Chad Orzel, CONTRIBUTOR
I write about physics, science, academia, and pop culture. FULL BIO
Opinions expressed by Forbes Contributors are their own.
Continued from page 1
If Alice does this on her particle, it does not, in fact, affect the state of Bob’s particle in any way– it’s still in an indeterminate state that’s a mix of 0 and 1. It breaks the correlation between the measurement results, though– Alice’s particle is no longer in a superposition, but only in state 1, so when Bob eventually makes a measurement that randomly picks 0 or 1, it doesn’t necessarily match Alice’s measurement, which is guaranteed to be 1.
It should be noted that the “breaking of entanglement” Ethan describes is actually a slightly tricky thing to do, requiring a fairly specific operation to make it work. You will sometimes hear people assert that entanglement is fragile, and that any disturbance of one of the particles will mess things up, but that’s not true. In fact, there are a huge number of things you can do to change the state of one of the two particles without destroying the entangled nature of the system, provided you keep track of what you did to it and adjust your final measurements accordingly. (I have a blog post and an
arxiv preprint discussing this in more detail…) The impossibility of keeping track of all the ways entangled states get shifted is crucial to (the way I think about) the process of “decoherence” that plays a key role in (the way I think about) the “Many-Worlds” interpretation of quantum physics , which is what I was hinting at when I said this gets into some deep stuff, though this post is already running long, so I won’t try to explain here.
Crucially, though, this is not the sort of thing that people talk about doing when they talk about using entanglement for faster-than-light communication. What they want is a measurement procedure that forces a particular outcome . That is, they want Alice to use some woo-woo mystical process to ask her particle “What is your state?” and make it come out to be 1, thus instantaneously forcing Bob’s particle into state 1 as well. If such a procedure existed, you could, in fact, exploit it to send messages (with disastrous consequences for causality); fortunately, God plays dice with the universe , and the results of a quantum measurement are unavoidably random. Which means that while Alice and Bob end up with measurements that are perfectly correlated, no information passes between them. They can only see the correlation when they get back together and compare lists, and they have to do that at or below the speed of light.
It should also be noted that the version of entanglement-based communication Ethan describes is a particularly naive sort that even fringe physicists mostly reject. A more plausible scheme for actually doing this would be to use different measurement bases to send information. That is, rather than “force the state to be 1 to send Bob a 1,” Alice would ask two different questions of her particle. If she wants to send Bob a 1, she would make a measurement asking “Are you in 0 or 1?,” but if she wants to send a 0 she makes a measurement asking “Are you in ‘0+1’ or ‘0-1’?” The latter operation puts Bob’s particle into the corresponding state, which has a 50% chance of returning either 0 or 1 for his measurement. So all Bob has to do is measure that probability distribution for each particle– if it’s either 0 or 1 with 100% probability, he knows Alice is sending a 1, and if it’s 50% of each, she’s sending a 0.
That scheme doesn’t work either, for a more subtle reason. The problem is that you can’t determine a probability distribution from a single measurement of “0” or “1,” so Bob would need to make a lot of copies of the state of his particle in order to distinguish Alice’s message. But there’s a very deep result (that Kaiser’s book claims was directly inspired by these FTL communication schemes) known as the “no-cloning theorem” showing that this is impossible– you can’t make faithful copies of a quantum state unless you already know what it is. There’s no way for Bob to unambiguously determine which measurement Alice made, so you’re back in the scenario where Alice and Bob each have random strings of 1’s and 0’s that only turn out to be perfectly correlated later on, when they get back together and compare.
Quantum randomness saves the day .
So, as I said, the whole business is subtle and complicated. The end result is always the same, though: While it’s one of the weirdest and coolest phenomena in physics, there is no way to use quantum entanglement to send messages faster than the speed of light.
Chad Orzel is a physics professor, pop-science author, and blogger. His latest book is Eureka: Discovering Your Inner Scientist (Basic Books, 2014).
Most people don’t want to be the uncool one to raise their hand and ask a question, but in many cases we really should. These occasional “Raise Your Hand and Ask” posts highlight cool “buzzwords” you may have heard. Learn More
By James Reinders
NOV 21, 2017
Rost-9D
Note: Most people don’t want to be the uncool one to raise their hand and ask a question, but in many cases we really should. These occasional “Raise Your Hand and Ask” posts highlight cool “buzzwords” you may have heard. My aim isn’t just to explain what they mean (that you can look up), but also why they matter.
You may have heard of quantum computing , and the related term qubit , but what is a qubit?
Wikipedia describes a qubit as the quantum analogue of the classical bit (can store a 0 or a 1). In other words, normal computers have bits, and quantum computers have qubits (can be a 0 or a 1 or both at the same time per
quantum mechanics !)
Superposition and entanglement
The “magic” in a quantum computer is that it makes direct use of quantum-mechanical phenomena, notably superposition and entanglement. This means two things for a qubit:
a qubit is not a 0 or a 1 until it’s observed; until then, it can be both (superposition)
multiple qubits can be entangled with each other (affect each other at any distance)
There is nothing in our everyday lives that prepares us for these two magical properties to be real. Therefore, I know of no intuitive explanation for why these phenomena exist.
Fragility
A big challenge with quantum computing is
fragility . Simply observing the state of a qubit changes it, and a qubit is also extremely difficult to isolate from outside noise that would also change its state. Solving these problems requires exotic technology and additional breakthroughs.
What can a quantum computer do?
Hype might suggest that quantum computers will replace all computers because they are so much faster. A more realistic assessment seems to be that quantum computers will be extraordinarily faster at some specific tasks (polynomial [P] and some non-polynomial [NP] problems) but not extraordinarily faster for most problems. There is no known way to solve an NP-complete problem efficiently, even with a quantum computer.
We already know that there are efficient quantum solutions for discrete logarithms and factoring. Quantum simulation will also be a compelling use for quantum computers. D-Wave Systems is focused on combinatorial optimization, and they often mention the
traveling salesman problem as a motivational example that is NP-hard (not NP-complete).
How many qubits does it take to be interesting?
This seems to depend on whether you’re a purist pursuing a universal quantum computer, or you’re interested in application-specific quantum computing. Jeremy Hilton, VP of processor development at D-Wave Systems, was quoted in EE-Times as saying “We believe that starting with an application-specific quantum processor is the right way to go—as a stepping stone to the Holy Grail—a universal quantum computer, and that’s what D-Wave does—we just [do] optimization problems using qubits.”
This is important because D-Wave Systems has a product claiming more than 1,000 qubits; IBM and Intel are heralding having delivered 20 and 17 qubits recently, respectively; and IBM (again) and Google are talking about 50 and 49 qubits, respectively. It seems generally accepted that D-Wave qubits are not the same as the qubits of a universal quantum computer.
At Intel’s recent HPC Developers Conference,
Jim Held , Intel Fellow & Director of Emerging Technologies Research at Intel Labs, gave the following sketch for what different sizes of quantum computers are likely to bring:
about 50 two-state qubits: proof of concept
computational power exceeds supercomputers on some problems
learning test bed for quantum systems
starting around 1,000 two-state qubits: small problems
has only limited error correction
most useful for chemistry, materials design, optimization
starting around 1,000,000 two-state qubits: commercial scale
will offer fault-tolerant operation
this is when cryptography by quantum computers is interesting (some cryptographic algorithms we rely on today become relatively easy to break, but not all)
useful for machine learning and more
A key reason for needing so many qubits is dealing with their fragility. At 1,000 qubits, there is only limited error correction, but at 1,000,000 the system has fault tolerance, which is a key to why it can become fairly general purpose.
If tens of qubits are hard, how do we get to millions of qubits?
There are many approaches being pursued to tackle this problem. One approach is to reject the notion that we are limited to qubits (which have two states plus superposition) and adopt a bit with more possible states. A recent publication focused on supporting “qudits” that can each assume 10 or more states (maybe we should call it a 10-state qubit). Other approaches look to higher density of qubits, possibly relying on the spin of a single electron. With multiple approaches being researched, how long will it be until we see millions of qubits?
Qubit: a rating for how-powerful-is-your-quantum-computer?
Quantum computing is defined by the common pursuit to harness quantum effects to build a new—and potentially superior—type of computer. I started this article with the concept that a qubit is to quantum computing as a bit is to regular computing. I’ll finish by suggesting that the real significance of a qubit is as a measure of the capabilities of a quantum computer, and quantum computers will change our lives.
Watch for some amazing results along the journey; but for the complete disruption of computing as we know it, we’ll need the equivalent of millions of two-state qubits in a computer that is truly harnessing quantum effects. With so many experts pursuing large-scale quantum computing, and breakthroughs in both density and error correction needed, it’s impossible to say if this will happen in a few years or a few decades. It does seem reasonable to posit that it’s coming, although not everyone agrees. Time will tell.
Vice-Chancellor, Federal University of Agriculture, Abeokuta,, Prof. Olusola Oyewole
Samuel Awoyinfa , Abeokuta
The Academic Staff Union of Universities , Federal University of Agriculture , Abeokuta chapter , has dissociated itself from the call for the sacking of the institution ’ s Vice -Chancellor , Prof . Olusola Oyewole , Pro – Chancellor , Senator Adeseye Ogunlewe , and members of the Governing Council .
The union made its stand known on Friday while briefing journalists about the crisis rocking the institution .
The ASUU chairman FUNAAB chapter , Dr . Adebayo Oni , said the VC and the Council were duly appointed in line with the laws establishing the university and could not be removed from office without due process .
It will be recalled that the FUNAAB chapter of the Senior Staff Association of Nigeria Universities, rising from its congress on Wednesday , had announced the officers ’ suspension .
The chairman SSANU in the institution , Mr . Rotimi Fasunwon , who made the announcement, said Oyewole had contravened Section 5 . 10 . 1 (Interdiction ) of the FUNAAB ’ s Senior Staff Rules and Regulations , which prohibit him from “ suspending three staff of the university since himself is presently undergoing criminal investigation under the Economic and Financial Crimes Commission . ”
Oni , who condemned the SSANU action , said the varsity is not a ‘ Banana Republic ’ where lawlessness could be condoned .
He said , “ Our union will vehemently resist any attempt to turn our highly revered university into a Banana Republic or Animal Farm .
“ We hereby dissociate ourselves from any clandestine move to drag the reputation of FUNAAB into the mud . ”
Oni advised aggrieved members of staff to explore the lawful internal mechanisms of due process in seeking redress .
The union restated its members ’ confidence in the ability of the institution ’ s incumbent administration and council to provide academic , research and administrative leadership .
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ASUU President, Prof. Biodun Ogunyemi
Adelani Adepegba, Abuja
The Joint Action Committee has directed the Senior Staff Association of Nigerian Universities , Non – Academic Staff Union of Universities and Associated Institutions and National Association of Academic Technologists to resume strike on Monday .
A letter to all the branch chairmen titled, ‘ Directives to immediately resume the suspended strike , ’ was signed by Samson Ugwoke , SSANU , Chris Ani , NASU and Sani Suleiman , NAAT .
The JAC had claimed that only a ‘ pittance ’ was given to the three unions out of the N 23 bn ‘ earned allowance ’ released by the Federal Government to the Academic Staff Union of Universities.
The union complained that the government failed to explain how the money was shared between ASUU and the non – academic teaching staff unions .
The strike notice read , “Please , recall our last correspondence to you in which we informed you of the letter written to the Minister of Education rejecting the allocation made by the office of the Permanent Secretary and signed by the PS himself .
“ In the said letter , the Federal Government was given seven days to explain the criteria for the said allocation and do the needful . The deadline has elapsed without any response from the Federal Government of Nigeria .
“ In view of the above therefore , you are hereby directed to resume the suspended indefinite strike action as from 12 midnight , Sunday , 3 rd December , 2017 .
“ During this period , the strike shall be total and comprehensive. ”
When contacted for reaction to the claims by the union that they were cheated in the disbursement of the allocation , the ASUU President , Prof . Biodun Ogunyemi , said he was on the road and requested our correspondent to call back later .
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Beautiful 26-year-old Desiree Gibbon, a model from New York was murdered in Jamaica while visiting her family there. Her father is Jamaican and his mother, Desiree’s grand mother owned an inn in the Island where Desiree was staying for a month.
According to local authorities, she was found last week Sunday badly beaten and her throat slashed, on the side of a rural road in the tiny town of Anchovy, near Montego Bay.
Read the full story from UK Daily Mail below…
Desiree Gibbon, 26, was spending about a month on her father’s home island, staying at a hotel that her grandmother owns in the tourist destination of Montego Bay.
The model was looking for work as a bartender so that she could go to film school in Europe to hone her craft as a documentary filmmaker.
But on Sunday, residents in the town of Anchovy found Gibbon’s remains in some bushes on the side of the road. She had been badly beaten and her throat had been slashed.
Days later, her family are still struggling to come up with an explanation for what happened.
Her mother Andrea Gibbon, (pictured above) back in Queens, New York, spoke to reporters and said she thinks that whoever is responsible knew her daughter.
‘My belief is it was a cold, calculated, planned out murder,’ she told CBS New York. ‘It wasn’t a random act of violence. It is somebody she knew, somebody she trusted, and somebody who betrayed her.’
She added to ABC: ‘She has family down there. She has cousins. She met a lot of new people that she had been hanging out for the last three weeks or so. So, she was comfortable with these new people she had met.’
Her father, who didn’t give his name, told the Jamaica Observer that he believes his daughter was ‘lured’ from her grandmother’s hotel ‘because she had nothing on her’.
Her mother added that Gibbon was especially safe when travelling.
‘She never traveled by herself. She didn’t leave the hotel by herself. She always left with somebody,’ Andrea Gibbon said. ‘They would take a car service provided by the hotel and the same driver would take them and drop them and bring them back.’
Her mother is also skeptical that she would have visited a small town like Anchovy, which is about four miles from her grandmother’s hotel in Montego Bay.
‘In a bush in the country where she would never have traveled, not ever. It was an isolated desolate area, nothing there,’ she said.
Gibbon’s uncle Claude also spoke out, and said police officers told him that they were looking for two women they think might be connected to the crime.
Claude Gibbon says he was the first person in the family to find out about Desiree’s death, when a police officer came to the hotel with a picture of her dead body and asked him to identify it.
‘The officer who came here told me he had people to question two young ladies,’ he told the New York Daily News.
Claude added that nothing seemed out of the ordinary in the days before his niece’s disappearance.
‘She was gone for a few days, but it wasn’t anything that was uncommon,’ he said. ‘She’d sometimes go in and out.’
He says he grew worried when she didn’t return on Monday.
Authorities have released no information on any leads they are pursuing.
Gibbon’s mother hopes that her daughter fought back and has some DNA of her killer left on her body.
‘I’m hoping that in her fight, she has obtained some DNA, whether under her fingernails, on her body or her teeth, somewhere,’ she told NBC New York.
She’s pictured with her boyfriend, who didn’t go with her to Jamaica…
And her friends…
Source: CBS New York
Wizkid’s manager Sunday Are, has finally opened up on the fight that ensued between Wizkid and Davido’s crew members, at the One Africa Music Fest in Dubai some week ago. The fight according to report started after Tekno ‘disrespected’ Sunday Are by offering him a handshake and got more intense when Davido defended Tekno, an act that led to a fight between the Davido’s crew and Wizkid’s. Speaking to Saturday Beats, Mr. Are said; Initially, I did not want to say anything about the issue I had with Tekno at the One Africa Music Fest because if I speak, the industry would not be happy about what happened. I just want to be silent on the matter because what actually happened was more or less like the quarrel of a father and son in the house. When a father has a problem with his child in a house, that is when the child will do something that is not good, you scold him and it ends there. What people have been reading was not actually what happened. When these young boys in the industry act sometimes, it makes me remember the Yoruba proverb which says, ‘a child can have as many clothes as an elder but he can never have as many rags as the elder.’. Also, what an elderly person sees while seated, a child cannot see it even if he climbs a skyscraper. With all due respect to every artiste in Nigeria both old and young, what happened on that day has never happened before. No artiste in Nigeria has ever disrespected me. Every artiste in this country knows that I am always there for them and I also try my best not to disrespect any one of them. They can all testify to this. I always wish every music artiste the best because I stand for African entertainment. I have always wished them the best including Tekno; my happiness is for him to grow higher than he is today. Source: Saturday Beats
Bread seller turned model Olajumoke Orisaguna, is really just not here for ‘know it alls.’
Olajumoke, savagely put a follower in her place when the latter tried to correct her spelling on IG. The model simply asked the lady to get a refund from her Primary school principal. See their exchange below and share your thoughts on this.