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Friday, May 26, 2017

If quantim computers become a widespread stable technololgy will there be any way to protect our communications with encryption? Will we just have to resign ourselves to the fact that people would be listening in on us?

If quantim computers become a widespread stable technololgy will there be any way to protect our communications with encryption? Will we just have to resign ourselves to the fact that people would be listening in on us?


If quantim computers become a widespread stable technololgy will there be any way to protect our communications with encryption? Will we just have to resign ourselves to the fact that people would be listening in on us?

Posted: 26 May 2017 05:45 AM PDT

Are there any physical laws preventing a reaction that produces an anti-proton and a positron from a proton and an electron?

Posted: 26 May 2017 06:27 AM PDT

Such a reaction would conserve mass and charge, but are there any other conservations it would violate?

If not, why isn't this reaction prevalent throughout Sci-fi as a way of achieving 100% mass-to-energy conversion (by subsequent reaction with matter)

submitted by /u/lexapi
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Is it true that giant mushrooms existed?

Posted: 26 May 2017 12:58 AM PDT

I've heard about giant mushrooms exsited before the trees came. Is this true and if it is how is this possible?

submitted by /u/KalleTheOne
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Is it possible to detect gravity lensing caused by Sun from Lagrange L2?

Posted: 26 May 2017 03:23 AM PDT

Einstein predicted gravitional lensing and made calculations to measure lensing caused by Sun. Due to Sun being bright(duh!) it is impossible to observe it from Earth on regular day.

This year in US there will be total Solar Eclipse that will allow to measure this effect again(forgot name of team that did it first) and giving more proff to Einstein theories.

My question is, is it possible to measure this effect via satelites that are placed in L2 point? Over there Earth is always in front of a Sun so it should cover Sun just like Moon does during Eclipse.

Here thou I say sorry for any mistakes I did in text above.

submitted by /u/Ijjergom
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Why doesn't temperature change during a phase change?

Posted: 25 May 2017 05:53 PM PDT

I was wondering what's so special about the melting point, boiling point etc. that makes temperature constant during these phase changes. I get that the molecules are being rearranged and the input of heat will allow them to break the intermolecular attractions that hold them in a particular phase, but why is there a point where this is so dramatic, if the IMFs are always being broken during the heating process (i.e. density is temperature dependent)? Thanks in advance!

submitted by /u/borednerd7
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How is a monument like Devils Tower in Wyoming created? I understand how mountains and volcanoes are created but a monument like that seems to vertical for it to be the result of smashing tectonic plates. Something else must be involved???

Posted: 25 May 2017 07:36 PM PDT

Why do clouds become dark when it's about to rain?

Posted: 25 May 2017 01:53 PM PDT

Do local sea levels in the ocean change with the seasons? In other words, is there a "tidal" high and low that is driven by temperature instead of the moon?

Posted: 25 May 2017 05:54 PM PDT

The ocean's mass will remain about the same, I understand that. But water's density is a function of temperature, so given a difference in the temperature of a region of the ocean in winter and a region of the ocean in the summer, the density of the ocean will vary. Assuming the following conditions (one being ocean in absolute winter, one being ocean in peak summer) consider the difference in volume between the two conditions:

Temp. (degrees centigrade) Density (slugs/cubic foot)
32 1.940
80 1.934

This is a mere .31% change in volume, but consider the total volume of the ocean is 300,000,000 cubic miles Does that mean that the 'summer' side of the globe has 93 million more cubic miles of ocean than the 'winter' side? If the earth's surface is 196.6 million cubic miles, that would mean temperature can raise or lower sea levels by almost half a mile!

I know this doesn't happen, I know there are thermal gradients that connect the peak high and low temperatures of ocean, and I know that the ocean is an open system and will want to self level. But do we see sea levels rise and fall slightly with average temperature? I would assume that shore lines would not notice this change because of ocean depth being small, and this difference being tremendous when the ocean is deep.

Thanks in advance.

submitted by /u/WhereThePeachesGrow
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Does the time in the other galaxies is like the time on Earth?

Posted: 26 May 2017 01:37 AM PDT

What I am trying to say is does the time in Andromeda or other galaxy is slower or faster compaired to ours becouse they are moving(maybe with different speed)? And if I were on spaceship that is not in any galaxy and it is completely stopped, how different would the time go for me compaired to someone that is on Earth? I can't get this questions out of my head.(Sorry for my bad English)

submitted by /u/Mitko199
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What would happen if you separated a fertilized human egg cell right after it split for the first time?

Posted: 25 May 2017 12:26 PM PDT

Does intense concentration cause the brain to use up more glucose?

Posted: 25 May 2017 06:13 AM PDT

and if so does one need to eat more while studying?

plz say yes.

submitted by /u/killybegssealion
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How was this video made?

Posted: 25 May 2017 01:24 PM PDT

How does the band of stability work?

Posted: 25 May 2017 03:42 PM PDT

I don't understand why there is a certain ratio that satisfies the "band of stability." Why are the isotopes that lie outside the band unstable?

submitted by /u/PoopsEveryday
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How soon do electrons stop flowing when the p.d. is removed from a circuit?

Posted: 25 May 2017 10:19 AM PDT

And what causes the force which decelerates the electrons in the wire?

Also, for a loop of wire forming a high voltage circuit 1 light year long, how long would​ you have to wait after removing the voltage so that it is safe to touch the bare wire half way along?

Edit: voltage

submitted by /u/xkimlam
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How will we know when we reach perfect values for physical constants that require measurement like G or e-?

Posted: 25 May 2017 12:17 PM PDT

Thursday, May 25, 2017

Why does removing a battery and replacing the same battery (in a wireless mouse for example) work?

Why does removing a battery and replacing the same battery (in a wireless mouse for example) work?


Why does removing a battery and replacing the same battery (in a wireless mouse for example) work?

Posted: 25 May 2017 06:25 AM PDT

Basically as stated above. When my mouse's battery is presumably dead, I just take it out and put it right back in. Why does this work?

submitted by /u/J011Y1ND1AN
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If a Voyager I type probe were to approach Earth, at what distance/ range would it be from us until we could faesibly interact with it or retrieve it?

Posted: 25 May 2017 06:37 AM PDT

Why is the inverse square law so prominent in physics?

Posted: 25 May 2017 06:40 AM PDT

Almost every subject that my physics coursework covers has included an inverse square law (Newton's law of gravitational attraction, Coulomb's Law, Biot-Savart Law, intensity of radiation, etc). Is there something fundamental about an inverse square law, or is this all just purely coincidental?

submitted by /u/darman92
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Why can't photon have spin 0?

Posted: 24 May 2017 09:58 AM PDT

The z-projection of the photon's spin could be m_s = 0, +-1. Why though is m_s always -1 or +1? I understand that if m_s was zero, this would imply that the spin lies in the x,y-plane. Why is this not possible?

submitted by /u/dengmam
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What happens to the entropy of an object that gets sucked into a black hole?

Posted: 25 May 2017 06:31 AM PDT

Thinking of a black hole as an infinitesimal point implies it to only have one microstate. Since entropy, as I remember, is proportional to the log(# of microstates), a black hole would have zero entropy. This appears to violate the second law of thermodynamics; the entropy cannot disappear??

submitted by /u/Tom_ginsberg
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What's the difference between soft and hard rubber on the molecular level?

Posted: 25 May 2017 06:31 AM PDT

Would an hourglass measure the same amount of time on a planet/moon with a different gravitational pull?

Posted: 24 May 2017 05:59 PM PDT

Discussion: MinuteEarth's Newest Video On The Geographic Origins Of Different Foods

Posted: 24 May 2017 09:35 AM PDT

Hello everyone! Today on AskScience we're going to learn about where our food comes from! No, not just the ground, but the geographic origins of different foods! You can check out MinuteEarth's new video about the topic here.

We are joined by the video creator Alex Reich (/u/reichale) as well as two experts on the subject.

Colin Khoury (/u/Californensis) is a research scientist at the International Center for Tropical Agriculture (CIAT) and the USDA National Laboratory for Genetic Resources Preservation. He studies how changes in global crop diversity affect human health and the environment, and is particularly interested in the wild relatives of food crops.

Nathanael Johnson (/u/Nathanael47) is a Grist staff writer and the author of two books. Nate specializes in stories about food, agriculture, and science. He has written pieces for Harper's, This American Life, and New York Magazine. He lives in Berkeley, California.

Feel free to hit them with username mentions in your comments.

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Can an endergonic reaction produce light?

Posted: 25 May 2017 04:47 AM PDT

Is the vapor from a liquid in equilibrium hotter than the liquid itself and if so does that violate thermodynamic principles?

Posted: 24 May 2017 08:28 AM PDT

In an adiabatic container, if you put a liquid there, at certain pressure there would be some particles with enough kinetic energy to overcome the inter-molecular forces and escape. So the gas must be made only of particles with high energy so the temperature must be higher.

Summing up, what would happen is that an object at temperature T would spontaneously "split up" into an object with less temperature and another with higher temperature. Isn't this against thermodynamic principles? What is wrong with my reasoning?

submitted by /u/clumsywatch
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Why is it currently less common for the earth to encounter a large comet or asteroid than it was millions of years ago?

Posted: 24 May 2017 03:26 PM PDT

I was reading Astrophysics for People in a Hurry and one of the lines gave me pause "earth's occasional encounters with large comets and asteroids, a formerly common event"

NDG doesn't explain why this is, simply that it was formerly a common event.

I assumed that it was either the universe was expanding and now there is more room and less collisions. Or perhaps that there are now less comets and asteroids since over time they have collided and been destroyed? Or something else I didn't think of at all? Thanks!

submitted by /u/NowMoreEpic
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Do we know the shape of the nucleus in an atom? We learned in school that its a a cluster of protons and neutrons but is there any proof of this? Can it be one round ball holding all of the information in a quantum state(meaning it could be in any place within the ball)?

Posted: 24 May 2017 05:00 PM PDT

If the size of electrons and protons are not equal, how is it that the charge/effect they have on the atom is equal?

Posted: 24 May 2017 04:57 PM PDT

I understand that protons are about 2000x bigger than an electron. For example, why, then, does it not require ≈ 2000 electrons in a Hydrogen atom for it to have a neutral charge? Why the 1:1 ration if the electron is so much smaller?

Even further, I suppose, how is it that these parts of the atom even have a charge? What is it about them that allow them to be positivie or negative? Thank you!

submitted by /u/Sealove64
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Is the Placebo Effect present in any animals beside humans?

Posted: 24 May 2017 03:58 PM PDT

What are some examples of environmental toxic outbreaks?

Posted: 25 May 2017 05:29 AM PDT

I'm looking to study environmental science in a few months and I'm reading up on toxic outbreaks but so far can only find examples such as toxic cynanobateria. I'm curious to know more. Does anyone know of any severe outbreaks? Is there an outbreak that has only presented in the last 10 years?

Thank-you :)

submitted by /u/Androidasylum
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What actually changes between weaker and more powerful versions of hardware? And what makes it more expensive?

Posted: 24 May 2017 09:12 AM PDT

Most all electronics come in vastly different levels of computational power, speed or storage space.

But iterations of one type of hardware - especially if they are the same brand and/or form factor - tend to look the exact same, externally.

CPU's are mostly the same size, aren't they? And even more so with storage devices: m.2 SSDs all look more or less the same! SD cards - or microSD - look all alike, even those times when I could find teardowns of them . . . yet, there is a vast difference between speeds or storage size!

Which brings me to the second part of this question: pricing. I would instinctively say that materials should make up most of the cost of any given piece of tech - with manufacturing, R&D, marketing and the like not being as incisive, given the sheer amount of products made and sold. And given that, as I said earlier, form factors are mostly the same, I would think that the internals shouldn't differ that much!

Yet, there is sadly an all too tangible difference between a i3 and a i7 CPU (and even more so across generations), or between a ~$13 32GB microSD, and a $200 256GB one!

submitted by /u/Yeltsin86
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Why is the southwest area of China cold?

Posted: 25 May 2017 07:38 AM PDT

As shown in this picture http://imgur.com/a/QqnJ6 from this website ventusky.com

What makes such a large difference between India and China?

submitted by /u/CasualTea_
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Why does FTL/tachyons defy causality?

Posted: 25 May 2017 05:18 AM PDT

It is my understanding that causality, being cause and effect, would be defied by reverse-time-travel. If I know Jim is going to die before he does, I can prevent it; causality broken. That being said, if I know he's going to die before the photons showing his death strike me, I am no more able to prevent it than if I find out by conventional means. No matter how fast you are, even including FTL movements and instantaneous reflexes, you can not prevent an event that has occurred.

I have a redditor's understanding of why FTL is impossible for known-particles, keep in mind that this question is about causality specifically.

edit: is it just because the object would also move backward in time?

submitted by /u/Carfiter
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Is Kirchhoff's law in electronic circuits just Faraday's law for electrostatics?

Posted: 25 May 2017 01:30 AM PDT

The integral of the electric field along a closed path is zero. Although electronic circuits aren't really electrostatics, as the charges are moving around.

submitted by /u/crih
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Radioactive decay, rocks, and helium, as radioactive material decay helium is released, shouldn't there be no helium in the rocks at this point due to the age of the earth and the rate of decay?

Posted: 24 May 2017 09:20 AM PDT

If a telescope can show light from a star 900 years ago, would a larger telescope one the same star show the light more recently?

Posted: 25 May 2017 04:49 AM PDT

I think that title is probably a mess.

I use telescope 1 to view star A and it took that light 900 years to travel to telescope 1.

If I use telescope 2 (which is much stronger than telescope 1) to view star A, would it be possible that the light is only 850 (random number) years old?

submitted by /u/ProgGirl
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How do we know that entangled particles don't have predetermined spins from the very start?

Posted: 24 May 2017 02:49 PM PDT

If we measure one of entangled particles, the other one immediately gets opposite spin. But how do we know that their spin wasn't "chosen" before we measured them? Like, upon creation one was up-ish and the other was down-ish. We can't possibly know their spin without measuring, right?

submitted by /u/adzik1
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Wednesday, May 24, 2017

If you throw a waterproof speaker under water, and then dive under water yourself, can you hear the sound?

If you throw a waterproof speaker under water, and then dive under water yourself, can you hear the sound?


If you throw a waterproof speaker under water, and then dive under water yourself, can you hear the sound?

Posted: 23 May 2017 11:35 AM PDT

How difficult is it to provide cell service on underground services such as subways?

Posted: 23 May 2017 11:18 AM PDT

If we can have cell assisted Internet access on above ground services like trains why can we not do the same underground?

submitted by /u/Fen-Jai
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How can we measure light precisely and how can the universe expand?

Posted: 23 May 2017 09:08 AM PDT

How is it possible that we can measure the speed of light so precisely?? The speed of something can only ve measured in reference to another object, can't we just measure the speed of light in two directions and have the exact speed at which that point in the earth is moving ( C - measured C = speed of that point of earth.

Extra question: How is it that the universe is expanding? I have a big theory on this but how is it that we can measure the expansion of the universe?? That doesn't make any sense to me because if the universe is expanding we are also expanding, how can we know that what we percieved as 10 meters is now 20 meters if our instruments for measures also expanded and our own body, mind, eyes, atoms, and even the photons in the universe also expanded?

I say this cause scientists say the universe expands faster than the speed of light...

Extra extra bonus final boss easy question

How can something not pass the speed of light if the momentum formula is f=m.v being f force, m mass and v volume. To move something of 1 kg faster than the speed of light you need more newtons than speed of light, does a newton always take the same energy to achieve or does one newton take more energy in relation to the one that was applied before??

Thanks in advance for clearing my mind! I think a lot about this things but school is shit, I'm 16 and we are learning movement, I wanna learn about plancks not fucking a.t+iv=fv, that's easy boring shit. (Sorry for small rant)

Edit: that's my record of internet points in this site, thanks to everyone for answering!!!

submitted by /u/Joseelmax
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Would a spherical shell rotated about 3 orthogonal axes simultaneously feel an evenly distributed outward pressure?

Posted: 23 May 2017 11:01 AM PDT

Does the human sinus cavity hold pressure?

Posted: 23 May 2017 05:09 AM PDT

How evenly distributed are different types of cold virus around the world?

Posted: 24 May 2017 02:57 AM PDT

Could an enclosed vacuum impart sufficient buoyancy to overcome earth's gravity?

Posted: 23 May 2017 09:46 AM PDT

Given current material, design and fabrication knowledge, is it theoretically possible that, by incorporating sealed internal chambers into an object's design and printing the object in a vacuum, one could create a sort of "permanent vacuum balloon" that would achieve lift in Earth's atmosphere?

submitted by /u/Scheissbanana
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Is there a way to calculate the polarization of atoms in molecules?

Posted: 24 May 2017 02:14 AM PDT

Like, calculate at least on a comparable scale the difference in polarization of H2O, NaNO3 and KNO3?

submitted by /u/pabra
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if atoms and particles have "rest mass" or "rest mass energy" when they're moving is their mass different? how does the higgs field relate to rest mass?

Posted: 23 May 2017 10:38 AM PDT

When a flock of birds are flying around together, they seem to all be doing the exact same movements, without an obvious leader. How do they know what they're doing without colliding or moving away from each other?

Posted: 23 May 2017 07:24 PM PDT

I don't mean geese or other birds that fly in a "V" shape, going north for the winter. More so birds like swallows and such that hang around suburban areas. I always see them flying together

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Ask Anything Wednesday - Economics, Political Science, Linguistics, Anthropology

Posted: 24 May 2017 08:07 AM PDT

Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Economics, Political Science, Linguistics, Anthropology

Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical /r/AskScience post? No question is too big or small for AAW. In this thread you can ask any science-related question! Things like: "What would happen if...", "How will the future...", "If all the rules for 'X' were different...", "Why does my...".

Asking Questions:

Please post your question as a top-level response to this, and our team of panellists will be here to answer and discuss your questions.

The other topic areas will appear in future Ask Anything Wednesdays, so if you have other questions not covered by this weeks theme please either hold on to it until those topics come around, or go and post over in our sister subreddit /r/AskScienceDiscussion , where every day is Ask Anything Wednesday! Off-theme questions in this post will be removed to try and keep the thread a manageable size for both our readers and panellists.

Answering Questions:

Please only answer a posted question if you are an expert in the field. The full guidelines for posting responses in AskScience can be found here. In short, this is a moderated subreddit, and responses which do not meet our quality guidelines will be removed. Remember, peer reviewed sources are always appreciated, and anecdotes are absolutely not appropriate. In general if your answer begins with 'I think', or 'I've heard', then it's not suitable for /r/AskScience.

If you would like to become a member of the AskScience panel, please refer to the information provided here.

Past AskAnythingWednesday posts can be found here.

Ask away!

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What exactly happens when a photon is "absorbed"?

Posted: 23 May 2017 05:20 PM PDT

Does it turn into something else? If so, what?

submitted by /u/Haplo781
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Why does the zero-point energy of the vacuum not cause a large cosmological constant? What cancels it out?

Posted: 23 May 2017 06:52 PM PDT

If we've only explored something like 5% of the ocean, how do we know The Marianas Trench is the deepest part?

Posted: 24 May 2017 05:52 AM PDT

Is it possible to extract a data series' singal-to-noise ratio, if we don't have any prior information about the shape or magnitute of the signal, and the only thing we know about the noise is that it's completely random (not even a guess about its magnitude)?

Posted: 23 May 2017 11:11 AM PDT

Why do star trails form concentric circles?

Posted: 23 May 2017 06:38 PM PDT

Also, does the star in the centre of the circles change depending on location? It seems counterintuitive that a star only does a set circular path. Even more so that there are points where the star is in the centre, implying the star never changes position.

submitted by /u/Therexin
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Is it possible for dogs to learn commands in 2 languages?

Posted: 24 May 2017 05:10 AM PDT

How come we don't inject probiotics intravenously?

Posted: 24 May 2017 04:37 AM PDT

Especially for individuals that have system infections primarily fungal in nature (candida).

We know that many cancers are a result of systemic candida. Why would we not inject probiotika intravenously?

Ive read research articles where there are pro's and con's but everything is sort of inconclusive

submitted by /u/yashiminakitu
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Why do some substances (metals, wax, etc.) lose density when heated, whilst others (egg, meat, etc.) tend to solidify?

Posted: 23 May 2017 06:19 PM PDT

What specific equipment would I need to recreate Eddington's 1919 solar eclipse test of Einstein's General Theory of Relativity?

Posted: 23 May 2017 01:27 PM PDT

What kind of star charts, proper telescope, camera equipment, etc. And how much would that all cost to rent or buy?

submitted by /u/S-WordoftheMorning
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Explain Gyroscopic Procession? Why 90deg? Why not 45 or RPM dependent?

Posted: 23 May 2017 09:48 AM PDT

What the title says, but can someone explain the physics of gyroscopic procession and why it manifests at 90 degrees. Why not rpm dependent (like something rotating REALLY fast would offset at 120 degrees while a slower rotation at 20 degrees?

submitted by /u/keepcrazy
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How can a single light bulb be controlled by two switches?

Posted: 23 May 2017 05:49 AM PDT

It seems simple and I'm sure it is, but I can't picture a circuit with two individual switches that can each control a light bulb independently from each other. Think of turning on a light at the top of the stairs and with that switch still closed turning it off at the bottom of the stairs, then somebody else at the top of the stairs turns it back on with the top switch, even though the bottom switch is still turned it off. If there's a simple answer to how this works I'm curious to know, thanks.

submitted by /u/Tom_ginsberg
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