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Monday, December 12, 2016

What is the derivative of "f(x) = x!" ?

What is the derivative of "f(x) = x!" ?

What is the derivative of "f(x) = x!" ?

Posted: 12 Dec 2016 04:15 AM PST

so this occurred to me, when i was playing with graphs and this happened

https://www.desmos.com/calculator/w5xjsmpeko

Is there a derivative of the function which contains a factorial? f(x) = x! if not, which i don't think the answer would be. are there more functions of which the derivative is not possible, or we haven't came up with yet?

submitted by /u/RAyLV
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What do we know about the surface of Venus? What does the surface consist of to withstand the corrosive atmosphere?

Posted: 12 Dec 2016 05:08 AM PST

In multi-star systems, what is the furthest known distance between two systems orbiting each other?

Posted: 11 Dec 2016 08:04 AM PST

Could someone explain the use of the different units utilized in radiation science?

Posted: 11 Dec 2016 11:38 PM PST

I'm so confused with all the units used for determining radiation. Can someone please explain to me what's the difference and the USE of the the units? I've been told to speak to patients in terms of BERTs... but then.... Grays, Siverts, Curies, Bequrels, Rads... etc... Is there also a difference when describing "generated" radiation (ie electron beam to a W target) vs natural? If I can't figure it out I'm going to be a completely shit clinician for my patients :( Why the hell can't we just have one set of units :(

submitted by /u/WH1PL4SH180
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How does the Large Hadron Collider work?

Posted: 11 Dec 2016 07:54 AM PST

Also what does it actually do?

submitted by /u/OinkGoesPig
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What is "strangeness"? And how does it affect subatomic particles?

Posted: 12 Dec 2016 05:26 AM PST

I'm learning about leptons, baryons and mesons and some of them have a value called "strangeness", my teacher doesn't know what it is a measurement for and everyone gives me weird looks when I ask what strangeness is. My point is, some particles are charged, with that charge, they repel other particles with the same charge and attract particles with opposing charges, that's how charge affects particles. But how does strangeness affect particles? At the moment, it's just a meaningless, faceless value to me. :/

submitted by /u/monjonltd
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When we say that nothing, not even light, can escape a black hole, does that just mean nothing that we currently know exists? is it concievable that something could have physical properties that would allow it to escape from the gravity of a black hole?

Posted: 11 Dec 2016 03:31 PM PST

Are face muscles controlled through the spine?

Posted: 11 Dec 2016 07:04 PM PST

I'm curious if the brain has to send signals through nerves in the spine to control face muscles, or if it can just go straight to the face because of the proximity.

submitted by /u/ChineseFountain
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Why is this silicone cover giving off dim light when warped?

Posted: 11 Dec 2016 11:53 PM PST

I recently bought an "object" covered in silicone, and while checking it for potential surface damage by warping it I noticed that it was giving off a very faint, but in low light conditions, rather apparent yet brief spurt of light.

Now the object is battery powered and was on at the time of discovery, so I at first assumed it was defective and that the batteries inside were transferring electricity to the silicone and giving off a slight spurt of light, and I was therefore rather reluctant to use it for it's intended purpose, so I decided to remove the batteries for the time being.

It has now been approximately been two days since I did this and any residual energy from the batteries should've disappeared, in case that was the culprit, but after checking again just now it's still happening and after a rather long time trying to phrase the question in a Google search I've found nothing.

So I come here today asking, what do you think is giving off photons from this silicone? Is it a small amount of static electricity being generated by the friction of the silicone and the inner lining plastic surface of the battery compartment? Am I through touch transferring enough energy to the silicone and resulting in it manifesting beneath the surface as static electricity?

submitted by /u/DevaKitty
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How does Noether theorem explains the constant speed of light?

Posted: 11 Dec 2016 08:01 PM PST

What symmetry causes the constant speed of light?

submitted by /u/Frigorifico
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Is space continuous? And if is it then why do we have Planck Length?

Posted: 11 Dec 2016 02:07 PM PST

I have always wondered if space can be quantized or not. We have always been told that space is continuous. But if that is the case then why does Planck Length exist?

submitted by /u/bitemyamygdala
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What is the chemistry behind toilet bowl cleaners that change color when the surface is "clean"?

Posted: 12 Dec 2016 02:41 AM PST

Chemical % Weight
Silica,amorphous,precipitated and gel 1.0 - 3.0
Butanedioic acid, hydroxy-, (.+-.)- 30 - 40
Sodium bicarbonate 50 - 60
Sodium carbonate 5 - 7
Butanedioic acid, sulfo-, C-dodecyl ester, disodium salt 2 - 3
Alcohols, C10-16, ethoxylated 1 - 4
submitted by /u/vocabularian
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Is there scientific evidence that chemical imbalance in the brain is a causal factor of chronic depression, or is it possible causality points in the other direction?

Posted: 11 Dec 2016 08:31 PM PST

How does a computer go from assembly to machine code to doing things?

Posted: 11 Dec 2016 04:23 PM PST

I understand that assembly almost directly corresponds with machine code, but what steps are required after the machine code translation to do something such as adding a value to the register?

submitted by /u/Artillect
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How often do "earth"quakes happen on other planets? Are some planets more prone or less prone to earthquakes?

Posted: 11 Dec 2016 04:29 PM PST

Can you measure the temperature of a single atom? If not, what is the smallest amount of matter that you can measure the temperature of?

Posted: 11 Dec 2016 10:32 AM PST

If I tell you what day of the week my birthday falls on every year, how many years (samples) will you need to determine my exact birthdate?

Posted: 11 Dec 2016 03:38 PM PST

How does a cryptographic attack know when it's succeeded?

Posted: 11 Dec 2016 04:06 PM PST

If you present a ciphertext to a computer program that was written to break the text's encryption, how would that program know it's made a successful attempt?

In a primitive brute force attack, you might have millions/billions/whatever amount of possible keys to iterate through, each one producing some sort of "plaintext" once it operates on the ciphertext. How would the program know it's actually produced the plaintext on one of these iterations?

submitted by /u/itCompiledThrsNoBugs
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How did we discover that certain materials could be used for data storage, such as in hard disk drives, magnetic tape and silicone based components?

Posted: 12 Dec 2016 01:41 AM PST

I've been looking data storage and I understand the principles of how data is stored on certain items like hard drives, SSDs, tapes, ect... but I'm curious as to how we discovered that these materials could store and hold data for long periods of time in the first place.

submitted by /u/SatSenses
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Why when you hold something very close to your eye, does it have a kind of aura around it?

Posted: 11 Dec 2016 02:21 PM PST

When I hold my finger or phone right up to my eye, it has a blurry aura around it.

What is it? Is it something to do with the human eye or the particles in the object?

submitted by /u/x45251s
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How does a cell know what kind of cell it is?

Posted: 11 Dec 2016 12:32 PM PST

As I understand, the "job" of a cell is determined by which parts of the DNA are loosely packed and which parts are tightly packed. But how does this packing look like in stem cells and what happens when they differentiate?

submitted by /u/theluke112
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Peanut Butter and Jelly each have about the same viscosity. Why do they behave so differently when stirred or spread?

Posted: 11 Dec 2016 04:02 PM PST

How is generator potential triggered in mechanoreceptors such as Merkel's discs, Ruffini corpsucles, and Meissner corpsucles?

Posted: 11 Dec 2016 11:27 PM PST

The closest I could figure out by googling is that generator potential is triggered when cells are deformed. How are they different from Lamellar corpsucles, the mechanism of which was "easily" found by searching google for a few hours instead of asking the experts here?

submitted by /u/JoshWithaQ
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Sunday, December 11, 2016

How do S orbital nodes work?

How do S orbital nodes work?

How do S orbital nodes work?

Posted: 10 Dec 2016 09:33 PM PST

I was reading in my O Chem book and reached nodes. So for the 1s node, is it like a ballon where an electron can be inside or outside, just not on the surface? Or is it a solid sphere where electrons cannot be?

submitted by /u/fuzzyglory
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When we say that a rotating gyroscope's axis is 'fixed', it is fixed relatively to what?

Posted: 11 Dec 2016 12:11 AM PST

Certainly not relative to Earth, as we can actually use gyroscopes to detect Earth's rotation. But does the gyroscope stay stable if we rotate the entire galaxy? What if we rotate the entire universe: will we, from inside the universe, observe the gyro rotating in opposite direction? The more I think about it, the more gyroscopes seem to violate the laws of relativity of frames of reference. Help!

submitted by /u/thetimujin
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Would the hallmarks of metallic bonding (eg. electron delocalisation) still be present if, rather than a very large number metal atoms, there were only 2 or 3?

Posted: 11 Dec 2016 03:34 AM PST

Basically, I have been teaching somebody some basics in structure and bonding at a UK GCSE level. I have explained that each metal atom has 8 nearest neighbours and, due to to close proximity of metal atoms in a piece of metal, the orbitals of the atoms are forced to overlap and form many molecular orbitals, within which the electrons are free to move around. So follows conductivity etc etc.

My student asked if the case would be the same if there were only 2 metal atoms?

I feel like the answer should be yes, as the species would still be a metal, and must therefore exhibit metallic bonding, but wasn't convinced that only 2 atoms would comply with the 8 nearest neighbour, vast orbital overlap conditions.

Many thanks,

submitted by /u/gebuckle
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If a star explodes because it ran out of fusion fuel how can it be that a new star can form out of the gas that the supernova leaves behind?

Posted: 10 Dec 2016 08:38 AM PST

Why are some materials opaque when viewed by themselves, but become more transparent when pressed against another material?

Posted: 10 Dec 2016 03:34 PM PST

I noticed this interesting bit of science at the post office today. Taking a piece of wax paper they had, I noticed that it was fairly opaque when held up in the air, but when i pressed it against something, such as the table, or my hand, it became almost entirely transparent. Why is this?

submitted by /u/untitled11235
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What does cpu0 do during sleep mode?

Posted: 10 Dec 2016 03:44 PM PST

Watching the dmesg output of my computer when I out it to sleep I see the kernel sleep cpu1-cpu3, as well as other devices. What happens to cpu0?

submitted by /u/FatGecko5
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Why are pneumonia shots only recommended for old people?

Posted: 10 Dec 2016 06:20 AM PST

I'm in my early 40s and I've had pneumonia a few times since the first time in high school. Pneumonia sucks, so I wanted to get a pneumonia shot, but it was very difficult to get because I'm not 65+.

Why is that? Is it just in perennially short supply, so they reserve it for the most needy? Is it less effective in younger people? Other?

(I eventually got one, so this isn't a request for medical advice)

submitted by /u/ShoelessHodor
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What would a universe with 2 temporal dimensions be like?

Posted: 10 Dec 2016 07:26 AM PST

If light is a wave/particle duality, how can its' speed be a constant under all circumstances?

Posted: 10 Dec 2016 11:43 AM PST

Waves certainly depend on the density of the space they travel through to determine the speed (i.e. waves travel faster through solids than gasses).

Also, given its particle attributes, I assume it would most likely have similar properties to a neutrino, passing through matter unimpeded. Though, its speed must somehow be affected by its wave duality, right?

A secondary question; If it were discovered that the speed of light is not a constant, and thus contradicted the Laws of Special Relativity, what would be the impact on our current understanding of the laws of physics? Would that part of Special Relativity just be simply re-written? Or would the entire framework have to be recalculated?

submitted by /u/SuperFishy
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Saturday, December 10, 2016

Why do we have two of certain organs while only one of certain others? What would an evolutionary reason to reject two hearts to one lung or one kidney to two livers for example be?

Why do we have two of certain organs while only one of certain others? What would an evolutionary reason to reject two hearts to one lung or one kidney to two livers for example be?

Why do we have two of certain organs while only one of certain others? What would an evolutionary reason to reject two hearts to one lung or one kidney to two livers for example be?

Posted: 09 Dec 2016 10:51 PM PST

If someone is above the clouds (ex: atop a mountain) is it still possible to be struck by lightning?

Posted: 09 Dec 2016 12:25 PM PST

Why isn't CO2 visible?

Posted: 10 Dec 2016 12:00 AM PST

I happened across a absorption spectrum of CO2 which included the very end of the visible spectrum. It seems to show CO2 absorbs light in the 630-700 nm wavelength, at least somewhat. I'm curious why, if CO2 seems to absorb some visible light, high concentrations of it are not visible as bluish/cyan gas (white light removing the deep reds). Is there something I am missing here?

What led me to this was an interest in replicating the sort of things shown here or here. These all seem to use mid wave IR and a narrow bandpass filter. I would imagine that if a narrow bandpass filter around 650 nm on a regular camera would let you see CO2, they would have done that instead. But I don't see why it wouldn't work.

EDIT: As Shookfoot notes below, the units on the graph are wavenumber, not nanometers wavelength. As such, the absorption isn't in the visible spectrum at all.

submitted by /u/hansn
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Is a black hole hot or cold?

Posted: 09 Dec 2016 05:25 PM PST

Given that a black hole's singularity is an infinitely dense object (theoretically) is it infinitely hot? Or because it can redirect all energy towards itself would it be cold as it could not radiate energy?

submitted by /u/Spankmewithataco
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With amber playing such an important role in the fossil record, I can't help wondering why big globs of resin were seemingly so abundant during ancient eras. Can someone explain?

Posted: 09 Dec 2016 11:15 AM PST

How can we estimate a quantifiable amount of mass to exist in the universe, and speculate the universe to be infinite simultaneously?

Posted: 10 Dec 2016 07:05 AM PST

When I Google "how much mass is in the universe", I get this answer:

Now, the size of the observable universe is about 14 billion light years, and using the above value of density gives you a mass (dark and luminous matter) of about 3 x 1055 g, which is roughly 25 billion galaxies the size of the Milky Way.

How can we say this, yet believe that the universe is infinite? Does an infinite universe not imply infinite matter & time & space also? Or am I thinking of this wrong- are these actually conflicting theories (an amount of mass versus infinite mass)?

submitted by /u/JOHANSENATOR
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Can an atom be more stable in a molecule?

Posted: 09 Dec 2016 11:37 PM PST

Four highly unstable atomic elements Nihonium (Nh), Moscovium (Mc), Tennessine (Ts), and Oganesson (Og) with half-lives of seconds or smaller were just named, and there is already speculation on their molecular possibilities. Can bonds with neighboring atoms and electrons keep an atom from decaying as fast as it would alone?

submitted by /u/Drakonic
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Can a planet have a non-rocky moon (i.e. gas)?

Posted: 09 Dec 2016 04:14 PM PST

Does the Sun ever get hotter or cooler at different times of the year?

Posted: 10 Dec 2016 07:27 AM PST

I know it get's hotter on Earth because of our orbit but does the sun actually change temperature

submitted by /u/bless_ure_harte
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Is it possible to represent the exact instant the universe began using everyday time notation? ie "3:43:11 am on Wednesday, March the third, 7,772,874,665 BC"?

Posted: 10 Dec 2016 05:53 AM PST

What would happen if you mixed all the chemical elements in the Ask Science logo?

Posted: 09 Dec 2016 08:42 PM PST

What happens when a hypothetical black hole would exist that's so big that metric expansion becomes noticeable across it's diameter? Would this affect its Schwarzschild radius? It's temperature? Anything else?

Posted: 09 Dec 2016 06:31 PM PST

What causes degradation of vision in astronauts who are in space for longer than 6 months?

Posted: 09 Dec 2016 10:07 PM PST

I heard that some astronauts were coming back to Earth with impaired vision. Sometimes going from 20/20 vision to 20/100. I theorize that this is due to a lack of use in viewing/focusing on object details at distances greater than 2-3m. When going for a daily stroll you view objects that are anywhere from 25cm up to 3km away. Your eyes are constantly being stimulated to make massive fluctuations in viewing distance and focusing in on the detail. In outer space, I imagine that your eyes don't get too much practice in viewing objects further than maybe 10 feet away at any given time. This leaves a huge gap in exercising your eyes on anything with a distance greater than a few feet. You could say that looking at the Earth exercise enough; but because human eyes cannot interpret that distance and due to it being outside of the flexible range of the lens in the human eye. It shows the earth as a relatively flat surface and is unable to show the planet in much detail and still leaves out the viewing distances of greater than 3m but less than 250km To fix this, there would need to be a tool or method of exercising the eyes of astronauts on a daily basis to slow the decay of vision. I understand that MRI scans have shown that the eyes of astronauts are flatter with swollen optic nerves, but I believe this to be due to a lack of muscle use in the eyes.

submitted by /u/BlackWidowSpider
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How much does the strength of rope increase by braiding?

Posted: 10 Dec 2016 01:50 AM PST

Also, is there a mathematical model that predicts this increase?

submitted by /u/oreo181
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Can I use resonant frequency to crack ice?

Posted: 09 Dec 2016 05:02 PM PST

In other words, would an oscillating harmonic force be sufficient enough to crack and separate compact snow/ice on a metal pole or driveway?

Thanks!

submitted by /u/KTong94
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How can you know when the Aurora Borealis will be be visible?

Posted: 09 Dec 2016 06:20 PM PST

I have a bucket list trip scheduled to Ivalo, Finland at the end of December to see the Northern Lights. Is there any way to know if they will be visible?

submitted by /u/amttaylor
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What does actual economic research say about ways to achieve a high amount of sustained growth?

Posted: 09 Dec 2016 11:56 AM PST

Why is blue light the hardest colour of light to focus our eyes on?

Posted: 09 Dec 2016 09:25 AM PST

My robotics teacher mentioned that blue LEDs are used in keyboards and other indicator lights, as it's the hardest colour to focus on and we don't pay much attention to it.

Googling around has verified that blue is hard to focus on but I can't find any credible research talking about it or verifying it, so is it the hardest colour to focus on and if so, why?

https://www.reference.com/science/hardest-color-see-d53b847eb1eeff5e#

Is the most credible source I've found, but all of the links it references are dead.

submitted by /u/TestPostPleaseIgnore
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How are tire treads designed?

Posted: 09 Dec 2016 05:46 PM PST

I learned about coefficients of friction in college but it can't be that simple, right? Does the tread pattern increase friction or is it more about redirecting water and dirt?

submitted by /u/Angrybagel
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Does there exist a chart or diagram which visually shows that the faster an object moves in a spacial dimension, the slower it moves in the time dimension?

Posted: 09 Dec 2016 05:41 PM PST

Special and General Relativity say that as a massive object's velocity increases through a spacial dimension, its velocity through the time dimension decreases. I imagine that it would be fairly easy to chart the relationship on a graph, but I can't find one that does this.

I remember once seeing a demonstration that all objects always move at c through spacetime, but an object can only move at c through spacial dimensions if its velocity through time is zero (i.e. it has no mass). An object with mass always has some non-zero velocity through time, and so can never reach c in spacial dimensions. In other words, it was something like, "an object's total velocity (c) = the object's velocity in space + the object's velocity in time."

Could somebody link a graph explaining the relationship between an object's velocity in space and it's velocity in time, and how those two numbers are related to c? Or, if you're feeling particularly generous, could you make one yourself? I'm hoping for an animated graph, but i understand that that may be asking a lot.

Thanks very much!

submitted by /u/non-troll_account
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Where do deepsea anglerfish get their bioluminescent bacteria?

Posted: 09 Dec 2016 11:45 AM PST

I learned that deepsea anglerfish commonly use bioluminescent bacteria to light up their lures. But where do the anglers get that bacteria from?

submitted by /u/xXHacknslasHXx
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Why does drinking alcohol lead to drunkenness?

Posted: 09 Dec 2016 10:16 PM PST

Follow up question- Why does drunkenness lead to nausea?

submitted by /u/doublebassed
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What's happening at the molecular level to cause the colour change during titration?

Posted: 09 Dec 2016 10:14 PM PST

Asking this due to the recent why is water blue question.

I do various titrations at work to ensure our process water is within spec. I will take our M-alkalinity test as the example since I've noticed a variation.

Normally, when I titrate with our M Indicator (60-100% Isopropanol/1-5% Methanol) it will start off blue when M-alk is present with the endpoint being orange. Now I've noticed when the water has higher than normal levels of free Cl2 the endpoint will be green-yellow.

The different colour for the endpoint has not affected the results. 250 ppm M-alk /w 0.13 ppm Free Cl2 & 250 ppm M-alk /w 2.18 ppm Free Cl2

Why do I see orange with low levels of free Cl2 and green-yellow with high levels of free Cl2?

submitted by /u/Ristake
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