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Sunday, October 28, 2018

Are there different climates in space and do specific areas have fluctuations in temperature?

Are there different climates in space and do specific areas have fluctuations in temperature?


Are there different climates in space and do specific areas have fluctuations in temperature?

Posted: 27 Oct 2018 09:39 PM PDT

Do volcanic islands preserve fossils in the same way as sedimentary rocks? If not, how do paleontologists reconstruct the evolutionary history of organisms on volcanic islands?

Posted: 27 Oct 2018 09:03 AM PDT

To be more specific, are there well understood evolutionary histories of the animals native to the Hawaiian Islands or Iceland, for example?

submitted by /u/VeryLittle
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Has there been an example of two species actively hunting each other for consumption?

Posted: 27 Oct 2018 07:02 PM PDT

Except for humans, of course.

submitted by /u/Mesahusa
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How bright is the center of a galaxy?

Posted: 27 Oct 2018 09:44 PM PDT

When you see pictures of other galaxies, from my understanding, there's a ton of light due to the supermassive black holes and probably a ton of stars near the center. If you were on a planet in that area, would your night sky always be bright? What would it look like?

Sorry for the bad formatting as I'm typing from mobile.

submitted by /u/icantthinkofacreativ
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Why do flames always burn upwards?

Posted: 27 Oct 2018 08:30 AM PDT

When we burn something, why does it always burn upwards? What causes the fire to take a particular shape?

submitted by /u/pdshah91
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If a childs parent or parents are drug addicts or alcoholics does this effect the child in any biologically?

Posted: 28 Oct 2018 07:00 AM PDT

Why isn’t 1 considered a prime number? And for that matter, maybe zero too?

Posted: 27 Oct 2018 07:30 PM PDT

This might be dumb... but I thought a prime number was a number that is only divisible by one and itself... well both are true for one. Sure it's redundant, but still. And zero—clearly it can be divided by one. I get that dividing by zero is a big no no, but it seems like a weird case for zero divided by zero.

submitted by /u/waking_dream96
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How do you calculate acoustic wavefront db dropoff?

Posted: 28 Oct 2018 12:44 AM PDT

I understand the inverse square law, and how to calculate point source volume, but how does this apply to a wavefront?
Say you had an infinite wall of speakers in two dimensions, would the volume at distance still behave as an inverse square from the source even though the pressure wave can't spread out?
Or more practically, if you had a single 30' speaker, would the speaker cone surface still be considered the point source? My intuition tells me that it would behave like the point source is further behind the speaker because the pressure wave wouldn't be able to disperse as rapidly, but I don't understand the physics enough to know if that's true or why.
Thanks!

submitted by /u/Red_Icnivad
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Why don't we use therapeutic hypothermia when dealing with anticoagulation, or brain bleeds, etc.?

Posted: 27 Oct 2018 01:37 PM PDT

If ice can help a bruise by constricting blood vessels, why don't we use that on a greater scale, like for people on blood thinners, or for brain bleeds that won't clot?

submitted by /u/GeminiJupiter
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Why do peoples’ sweat smell so differently? Is it purely because of ones lifestyle?

Posted: 27 Oct 2018 03:05 PM PDT

How big does Reynolds Number get in real life pipelines, such as oil pipelines?

Posted: 27 Oct 2018 12:00 PM PDT

I couldn't find any actual numbers for this, wanted it as a reference point for a project I am doing. Thanks in advance.

submitted by /u/NTheGreater
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What is charge?

Posted: 27 Oct 2018 12:55 PM PDT

According to Wikipedia

"Charges correspond to the time-invariant generators of a symmetry group, and specifically, to the generators that commute with the Hamiltonian"

Can someone dumb that down a bit?

How does charge lead to two particles exhibiting a force?

Do the different type of charge lead to the same type of force being exerted on carriers of a charge (i.e. does color charge attract or repel like electric charge)?

submitted by /u/hvgotcodes
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There was a post recently that states that blind people use the same facial expressions to show emotions as non-blind people. That means that these reactions are innate, not learnt. At biological level, how does this information is coded on our DNA and how it s transformed is some neural connection?

Posted: 27 Oct 2018 06:48 AM PDT

Does NASA's water deluge system during rocket launches use salt water (from the sea) or fresh/distilled water?

Posted: 27 Oct 2018 08:05 AM PDT

I wasn't sure if the salt in the sea water would cause issues or not. I also figured that using sea water might be more cost effective with where Cape Canaveral is situated.

submitted by /u/humidstraw
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How have we found out about how big the universe is, how far the Andromeda Galaxy is away from us etc. without any exploration that far?

Posted: 27 Oct 2018 08:13 AM PDT

Can a linear particle accelerator be powered by chemical cells? Where does the energy come from?

Posted: 27 Oct 2018 06:18 AM PDT

That is, can a battery be used to create an electric field between two plates, which is used to accelerate an electron for example? Would the battery discharge? If so, how?

Edit: the electron would be produced by another source, and the battery is just used to accelerate it

submitted by /u/StirFru
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At a molecular level, why does exposing proteins to low pH levels cause them to denature?

Posted: 27 Oct 2018 09:57 AM PDT

Why do Muon Catalyzed Fusion happen at such low temperatures?

Posted: 27 Oct 2018 05:39 AM PDT

I saw a minutephysics video talking about how Muon Catalyzed Fusion can occur at room temperature because using Muons instead of electrons makes atomic radii much smaller and therefore much more likely to reach with each other.

However, by that logic, shouldn't nuclear fusion happen all the time around the temperature where hydrogen gas becomes ionized because then the atomic radii become as small as the nucleus?

I thought the reason that nuclear fusion requires such high energy is because you need to be able to overcome to proton-proton repulsion enough to let the strong force take over at close distances. How does using Muons allow us to accomplish this at less than room temperature?

submitted by /u/UberEinstein99
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How do we actually know the age of the Earth? (Repost)

Posted: 27 Oct 2018 02:55 PM PDT

I come from a math background and I'd like to know the methodology of how we get the estimates we all agree upon today regarding the age of the Earth. I have looked at many websites and articles but they always beat around the bush and never answer the question. I just want to know how to calculate the age of the Earth, which I think would be a good activity in a math class. I've heard about radiometric dating but I haven't found a clear presentation on it. So, how do we get that the earth is 4.543 billion years?

Note: I posted this under Chemistry, here. I wasn't sure what flair to choose.

submitted by /u/dirtycapitalistpigs
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The moon is able to redirect the sun's illumination onto the earth. Does the earth also illuminate the moon the same way? With less, or more intensity?

Posted: 27 Oct 2018 01:06 AM PDT

Is it possible to create a triplet of quantum entanglement?

Posted: 26 Oct 2018 10:01 PM PDT

So in other words you entangle 1 qubit to another, the 2nd to a 3rd and the 1st to the 3rd. Because if you are, if you read the first qubit as a 1 what would the other 2 display?

submitted by /u/aberki1234
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Why do humans not enter the rage phase of rabies and begin attacking others?

Posted: 26 Oct 2018 08:25 PM PDT

I was reading this and then did my own research on this twisted, evil microorganism and it occured to me that not one human has entered the rage phase. At most I saw a vid of a clearly infected child under its partial control with a entirely red body, a foamy mouth and screaming out once.

submitted by /u/EldritchEmoji
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What is at the edge of the universe?

Posted: 27 Oct 2018 08:28 AM PDT

When scientists say the universe is all "space and time" do they mean all space and time within which matter and energy can exist? (I always thought space was infinite) If not I have some questions:

If the universe is finite (including space), then if I am at the edge of the universe, what would I see? If I was at the edge of the universe and kept going, where would I end up, given that there is no space? Is there a wall or something?

submitted by /u/1235678asd
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Saturday, October 27, 2018

Why don't single engine planes roll in the opposite direction the propellor is turning, similar to helicopters with no tail rotor?

Why don't single engine planes roll in the opposite direction the propellor is turning, similar to helicopters with no tail rotor?


Why don't single engine planes roll in the opposite direction the propellor is turning, similar to helicopters with no tail rotor?

Posted: 26 Oct 2018 10:36 AM PDT

A helicopter requires a tail rotor because otherwise it would spin in the opposite direction.

How do single engine planes cope with that problem? I'm asking specifically about single engine planes because the mechanics of 2+ engines are different, as the engines aren't located at the roll axis of the plane but instead, they're on the wings.

submitted by /u/ButtFlapMan
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How does a laptop computer display advertisements on a social media site, which are products searched for on a mobile phone, that does not have any email or social media accounts active on it?

Posted: 27 Oct 2018 12:34 AM PDT

yesterday i was in front of the television and i did a search on my phone for a white dressing table - i have just logged onto my computer and a social media site has the exact same dressing tables as i was looking at yesterday- my phone doesn't have any social media or emails on it - how does this happen?

submitted by /u/alterlightone
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How do bats and other creatures that hang upside down for prolonged periods not risk their blood rushing to their heads?

Posted: 26 Oct 2018 11:29 AM PDT

Do Weddell seals echolocate?

Posted: 26 Oct 2018 10:07 PM PDT

Weddell Seals make eerie, otherworldly vocalizations when underwater (and above). It sounds very purposeful, but it's unclear whether they're making these noises for the sake of navigation, or if they're simply communicating with other seals. I'm finding a lot of contradictory information in my searches. Are there any seal biologists who could help me out?

submitted by /u/croc_lobster
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Is there still any category-1 SNM at the Chernobyl sight, or has it been completely cleaned up? It would seem rather dangerous to open the plant as a tourist attraction with something so dangerous just lying there.

Posted: 26 Oct 2018 05:03 PM PDT

Why is it that the deepest parts of the ocean can get down to -2 degrees Celsius, without freezing at 0 Celsius?

Posted: 26 Oct 2018 09:55 AM PDT

Is it possible to measure the change in concentration of a reaction from a change in temperature of the reaction?

Posted: 26 Oct 2018 09:42 AM PDT

I have a neutralization reaction of 10mL 1M HCl and 10mL 1M NaOH, and I measured the temperature of the solution and the reaction. I have the initial change in temperature at ∆1.6˚C/s. Is it possible to convert the change in temperature of reaction to a change in the concentration of a reaction? If so, how?

submitted by /u/RealMHLee03
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How is it possible for a nuclear power plant's capacity factor to be over 100%?

Posted: 26 Oct 2018 11:05 AM PDT

I am sifting through the USNRC's dataset on power reactors, and I noticed that in 2017 some reactors (Surry Power Station Unit 1, Oyster Creek Nuclear Generating Station,Nine Mile Point Nuclear Station Unit 2, Donald C. Cook Nuclear Plant Unit 2) had capacity factors in the range of 101-113%.

is this a data error or is there some way to explain this? I am not a nuclear engineer, just a budding data analyst.

submitted by /u/BradleyPublic
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What exactly is this property that things have called 'momentum'?

Posted: 26 Oct 2018 06:02 AM PDT

When I started studying classical mechanics, momentum was mass x velocity. Later I learned that Newton's second law was actually expressed as force being proportional to the the rate of change of momentum, which mathematically I'm happy with if you accept as momentum = mv.

This is especially true when I also learned that term impulse is the change in momentum and again thinking in classical terms I can see that something that is massive and travelling fast has greater energy than something less massive or slower - hence impulse is larger or smaller in collisions.

However when I read about the quantum world momentum seems to be a much more basic attribute that either mass or velocity. So:

  • What exactly is momentum at it's core?
  • Where does it originate in terms of building blocks?
  • And why is it so fundemental to our universe that laws are expressed in it.

edit. looking at the the classical energy equation 1/2 mv2 - this is an integration of mv, This makes me think that perhaps momentum is perhaps a component of energy? Is this just nonsense?

submitted by /u/extra_specticles
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Is there a specific number of equal-length pendulums that produces the most "chaotic" behavior when linked together (e.g., a triple pendulum)? How would the chaos be compared?

Posted: 26 Oct 2018 05:04 PM PDT

I noticed that adding more pendulums to a system makes it look more chaotic (I'm not sure how to measure that), but at some point, the behavior of the entire system seems less chaotic in terms of the overall shape of the chain.

I looked up this 100-pendulum video, and it looks like larger numbers of pendulums exhibit behavior that is closer to that of a string let loose without any resistance. However, this is also just for one starting state.

For lack of better words to describe this, is there a way to describe how chaotic a dynamic system is, and if it can be used to compare different n-pendulum systems?

submitted by /u/antirabbit
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Does a tectonic plate only move in one direction at a time, or can parts of it move in different directions simultaneously? Wouldn't this break them down into smaller plates?

Posted: 26 Oct 2018 10:22 AM PDT

This image on Wikipedia is confusing, since it seems that different sides of a plate can move in different directions. Can someone explain this?

https://en.wikipedia.org/wiki/Plate_tectonics#/media/File:Plates_tect2_en.svg

submitted by /u/monkeeeeee
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How long does an atmosphere usually take to develop?

Posted: 26 Oct 2018 10:18 AM PDT

For the sake of creative writing: If all the planets in the galaxy suddenly lost their atmospheres, how long would it take for them to form again? I would imagine that volcanic, active planets would develop atmospheres faster than quiet, cooler planets due to all the gasses they expell. Is there a range of time I could use?

Bonus question: What would it look like to be on earth with no atmosphere? I imagine the sky wouldn't be so blue, but would you see the stars? Would they get drowned out by the sun?

submitted by /u/Spartan2005
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Why do things only burn in high atmosphere?

Posted: 26 Oct 2018 11:32 AM PDT

You see things like rockets and meteorites with burning trails when they first enter the atmosphere but not when they get lower. I get that it's the friction but wouldn't there be less friction that high up with the atmosphere being less dense?

submitted by /u/PandaKing185
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Why do some galaxies form spirals?

Posted: 26 Oct 2018 04:45 AM PDT

Why not just a uniform circle shape?

submitted by /u/Heptagonalhippo
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What is the “spin” of an electron?

Posted: 26 Oct 2018 03:01 AM PDT

First of all, I have absolutely no education in quantum physics whatsoever. I imagine the spin of an electron like a planet rotating on its axis, if the orbital is complete, one electron clockwise and the other anti clockwise. The problem with this reasoning is that it only work with a 2 dimensional orbit, if we think of electrons like small balls rotating, for example in a sphere/ orbital s then there is not a clockwise and anti clockwise.

submitted by /u/iKeyvier
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Can somebody explain to me how a Penrose diagram works?

Posted: 26 Oct 2018 09:23 AM PDT

Wikipedia is only confusing me more on this. All I can get is that it's used to explain the relationship between space and time, and is drawn in such a way as to make each axes represent infinite space/time.

submitted by /u/Audrey_spino
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What is the weather like in other planets? Do they have storms and tornadoes like we do? Do they have equivalents?

Posted: 26 Oct 2018 08:51 AM PDT

Friday, October 26, 2018

(Chemistry) Why do the orbitals of an atom only hold a certain amount of electrons?

(Chemistry) Why do the orbitals of an atom only hold a certain amount of electrons?


(Chemistry) Why do the orbitals of an atom only hold a certain amount of electrons?

Posted: 25 Oct 2018 09:19 PM PDT

I tried asking my 8th grade science teacher but she just said because it just is that way. Can someone give me an actual answer?

submitted by /u/Astronomytwin
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How does physical exercise reduce the risk of getting cancer?

Posted: 25 Oct 2018 12:38 PM PDT

How does light "slow down" in materials with an index of refraction higher than 1 if light always moves at the speed of light?

Posted: 25 Oct 2018 05:26 PM PDT

Why do electrical arcs produce their signature buzzing sound?

Posted: 25 Oct 2018 06:34 PM PDT

Why are position and momentum related by Fourier Transform?

Posted: 26 Oct 2018 04:41 AM PDT

For the context, here is a brief description of my understanding level -

  1. I understand De Broglie Theorem and that momentum is inversely proportional to wavelength.
  2. I understand the rough idea behind Schrodinger equation
  3. I understand Fourier Transform and how Fourier transform can result in the Uncertainity principle.
  4. I have formal background in Computer Science, so I am reasonably competent with mathematics and physics but definitely inferior to the level of any good graduate student in Physics.

I want to understand why the Heisenberg Uncertainity Principle is true and although, I feel like I am being thick headed or something, I really cannot figure out how we went from momentum is inversely proportional to wavelength to the Uncertainity principle. The most common answer is that it results in position and momentum being linked by Fourier transform, but I fail to make the jump. Does it come from Schrodinger equation or is it more fundamental than that?

I would be really thankful if you can add some comments.

submitted by /u/QuotheFan
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Has anyone ever pin-pointed the geographic north/south pole, and would it be possible to walk/sail around it in a tiny circle to see a compass needle change continuously?

Posted: 26 Oct 2018 03:48 AM PDT

Bonus related question; is it known if antarctic explorers have had to adjust for their proximity to the magnetic pole when venturing inland and mapping out the regions?

submitted by /u/ElisaKristiansen
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What is the most common type of planet ?

Posted: 26 Oct 2018 01:42 AM PDT

What is the most common type among the observed planets in the universe ( Rocky, gas giants, other that I don't know about) or are they uniformly found.

submitted by /u/Metatonic
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How do astronomers identify gravitational lenses?

Posted: 25 Oct 2018 11:21 PM PDT

Do they just look for distortions in the galaxies shapes? how do we know then that the distortion is caused by a mass altering space-time in front of the galaxy and not because the galaxy really has that distorted shape?

I am asking this because looking at the two lenses in the bullet cluster, I can clearly see the 'small' lens on the right cluster but not so well the bigger one on the left cluster (see this image of the bullet cluster without the typical coloring for reference)

edit: of course, I'm not saying that astronomers are making things up and seeing lenses where there is nothing. I'm just curious about what techniques can be used to stablish that in a certain region of space this effect takes place.

submitted by /u/juansinmiedo
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Is it possible for a planet to be hit by another object (e.g. astroid, another planet) and get split in the middle as a result?

Posted: 25 Oct 2018 10:53 AM PDT

If it is possible, what would happen to the planet (say, Earth) besides being cut in half?

submitted by /u/TrippinOnCheese
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How long would it take the air currents from a butterfly to noticeably alter large-scale weather?

Posted: 25 Oct 2018 02:54 PM PDT

I've often heard the phrase "butterfly effect" to imply that a single butterfly could eventually alter the weather. Given that weather is a chaotic system this seems plausible. But how long would it take for the effect to make a noticeable difference?

submitted by /u/-Metacelsus-
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Theoretically, if lightning were to strike in a sandstorm, could it rain glass?

Posted: 25 Oct 2018 10:02 AM PDT

Would lightning cause this much of a change in the sand?

submitted by /u/FotzeGotze
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How does intelligence work with physical brain size?

Posted: 25 Oct 2018 08:36 AM PDT

Context: I am very small; I'm 4' 10.75" and 95 pounds. I'm only 70% of the average size person. Therefore everything is smaller including things like organ size and cranial volume.

So that said, why is it I'm equally intelligent as someone who's 6 feet and a healthy 160-180 pounds? If the average human brain is about 3 pounds and mine is closer to 2 pounds then why is my intelligence unchanged?

submitted by /u/OldManOaks
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Do animals get cavities?

Posted: 25 Oct 2018 01:08 PM PDT

If red and violet are on oposite ends of the color spectrum, why does it appear to flow naturally into one another on a color wheel?

Posted: 25 Oct 2018 07:35 AM PDT

What is the relationship between sex chromosomes and physical sex, in animals that change sex?

Posted: 25 Oct 2018 10:44 AM PDT

Thinking about those fish that change from female to male when they reach a certain weight, or the sea slugs that fight with their penises until one get broken off and it turns female, how does their sex relate to whether they have XX or XY chromosomes?

Is the sperm-producing fish genetically male and the egg-producing slug genetically female?

submitted by /u/Roxygen1
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Why do people with asthma's bronchi constrict when performing physical activity?

Posted: 25 Oct 2018 08:08 AM PDT

During physical activity, it is my understanding that the sympathetic nervous system causes bronchodilation to allow greater uptake of oxygen from the atmosphere. So why is it the opposite in people with sports-induced asthma??

submitted by /u/rolensmash
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What are some forestry management and public policy best practices to minimize the damage caused by wildfires?

Posted: 25 Oct 2018 09:55 AM PDT

I have a sheet of plastic-like material that is claimed to be polyetherimide. I suspect it may be polycarbonate. How can I check?

Posted: 25 Oct 2018 11:03 AM PDT

I recently bought a sheet of material that was claimed to be PEI. As people who are into 3D printing know, PEI (Polyetherimide) is renowned for its qualities as a build surface (namely, it helps prints adhere extremely easily).

I bought a smaller sheet of PEI before, from a different company, and that seems to adhere prints extremely well. This new sheet of "PEI", doesn't seem to hold prints well at all.

I'd like to try to test if this sheet is actually PEI (and if it is, I would hope not to entirely destroy it, but if it's PC instead, I'm fine with it being destroyed). Given the price paid, I suspect that it is a fake. I'm a hobbyist and thus don't believe I have access to an IR spectrometer, but if there are common ways to get access to one, I'd love to know. Alternatively, are there simpler ways of testing if it is PEI or not?

My initial thoughts were melting tests or hardness tests or maybe some kind of chemical reaction, but I'm not sure what exactly to do.

Thanks for your help!

(P.S. I have removed all protective coverings, so that's not the issue.)

submitted by /u/Ronnocerman
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How does the spin of a ball affect its trajectory after bouncing?

Posted: 25 Oct 2018 10:59 AM PDT

How does calories relate to weight?

Posted: 25 Oct 2018 10:08 AM PDT

Something I've really understood is how calories relate to weight. I've heard you have to burn 3,500 calories to lose a pound. Let's say there's a man weighing 200 lbs. He eats a whole Jack's frozen pizza that in total has 1,110 calories and weighs 16.085 ounces, or about one pound. That means he'd weigh roughly 201 lbs after only taking in 1,100 calories, 2,400 short of the 3,500 number. I'm sure there's denser foods out there that have a larger mass, but lower calories. How does calories really tie in with weight?

submitted by /u/pizzanarwhal
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Why do aerosol cans of compressed air get really cold?

Posted: 25 Oct 2018 09:14 AM PDT

I was cleaning out dust on my PC and there was frost on the outside of the container after I set it down.

submitted by /u/KommaisonReddit
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How is it possible for pi bond formation between d-sigma*?

Posted: 25 Oct 2018 12:41 PM PDT

Since sigma* is a spherical orbital how can there be side overlap between the d ( specifically t2g orbital ) ? Also there isn't two signs in sigma* ( i suppose) so no way there would be a formation of pi bond between them . From MO theory for pi bonding in octahedral complexes .

submitted by /u/ila1998
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