(ROOT (S (NP (NP (DT The) (NN majority)) (PP (IN of) (NP (NNS physicists)))) (ADVP (RB once)) (VP (VBD believed) (SBAR (IN that) (S (NP (NP (DT the) (NN universe) (POS 's)) (NN expansion)) (VP (VBD was) (VP (VBG slowing) (PRT (RP down))))))) (. .)))
The majority of physicists once believed that the universe's expansion was slowing down.
det
Definite=Def|PronType=Art
the
The
DET
DT
nsubj
Number=Sing
majority
majority
NOUN
NN
case
of
of
ADP
IN
nmod
Number=Plur
physicist
physicists
NOUN
NNS
advmod
NumType=Mult
once
once
ADV
RB
root
Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin
believe
believed
VERB
VBD
mark
that
that
SCONJ
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
nmod:poss
Number=Sing
universe
universe
NOUN
NN
case
's
's
PART
POS
nsubj
Number=Sing
expansion
expansion
NOUN
NN
aux
Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin
be
was
AUX
VBD
ccomp
Tense=Pres|VerbForm=Part
slowing
slowing
VERB
VBG
compound:prt
down
down
ADP
RP
punct
.
.
PUNCT
.
(ROOT (S (PP (IN In) (NP (CD 1998))) (, ,) (NP (PRP they)) (VP (VBD were) (ADJP (VBN proven) (S (ADJP (RB completely) (JJ wrong))))) (. .)))
In 1998, they were proven completely wrong.
case
in
In
ADP
IN
obl
NumForm=Digit|NumType=Card
1998
1998
NUM
CD
punct
,
,
PUNCT
,
nsubj:pass
Case=Nom|Number=Plur|Person=3|PronType=Prs
they
they
PRON
PRP
aux:pass
Mood=Ind|Number=Plur|Person=3|Tense=Past|VerbForm=Fin
be
were
AUX
VBD
root
Tense=Past|VerbForm=Part|Voice=Pass
prove
proven
VERB
VBN
advmod
completely
completely
ADV
RB
xcomp
Degree=Pos
wrong
wrong
ADJ
JJ
punct
.
.
PUNCT
.
(ROOT (S (SBAR (IN Though) (S (NP (PRP it)) (VP (VBZ flies) (PP (IN in) (NP (NP (DT the) (NN face)) (PP (IN of) (NP (JJ scientific) (NN theory)))))))) (, ,) (NP (DT the) (NN universe)) (VP (VBZ is) (VP (VBG expanding) (PP (IN at) (NP (DT an) (JJ ever-increasing) (NN rate))))) (. .)))
Though it flies in the face of scientific theory, the universe is expanding at an ever-increasing rate.
mark
though
Though
SCONJ
IN
nsubj
Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
it
PRON
PRP
advcl
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
fly
flies
VERB
VBZ
case
in
in
ADP
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
obl
Number=Sing
face
face
NOUN
NN
case
of
of
ADP
IN
amod
Degree=Pos
scientific
scientific
ADJ
JJ
nmod
Number=Sing
theory
theory
NOUN
NN
punct
,
,
PUNCT
,
det
Definite=Def|PronType=Art
the
the
DET
DT
nsubj
Number=Sing
universe
universe
NOUN
NN
aux
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
root
Tense=Pres|VerbForm=Part
expand
expanding
VERB
VBG
case
at
at
ADP
IN
det
Definite=Ind|PronType=Art
a
an
DET
DT
amod
Degree=Pos
ever-increasing
ever-increasing
ADJ
JJ
obl
Number=Sing
rate
rate
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (NFP  ))
root
PUNCT
NFP
(ROOT (S (NP (CD One) (JJ possible) (NN explanation)) (VP (VBZ is) (SBAR (IN that) (S (NP (JJ empty) (NN space)) (VP (VBZ has) (NP (NP (NP (DT a) (NN thing)) (VP (VBN called) (S (NP (JJ dark) (NN energy))))) (, ,) (SBAR (WHNP (WDT which)) (S (ADVP (RB supposedly)) (VP (VBZ makes) (PRT (RP up)) (NP (NP (QP (RB about) (CD three)) (NNS quarters)) (PP (IN of) (NP (DT the) (NN universe)))))))))))) (. .)))
One possible explanation is that empty space has a thing called dark energy, which supposedly makes up about three quarters of the universe.
nummod
NumForm=Word|NumType=Card
one
One
NUM
CD
amod
Degree=Pos
possible
possible
ADJ
JJ
nsubj:outer
Number=Sing
explanation
explanation
NOUN
NN
cop
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
mark
that
that
SCONJ
IN
amod
Degree=Pos
empty
empty
ADJ
JJ
nsubj
Number=Sing
space
space
NOUN
NN
root
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
have
has
VERB
VBZ
det
Definite=Ind|PronType=Art
a
a
DET
DT
obj
Number=Sing
thing
thing
NOUN
NN
acl
Tense=Past|VerbForm=Part
call
called
VERB
VBN
amod
Degree=Pos
dark
dark
ADJ
JJ
xcomp
Number=Sing
energy
energy
NOUN
NN
punct
,
,
PUNCT
,
nsubj
PronType=Rel
which
which
PRON
WDT
advmod
supposedly
supposedly
ADV
RB
acl:relcl
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
make
makes
VERB
VBZ
compound:prt
up
up
ADP
RP
advmod
about
about
ADV
RB
nummod
NumForm=Word|NumType=Card
three
three
NUM
CD
obj
NumForm=Word|NumType=Frac|Number=Plur
quarter
quarters
NOUN
NNS
case
of
of
ADP
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
nmod
Number=Sing
universe
universe
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (NP (JJ Dark) (NN energy)) (ADVP (RB supposedly)) (ADVP (RB very) (RB sparsely)) (VP (VBZ exists) (PP (IN in) (NP (NP (PDT such) (DT a) (NN way)) (SBAR (IN that) (S (NP (PRP it)) (VP (VBZ interacts) (PP (IN with) (NP (JJ other) (NNS objects))) (PP (ADVP (RB only)) (IN through) (S (VP (VBG attracting) (NP (NN force))))))))))) (. .)))
Dark energy supposedly very sparsely exists in such a way that it interacts with other objects only through attracting force.
amod
Degree=Pos
Dark
Dark
ADJ
JJ
nsubj
Number=Sing
energy
energy
NOUN
NN
advmod
supposedly
supposedly
ADV
RB
advmod
very
very
ADV
RB
advmod
sparsely
sparsely
ADV
RB
root
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
exist
exists
VERB
VBZ
case
in
in
ADP
IN
det:predet
such
such
DET
PDT
det
Definite=Ind|PronType=Art
a
a
DET
DT
obl
Number=Sing
way
way
NOUN
NN
mark
that
that
SCONJ
IN
nsubj
Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
it
PRON
PRP
acl
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
interact
interacts
VERB
VBZ
case
with
with
ADP
IN
amod
Degree=Pos
other
other
ADJ
JJ
obl
Number=Plur
object
objects
NOUN
NNS
advmod
only
only
ADV
RB
mark
through
through
SCONJ
IN
advcl
VerbForm=Ger
attract
attracting
VERB
VBG
obj
Number=Sing
force
force
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (NP (PRP It)) (VP (VBZ has) (NP (NP (DT a) (JJ strong) (JJ negative) (NN pressure)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ causes) (S (NP (PRP it)) (VP (TO to) (VP (VP (VB pull) (PRT (IN on)) (NP (PRP$ its) (NNS surroundings))) (CC and) (VP (PP (IN as) (NP (DT a) (NN result))) (, ,) (VB pull) (PRT (RB apart)) (NP (DT the) (NN universe))))))))))) (. .)))
It has a strong negative pressure, which causes it to pull on its surroundings and as a result, pull apart the universe.
nsubj
Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
It
PRON
PRP
root
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
have
has
VERB
VBZ
det
Definite=Ind|PronType=Art
a
a
DET
DT
amod
Degree=Pos
strong
strong
ADJ
JJ
amod
Degree=Pos
negative
negative
ADJ
JJ
obj
Number=Sing
pressure
pressure
NOUN
NN
punct
,
,
PUNCT
,
nsubj
PronType=Rel
which
which
PRON
WDT
acl:relcl
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
cause
causes
VERB
VBZ
obj
Case=Acc|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
it
PRON
PRP
mark
to
to
PART
TO
xcomp
VerbForm=Inf
pull
pull
VERB
VB
compound:prt
on
on
ADP
IN
nmod:poss
Case=Gen|Gender=Neut|Number=Sing|Person=3|Poss=Yes|PronType=Prs
its
its
PRON
PRP$
obj
Number=Plur
surroundings
surroundings
NOUN
NNS
cc
and
and
CCONJ
CC
case
as
as
ADP
IN
det
Definite=Ind|PronType=Art
a
a
DET
DT
obl
Number=Sing
result
result
NOUN
NN
punct
,
,
PUNCT
,
conj
VerbForm=Inf
pull
pull
VERB
VB
compound:prt
apart
apart
ADV
RB
det
Definite=Def|PronType=Art
the
the
DET
DT
obj
Number=Sing
universe
universe
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (NP (DT This)) (ADVP (RB neatly)) (VP (VBZ explains) (NP (NP (DT the) (NN universe) (POS 's)) (NN expansion)) (PP (IN without) (S (ADVP (RB completely)) (VP (VBG changing) (NP (NP (PRP$ our) (NN understanding)) (PP (IN of) (NP (DT the) (NN universe)))))))) (. .)))
This neatly explains the universe's expansion without completely changing our understanding of the universe.
nsubj
Number=Sing|PronType=Dem
this
This
PRON
DT
advmod
neatly
neatly
ADV
RB
root
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
explain
explains
VERB
VBZ
det
Definite=Def|PronType=Art
the
the
DET
DT
nmod:poss
Number=Sing
universe
universe
NOUN
NN
case
's
's
PART
POS
obj
Number=Sing
expansion
expansion
NOUN
NN
mark
without
without
SCONJ
IN
advmod
completely
completely
ADV
RB
advcl
VerbForm=Ger
change
changing
VERB
VBG
nmod:poss
Case=Gen|Number=Plur|Person=1|Poss=Yes|PronType=Prs
our
our
PRON
PRP$
obj
Number=Sing
understanding
understanding
NOUN
NN
case
of
of
ADP
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
nmod
Number=Sing
universe
universe
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (NP (NNS Scientists)) (VP (MD can) (ADVP (RB merely)) (VP (VB claim) (SBAR (IN that) (S (NP (JJ dark) (NN energy)) (`` ``) (VP (MD should) (`` '') (VP (VB exist))))))) (. .)))
Scientists can merely claim that dark energy "should" exist.
nsubj
Number=Plur
scientist
Scientists
NOUN
NNS
aux
VerbForm=Fin
can
can
AUX
MD
advmod
merely
merely
ADV
RB
root
VerbForm=Inf
claim
claim
VERB
VB
mark
that
that
SCONJ
IN
amod
Degree=Pos
dark
dark
ADJ
JJ
nsubj
Number=Sing
energy
energy
NOUN
NN
punct
``
``
PUNCT
``
aux
VerbForm=Fin
should
should
AUX
MD
punct
''
''
PUNCT
``
ccomp
VerbForm=Inf
exist
exist
VERB
VB
punct
.
.
PUNCT
.
(ROOT (NFP  ))
root
PUNCT
NFP
(ROOT (S (PP (VBG According) (PP (IN to) (NP (NP (NP (NNP Einstein) (POS 's)) (NN theory)) (PP (IN of) (NP (NN relativity)))))) (, ,) (NP (NP (PRP it))) (VP (VBZ is) (ADJP (JJ impossible)) (S (VP (TO to) (VP (VB travel) (ADVP (ADVP (JJR faster)) (PP (IN than) (PP (IN at) (NP (NP (DT the) (NN speed)) (PP (IN of) (NP (NN light))))))))))) (. .)))
According to Einstein's theory of relativity, it is impossible to travel faster than at the speed of light.
case
ExtPos=ADP|VerbForm=Ger
accord
According
VERB
VBG
fixed
to
to
ADP
IN
nmod:poss
Number=Sing
Einstein
Einstein
PROPN
NNP
case
's
's
PART
POS
obl
Number=Sing
theory
theory
NOUN
NN
case
of
of
ADP
IN
nmod
Number=Sing
relativity
relativity
NOUN
NN
punct
,
,
PUNCT
,
expl
Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
it
PRON
PRP
cop
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
be
is
AUX
VBZ
root
Degree=Pos
impossible
impossible
ADJ
JJ
mark
to
to
PART
TO
csubj
VerbForm=Inf
travel
travel
VERB
VB
advmod
Degree=Cmp
fast
faster
ADJ
JJR
case
than
than
ADP
IN
case
at
at
ADP
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
obl
Number=Sing
speed
speed
NOUN
NN
case
of
of
ADP
IN
nmod
Number=Sing
light
light
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (NFP  ))
root
PUNCT
NFP
(ROOT (S (SBAR (IN With) (S (NP (DT this)) (PP (IN in) (NP (NN mind))))) (, ,) (NP (NNS physicists)) (VP (VP (VBD set) (PRT (RP out)) (S (VP (TO to) (VP (VB do) (NP (DT the) (JJ impossible)))))) (CC and) (VP (VBD succeeded))) (. .)))
With this in mind, physicists set out to do the impossible and succeeded.
case
with
With
ADP
IN
nsubj
Number=Sing|PronType=Dem
this
this
PRON
DT
case
in
in
ADP
IN
advcl
Number=Sing
mind
mind
NOUN
NN
punct
,
,
PUNCT
,
nsubj
Number=Plur
physicist
physicists
NOUN
NNS
root
Mood=Ind|Number=Plur|Person=3|Tense=Past|VerbForm=Fin
set
set
VERB
VBD
compound:prt
out
out
ADP
RP
mark
to
to
PART
TO
xcomp
VerbForm=Inf
do
do
VERB
VB
det
Definite=Def|PronType=Art
the
the
DET
DT
obj
Degree=Pos
impossible
impossible
ADJ
JJ
cc
and
and
CCONJ
CC
conj
Mood=Ind|Number=Plur|Person=3|Tense=Past|VerbForm=Fin
succeed
succeeded
VERB
VBD
punct
.
.
PUNCT
.
(ROOT (S (PP (IN In) (NP (CD 2000))) (, ,) (NP (NP (NNS scientists)) (PP (IN in) (NP (NP (NNP Princeton)) (, ,) (NP (NNP New) (NNP Jersey))))) (VP (VBD sent) (NP (NP (DT a) (JJ small) (NN pulse)) (PP (IN of) (NP (NN laser) (NN light)))) (PP (IN through) (NP (NP (DT a) (NN vapor)) (VP (VBN made) (PRT (RP up)) (PP (IN of) (NP (JJ gaseous) (NN cesium))))))) (. .)))
In 2000, scientists in Princeton, New Jersey sent a small pulse of laser light through a vapor made up of gaseous cesium.
case
in
In
ADP
IN
obl
NumForm=Digit|NumType=Card
2000
2000
NUM
CD
punct
,
,
PUNCT
,
nsubj
Number=Plur
scientist
scientists
NOUN
NNS
case
in
in
ADP
IN
nmod
Number=Sing
Princeton
Princeton
PROPN
NNP
punct
,
,
PUNCT
,
appos
Degree=Pos
New
New
ADJ
NNP
flat
Number=Sing
Jersey
Jersey
PROPN
NNP
root
Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin
send
sent
VERB
VBD
det
Definite=Ind|PronType=Art
a
a
DET
DT
amod
Degree=Pos
small
small
ADJ
JJ
obj
Number=Sing
pulse
pulse
NOUN
NN
case
of
of
ADP
IN
compound
Number=Sing
laser
laser
NOUN
NN
nmod
Number=Sing
light
light
NOUN
NN
case
through
through
ADP
IN
det
Definite=Ind|PronType=Art
a
a
DET
DT
obl
Number=Sing
vapor
vapor
NOUN
NN
acl
Tense=Past|VerbForm=Part
make
made
VERB
VBN
compound:prt
up
up
ADP
RP
case
of
of
ADP
IN
amod
Degree=Pos
gaseous
gaseous
ADJ
JJ
obl
Number=Sing
cesium
cesium
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (NP (DT The) (NN pulse)) (VP (VBD traveled) (ADVP (ADVP (RB so) (RB quickly)) (SBAR (IN that) (S (NP (PRP it)) (VP (VBD was) (ADVP (RB already)) (VP (VBG leaving) (NP (DT the) (JJ vapor-filled) (NN chamber)) (SBAR (IN as) (S (NP (PRP it)) (VP (VBD was) (ADVP (RB still)) (VP (VBG entering) (, ,) (ADVP (ADJP (QP (RB roughly) (CD 300) (NNS times)) (JJR faster)) (SBAR (IN than) (S (NP (PRP it)) (VP (MD would) (VP (VB have) (PP (IN in) (NP (DT a) (NN vacuum)))))))))))))))))) (. .)))
The pulse traveled so quickly that it was already leaving the vapor-filled chamber as it was still entering, roughly 300 times faster than it would have in a vacuum.
det
Definite=Def|PronType=Art
the
The
DET
DT
nsubj
Number=Sing
pulse
pulse
NOUN
NN
root
Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin
travel
traveled
VERB
VBD
advmod
so
so
ADV
RB
advmod
quickly
quickly
ADV
RB
mark
that
that
SCONJ
IN
nsubj
Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
it
PRON
PRP
aux
Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin
be
was
AUX
VBD
advmod
already
already
ADV
RB
ccomp
Tense=Pres|VerbForm=Part
leave
leaving
VERB
VBG
det
Definite=Def|PronType=Art
the
the
DET
DT
amod
Degree=Pos
vapor-filled
vapor-filled
ADJ
JJ
obj
Number=Sing
chamber
chamber
NOUN
NN
mark
as
as
SCONJ
IN
nsubj
Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
it
PRON
PRP
aux
Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin
be
was
AUX
VBD
advmod
still
still
ADV
RB
advcl
Tense=Pres|VerbForm=Part
enter
entering
VERB
VBG
punct
,
,
PUNCT
,
advmod
Degree=Pos
roughly
roughly
ADV
RB
nummod
NumForm=Digit|NumType=Card
300
300
NUM
CD
obl:npmod
Number=Plur
time
times
NOUN
NNS
advmod
Degree=Cmp
fast
faster
ADJ
JJR
mark
than
than
SCONJ
IN
nsubj
Case=Nom|Gender=Neut|Number=Sing|Person=3|PronType=Prs
it
it
PRON
PRP
aux
VerbForm=Fin
would
would
AUX
MD
advcl
VerbForm=Inf
have
have
VERB
VB
case
in
in
ADP
IN
det
Definite=Ind|PronType=Art
a
a
DET
DT
obl
Number=Sing
vacuum
vacuum
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (S (ADVP (RB Thus)) (, ,) (NP (NN light)) (VP (VBD moved) (ADVP (ADVP (JJR faster)) (PP (IN than) (NP (NP (DT the) (NN speed)) (PP (IN of) (NP (NN light))))))) (. .)))
Thus, light moved faster than the speed of light.
advmod
thus
Thus
ADV
RB
punct
,
,
PUNCT
,
nsubj
Number=Sing
light
light
NOUN
NN
root
Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin
move
moved
VERB
VBD
advmod
Degree=Cmp
fast
faster
ADJ
JJR
case
than
than
ADP
IN
det
Definite=Def|PronType=Art
the
the
DET
DT
obl
Number=Sing
speed
speed
NOUN
NN
case
of
of
ADP
IN
nmod
Number=Sing
light
light
NOUN
NN
punct
.
.
PUNCT
.
(ROOT (NFP  ))
root
PUNCT
NFP
(ROOT (S (NP (JJ Other) (NNS experiments)) (VP (VBP have) (ADVP (RB since)) (VP (VBN managed) (S (VP (TO to) (VP (VB conquer) (NP (NP (NN light) (POS 's)) (VBN supposed) (NN speed) (NN limit))))) (, ,) (SBAR (IN though) (S (NP (DT all) (NNS claims)) (VP (VBP have) (VP (VBN had) (NP (NP (JJ fine) (NN print)) (SBAR (WHNP (WDT that)) (S (VP (VBZ keeps) (NP (PRP them)) (PP (IN from) (S (VP (VBG being) (ADJP (RB especially) (JJ groundbreaking))))))))))))))) (. .)))
Other experiments have since managed to conquer light's supposed speed limit, though all claims have had fine print that keeps them from being especially groundbreaking.
amod
Degree=Pos
other
Other
ADJ
JJ
nsubj
Number=Plur
experiment
experiments
NOUN
NNS
aux
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
have
have
AUX
VBP
advmod
since
since
ADV
RB
root
Tense=Past|VerbForm=Part
manage
managed
VERB
VBN
mark
to
to
PART
TO
xcomp
VerbForm=Inf
conquer
conquer
VERB
VB
nmod:poss
Number=Sing
light
light
NOUN
NN
case
's
's
PART
POS
amod
Tense=Past|VerbForm=Part
suppose
supposed
VERB
VBN
compound
Number=Sing
speed
speed
NOUN
NN
obj
Number=Sing
limit
limit
NOUN
NN
punct
,
,
PUNCT
,
mark
though
though
SCONJ
IN
det
all
all
DET
DT
nsubj
Number=Plur
claim
claims
NOUN
NNS
aux
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
have
have
AUX
VBP
advcl
Tense=Past|VerbForm=Part
have
had
VERB
VBN
amod
Degree=Pos
fine
fine
ADJ
JJ
obj
Number=Sing
print
print
NOUN
NN
nsubj
PronType=Rel
that
that
PRON
WDT
acl:relcl
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
keep
keeps
VERB
VBZ
obj
Case=Acc|Number=Plur|Person=3|PronType=Prs
they
them
PRON
PRP
mark
from
from
SCONJ
IN
cop
VerbForm=Ger
be
being
AUX
VBG
advmod
especially
especially
ADV
RB
advcl
Degree=Pos
groundbreaking
groundbreaking
ADJ
JJ
punct
.
.
PUNCT
.
(ROOT (S (NP (NP (DT Those)) (VP (VBG seeking) (S (VP (TO to) (ADVP (RB truly)) (VP (VB prove) (S (NP (NNP Einstein)) (ADJP (JJ wrong)))))))) (VP (MD must) (ADVP (RB instead)) (VP (VB turn) (PP (IN to) (NP (NP (NP (NNS objects)) (PP (IN like) (NP (JJ black) (NNS holes)))) (, ,) (SBAR (WHNP (WDT which)) (S (VP (MD could) (ADVP (RB theoretically)) (VP (VB cause) (S (NP (NNS things)) (VP (TO to) (VP (VB move) (PP (IN at) (NP (JJ faster-than-light) (NNS speeds)))))))))))))) (. .)))
Those seeking to truly prove Einstein wrong must instead turn to objects like black holes, which could theoretically cause things to move at faster-than-light speeds.
nsubj
Number=Plur|PronType=Dem
that
Those
PRON
DT
acl
VerbForm=Ger
seek
seeking
VERB
VBG
mark
to
to
PART
TO
advmod
truly
truly
ADV
RB
xcomp
VerbForm=Inf
prove
prove
VERB
VB
obj
Number=Sing
Einstein
Einstein
PROPN
NNP
advmod
Degree=Pos
wrong
wrong
ADJ
JJ
aux
VerbForm=Fin
must
must
AUX
MD
advmod
instead
instead
ADV
RB
root
VerbForm=Inf
turn
turn
VERB
VB
case
to
to
ADP
IN
obl
Number=Plur
object
objects
NOUN
NNS
case
like
like
ADP
IN
amod
Degree=Pos
black
black
ADJ
JJ
nmod
Number=Plur
hole
holes
NOUN
NNS
punct
,
,
PUNCT
,
nsubj
PronType=Rel
which
which
PRON
WDT
aux
VerbForm=Fin
could
could
AUX
MD
advmod
theoretically
theoretically
ADV
RB
acl:relcl
VerbForm=Inf
cause
cause
VERB
VB
obj
Number=Plur
thing
things
NOUN
NNS
mark
to
to
PART
TO
xcomp
VerbForm=Inf
move
move
VERB
VB
case
at
at
ADP
IN
amod
Degree=Pos
faster-than-light
faster-than-light
ADJ
JJ
obl
Number=Plur
speed
speeds
NOUN
NNS
punct
.
.
PUNCT
.
(ROOT (S (S (NP (JJ Black) (NNS holes)) (VP (VBP have) (VP (VBN been) (VP (VBN proven) (S (VP (TO to) (VP (VB be) (NP (ADJP (RB particularly) (JJ uncooperative)) (NN test) (NNS subjects))))) (ADVP (RB though)))))) (, ,) (CC and) (S (PP (IN for) (ADVP (RB now))) (NP (DT this)) (VP (VBZ remains) (NP (DT a) (NN guess)))) (. .)))
Black holes have been proven to be particularly uncooperative test subjects though, and for now this remains a guess.
amod
Degree=Pos
Black
Black
ADJ
JJ
nsubj:pass
Number=Plur
hole
holes
NOUN
NNS
aux
Mood=Ind|Number=Plur|Person=3|Tense=Pres|VerbForm=Fin
have
have
AUX
VBP
aux:pass
Tense=Past|VerbForm=Part
be
been
AUX
VBN
root
Tense=Past|VerbForm=Part|Voice=Pass
prove
proven
VERB
VBN
mark
to
to
PART
TO
cop
VerbForm=Inf
be
be
AUX
VB
advmod
particularly
particularly
ADV
RB
amod
Degree=Pos
uncooperative
uncooperative
ADJ
JJ
compound
Number=Sing
test
test
NOUN
NN
xcomp
Number=Plur
subject
subjects
NOUN
NNS
advmod
though
though
ADV
RB
punct
,
,
PUNCT
,
cc
and
and
CCONJ
CC
case
for
for
ADP
IN
obl
now
now
ADV
RB
nsubj
Number=Sing|PronType=Dem
this
this
PRON
DT
conj
Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin
remain
remains
VERB
VBZ
det
Definite=Ind|PronType=Art
a
a
DET
DT
xcomp
Number=Sing
guess
guess
NOUN
NN
punct
.
.
PUNCT
.
The majority of physicists once believed that the universe's expansion was slowing down. In 1998, they were proven completely wrong. Though it flies in the face of scientific theory, the universe is expanding at an ever-increasing rate.  One possible explanation is that empty space has a thing called dark energy, which supposedly makes up about three quarters of the universe. Dark energy supposedly very sparsely exists in such a way that it interacts with other objects only through attracting force. It has a strong negative pressure, which causes it to pull on its surroundings and as a result, pull apart the universe. This neatly explains the universe's expansion without completely changing our understanding of the universe. Scientists can merely claim that dark energy "should" exist.  According to Einstein's theory of relativity, it is impossible to travel faster than at the speed of light.  With this in mind, physicists set out to do the impossible and succeeded. In 2000, scientists in Princeton, New Jersey sent a small pulse of laser light through a vapor made up of gaseous cesium. The pulse traveled so quickly that it was already leaving the vapor-filled chamber as it was still entering, roughly 300 times faster than it would have in a vacuum. Thus, light moved faster than the speed of light.  Other experiments have since managed to conquer light's supposed speed limit, though all claims have had fine print that keeps them from being especially groundbreaking. Those seeking to truly prove Einstein wrong must instead turn to objects like black holes, which could theoretically cause things to move at faster-than-light speeds. Black holes have been proven to be particularly uncooperative test subjects though, and for now this remains a guess.