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Saturday, February 25, 2017

Are there Soviet Venera landers still intact, or even recognizable as Earth artifacts?

Are there Soviet Venera landers still intact, or even recognizable as Earth artifacts?


Are there Soviet Venera landers still intact, or even recognizable as Earth artifacts?

Posted: 25 Feb 2017 04:52 AM PST

Obviously we cannot send anyone to Venus' surface to check on their status. I was wondering if the good folks of this subreddit could put their minds together and try to extrapolate what the surface conditions of Venus have done to those landers in the decades since their respective missions. How long might it take for Venus' surface conditions to, for lack of a better term, degrade them out of existence?

submitted by /u/AveKender
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How do they put a rod into a broken femur?

Posted: 25 Feb 2017 05:53 AM PST

I know someone who broke their femur in half while skiing. I saw their x-ray and the doctors put a rod actually inside the bone to hold the two halves together while it healed. How would they do this?

submitted by /u/TougherLoki26
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How can we be sure of the precision and accuracy of modern measurement tools?

Posted: 25 Feb 2017 06:37 AM PST

Suppose I have defined a 'redditmeter' [rm] in some acceptable way (that is - I can always know that this 'thing' that I measure is indeed rm units in size). After a few months, a new way was invented to measure 0.5rm, so on so forth - we get to the smallest scales.

I logically conclude that this process is a very crude way of what happened in the way we humans measure things like length, weight etc.

But how can we be sure that the scales we measure today are actually accurate? if we can measure 0.5rm with 99% accuracy, then measuring 0.25rm might have even less accuracy, going all the way to 1*10-[integer] rm.

How can we know that our measurement tools are actually acceptably precise?

Or to put it in another words - How do we check our most modern and precise measurement tools?

Edit

Thank you for your current attempts of answering, but my question wasn't how can we be sure that a kilogram is a kilogram. To clarify furthermore - How can we be sure that the most modern measurement device actually measures with a good enough precision and not with it's measurement fault being 50% of accuracy (50% of times or 50% of given value).

submitted by /u/caluser
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What is in a vacuum?(Not the machine)

Posted: 25 Feb 2017 06:38 AM PST

Just curious what really is left when a vacuum is created. I know it's most likely going to be a quantum mechanically related answer, so please explain because I don't know much about quantum mechanics! Thanks!

submitted by /u/NotTidder
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Why are there so many different units of radiation, and how do they differ?

Posted: 24 Feb 2017 09:37 AM PST

During a recent Wikipedia tab death spiral, I was struck by how many different units we use for measuring radiation- becquerel, curie, rad, roentgen, sievert... how do they differ? Do different industries/fields use a particular unit for one reason or another?

submitted by /u/Brunoise
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How are you supposed to picture complex wave functions?

Posted: 24 Feb 2017 07:35 PM PST

intro quantum mechanics.

submitted by /u/FailAtomic
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Has geographically localized human activity in aggregate been able to impact weather patterns / other things on a small time scale?

Posted: 25 Feb 2017 12:48 AM PST

Not sure if the question is specific enough, but for example: Human population density congregates the coasts of the U.S. Is maybe the heat released from things like lighting buildings, pure body heat of that many humans, automobiles, etc -- enough to warm the air enough to maybe produce wind currents or something?

Is that many feet hitting the ground enough enough to cause some kind of impact?

(As opposed to like industrial activity or actually digging into the ground, or releasing pollutants, or global warming, etc).

submitted by /u/Reddits_For_Answers
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Why are some astronomical masers circularly polarized while others are linearly polarized?

Posted: 24 Feb 2017 07:09 PM PST

Even for particular transitions (e.g. OH 1665 MHz), there appears to be emission with both types of polarization present. Is this simply because of the stimulating photons from some external radiative pump?

submitted by /u/CallMeDoc24
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If the Planck length is 0 and the observable (or infinite) universe is 100, what value is the Earth?

Posted: 24 Feb 2017 10:31 AM PST

Just curious as to size comparison between the smallest and largest things possible.

submitted by /u/CarbonDouble
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Do all planets travel around their orbit at a fixed speed?

Posted: 24 Feb 2017 04:48 PM PST

Part 1- Do individual planets always maintain a constant speed during their orbit?

Paer 2- Do all planets in a solar system orbit their sun at the same speed? Obviously they complete an orbit at different times due to the distance but are they traveling at the same speed as each other? It seems like the gravitational pull would be weaker the father out you go, but at the same time they are moving through empty space so there doesn't seem like there would be any resistance to lessen the gravitational pull of the sun. So I guess these are physics questions.

These might be dumb questions but they've come up a few times so I figured I'd ask. Thanks for any thoughts.

submitted by /u/Zenkoopa
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[Chemistry] How do you find the Dielectric Constant of a solution?

Posted: 24 Feb 2017 04:21 PM PST

I am having a little trouble with this. I am working on finding the Debye length of solutions, but I can't find how to find the dielectric constant. I think I figured out KCl, but I am 100% stuck on CaCl2.

submitted by /u/mloos93
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If shadow can travel "faster than light", can't we use that to convey information at that rate?

Posted: 24 Feb 2017 09:29 AM PST

Okay, so my source for this assumption is actually a Vsauce video - this one (I've linked to the relevant time) - where Micheal says that if we were to cast a shadow on the Moon, and then move it, the shadow would move faster than c. This, he claims, is possible because shadows carry no information, and hence A on Earth can't communicate with B on Moon faster than light.

But why can't shadow carry information? If in front of a light source, I put a 2x2 inch grid of glass, light will go through it, and if I cover a square inch at the corner, light won't go through that bit. But now I can convey 4 on-off bits of information, so someone on the Moon could see that the shadow covers, out of the four bits on the 2x2 grid, and infer 4 binary values from them, and interpret those four values at the speed of the shadow - that is, faster than light.

What am I thinking wrong here?

submitted by /u/NSDCars5
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Friday, February 24, 2017

Is it possible to Yo-Yo in space?

Is it possible to Yo-Yo in space?


Is it possible to Yo-Yo in space?

Posted: 23 Feb 2017 10:52 AM PST

We had a heated debate today in class and we just want to know the answer

submitted by /u/TasteeTreez
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Is there an "absolute zero" speed?

Posted: 24 Feb 2017 05:03 AM PST

It's pretty commonly known that the speed of light is the fastest possible speed in the universe, and that it is impossible for matter to go that fast. Even if they did reach that speed things would appear strange thanks to relativity. What about the opposite though? Is there an equivalent "absolute zero" speed? Would there be any weird consequences with relativity?

submitted by /u/scamp41
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What body system does fat belong to?

Posted: 24 Feb 2017 06:36 AM PST

If they can be part of different systems, are there other examples of tissues that are not strictly monogamous?

submitted by /u/stikkit2em
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If I were to dip a white hot steel rod in water, would it produce higher/lower pitched hiss than if I were to dip a red hot steel rod in water? Would the temperature of the water also have an effect on the pitch of the hiss?

Posted: 23 Feb 2017 09:31 PM PST

Why are the air intakes of fighter jets so often on the bottom of the plane?

Posted: 24 Feb 2017 03:27 AM PST

Just as an example, the F-16 is like a vacuum cleaner, and will suck up ANYTHING off the ground nearby. That's a problem when rocks, tools, and bolts, get sucked up into the air intake, so I'm wondering why they continue to be below wing level.

As I'm not an aeronautical engineer, the only good reason I can think of so far is to have the cockpit out from in front of the intake. Is there more to it?

submitted by /u/spudman238
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[Psych] Is priming though question order a concern when creating psychometric tests?

Posted: 23 Feb 2017 08:30 PM PST

For instance, if you ask someone how many dates they've had in the last month, and then ask them how happy they are, their second answer is likely to be more affected by the first than if you'd just asked them about their happiness, since they're now thinking about happiness with a focus on romantic success. I would imagine that this kind of thing happens in a lot of cases, and that question order has a significant impact on the results of psychometric tests. Does this have a significant effect, and if so, how do psychologists tackle this issue when creating questionnaires?

submitted by /u/meatotheburrito
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On 'Frozen Planet' David Attenborough said some birds migrated 11,000 miles for food. How do they know how to do that, and where to go?

Posted: 23 Feb 2017 10:23 PM PST

Whats the largest known Hydrocarbon and what are its properties? I have tried looking in all available books, text books and the internet.

Posted: 23 Feb 2017 08:26 PM PST

Time Dilation from the perspective of a Muon?

Posted: 23 Feb 2017 10:32 PM PST

Hello everyone. I've been trying to wrap my head around this fully for the past couple of days, but I haven't found a clear answer on this specifically. In regards to time dilation,we know that on earth, we observe a much longer lifetime for the muon than they do, with their proper time being around 2.2 us. From the muon perspective, though, shouldn't it also see us as being slower as well? Mathmatically, would it observe a time dilation of t/gamma2, where t is the original measured time by a a stationary observer on the earth? If not, what am I missing, as I am still struggling with this.

submitted by /u/Quick_Question404
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What makes something a strong acid?

Posted: 23 Feb 2017 11:08 PM PST

I understand that strong acids, like HCl, completely dissociate in solution but what makes HCl a strong acid in the first place? What are the properties of its individual components that cause it to be a strong acid?

submitted by /u/cqferrier
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Would you see the same constellations on the Moon or Mars as you do on Earth?

Posted: 23 Feb 2017 11:03 PM PST

Are there better odds if the person switches the case at the end of Deal or no deal?

Posted: 23 Feb 2017 11:59 PM PST

Wouldn't it be the same s the monty hall paradox or is it different because the person chose the cases and not the host?

here is what I mean. https://www.youtube.com/watch?v=H9CQscwXBt0&lc=z13jcbwaewvkwz1i504cc11rtvnjjjdrixg0k.1487888698718059

submitted by /u/LiquidNipples
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How do we clean oil spills and what effect do spills have on the environment?

Posted: 23 Feb 2017 05:10 PM PST

Where did the variable names x y and z come from for axis?

Posted: 23 Feb 2017 12:06 PM PST

Will being near a large particle accelerator such as the LHC cause a magnetic compass to drift from true north?

Posted: 23 Feb 2017 07:47 AM PST

If I am walking near the LHC on the surface how close would I have to be for my magnetic compass to drift an appreciable amount due to the strong magnetic field?

submitted by /u/casablunka
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How can landslides be minimized?

Posted: 23 Feb 2017 07:37 PM PST

How much of a problem are the high energy neutrons from the ITER?

Posted: 23 Feb 2017 09:02 PM PST

I know that they're apparently using a lithium blanket to absorb them, but I was unclear if it completely addresses the problem.

submitted by /u/Rijn123
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Is there a good way to utilize heat energy (steam mechanical) to yield electricity that bypasses the counter-electromotive force?

Posted: 23 Feb 2017 02:48 PM PST

I'm thinking not...

submitted by /u/FondOfDrinknIndustry
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Why did we have to defrost freezers and why don't we have to do it anymore?

Posted: 23 Feb 2017 10:36 AM PST

Can food be charred to where it will not be digested or adsorbed?

Posted: 23 Feb 2017 10:44 PM PST

Can food be cooked to the point where the body is unable to absorb it for nutrition?

submitted by /u/somethingtosay2333
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How does the body handle excess amounts of Vitamin C?

Posted: 23 Feb 2017 07:59 AM PST

Many people start mega dosing Vitamin C when they feel the effects of a cold coming on. After reading a few sources today, I've come across a few that say that, as vitamin C is water soluble, a small amount exceeding the DV is excreted. I've also read that it definitely is not excreted, and that Vitamin C excretion is a blatant myth. Additionally, some sources say that in times of sickness or a stressed immune system, exceeding the DV, as long as the dosing is broken up throughout the day, does help boost the immune system and, as the body uses this excess Vitamin C, it is generally not excreted.

So what's the truth? Any recommended sources I can read?

(My last post was worthy of r/titlegore, so I reposted.)

submitted by /u/wystful
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Is the power spectrum of a real signal always of positive amplitude?

Posted: 23 Feb 2017 09:33 PM PST

The power spectrum, P_T1, of a time series, T1, is the Fourier transform of the autocorrelation of T1. If T1 is purely real, then for negative frequencies, P_T1 is simply the complex conjugate of itself for positive frequencies.

But does the amplitude of P_T1 have to be positive? As far as I can tell, there is nothing specific about the Fourier transform or autocorrelation that requires P_T1 to have a positive amplitude for its entire (frequency) domain. Yet for all the spectra I see, they are always positive-valued. Why is this?

submitted by /u/CallMeDoc24
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Thursday, February 23, 2017

Trappist-1 Exoplanets Megathread!

Trappist-1 Exoplanets Megathread!


Trappist-1 Exoplanets Megathread!

Posted: 22 Feb 2017 02:50 PM PST

There's been a lot of questions over the latest finding of seven Earth-sized exoplanets around the dwarf star Trappist-1. Three are in the habitable zone of the star and all seven could hold liquid water in favorable atmospheric conditions. We have a number of astronomers and planetary scientists here to help answer your questions!

submitted by /u/AskScienceModerator
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What are researchers and scientists primarily doing on Antarctic missions? What have been the most significant discoveries or advancements from this study?

Posted: 23 Feb 2017 03:01 AM PST

Robots are being used to investigate and clean-up the Fukushima reactor, but these breakdown due to the high radiation levels. How does nuclear radiation cause malfunctions in robots, and what components will be most affected?

Posted: 23 Feb 2017 02:27 AM PST

How do electrons behave at Absolute Zero?

Posted: 23 Feb 2017 07:00 AM PST

Physics / Chemistry

Things I think I know:

Atoms slow down as temperature decreases.

Absolute Zero is the temperature at which atoms stop moving

Scientists apparently reached temperatures below Absolute Zero in 2013 Source: https://www.mpg.de/research/negative-absolute-temperature

My question: Do electrons slow down or even stop at Absolute Zero or temperatures below Absolute Zero?

I'm assuming there is going to be a quantum mechanics related answer but I'm not too educated on that field so an explanation is also appreciated. Thanks!

submitted by /u/NotTidder
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Expansion of the universe: Has the universe ever had a Temperature of for example 68°F/15°C ?

Posted: 22 Feb 2017 04:46 PM PST

We all know the universe is expanding and getting colder. It's about 1-2 kelvin now (-271°C or -456°F) if I remember right. During the Big Bang it was kind of several trillion degrees kelvin. So it got colder and still cools due to its expansion. So my question is, was the temperature of the universe ever ''temperate'' ? Logically it must have been temperate for some amount of time during its cooldown. How long could the universe have been in that state (only minutes, or much longer like millions of years?) and how would it look like? Would planets with no parent (if they existed in that state) star be habitable nevertheless because space is kind of warm enough ? (not all life form require sun light) Was there a vacuum yet or not? (Thermal conduction in a vacuum can only happen due to radiation which is not that efficient)

Hope some of you can help me to find some answers. :)

submitted by /u/DickusLongusMaximus
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How do we fight confirmation bias?

Posted: 22 Feb 2017 09:25 AM PST

I recently read this article from the New Yorker. Its subtitle, 'New discoveries about the human mind show the limitations of reason', really annoys me.

For one thing, none of this is all that new. It's just more evidence to add to the pile. Confirmation bias and a host of other failures of reason have been well documented and supported for a while now.

Though it may help a little, spreading awareness about the existence of confirmation bias does not seem be enough to prevent people from succumbing to it.

It seems to me the problem has been emphasized enough. It's time for some damn solutions!

What does the research show so far? Are there any effective interventions for overcoming confirmation bias?

submitted by /u/pikeandzug
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Given current technology, what is the fastest space probe humans could make?

Posted: 22 Feb 2017 11:59 AM PST

.1c? .05c? Less? What about technology we might have available in the next 50 years (I know this becomes hugely speculative, but I like speculation).

The news about the newly-discovered exoplanets got me thinking that if we can get a probe going .1c, we could have one there within 500 years!

submitted by /u/CBryce
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Will quantum mechanics and general relativity ever be able to come together, or must we invent new kinds of mathematics (ways to solve the problem)?

Posted: 22 Feb 2017 07:10 PM PST

How do oil paints dry?

Posted: 22 Feb 2017 02:30 PM PST

Acrylic based paints dry by water evaporating, and oil paints dry by "oxidation." What is being oxidized, why does it cause the paint to become less wet, and why does it take so long?

submitted by /u/deacon_soley
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What are these weird circles and bumps on these rocks?

Posted: 22 Feb 2017 07:32 PM PST

Recently took a trip to the Valley of Fire in the Nevada desert, and found these really interesting rocks. What are the circles and bumps on the rocks? They look like they could be fossils, but of what? Trees? Carrots?

Can anybody tell me what these are?

submitted by /u/ToeInDigDeep
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What causes sufferers of dyslexia to perceive words as jumbled up?

Posted: 22 Feb 2017 11:10 AM PST

If a proton was fired into a neutron star, what would happen? And why would it not just be the largest hydrogen atom in the universe?

Posted: 22 Feb 2017 11:37 AM PST

[ASTRONOMY] Do we keep finding tidally-locked exoplanets because being tidally locked is the more common state for planets, or because such planets are easier to detect?

Posted: 22 Feb 2017 02:24 PM PST

Can 2 planets share the same orbit as each other around a sun?

Posted: 22 Feb 2017 12:36 PM PST

I was thinking about the idea of moving Mars to the same distance as Earth and matching its velocity and direction to Earth's so that we could have more inhabitable space inside the 'sweet spot' distance to provide the perfect conditions for life.

It got me thinking about how difficult this may be to align in reality.

Any insight would be great thanks!

edit: grammar

submitted by /u/Stepjamm
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Would it be possible to create a car that is powered by the driver's body heat?

Posted: 23 Feb 2017 06:01 AM PST

What is the science behind the "Euler's Disk"?

Posted: 22 Feb 2017 01:53 PM PST

If you don't know it, then it is pretty easy to look up. It's pretty damn mesmerizing and I've been wondering what the science is behind it

submitted by /u/CaiCaCola
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Why do protons not repulse themselves in atom nuclei?

Posted: 22 Feb 2017 11:20 AM PST

As particles with positive charge, they should NOT be aggregated. Why then are atoms (such as, lets say, uranium) posible?

submitted by /u/Heliosaez
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It is known that Antarctica was once at least partially forested. Around what time in the past did the last trees on the continent die off?

Posted: 22 Feb 2017 07:46 AM PST

I can't seem to find anything that estimates when the last trees vanished from the continent. I am very curious about this. I assume that the majority of the forests disappeared first, but that straggler populations persisted in favorable areas for a while afterward. Is this thought to be true? Do we have any real data on this, or just estimates?

submitted by /u/duroo
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What did the sun look like just before it "ignited"?

Posted: 22 Feb 2017 09:20 AM PST

I'm curious as to how a star appears before it reaches the mass required for fusion.

submitted by /u/NeverBob
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So if we see a andromeda galaxy as it was two million light years ago and its traveling towards us at a set speed how close is it now in light years?

Posted: 22 Feb 2017 10:53 AM PST

Why are some common lab-grade reagents used in food production, such as NaCl, labeled as "lab use only" and "not for consumption"?

Posted: 22 Feb 2017 08:16 AM PST

I have a 12 gallon HDPE chemical container with a NaCl MSDS attached to it. I want to use for storage of food grade liquids, but the container says the NaCl is for lab use only and not for consumption. By all accounts, my other containers should not be used for storage as they once held acids of various types. If cleaned and sanitized using food-safe chemicals, why should I not use these NaCl containers?

submitted by /u/jag0007
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