, what now?
Theoretical developments way ahead of experiments
Waiting experiments are not fully complementary
New ideas?
2
Monday, November 7, 11
Pre 1909:
2 ½ millennia ago: Democritus & Leucippus, …
18th–19th century chemists (John Dalton, 1801–1803)…
1897: Joseph J. Thomson discovered:
y
r
o
t
a
r
bo rsity
a
L
h
s
e
i
v
d
i
n
n
e
U
v
Ca
ge
d
i
r
b
at Cam
cathode rays = beams of electrons,
~2 000 times lighter that the lightest atom.
An atom is neutral and of ~1 Å size.
~1 Å
So:
+
e–
e–
≪1Å
e–
e–
e–
3
Monday, November 7, 11
+
e–
e–
m
u
l
“p ing”
d
d
u
p
Pre 1909:
Manchester Litera
ry and Philosophic
(““Lit & P
al S
hil”), where John
ociety
D
alton introduced
atomism a centu
ry earlier…
Ernest Rutherford
Student of J.J. Thomson, but situated in Manchester
Defined #-rays (w/ Paul Villard) 1899–1900,
…proved #-particles to be Helium ions (w/Thomas
Royds, 1907)…
…used these #-particles
(w/Hans Geiger & Ernest
Marsden) to bombard a
gold foil…
…than record and study
the scattering pattern.
4
Monday, November 7, 11
Pre 1909:
Manchester Litera
ry and Philosophic
(““Lit & P
al S
hil”), where John
ociety
D
alton introduced
atomism a centu
ry earlier…
Ernest Rutherford
Student of J.J. Thomson, but situated in Manchester
Defined #-rays (w/ Paul Villard) 1899–1900,
…proved #-particles to be Helium ions (w/Thomas
Royds, 1907)…
…used these #-particles
(w/Hans Geiger & Ernest
Marsden) to bombard a
gold foil…
…than record and study
the scattering pattern.
4
Monday, November 7, 11
1909–1911:
Ernest Rutherford (+ Hans Geiger & Ernest Marsden)
template experiment
mathematical analysis
planetary model
+
e–
e–
e–
e–
}
sma
exp shin
erim g
ents
e–
e–
expected
Monday, November 7, 11
legacy of the
20th century Physics
5
?
observed
1911:
Manchester Literary and
Philosophical Society
110 years after J. Dalton’s indivisible atoms
Rutherford:
d⇧
=
d
2
e /4⇤⇥
2m
0
2
v0
6
Monday, November 7, 11
⇥2
1
4
sin (⌅/2)
400
Intensity
1911:
4
3
300
2
Rutherford:
d⇧
=
d
e2 /4⇤⇥
2m
0
v02
⇥2
1
sin4 (⌅/2)
describes that:
200
1
!
100
150
250
100
Angle
0
50
100
150
vast majority of #-particles
passes unhindered
a few #-particles deflect
a little from their direction
a teeeeee nsy few #-particles
ricochet “straight back”!?!
ee
6
Monday, November 7, 11
200
200
250
300
350
–
–
+
++
–
–
–
–
400
Intensity
1911:
4
3
300
2
Rutherford:
d⇧
=
d
e2 /4⇤⇥
2m
0
v02
⇥2
1
sin4 (⌅/2)
describes that:
200
1
!
100
200
250
100
Angle
0
50
vast majority of #-particles
passes unhindered
a few #-particles deflect
a little from their direction
a teeeeee nsy few #-particles
ricochet “straight back”!?!
ee
6
Monday, November 7, 11
150
100
150
200
250
300
350
Planetary model
–
–
+
+
+
–
–
–
–
1911:
Rutherford’s experiment, analysis & result
Nixed his former advisor’s “plum pudding” model;
proved that the atom (formerly named as indivisible),
…the smallest portion of any element…
…is in fact mostly void;
ushered the planetary model
Planetary model
…where negative electrons…
–
…orbit the positive nucleus…
–
…held by Coulomb’s force,
+
+
just as planets are held by…
+
–
–
…Newton’s force of gravity.
–
–
A remarkable repetition in structure!
7
Monday, November 7, 11
1911:
Rutherford’s planetary model of the atom
also opened Pandora’s box of new questions.
“… the stability of the atom proposed need not be considered
at this stage…” – wrote Rutherford in his 1911 paper
Niels Bohr
May 1911, PhD
Planetary model
6 months with Thomson,
–
March 1912 with Rutherford,
–
…angular momentum is an
+
+
+
integral multiple of …
–
–
Quantum physics (Planck, Einstein,
–
–
Bohr, Compton, Heisenberg, Schrödinger, Dirac, …)
8
Monday, November 7, 11
HOWEVER,
THAT’S NOT ALL, FOLKS!
Conceptual shift in understanding
Legacy in experimenting methods
ections; thank you! — DRAFT
Let me sleep, already!
Monday, November 7, 11
knock
knock
Input signal
Outcome signal
Divisibility & Atom Structure
divisibility implies
(sub)structure:
10
Monday, November 7, 11
Divisibility & Atom Structure
Indivisibility implies not the lack of (sub)structure:
Hydrogen atom:
Not divisible
by chemical
processes!
Not a chemical
process!
p+
e–
p+
Ionization
Recombination
(“all by themselves”)
10
Monday, November 7, 11
Thus, quite
literally, a
Hydrogen atom
is never
really divided.
e–
Nevertheless,
it evidently
does have a
(sub)structure.
Divisibility & the Structure of Matter
Indivisibility implies not the lack of (sub)structure:
Atomic nuclei:
Not divisible by
chemical/atomic
processes.
p+
n0
Nevertheless, there
is a (sub)structure.
Proton, neutron:
Again, there is a
(sub)structure.
Not divisible by
any known process.
(Regardless of the
fact that quarks
cannot, in fact,
be isolated!)
quarks
11
Monday, November 7, 11
[email protected], with any comments / suggestions / corrections;
spring.
At a certain
point,
determined
the spring
elasticity,
the sp
dretched
spring.
At a certain
point,
determined
bydetermined
the by
spring
elasticity,
the spring
of
the stretched
spring.
At
a
certain
point,
by
the
spring
elasticity
of the stretched spring. At a certain point, determined by the spring
reaks.
Analogously,
two particles
(so-called
quarks)
bound
the strong
nuclear
Analogously,
two
particles
(so-called
quarks)
bound quarks)
by the by
strong
nuclear
insimply
breaks.
Analogously,
two
particles
(so-called
bound
by
the
strong
simply breaks. Analogously, two particles (so-called quarks) bound by t
nbe
may
be separated
tolarder
ever larder
distances—only
by incessant
investing
ever m
separated
tobeever
distances—only
by incessant
investing
ever more
teraction
may
separated
to
ever
larder
distances—only
by
incessant
investin
teraction may be separated to ever larder distances—only by incessant
This be
could
becould
doable
arbitrarily
long,
and
the
two the
quarks
could
becould
separated
a
ould
doable
arbitrarily
long,arbitrarily
and
the
two
quarks
could
be
separated
arbienergy.
This
be
doable
long,
and
two
quarks
be
sep
energy. This could be doable arbitrarily long, and the two quarks coul
fromother,
each
other,
it not
the
fact
that
the that
invested
work sooner
l
mar
each
were
itwere
not
for
thefor
fact
that
the
invested
work
sooner
orwork
lateror
trarily
far
from
each
other,
were
it
not
for
the
fact
the
invested
soo
trarily far from each other, were it not for the fact that the invested w
sufficient
to create
acreate
particle-antiparticle
pair. one
Each
of newly
these
newly
min
ient
to create
a particle-antiparticle
pair. Each
ofone
these
minted
Indivisibility
implies
not
becomes
sufficient
to
a
particle-antiparticle
pair.
Each
one
of
these
ne
becomes sufficient to create a particle-antiparticle pair. Each one of
thenwith
binds
with
of the
“old”
ones,
so
that
the
attempt
to separate
two quark
binds
one
of one
thewith
“old”
ones,
so
that
the
attempt
to the
separate
twotoquarks
to tw
particles
then
binds
one
of
the
“old”
ones,
so
that
attempt
separate
Qualitatively,
particles
then
binds with one of the “old” ones, so that the attempt to se
the
lack
of15(sub)structure:
15
15 instead
sr bigger
⇠m
10
minstead
fails:
of
having
separated
one
quark
from
thefro
ot
than ⇠than
10
fails:⇠
offails:
having
separated
one quark
from
the
other,
just
like
15
distances
bigger
than
10
m
instead
of
having
separated
one
quark
distances bigger than ⇠ 10
m fails: instead of having separated one q
k we
werewe
trying
totrying
movetobecomes
bound
with
thewith
newly
minted
antiquark,
were
trying
to were
move
becomes
bound
with the
newly
minted
antiquark,
andant
Protons,
neutrons,
hadrons:
springs
the
quark
move
becomes
bound
the
newly
minted
the quark we were trying to move becomes bound with the newly mi
ruark
oldother
quark
is quark
joined
the newly
minted
quark
replacing
the
oldThis
one.
This
qu
is
joined
by theisby
newly
minted
quark
replacing
the old
one.
quarkstrings
the
old
joined
by
the
newly
minted
quark
replacing
the
old
one.
thebound
other old
quark
joined by the newly minted quark replacing the
states
of is
(anti)quarks,
k pair aforms
a
new
system
(so-called
meson)
that
really
be separated
arbitra
forms
new
system
(so-called
meson)
that really
can
be can
separated
arbitrarily
antiquark
pair
forms
a
new
system
(so-called
meson)
that
really
can
be
separate
antiquark pair forms a new system (so-called meson) that
really can be
dist.
…which
cannot
be
observed
he original
quarks
un-extracted
[+ –1.5].
figure
–1.5].
ginal
quarks
remainremain
un-extracted
[+
figure
far,
but
the
original
quarks
remain
un-extracted
[+
figure[+
–1.5].
far, but the original quarks remain un-extracted
figure –1.5].
Potential Energy
Divisibility & the Structure of Matter
as sufficiently isolated particles.
No
qu free
ark
s
(so as to be handled regardless of the rest)
–1.5: Inseparability
ofInseparability
quarks
and antiquarks
investing
everbymore
Figure
–1.5:
Inseparability
of quarks
and
antiquarks
by investing
everenergy
moreever
energy
12 by
Figure
–1.5:
of
quarks
and
antiquarks
investing
moreever
en
Figure –1.5: Inseparability of quarks and antiquarks by investing
Monday, November 7, 11
Divisibility & the Structure of Matter
Indivisibility implies not the lack of (sub)structure:
But, why can we separate e– and p+, but not quarks?
Binding energy of H-atom = 13.6 eV.
Rest energy of e– = 510,999 eV.
En = – ½ !e2 m c2
#e = ⅟&'(
Ratio ≈ 0.000 0266 ≈ 1/37,573.
On the other hand,
Rest energy of u,d quarks = 1–6 MeV.
Binding energy in (u,d)-mesons is at least as big!
Ratio ≥1!!!
#s ~1
13
Monday, November 7, 11
Divisibility & the Structure of Matter
1
1
Fundamental physics of elementary particles…20
Table 0.3: The content of the Standard Model of elementary particle physics; see (0.46a)
Substance
Gen.
1.
2.
3.
Leptons
ne
nµ
nt
Interactions
(spin-1/2 fermions)
e
µ
t
Quarks
u
c
t
d
s
b
onelectromagnetico
g
interaction
±
0
W ,Z
weak nuclear
gluons
strong nuclear interaction
dgµn
gravitation
(bosons)
(spin-1)
(spin-1)
(spin-2)
Higgs boson (spin-0): gives mass to the particles with which it interacts
…describes all tangible matter
and all its fundamental interactions
…in agreement with all experiments ever performed
to date. (Except that the Higgs particle is still sought for…)
(And, perhaps… just very, very perhaps, the impish neutrinos of the recent fervor…)
14
Monday, November 7, 11
…& experiments
PP
E
f
o
st
o
m
r
o
ts
f
n
e
e
t
m
a
i
l
er
p
x
e
Temp
y
ur
t
n
e
c
20t h
Rutherford-esque colliding processes!
15
Monday, November 7, 11
…& experiments
PP
E
f
o
st
o
m
r
o
ts
f
n
e
e
t
m
a
i
l
er
p
x
e
Temp
y
ur
t
n
e
c
20t h
Rutherford-esque colliding processes!
human!
15
Monday, November 7, 11
…& experiments
PP
E
f
o
st
o
m
r
o
ts
f
n
e
e
t
m
a
i
l
er
p
x
e
Temp
y
ur
t
n
e
c
20t h
Rutherford-esque colliding processes!
15
Monday, November 7, 11
…& experiments
PP
E
f
o
st
o
m
r
o
ts
f
n
e
e
t
m
a
i
l
er
p
x
e
Temp
y
ur
t
n
e
c
20t h
Rutherford-esque colliding processes!
•CERN is a
•multi-national
•multi-cultural
•multi-social
•multi-political
•multi-financed
•complex structure
•Really, really, really
•…expensive.
•& Foreordained.
You can’t turn
CERN on a dime!
15
Monday, November 7, 11
…& experiments
And then there are the “waiting experiments”
Deck out an abandoned mine with detectors…
…fill it with water (the price is right)…
…and wait.
The more time passes without registering an event,
the smaller the probability for the event to happen at all.
Typically, not as complex/political/expensive/BIG
as the smashing experiments…
…but, they tend to produce “limits from one side,”
…and they too are carefully planned/designed.
16
Monday, November 7, 11
…& experiments
You cannot plan/design for “accidental discoveries”
Thales noticed that amber (ήλεκτρον) attracts lint…
Alessandro Volta poked frog legs with various wires…
Hans Christian Ørsted saw the magnetic needle turn…
Henry Becquerel noticed materials to affect photo-plates…
…and there’s nothing accidental about multi-complex
experimentation as is being done nowadays.
Needed: a radically new type of experiment
complementary to “waiting experiments”
more maneuverable than CERN, SLAC, FNAL, …
A world of new discovery left to the Young!
17
Monday, November 7, 11
Don't Panic !
THANKS!
See you, if virtually, at:
http://homepage.mac.com/thubsch/
Monday, November 7, 11