It’s a bad day both for Albert Einstein and for
hackers. The most rigorous test of quantum
theory ever carried out has confirmed that the
‘spooky action at a distance’ that the German
physicist famously hated — in which
manipulating one object instantaneously seems
to affect another, far away one — is an
inherent part of the quantum world.
The experiment, performed in the Netherlands,
could be the final nail in the coffin for models
of the atomic world that are more intuitive
than standard quantum mechanics, say some
physicists. It could also enable quantum
engineers to develop a new suite of ultrasecure
cryptographic devices.
“From a fundamental point of view, this is
truly history-making,” says Nicolas Gisin, a
quantum physicist at the University of Geneva
in Switzerland.
Einstein’s annoyance
In quantum mechanics, objects can be in
multiple states simultaneously: for example, an
atom can be in two places, or spin in opposite
directions, at once. Measuring an object forces
it to snap into a well-defined state.
Furthermore, the properties of different
objects can become ‘entangled’, meaning that
their states are linked: when a property of one
such object is measured, the properties of all
its entangled twins become set, too.
This idea galled Einstein because it seemed that
this ghostly influence would be transmitted
instantaneously between even vastly separated
but entangled particles — implying that it
could contravene the universal rule that
nothing can travel faster than the speed of
light. He proposed that quantum particles do
have set properties before they are measured,
called hidden variables. And even though those
variable cannot be access, he suggested that
they pre-program entangled particles to
behave in correlated ways.
In the 1960s, Irish physicist John Bell
proposed a test that could discriminate
between Einstein’s hidden variables and the
spooky interpretation of quantum mechanics.
He calculated that hidden variables can explain
correlations only up to some maximum limit.
If that level is exceeded, then Einstein’s model
must be wrong.
The first Bell test was carried out in 1981, by
Alain Aspect’s team at the Institute of Optics in
Palaiseau, France. Many more have been
performed since, always coming down on the
side of spookiness — but each of those
experiments has had loopholes that meant that
physicists have never been able to fully close
the door on Einstein’s view. Experiments that
use entangled photons are prone to the
‘detection loophole’: not all photons produced
in the experiment are detected, and sometimes
as many as 80% are lost. Experimenters
therefore have to assume that the properties
of the photons they capture are representative
of the entire set.
To get around the detection loophole,
physicists often use particles that are easier to
keep track of than photons, such as atoms. But
it is tough to separate distant atoms apart
without destroying their entanglement. This
opens the ‘communication loophole’: if the
entangled atoms are too close together, then,
in principle, measurements made on one could
affect the other without violating the speed-of-
light limit.
Entanglement swapping
In the latest paper, which was submitted to the
arXiv preprint repository on August 24 and has
not yet been peer reviewed, a team led by
Ronald Hanson of Delft University of
Technology reports the first Bell experiment
that closes both the detection and the
communication loopholes. The team used a
cunning technique called entanglement
swapping to combine the benefits of using
both light and matter. The researchers started
with two unentangled electrons sitting in
diamond crystals held in different labs on the
Delft campus, 1.3 kilometers apart. Each
electron was individually entangled with a
photon, and both of those photons were then
zipped to a third location. There, the two
photons were entangled with each other — and
this caused both their partner electrons to
become entangled, too.

This did not work every time. In total, the
team managed to generate 245 entangled pairs
of electrons over the course of nine days. The
team's measurements exceeded Bell’s bound,
once again supporting the standard quantum
view. Moreover, the experiment closed both
loopholes at once: because the electrons were
easy to monitor, the detection loophole was
not an issue, and they were separated far
enough apart to close the communication
loophole, too.
“It is a truly ingenious and beautiful
experiment,” says Anton Zeilinger, a physicist
at the Vienna Centre for Quantum Science and
Technology.
“I wouldn’t be surprised if in the next few
years we see one of the authors of this paper,
along with some of the older experiments,
Aspect’s and others, named on a Nobel prize,”
says Matthew Leifer, a quantum physicist at
the Perimeter Institute in Waterloo for
Theoretical Physics, Ontario. “It’s that
exciting.”
A loophole-free Bell test also has crucial
implications for quantum cryptography, says
Leifer. Companies already sell systems that use
quantum mechanics to block eavesdroppers.
The systems produce entangled pairs of
photons, sending one photon in each pair to
the first user and the other photon to the
second user. The two users then turn these
photons into a cryptographic key that only
they know. Because observing a quantum
system disrupts its properties, if someone tries
to eavesdrop on this process it will produce a
noticeable effect, setting off an alarm.
The final chink
But loopholes, and the detection loophole in
particular, leave the door open to
sophisticated eavesdroppers. Through this
loophole, malicious companies could sell
devices that fool users into thinking that they
are getting quantum-entangled particles, while
they are instead being given keys that the
company can use to spy on them. In 1991,
quantum physicist Artur Ekert observed that
integrating a Bell test into the cryptographic
system also would ensure that the system uses
a genuine quantum process. For this to be
valid, however, the Bell test must be free of
any loopholes that a hacker could exploit. The
Delft experiment “is the final proof that
quantum cryptography can be unconditionally
secure”, Zeilinger says.
In practice, however, the entanglement-
swapping idea will be hard to implement. The
team took more than week to generate a few
hundred entangled electron pairs, whereas
generating a quantum key would require
thousands of bits to be processed per minute,
points out Gisin, who is a co-founder of the
quantum cryptographic company ID Quantique
in Geneva.
Zeilinger also notes that there remains one last,
somewhat philosophical loophole, first
identified by Bell himself: the possibility that
hidden variables could somehow manipulate
the experimenters’ choices of what properties
to measure, tricking them into thinking
quantum theory is correct.
Leifer is less troubled by this ‘freedom-of-
choice loophole’, however. “It could be that
there is some kind of superdeterminism, so
that the choice of measurement settings was
determined at the Big Bang,” he says. “We can
never prove that is not the case, so I think it’s
fair to say that most physicists don’t worry too
much about this.”

http://www.scientificamerican.com/article/quantum-spookiness-passes-toughest-test-yet/

99% of all nairalanders don't know the meaning or significance of this post, hence they will pass without commenting. On their way to the politics section to display childlishness and tribalism.

If you are not among, you are welcome to comment. Or like.

See this one above me o what is he feeling like

In quantum mechanics, objects can be in
multiple states simultaneously

I thought that in quantum mechanics - even tho this is what i learned in chem tho im not sure how/if it applies in physics - energies/electrons have quantized energies and can only make jumps (quantum leaps) between states no simultaneous or inbetween ish

MrsPhyno:
See this one above me o what is he feeling like

In quantum mechanics, objects can be in
multiple states simultaneously

I thought that in quantum mechanics - even tho this is what i learned in chem tho im not sure how/if it applies in physics - energies/electrons have quantized energies and can only make jumps (quantum leaps) between states no simultaneous or inbetween ish

Did u jux quote sec physics?

MrsPhyno:
See this one above me o what is he feeling like

In quantum mechanics, objects can be in
multiple states simultaneously

I thought that in quantum mechanics - even tho this is what i learned in chem tho im not sure how/if it applies in physics - energies/electrons have quantized energies and can only make jumps (quantum leaps) between states no simultaneous or inbetween ish

hey there! I'm feeling fly actually.

What you just said above is very elementary quantum mechanics. Just forget that one here. here we are dealing with another aspect called quantum entanglement.

Which basically means that two particles are connected in such a way that action on one affects the other simultaneously. Now in physics, we ask why. What is sending information from one to the other. Or, are they just AWARE of one another?

Of course we found that basically nothing was being exchanged between the, and that has made many physicists very angry and frustrated. Including me.

So we'be all been trying to prove this wrong, that something else must be going on. And these mumu scientists just spoiled our ministry.

Teempakguy:
hey there! I'm feeling fly actually.

What you just said above is very elementary quantum mechanics. Just forget that one here. here we are dealing with another aspect called quantum entanglement.

Which basically means that two particles are connected in such a way that action on one affects the other simultaneously. Now in physics, we ask why. What is sending information from one to the other. Or, are they just AWARE of one another?

Of course we found that basically nothing was being exchanged between the, and that has made many physicists very angry and frustrated. Including me.

So we'be all been trying to prove this wrong, that something else must be going on. And these mumu scientists just spoiled our ministry.

Quite right sir.

frankg1:


Did u jux quote sec physics?

Lol no I didn't quote anyone but u....

I was referring to chemistry actually

Teempakguy:
hey there! I'm feeling fly actually.

What you just said above is very elementary quantum mechanics. Just forget that one here. here we are dealing with another aspect called quantum entanglement.

Which basically means that two particles are connected in such a way that action on one affects the other simultaneously. Now in physics, we ask why. What is sending information from one to the other. Or, are they just AWARE of one another?

Of course we found that basically nothing was being exchanged between the, and that has made many physicists very angry and frustrated. Including me.

So we'be all been trying to prove this wrong, that something else must be going on. And these mumu scientists just spoiled our ministry.

Lol abeg o. I no be physicist, biology na my tin I jus dey learn work

I read this ur essay sha very interesting thanks for teaching me oluko

Very exciting news, though I'm in science field, I always hate it when 'limitations' are proposed and imposed on 'universal possibilities' by scientists based on LIMITED KNOWLEDGE via theories and laws.

Its therefore wonderful to see that the speed of light can be exceeded. I'm sure other particles and phenomenon that surpasses SOL will be discovered in the future. Similar breakthroughs are expecting in energy, matter, gravity and so on.

It's indeed a brave new world, too bad my country is seriously lagging behind!

Teempakguy, WHY IS EINSTEIN WICKED NAH??

It was E=MC^2. Now this. . . Him chop winsh? Na only him waka come??

Reason I love NEWTON. English are too smart and interesting a people.


Se Germans ehn, they are something. . Leibnitz , Einstein, Wolfgang, Planck alot of them. Their work are usually intimidating.

To topic :

I HAVE ALWAYS WONDERED AT QUANTUM ENTANGLEMENT. Why are they entangled? How are they telling each other to change depending on whats happening to one?

In short : QUANTUM MECHANICS abi nah PHYSICS is TOOOO SCARY and requires VERY HIGH INTELLIGENCE.

seunot:
Very exciting news, though I'm in science field, I always hate it when 'limitations' are proposed and imposed on 'universal possibilities' by scientists based on LIMITED KNOWLEDGE via theories and laws.

Its therefore wonderful to see that the speed of light can be exceeded. I'm sure other particles and phenomenon that surpasses SOL will be discovered in the future. Similar breakthroughs are expecting in energy, matter, gravity and so on.

It's indeed a brave new world, too bad my country is seriously lagging behind!

bro God (though he is a fable) bless you.

Instead of them to invest and support science, they are doing competition of SHAKITIBOBO. Like shakitibobo is meaningful. Instead of them to organize science exhibitions, they are doing COMEDY SHOW (Glo). This country tire me, I swear

.

This only goes to show how much genius of a guy Einstein was. Though he hated this idea of what in entails but even your guts cannot change the way quantum feels.

No information is sent faster than light, one measurement of a quantum linked particle merely tells you what spin the other one is.