> quantum-mech > fonda-interpret > can-we-send-data-back-in-time-with-a-delayed-choice-quantum-eraser-pbs-space-time

Quantum Eraser Lottery Challenge | Space Time | PBS Digital Studios

PBS Space Time - 2016-08-17

Matt challenges you to use quantum physics to win the lottery. Are you up to the task?

Previous Episode on Quantum Eraser  https://www.youtube.com/watch?v=8ORLN_KwAgs

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The Quantum Eraser experiment seems to show that information can travel backwards in time. On today’s episode of Space Time, we are going to create a time-traveling communication device and use it to cheat on the lottery! 

Here's Your Challenge question:
Why am I going to be sadly disappointed after turning on my invention? I do get a signal – nice work future me –  and that signal DOES contain the interference patterns from my future choices with perfect fidelity. But for some reason I can’t read the numbers. What went wrong?

Written and hosted by Matt O’Dowd

Made by Kornhaber Brown (www.kornhaberbrown.com)

Challenge Answers 
Submit your answers with full work to pbsspacetime@gmail.com for a chance to win a Space Time t-shirt. 
Make sure you use the subject title “Quantum Eraser Challenge question” to be in the running. Submit answers before August 24, 2016.

Moonmoss - 2016-08-23

Everyone knows the lottery is just the government's way to catch time travelers.

Yurii Selinnyi - 2019-05-25

Moonmoss thanks for a heads up)

jen woodward - 2019-10-27

Multiverse theory proven detatchedmatterobly thing being propetual

LisztyLiszt - 2016-08-17

Thanks to the Quantum Eraser, this comment is actually first.

celio gouvea - 2017-05-18

Gareth Dean https://drive.google.com/file/d/0B4QFebWuIuDUUTFnWFZraHhiWDQ/view?usp=drivesdk

I Drew two situations in the same setup so you can better understand the geometry. I know already Einstein used such setup to determine the speed of light but, we don't need necessarily use a very high speed, it could be 5,6,7 spins/second randomly, as long as we don't know, we'll loose the path information, if we know the position of the splitters at the time they shoot the photon, we can than track the photon and see if the results changes. Our knologe of the spin will determine the results. Sorry about my English, it's terrible, I am Brazilian.

Gareth Dean - 2017-05-19

Aaah, I see. A circular mirror is a totally different story and an ingenious bit of work.

The problem then becomes whether the universe knows the orientation of the mirror; we cannot leave a cat in a box and have it be both alive and dead because the cat observes itself. Similarly even things like rocks or plants don't show quantum weirdness because they're too large.

The mirror as a whole is macroscopic, big. It will be turned by some sort of motor that takes energy from somewhere and probably emits sound and heat as it does. This I think would be enough for the universe, though not us, to know the orientation of the mirror and thus the photon paths, though I couldn't be sure until the experiment were tried.

celio gouvea - 2017-05-24

+Gareth Dean I don't know if you got my point, if we merge both setups, we can find out if our knologe affects the results. If we shoot two entangled photons, one in the traditional setup, we will know the results but, if the second entangled photon takes another direction in my setup, what's the results going to be? This will create a paradox so, we can not take this experiment as the final one.

Gareth Dean - 2017-05-27

Indeed, one of us is not getting something the other is saying. It's probably the difficulty of explaining an idea in pictures and words rather than being able to do so in more detail, as you might in a conversation. It does sound like an interesting setup, maybe you'll get an answer for it one day.

quantumbits - 2019-11-28

And that affected all the comments that followed?

Pietro Celano - 2016-08-18

Plot twist: He asks us a really hard physics problem and then publish the results in a scientific paper.

Gareth Dean - 2016-08-18

You figure it out and then he appears 60 years earlier and assassinates your grandparents. He never has to share that lottery money.

Drew - 2016-08-23

Malcolm in the Middle had an episode with that plot.

Jjh Hand k - 2019-02-20


Josaph - 2019-03-30

Or even worse, a patent!

David Hughes - 2016-08-18

Lmao the next video is so true I agree wow good point. Oh right you guys haven't seen it yet.

Killer Gaming - 2016-10-25

Аsk me how tоооо win lottеry рrizes in 9 out ooооf 10 gamеs!Works fоr most lottеry gamеs in the wоrld.Go here ==> https://twitter.com/fa461de27c1c2bb34/status/742626059930198016 Quаntum Erаsеr Lоttеrу Challenge Spаcе Тime РBS Digitаl Studiooos

Yash Pandey - 2017-11-21

Areo Malshan 'time stops.... realises no one is in the chronosphere...for no one' lol

Mr Legoboy - 2018-01-14

yo what the fuck

Mr Legoboy - 2018-02-23

how can you make a contest, hype it up, and not make the video on it?

Mr Legoboy - 2018-07-15

What the fuck?

Dennis Haupt - 2016-08-20

i figured it out! the reason is that there is no love in it when ou're trying to get money! as we learned in interstellar, only love can transcend both space and time!
i guess that means to shirt for me

Mark - 2018-07-29

Dennis Haupt when you’re watching that movie with people who are eating it up 😱

B L - 2018-08-28

love AND gravity, don't forget that important part - or else he'd never been able to communicate across time

Bret van den Akker - 2016-08-25

since the challenge is over... here's the answer

You can't read the interference patterns until the entangled pairs hit their respective detectors. Without the information about which detectors have been triggered the detection screen just looks like static. It's only after the fact once you know which detectors triggered can you separate out the interference patterns from the rest of the signal on the detection screen.

Martin Pavlíček - 2019-03-17

Could not you solve this problem if you fire many photons for every bit of information? Lets say you want to send 1 so you let enough photons to enter eraser to produce interference patern, then you wait for some time and send another bit and another group of photons, than wait for some time and send another bit and so on. You should get many paterns or mess diveded by silence.

Raja Jagati - 2019-03-31

@Martin Pavlíček no both of the interference pattern in c and d are complimentary
You can't distinguish between them

3a3a3a - 2020-01-12

@Raja Jagati what if there is detector e?

Kurt Langberg - 2020-03-02

3a3a3a At what location in the setup? Remember, in this experiment, it’s all about location. Everything is geometrically set up.

2stroke4me - 2016-08-18

But i already answered it next week!

Treble Bass - 2016-08-21


Die Discordische Welle - 2016-08-17

Because the lottery is a fraud, thats why.

Slowburn - 2016-10-19

@Asd Fg I agree 100%, and never said any different, just don't think lottery and cheat have anything in common. Odds are clearly defined. I take that back, not 100% agree, my statement wasn't an oxymoron...

HB - 2017-09-06

Hksb hdj I am from the past, Trump won.

Arthur St.patrick - 2018-04-02

Die Discordische Welle Yes agreed.I think they use a computer to pick the combination of numbers no one chosed then rig the balls to play these digits.

István Godány - 2019-06-17


wicked magickal - 2019-07-06

Actually I can show you the lottery numbers are drawn according to where the universe links the day together and actually recognizes past events in history.

Wanna see ? The easiest example is 9 11. Look at drawings that were done on that day. Note how number 5 comes up nearly every time. Look at how the other numbers are symbolic of different things related to the attack.

There have been drawing that represent people like the life of James Dean and many more celebrities who have transcended but left a huge mark in society in some way.

lifebarier - 2016-08-18

"What went wrong"
Photons forgot lottery numbers.

AlphaOmega - 2016-08-18

What went wrong? Quantum mechanics is a selfish ho, that's what.

Sal C - 2016-08-17

I had this idea for turn signals. Making the turn would collapse the wave function and make the appropriate signal trigger before the turn is made. That way people would never need to manually indicate their turns.

Toughen Up, Fluffy - 2016-10-25

Many sheeple don't use their turn signals anyway. Baa.

Kevin Osman - 2017-03-12

can you read that sentence again please. you said "making the turn would..... before the turn is made." so we're just ignoring equation structure now? That's like me saying I'm gonna go spend a million dollars before I have it.

Mr Legoboy - 2018-01-07


Kenneth Ferland - 2018-07-29

That is literally the best use someone could make of the ability to send information into the past.

Routanne the Gamer - 2018-10-04

Yup, because technology never malfunctions, and it's impossible to hack anything :)

Kai Widman - 2016-08-17

He just forgot to put on his reading glasses. Where's my T-shirt?

TheWise Owl - 2016-08-18

4:20 you can definitely freeze photons and you should do a video about it! Look into the experiment of Susanne Yelin and Mikhail Lukin(if you haven't already). This actually had a great impact on quantum information theory so it would fit right into the current topic.
Thumbs up so he can see.

Red Berry - 2016-08-17

Ugh I'm really eagerly awaiting the solution of this challenge!!! It's gonna be such a long week :/

Gustav - 2016-08-18

+loungezinger Buy a pair of glasses.

TheBoagboy - 2016-08-19

Me to!

PSI Rocker - 2016-08-19

Holy s#it! I think I figured it out!!

Paul Freedman - 2016-08-20

I already knew the solution because I built the machine and got the answer from the future.

TheFatlazyguy - 2016-08-22

Me too man. I'm stuck thinking time travel is possible until then.

Denis Li - 2016-08-23

If the position of the landed photon changes after landing ("back in
time"), how does the change look like? Are we able to detect this change
which occurs at a fraction of a second before the paired photon is
(not) detected? If yes...does the first photon (i.e. the photon trail
left at the detector) "teleport" itself to another position?

Armando - 2016-08-18

That good feeling when my friends peek at my screen and read the video title
and think i'm some genius even though i kinda only understand 20% of what i watch

Promethor - 2016-08-17

It sound like if it worked it would create a paradox.

christian babis - 2019-08-26

Promethor Shut the fuck up with your fucking nature, FUCK NATURE AND FUCK TIME.

christian babis - 2019-08-26

Gareth Dean I hope you are not fucking possible, look at ibm reverse that shit time and hope you get proved wrong.

christian babis - 2019-08-26

nicocoolpants I hope you are fucking impossible. Look at ibm reverse time using a quantum computer and hope you get proved wrong.

Kie 7077 - 2019-12-01

That depends on how you view time, if you were extra-dimensional and could view all of time then it could cease to be paradoxical, light's wave function would collapse across a part of time and that would be it. It's only a paradox if you insist on saying that we must have cause and effect. Remember that nothing is supposed to travel as fast as light - but light travels as fast as light so that right there is straight off a paradox.

GaunletofDestruction - 2020-02-10

Ayush Saha Yes!

Josef Stodola - 2019-04-04

We would see the sum of interference patterns C + D which results in no interference pattern at all.

holdmybeer - 2016-08-18

I need to watch the last video 20 more times before I can even attempt to use the quantum eraser.

Matt Steele - 2016-08-17

"Why am I going to be sadly disappointed after turning on my invention?" Because research has shown a correlation between depression and winning the lottery thanks to "hedonic adaptation"?

Hugo Mendes - 2016-08-18


Gareth Dean - 2016-08-18

You fool! You just caused 9/11!

Gareth Dean - 2016-08-20

'Positively charged'?

Toughen Up, Fluffy - 2016-10-25

Challenge accepted. Baa.

Yash Pandey - 2017-11-21

Why can't we take a snap of the screen every second(assuming the binary numbers are entered every second) and interpret our lottery number from that??

Quality Control - 2016-08-20

A working time communication device is the great filter that keeps intelligent life from colonizing the universe.

Erik Youngren - 2016-08-18

5:30 Not interested in "half of any lottery winnings." Am interested in "half of all profits."

MAGNIFFs digital devices - 2016-08-17

Even though for some reason I cant read the actual numbers I would still get some signal? In other words I would be 100% positive that future me sending me some unreadable information, if so, that is amazing.

VeracityMedia - 2016-08-18

Those of us with a predilection for the Everett model have already won the lotteries we've played by simply buying the tickets. :)

VeracityMedia - 2016-08-18

......an infinite number of times.

Just a bit of Junkie - 2016-08-18

I'm one of those people ^_~ Many-Worlds has the preponderance of evidence in comparison to other QM theories.

Pika250 - 2016-08-24

This concept was explored in Majora's Mask, at least in the 3DS remake...

DJ Toddles - 2018-12-29

"Nice work future me" Hopefully future versions of ourselves can appreciate sarcasm

Nelson Mongare - 2016-08-17

This has me thinking, may be interstellar(the movie) was right.

Rabbitastic - 2017-08-13

God damn, just re-sum up. "Oh, watch this video first." Me watching first video: "Oh but watch this other video before this one."

Me: Jesus Christ I was just trying to kill 5 minutes.

Vakus Drake - 2016-08-18

It's funny I thought of the same general idea a long time ago, and when I found I found out about the weal or woe spell in D&D I immediately devised a way to use it for backwards information transfer.

Patrick Davison - 2016-08-18

Welp I sent in my solution, I'll be expecting my portion of lottery winnings in cash please.

James Trodd - 2016-08-18

Due to the light being coherent when it leaves the detector it will interfere with itself on the way to the moon and back and as a result will alter the results

pi314159265358978 - 2016-08-17

I was wondering about this. Very well explained. Thank you.

Kanu Akinya - 2016-08-18

My gud its u!

Pet - 2016-08-18

Of course Pi watches Spacetime.

YouDabian - 2016-08-20

+Apple You cannot calculate the circumference of a circle with only the radius and starving people. However, with only the radius and π, you can.

YouDabian - 2016-08-20

+Stuart Wallace (Stu) Did you edit your answer, or did you just have nothing to say?

F. L. - 2016-08-27

+Stuart Wallace (Stu) pies are mostly round.

EastingAndNorthing - 2016-08-17

I've sent an answer, here's what I know (let's discuss how we could make this experiment work!) Original message:

As far as I know, this experiment only works when analysing the data/measurements at a later time. The value that is measured is the time at which an photon hits the 'screen' and when it's entangled partner hits a detector, by firing one photon at a time. As for the interference pattern, you stated that the patterns from detectors C and D were the inverse of eachother. Combined, they will produce a regular pattern, which seems not to have any interference patterns. However, the quantum eraser will 'create' an interference pattern, only because it is possible to extract the which-path information from the analysed data -> I believe it is called 'joint detection'.

Basically, you could only get your sent information back if you knew the whole dataset; the data for the interference pattern is only from a subset of all the photons.

I could take this further and say that it doesn't seem like data is being sent back in time. The interference pattern from the quantum eraser is just hidden within that regular pattern.

Rostyslav Lesiv - 2016-08-19

Do you know by chance why there is Pi shift between patterns?

EastingAndNorthing - 2016-08-21

I haven't found a proper explanation for that. Most of the articles I've read just simply state it, like an assumption. It's something I'd love to find out, though!

lamcho00 - 2016-08-21

Please down-vote this discussion, because it contains the correct answer. If everybody copies it, we won't get T-shirts :(

Rostyslav Lesiv - 2016-08-22

buy a T-shirt and support the channel :)

lamcho00 - 2016-08-22

Yeah you are right, but having a T-shirt earned with knowledge is much more meaningful, at least to me.

Alex Knauth - 2016-08-18

This is the my favorite Challenge Question ever! (so far)

Fine Wine Daily - 2016-08-18

Hooray! I'm so glad I won a t-shirt!

Space Pope - 2016-08-17

Do you recommend watching the last two episodes dealing with the double slit experiment in order to answer the challenge question better?

FDJustin - 2016-08-28

You do that, I'll keep staring into my crystal ball.

David Igboanugo - 2016-08-18

This is actually the most interesting challenge yet. Can't wait for the answer from Matt.

SlyPearTree - 2016-08-17

That's what I was thinking when I watched the quantum episode. I did think it would not work but I don't know why.

SamuelElPesado - 2016-08-18

This is exactly what I was wondering at the end of last video! AAA!! I FEEL SO SMART!!!!

Now if only I can figure out the answer to your question...

Seth Lawson - 2016-08-18

This video actually made the quantum entanglement video make much more sense, the whole thing is simpler(at least to me) when you don't include detector B.

Steve 1122 - 2016-08-17

"QUANTUM ERASER CHALLENGE QUISTION" so every thing was done correctly we got a pattern but it wasent clear we couldn't read it that's caus as I think that it was the wrong pattern it shows somthing horrific happening

zingadooda - 2016-08-18

"Go watch this episode first" gets there "you should watch the first episode first"... What?

カダージュKadaj - 2016-08-20

Click bait and switch tactic, also segmented 2 part video here.. I think uploader is desperate

lelcetz - 2016-08-25

no. you won't understand jiggly shit if you don't watch those.
this is quantum mechanics after all.

vanssh Parikh - 2016-08-20

I love this show gives us great knowledge I love the animation work content and everything thanks for all the knowledge love the show👍🏻

VaDRitoX - 2016-08-17

Hands down, best science channel on YT

JazzyJacksJokeShack - 2016-08-19

Say I am going through space in a warp drive, I have a telephone connected to a quantum entangled transmitter/receiver (connected to another on Earth) and I am using it to talk to someone. How would the communication work?

Nick Moore - 2016-08-20

I believe people on earth wouldn't be able to gain any information from the telephone. they might see it do something but they wouldn't be able to decode it. that's my best guess

Nulono - 2016-08-18

4:23 "lorry tickets"

Joel Boudreau - 2016-08-19

said simply, the one who gets the information from the future is now in a parallel universe