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Friday, April 20, 2018

In the last 5-10 years, there’s been tremendous efforts made by many of the first world countries to curb carbon emissions. Have we made a dent?

In the last 5-10 years, there’s been tremendous efforts made by many of the first world countries to curb carbon emissions. Have we made a dent?


In the last 5-10 years, there’s been tremendous efforts made by many of the first world countries to curb carbon emissions. Have we made a dent?

Posted: 19 Apr 2018 06:40 PM PDT

Where do we stand on present day global carbon emissions vs say 10-20 years ago?

submitted by /u/BimmerJustin
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Why doesn't microwave energy escape through the holes in the screen of a microwave oven?

Posted: 19 Apr 2018 03:03 PM PDT

I've heard the classic explanation as to the wavelength being longer than the spatial frequency of the holes, so the radiation can't "see" the holes. But this is hard for me to visualize since the spatial frequency of the holes would be orthoganol to the wavelength of radiation. Can anyone provide an intuitive explanation?

submitted by /u/lcarusLlVES
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Why is an Alpha particle denoted as a Helium atom?

Posted: 19 Apr 2018 03:43 PM PDT

How is it that we aren't getting cancer after inhaling large volumes of helium gas to change our voice as kids?

What makes an alpha particle highly ionizing but not helium gas?

submitted by /u/Laloquera
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If Radiation is cumulative in our body, is Bluetooth (even with BLE) harmful to humans if we are constantly exposed to it with cellphones, smartwatch, etc. and also from other's electronic devices around us?

Posted: 20 Apr 2018 03:41 AM PDT

Are there any "weird" uses for heavy/transuranic elements?

Posted: 19 Apr 2018 08:04 AM PDT

I recently came across the fact that Americium is used in smoke detectors (Wikipedia). Are there any other interesting applications of other heavy elements?

submitted by /u/lordvigm
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How can we get only sunlight through glass without heating the building?

Posted: 20 Apr 2018 02:34 AM PDT

Sunlight is excellent but it comes with heat, so how do we get only sunlight in a building without heating it up?

submitted by /u/Thammarith
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If we travel 65 million light years, we would be able to see the extinction of dinosaurs, but how is that possible and why?

Posted: 19 Apr 2018 02:59 PM PDT

with super telescopes of course.

submitted by /u/han_gymolo
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Why in some metals is the Hall Effect opposite of what is expected? Like in aluminum for example, say in your set up you expect a buildup of negative charge at the top side of the sample, but instead you get it at the bottom.

Posted: 19 Apr 2018 02:05 PM PDT

In my solid state materials lecture, this was asked as one of our thought starters for lecture last week, and we never really got a satisfactory answer as to why that is. I know it has to do somewhat with the wave-particle duality of the electron, but what exactly that has to do with it I'm not sure.

Any good explanations or links to articles for more reading are appreciated!

submitted by /u/Sublethal_Panic
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How does Ozone stop UV-B and UV-C from reaching the earths surface, what makes it different from nitrogen that allows it to stop the radiation?

Posted: 19 Apr 2018 07:23 PM PDT

How does the SpaceX Merlin rocket engine achieve a TWR of 300?

Posted: 19 Apr 2018 04:40 PM PDT

Edit: Typo. ~200 TWR, impressive nonetheless

submitted by /u/t001_t1m3
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Why are thermal images so blurry? What is hard about making thermal imaging lenses?

Posted: 19 Apr 2018 02:26 PM PDT

Do man made magnets affect the Earth's magnetic field?

Posted: 19 Apr 2018 06:56 PM PDT

I just learned that we've made much stronger magnets than Earth's own magnetic field. The largest magnet reaches 25 tesla but Earth only puts out about 0.000065 tesla. Do they interfere with Earth's? Why does Earths magnetic field reach so far but ours don't? Does that play a role in it?

submitted by /u/Piggs123
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How can electrons and holes have different mobility within a semiconductor?

Posted: 19 Apr 2018 07:59 PM PDT

Holes are just the absence of a balancing electron, so how do electrons move (on average) at a different rate than their absence and vice versa?

submitted by /u/popkornking
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Will we ever be able to see beyond the edge of our observable universe? As time goes on we are able to see further and further, but is the edge just going to stay the same, or possible have less to see since the outer galaxies are expanding faster?

Posted: 19 Apr 2018 01:34 PM PDT

Is there a difference between electrets and ferroelectric materials?

Posted: 19 Apr 2018 10:58 AM PDT

With Wikipedia as my only resource I'm having trouble differentiating the two. What are some common applications for these materials ?

submitted by /u/mattbros
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If the speed of sound is around 420 knots at 30,000 feet, why did Chuck Yeager have to go over 700 mph to break the sound barrier?

Posted: 19 Apr 2018 02:41 PM PDT

I've been playing DCS World and noticed how the speed of sound is different at different altitudes. And also, the Bell X-1 was dropped from around 29,000 feet. It seems to make sense that Chuck Yeager would've had to only go about 500 kn to achieve Mach 1.06.

Edit: he actually flew to 45,000 feet, so it seems he could have gone even slower to reach Mach 1.

submitted by /u/Maelshevek
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Are there any events in history or pre-history similar to the now discredited Tabo Catastrophe?

Posted: 19 Apr 2018 03:23 PM PDT

I heard about the Tabo Catastrophe Theory a while ago and recently saw after some help from a user on r/geology that the theory is no thought to not be true. Are there any examples from planetary science of genetic bottlenecks or loss of civilizations or communities due to natural catastrophe?

submitted by /u/abaxtastic
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Why was Miranda discovered almost a century after the rest of the major moons of Uranus were discovered?

Posted: 19 Apr 2018 05:31 PM PDT

Oberon and Titania were discovered in 1787, Umbriel and Ariel were discovered in 1851 but Miranda was only discovered in 1948 almost 100 years after the previous moons were discovered. How did we miss that Uranus had a fifth moon until after we figured out nuclear bombs and were less than a decade from Sputnik? I looked at the data that Wikipedia had and did a quick back-of-the-envelope estimate of Miranda's visual cross-section and calculated that it was around ~4/25 that of Umbriel's. That explains why it was discovered later than the other moons but why did it take almost a century when it would only have taken an increase of a telescopes diameter by 2.5 would have boosted light collection enough to make it as bright as the other moons seen with the smaller telescope. It isn't that dark, in fact its albedo seems relatively high so that isn't why we didn't find it. How did an entire moon nearly 500 km across manage to go unnoticed until the first half of the the 20th century was almost over?

Edit:I just took another look at Miranda's Wikipedia page and it says that Miranda is the innermost of Uranus's five major moons. Was this part of why we didn't find it? Was it's light drowned out by Uranus's?

submitted by /u/Dovahkiin1337
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How do you break time reversal symmetry without breaking inversion symmetry?

Posted: 19 Apr 2018 11:50 PM PDT

I'm sorry I'm a little tipsy and do not understand magnetism.

submitted by /u/rishlumbaugh
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Scientifically what makes a food burnt And at what state and why does burntness taste so distinct?

Posted: 19 Apr 2018 05:11 PM PDT

Are there any stars that have multiple stars orbiting them?

Posted: 19 Apr 2018 12:05 PM PDT

I know that binary solar systems make up about half of the visible points of light in the galaxy, but those are orbiting each other. Do we know of any stars that have other stars orbiting them? Like, one really big or dense star with other, smaller or less dense stars orbiting them?

submitted by /u/TrueScorpio
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Thursday, April 19, 2018

This may be a stupid question, but what defines GMO. Is it simply changing a plant through cross pollinating (at its simplest level) such as Mendel, or does GMO mean laboratory tested and genetically altered through a laboratory?

This may be a stupid question, but what defines GMO. Is it simply changing a plant through cross pollinating (at its simplest level) such as Mendel, or does GMO mean laboratory tested and genetically altered through a laboratory?


This may be a stupid question, but what defines GMO. Is it simply changing a plant through cross pollinating (at its simplest level) such as Mendel, or does GMO mean laboratory tested and genetically altered through a laboratory?

Posted: 18 Apr 2018 09:59 PM PDT

How is it possible for every human to have different voices?

Posted: 18 Apr 2018 07:54 PM PDT

If microwaves are "non-ionizing", how does a grape create plasma in a microwave oven?

Posted: 18 Apr 2018 04:24 PM PDT

Is non-ionizing radiation really incapable of ionizing ANY molecule?

submitted by /u/lcarusLlVES
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How do swept wings differ from straight wings in performance?

Posted: 18 Apr 2018 04:12 PM PDT

Are bird/whale (animals in general) songs learned or genetically programed? IOW, are animal songs the same in captivity as nature?

Posted: 18 Apr 2018 08:12 PM PDT

Are bird/whale (animals in general) songs learned or genetically programed? IOW, are animal songs the same in captivity as nature?

My dad and I were talking about this and we didn't know. We heard (but after googling I couldn't find this) that there was a university test whereby chickens were raised for generations in captivity and never squawked seeing shapes (such as squares and triangles) fly over, but then fifteen generations later the researchers sent one hawk and all the chickens were frightened.

This is a general question about genetically remembered fears or traits that aren't exactly taught.

Edit: I wasn't sure which flair to put this under. I think it would be more appropriate for zoology (but that is not present); so, I put it under biology. I think this is accurate since I ultimately am asking about the biological questions relating to genetically implied actions.

submitted by /u/Isatis_tinctoria
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Does rate of dissolution of salt change while a quantity of salt is being dissolved?

Posted: 19 Apr 2018 07:07 AM PDT

I have two buckets full of enough water that the amounts of salt I am attempting to dissolve will not saturate the solution. I want to dissolve a quantity of salt, X cups, in one bucket. In the other bucket I want to dissolve 2*X cups. Will these two quantities finish dissolving at the same time? Does the amount of salt already dissolved in the solution affect the rate of dissolution?

submitted by /u/electrodynamometer
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Why do some solids (like metals) make a *ting* noise when struck, and others (like wood or plastic) make a *thunk* noise?

Posted: 18 Apr 2018 07:32 PM PDT

Why do the acoustics of certain materials vary? Why can't you make a guitar string out of carbon fiber for instance?

submitted by /u/JohnH550
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Does bees' honey concentrate or filter out toxins from the original flowers?

Posted: 18 Apr 2018 02:54 PM PDT

I was thinking of this recently when reading an article on the main page about NYC beekeepers. In a pollution-heavy area, where flowers might be exposed to toxins in the ground/water/air, can those toxins concentrate into honey? Or is pollen and/or honey somehow insulated from toxins by some mechanism? Since I imagine it will be asked, we can break them out into earthly/local contaminants (heavy metals in the soil, agricultural runoff, etc) and air pollution from cars/trucks/smog/etc.

submitted by /u/polishprocessors
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Sending a rainbow into a prism?

Posted: 19 Apr 2018 02:56 AM PDT

If colored light rays were to send into a prism in the correct angles (Just the reverse of what happens to white light), would it produce actual white light?

submitted by /u/mantlair
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How does voyager 1 not run out of fuel?

Posted: 18 Apr 2018 08:06 PM PDT

Sorry if this is a dumb question, but that thing is in space since 1977 if I'm not wrong. How has it not ran out of fuel? Or hit a meteor or something?

submitted by /u/M33RHARIS
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Are Fourier transforms something fundamental in our Universe?

Posted: 19 Apr 2018 03:49 AM PDT

So I was watching a Sixty Symbols video about bandwidth and Fourier transform and in some part of it, it is said that Δf x Δt ≈ 1, where Δf is the range of frequencies that can pass through the cable and Δt is the minimum pulse width that those frequencies can make(Fourier). So for example in an optical fiber cable you can't send very short pulses because the Fourier transform of that pulse would have frequencies components beyond the limit of the optical fiber. My question is: That doesn't imply that the Fourier transform(and its sinusoids components) are not only a mathematical tool but a fundamental part of our universe? I mean, shouldn't the minimum pulse width be determined only by the wavelength of the frequency carrying the signal?

submitted by /u/jrmiranda
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Why do I sometimes get the urge to jump from a great height, randomly destroy something expensive, or to put something disgusting in my mouth?

Posted: 19 Apr 2018 03:07 AM PDT

In islands such as Hawaii which are made from lava hit spots how does the lava stack up to make a island since the lava comes from the bottom up?

Posted: 19 Apr 2018 01:31 AM PDT

Is it possible to transmit wireless data at the frequency of visible light? In that case, we could see the data transmission.

Posted: 18 Apr 2018 09:38 PM PDT

If a supersonic aircraft gets hot from compression heating, does that mean that the air behind it is colder because it transferred heat to the aircraft?

Posted: 19 Apr 2018 12:33 AM PDT

Additionally, if you had a perfect theoretical model (ignoring the inconvenient physics) could you fly a second aircraft behind the first that would get colder?

submitted by /u/18107
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How do LIGO results infer distance/size etc of source?

Posted: 19 Apr 2018 01:25 AM PDT

I have some questions about how LIGO works... I understand the basics and how it works by basically detecting very small changes in a laser beams path. Thats fine I get that that is an indicator of gravitational waves.

So..

  1. How can we identify that the waves are from X billion years ago?
  2. How do we know the direction the wave came from?
  3. How do we know the decay rate of a wave?
submitted by /u/liltbrockie
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This is not a medical advice request. Lansoprazole - a common PPI (as prescribed to me) states not to take indigestion remedies "2 hours before, or after" taking the medicine. Why? I have searched, no actual answers.

Posted: 18 Apr 2018 11:05 PM PDT

I am not asking for medical advice.

I am struggling to find out why this time line is stated on the pamphlet, and the label my pharmacist(s) put on the packaging. Basic searching (as far as I have delved) only results in the actual medicine and its uses, not why you shouldn't take "indigestion remedies" within in this period. I also cannot find what types of indigestion remedies they are saying to avoid.

I respect this isn't ELI5, but I'd appreciate some clarification as to why, that a layman can understand. If not, I'm happy to read papers relating to this to try and figure my own way around, slowly. Thank you.

Oh, they are gastro-resistant (enteric, if you prefer) capsules.

submitted by /u/neffs
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A catalyst lowers the activation energy for a reaction. Is there something that increases it, like an anti-catalyst?

Posted: 18 Apr 2018 09:45 AM PDT

How (if they do at all) do orb-weaver spiders establish territories?

Posted: 18 Apr 2018 09:07 PM PDT

There's lots of spiders near my house. How do they determine which one gets to build its web in the sunny spot near the outside faucet (which is like an all-you-can-eat insect buffet), and which ones have to go up to the third floor (where there never seems to be as many insects caught in the webs).

Strangely the spiders on the ground level, with the prime insect supply, seem to be smaller than the vast monsters on the third floor.

submitted by /u/AWinterschill
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Where exactly does the LHC get protons?

Posted: 18 Apr 2018 12:35 PM PDT

I want to a talk recently that stated that the LHC accelerates protons to relativistic speeds, and I was wondering where they get the protons? I was under the assumption that they create a positive hydrogen ion, leaving just the proton - is this correct? And if so, how is it done?

Thanks!

submitted by /u/Undercover_Ostrich
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What's The Deal With ITER's Funding & Timeline?

Posted: 18 Apr 2018 06:29 PM PDT

It's supposed to take until 2025 to be assembled and then another 10 years for the full scale experiments.

It's estimated to cost 20 billion Euros. This seems like a paltry sum for Europe, China, or the USA, let alone a collaboration between them and Japan, India, Russia, etc. so it seems like participants could fairly easily pony up additional funding.

Does building it just take that long due to the nature of the project or is it a matter of funding such that doubling the funding move the 2035 date up to the 2020s?

submitted by /u/pennypurplepyramid
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Wednesday, April 18, 2018

Does the velocity of a photon change?

Does the velocity of a photon change?


Does the velocity of a photon change?

Posted: 18 Apr 2018 04:39 AM PDT

When a photon travels through a medium does it's velocity slow, increasing the time, or does it take a longer path through the medium, also increasing the time.

submitted by /u/jpn1405
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When your body responds to changes in temperature by doing things like sweating or shivering, is it our minds’ perception of the temperature that causes this or does the temperature somehow directly do this?

Posted: 18 Apr 2018 05:39 AM PDT

Since that was probably a confusing title, here's an example: if you were sitting in the snow and it was below freezing out, yet somehow in your mind you were completely convinced that it was warm out and that you weren't cold at all, despite your internal temperature dropping, would you still start shivering?

submitted by /u/CoalVein
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What exactly composes the taste of freezer burn? Is it a chemical in the food that tastes like freezer burn?

Posted: 18 Apr 2018 06:53 AM PDT

Not asking how freezer burn happens, but rather once it happens, what are the constituents of the taste?

submitted by /u/GregJamesDahlen
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Do recreational drugs effect different ethnic groups differently?

Posted: 18 Apr 2018 05:52 AM PDT

I'm not trying to sound or be racist racist. I'm curious about the effects of drugs on different ethnic groups. I believe certain drugs may effect people with certain DNA SNP's differently. I put my DNA into a SNP reader and it says I could have poor metabolization to certain medications. So I was wondering if the effects of say alcohol on someone who's say British/Irish ethnicity would differ to someone who's say Japanese ethnicity.

submitted by /u/whoknowwhatthatmean
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Ask Anything Wednesday - Biology, Chemistry, Neuroscience, Medicine, Psychology

Posted: 18 Apr 2018 08:13 AM PDT

Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Biology, Chemistry, Neuroscience, Medicine, Psychology

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!

submitted by /u/AutoModerator
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How do you determine the amount of CO2 in the air in the past?

Posted: 18 Apr 2018 03:48 AM PDT

Specifically for time periods before the formation of permenant ice caps? Asking because I got curious after a PBS Eons episode on the Paleogene-Eocene Thermal Maximum.

submitted by /u/SomewithCheese
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Does alcohol consumption have permanent negative effects on a person's intelligence?

Posted: 18 Apr 2018 03:19 AM PDT

Why do we sometimes keep strong memories of mundane or unimportant events in our lives? Is there a specific reason why we do so?

Posted: 17 Apr 2018 12:11 PM PDT

We can recall very insignificant things like a statement, joke, image, or object from a particular moment even if we sometimes forget everything else about it. These memories can also feel very lucid, kind of like the popular statement, "I remember like it happened yesterday". Do we know the process behind it?

submitted by /u/Kaleidostorm
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Under what circumstances could a sea or ocean become carbonated, like a tonic water?

Posted: 17 Apr 2018 07:18 PM PDT

Why do fast-moving things appear as a blur? Theoretically what would it take for us to increase our visual "framerate"?

Posted: 18 Apr 2018 02:00 AM PDT

For example the blades of a fan appear as a blur. Is there any theoretical way to see each blade moving separately?

Or is it just the way light works?

submitted by /u/xplosiveshake
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how are electrons able to produce magnetic field inside an orbital. how does changes in spin up and spin down motion changes the overall magnetic field of an atom?

Posted: 18 Apr 2018 12:02 AM PDT

so i know that in bohr's theory it is simple to know the magnetic moment of an electron revolving around a nucleus cause it is an orbit and performing circular motion. But in an orbital where motion of electron is not specified, how are we able to know the magnetic moment it produces, by knowing the spin of the electron?

and then how are we able to categorize the nature of an element in para, dia, ferro, ferri, anti-ferri? just on the basis of electron's spin?????

submitted by /u/JordaNova73
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What is the chemistry behind pop rocks?

Posted: 17 Apr 2018 03:47 PM PDT

What reaction causes the popping sensation?

submitted by /u/erik2420
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If photons lose kinetic energy when colliding with objects but by definition travel at the speed of light and have no mass, where does that energy come from? Can a photon’s energy level be reduced to the point of being below the speed of light?

Posted: 17 Apr 2018 05:25 PM PDT

Is there a venom that isn't a poison?

Posted: 18 Apr 2018 01:50 AM PDT

The difference between poison and venom to my low biology knowledge is that the former kills you after you ingest it while later kills you after it gets into your bloodstream. So is there any venom that can be safely digested?

submitted by /u/DreamerGhost
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What does this chemical notation mean?

Posted: 18 Apr 2018 01:30 AM PDT

I was recently in the Natural History Museum in London, where there is a wonderful geology room filled with hundreds of rocks and minerals. Looking through these I stumbled upon a chunk of Empressite which was tagged with the chemical formula:

Ag5-xTe3

What does the (5-x) mean?

(Apologies for the use of superscript - I have no idea how to subscript.)

submitted by /u/FaustsDaemon
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How do most antidepressant drugs cause weight gain?

Posted: 17 Apr 2018 02:32 PM PDT

Do they make us eat more? Does it change the metabolism? Can they be used in anorexia?

submitted by /u/zorbix
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When Venus was in the Goldilocks zone, what would potential life have been like with it’s retrograde rotation?

Posted: 18 Apr 2018 04:34 AM PDT

Insects, with their compound eyes, don't have irises like mammals, etc, do. Our irises help protect our retinas from damage in bright light while letting us see okay in dark light still. Do insects forego this versatility? Or do they solve it some other way?

Posted: 17 Apr 2018 03:21 PM PDT

Do languages that read from right to left think of time as progressing from right to left?

Posted: 17 Apr 2018 02:41 PM PDT

As an English speaker I, and I assume most people, think of time progressing in the forward direction to the right. For example when plotting a time line, the most recent events would be to the right, and historic events to the left. Does the direction of reading affect this?

submitted by /u/thuww
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What do we use our current super computers for? And why do we need for powerful ones?

Posted: 17 Apr 2018 02:54 PM PDT

Is there a rigorous definition of “information”?

Posted: 17 Apr 2018 04:18 PM PDT

Is there a rigorous definition in physics of what constitutes information? Is there a difference between a hydrogen atom and a Collected Works of William Shakespeare outside of pure physical composition? How does that difference relate to the black hole information paradox?

submitted by /u/gsg121
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How do we know that different animals see more colors than us?

Posted: 17 Apr 2018 02:59 PM PDT

I've been researching on color lately and how we look at it. I found a few articles that talk about how animals see more colors than us but none of them really explain it. Is there any evidence that they for sure do see more colors than us and how this been proven?

submitted by /u/R3w1
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