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Friday, November 29, 2019

Do we know why the inner planets of the solar system are all rocky compared to the outer planets which are all gas giants?

Do we know why the inner planets of the solar system are all rocky compared to the outer planets which are all gas giants?


Do we know why the inner planets of the solar system are all rocky compared to the outer planets which are all gas giants?

Posted: 29 Nov 2019 02:29 AM PST

Humans can easily identify other humans using their faces alone, but we generally can't easily distinguish one member of a species from another by face alone (e.g. a lion from the others). Do animals have the same ability to recognize each other (same species) from face alone?

Posted: 29 Nov 2019 06:49 AM PST

How does our body regulate white blood cell count?

Posted: 29 Nov 2019 03:28 AM PST

It seems really good at ensuring it isn't over/under producing white blood cells so I was wondering how it achieves this. I tried googling this expecting a pretty straightforward answer but I can't find anything.

submitted by /u/grummybum
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If I were on a space station 2 light years away?

Posted: 28 Nov 2019 11:21 PM PST

Ok, so basically say I, right now, was instantaneously teleported via some kind of magic to a space station 2 light years away. I have a telescope on this space station that is so powerful I can see people walking around on city streets in minute detail, would the planet I see be Earth in the year 2017?

And if so could I theoretically see myself walking around on the surface of planet back in 2017?

submitted by /u/PropheticVisionary
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When getting a brain scan, doctors will typically compare your results with a “normal” functioning brain. How did we decide how a “normal” brain is supposed to work and who did we use to measure this?

Posted: 28 Nov 2019 11:24 PM PST

How can Ethylene carbonate be organic solvent for liquid eletrolytes?

Posted: 29 Nov 2019 05:35 AM PST

In relation with Li-ion batteries EC and DC form solids at room temperature. additives or lithium salts increase their melting points?

submitted by /u/iiiiiiffy
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Why is lactose-negative bacteria are more likely to be the pathogen in fecal samples than lactose positive-bacteria?

Posted: 29 Nov 2019 01:23 AM PST

Before ~1850, did people know the effects of drinking while pregnant? Or were many children just born with fetal alcohol syndrome?

Posted: 28 Nov 2019 12:02 PM PST

What is the 'darkest' place on the surface of the earth - in terms of light pollution?

Posted: 28 Nov 2019 01:39 PM PST

(with the 'surface' part I just mean that it's a spot where the sky/universe can be seen, not like any cave or something like this)

submitted by /u/Ebenberg
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Does the size of an individual cell within a multicellular organism scale up or down with the size of the whole organism?

Posted: 28 Nov 2019 10:11 PM PST

Like compare a human and an ant. Are our epithelial (skin) cells roughly the same size, and humans just have way more than ants, or are there about the same number of cells and human skin cells are just considerably bigger?

What about neuronal (brain) cells? Or blood cells?

How does the size of individual cells typically compare between the biggest organisms on the planet (like whales) and the smallest (like ants)?

Thanks!

submitted by /u/FortCollinsPornAlt
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Why does a pot of water that's been heating on a stove sometimes suddenly boil if it's moved even just a little bit on the burner?

Posted: 28 Nov 2019 04:44 PM PST

How does streaming work?

Posted: 28 Nov 2019 01:36 PM PST

Can somebody point me to a decent online course or YouTube videos or a textbook on this? I got off the technical track about the time streaming vids became easy, and now that I've cut the cord and am dealing with Roku and YouTubeTv with the discussions of compression, interlacing, upconverting, etc. I need to go back to school.

And if this isn't the right sub for this type of question, can you point to a better one? r/streaming is just gamers.

submitted by /u/p0rnflow
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Studying theatre, I've heard teachers talk about the long "E" phoneme sounding excited but tinny and irritating, or the long "O" phoneme sounding melancholy and solemn... is there any science behind the emotions that specific phonemes elicit? If so, what sounds match to what emotions?

Posted: 28 Nov 2019 06:06 PM PST

What processes do vaccine manufactures use to make sure inactivated viruses are truly, 100% inactivated?

Posted: 28 Nov 2019 11:24 AM PST

and what's the scientific/realistic probability that in the modern day, a tiny portion of a batch of vaccine may actually contain un-inactivated virus?

submitted by /u/PuppyPriest
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How does the lac repressor prevent transcription of the operon?

Posted: 28 Nov 2019 09:34 AM PST

Does the repressor completely block binding of RNA polymerase to the promoter or does it only prevent the initiation of transcription?

I'm asking this because we talked about 2 experiments in class that seemed to contradict each other

One experiment used a run off transcription assay and found that a run-off product was generated, suggesting that RNAP was capable of binding to the promoter when the repressor was bound to the operator.

Another experiment used ChIP and concluded that RNAP could only bind to the promoter when the repressor was not bound to the operator.

I thought it might have to do with the fact that the operon has 3 operators (O1, O2, and O3) but im not sure. Sorry if the experiments are vague, i can describe them in more detail if needed.

submitted by /u/Interferon-Gamma
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How can one side of the brain do "all the work" after a Hemispherectomy?

Posted: 28 Nov 2019 01:19 PM PST

I've been reading about hemispherectomies and I find the operation both fascinating and baffling. I understand that the brain can only adapt when it's done to children because they have a higher degree of neuroplasticity and that at an early age the brain can "rewire" itself and basically be a completely functional brain; what I don't understand is, how can the brain adapt to losing half of its neurons? I know that the number of neurons isn't the only relevant number and I assume that the number of synapses grows significantly in the remaining hemisphere, but it's baffling that the brain can adapt to such damage. Is the number of synapses that much more important?

The idea that the brain can function after losing 50% of it's matter also brings up a lot of questions I'd love to know the answer to. Is the brain simply not as efficient as it could be in normal people and that's why one half (that is I assume more efficient) can compensate so well? If so, is this the reason why there is a such an immense difference between people? Is the brain of a genius simply more like the remaining half of someone who went through a hemispherectomy? Are most brains simply stupid compared to what they could be if they reached their full potential?

I know that this is a loaded question and I assume that there isn't a definitive answer to most of my questions but I'd still love to hear more about the topic. Thanks in advance!

submitted by /u/chairflunger
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How are our diaphragms able to function as both a voluntary and involuntary muscle?

Posted: 28 Nov 2019 05:56 AM PST

From what I remember from biology 101, skeletal muscles are controllable but interior smooth muscles around our organs aren't. What type of muscle cells make up our diaphragms? How are the nerves that connect our brains to our diaphragms different than other organs and body parts?

submitted by /u/William_Wisenheimer
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How should "t-channel" fermions in feynman diagrams be interpreted?

Posted: 28 Nov 2019 12:49 PM PST

So, in feynman diagrams, usually a fermion where the arrow points goes from left to right is a fermion, while if it goes from right to left, it is an antifermion, which is then interpreted as going backwards in time, as the x-axis is the axis of time.

But in many diagrams, you have a fermion line that goes vertically (examples: one diagram of compton scattering, neutral pion decay).

As I interpret it, this actually stands for a superposition of two diagrams - one where this line represents a fermion and one where it represents an antifermion. You would then have to sum over those two matrix elements. Is that a valid interpretation?

submitted by /u/PockSuppet123
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How does a computer know which 0s and 1s belong to a color vs a number representation?

Posted: 28 Nov 2019 06:11 AM PST

For example:

I know that the binary system translates 0s and 1s to let's say the number 76. And this 76 is translated on to a map named unicode to translate it into a character.

Then there is RGB which is also regulated by 0s and 1s to represent any color you like on your computer screen.

But how does a computer distinguish these two?

submitted by /u/Smashball96
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If Genomic imprinting is the only thing that stops an egg from fusing with another egg, would this mean there is nothing to stop an egg from fusing with another egg in species that lack Genomic imprinting?

Posted: 28 Nov 2019 05:41 AM PST

My questions are; 1) If Genomic imprinting is the only thing that stops an egg from fusing with another egg, would this mean there is nothing to stop an egg from fusing with another egg and forming a zygote in species that lack Genomic imprinting?

2) But if in species that lack Genomic imprinting, an egg can never fuse with another egg, that would mean Genomic imprinting is not the only reason an egg can not fuse with another egg, right?

3) Do species that lack Genomic imprinting have analogous processes similar to Genomic imprinting that have helped and help decipher the mechanisms of specific gene expression which stop an egg from fusing with another egg and forming a zygote? If yes, what are the names of these similar processes?

4) Hypothetically speaking, would an egg "fusing" with another egg mean this egg is "fertilizing" another egg? And is this "sexual reproduction"?

submitted by /u/Realistic_Abies
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How often do people actually use the stem cells that they have banked?

Posted: 27 Nov 2019 05:00 PM PST

I've heard of saving cord blood and the like and was curious how often people actually use it. I understand that it is only used when needed but is there a large percentage of the people who use their saved cells?

submitted by /u/psych_guy80
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Thursday, November 28, 2019

Is there a proof that the maximum value for the multiplication of a set of positive numbers of finite sum is achieved when the numbers are all "e"?

Is there a proof that the maximum value for the multiplication of a set of positive numbers of finite sum is achieved when the numbers are all "e"?


Is there a proof that the maximum value for the multiplication of a set of positive numbers of finite sum is achieved when the numbers are all "e"?

Posted: 27 Nov 2019 10:31 PM PST

I have noticed a curious numerical association, and I can not find a method to prove whether my assumption about it is correct or not.

(Please note that my background is engineering, not pure math, so my explanation might be a bit simplistic).

Given a positive number, "a", expressed as an arbitrary sum of smaller positive numbers: a = a(1) + a(2) + ... + a(n).

Let x = a(1) * a(2) * ... * a(n).

It appears that the value of x is maximized when a(1) = a(2) = ... = a(n) = e (as near as possible).

I have no idea why this should be, but I'd be interested to know if there is a mathematical proof of why it be as it seems to be...

Thanks!

submitted by /u/foodfighter
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After a nuclear detonation, why do rings appear sometimes around the mushroom cloud?

Posted: 28 Nov 2019 05:10 AM PST

How is data stored on Discs and other memory devices?

Posted: 27 Nov 2019 09:34 AM PST

Why do compounds that have partially filled d-orbitals usually form colored solutions when dissolved?

Posted: 27 Nov 2019 03:45 PM PST

Why do compounds that have partially filled d-orbital subshells tend to form colored solutions?

Are there certain properties that allow compounds with partially filled d subshells to emit more visible light, or am I thinking of it incorrectly? I assume it has to do something with energy levels and electrons, but I'm not entirely sure what.

Some examples are CoCl2 (Cobalt (II) Chloride) or KMnO4 (Potassium Permanganate).

submitted by /u/virtualakiko
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How do rebreathers work?

Posted: 27 Nov 2019 09:25 AM PST

Can you shoot electrons at photons to absorb [some portion of] the photon's energy?

Posted: 27 Nov 2019 05:51 PM PST

(I think the answer is yes, but I'm not sure - it's a lead in question to the following two, based on an assumed yes) Is there any configuration of combined state between these two particles that would produce some interesting results if you shot them at each other? What about with very high energy states (gamma rays)?

submitted by /u/bass1012dash
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Why do people get put in induced comas?

Posted: 27 Nov 2019 06:30 AM PST

What is the difference between being unconscious, and being, awake and resting, when your body is dealing with trauma and healing?

submitted by /u/Kizza178
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Why is regular/dark matter (w=0) said to slow down expansion? I thought the Friedman equations say that energy density, regardless of equation of state, cause expansion?

Posted: 27 Nov 2019 05:36 AM PST

I know that w=0 for matter leads to a shrinking energy density as the universe grows, and therefore the contribution to H from matter will shrink, but this is different from matter reducing the value of H. If more dirt was added to the universe, wouldn't the energy density and thus acceleration increase? Eventually the dirt would become spread out by the size of the universe and its contribution would tend toward 0, but never is this dirt slowing the expansion.

 

It sounds pedantic, but as I understand it a better description would be that: w=0 matter adds to expansion in a way that decreases with a and therefore time, and so in a matter dominated universe the expansion slows (but doesn't stop, see the a~t2/3 equation or whatever) due to a's increasing, not directly due to that matter. This makes a difference as when I was taught it, the reductive "dark matter slows expansion" statement misled me greatly.

 

Additionally, I know the H2 ~ density equation, but is there anything that says when solving for H we must take the positive square root for expansion and not the negative for shrinkage?

submitted by /u/DiamondGP
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How much do flies actually contribute to the distribution of pathogens, especially in places where diseases like dysentery are not really found?

Posted: 26 Nov 2019 02:38 PM PST

Wednesday, November 27, 2019

How do CO2 scrubbers work?

How do CO2 scrubbers work?


How do CO2 scrubbers work?

Posted: 27 Nov 2019 03:58 AM PST

Why do we use three phase instead of two phase?

Posted: 26 Nov 2019 02:20 PM PST

I understand why we use three phase electricity instead of 4,5,6 etc but why don't we use 180 degree shifted two phase systems? Thanks in advance

submitted by /u/Hopp5432
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Ask Anything Wednesday - Biology, Chemistry, Neuroscience, Medicine, Psychology

Posted: 27 Nov 2019 07:09 AM PST

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!

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Do leaves keep photosynthesising after the fall of the tree if they are still green?

Posted: 26 Nov 2019 05:04 PM PST

A few weeks back I got curious and read an article about what frequencies of light plants use in photosynthesis and where that evolved from. With fall coming ever so slowly to my home in Denton Texas I've noticed many of the leaves i see on the ground are still green and so presumably still absorbing those same frequencies of light they use in photosynthesis. Does this mean that these leaves are still, if only partially, photosynthesising or are they just holding on to the chlorophyll?

submitted by /u/BurAMG
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How does CRISPR target specific genes?

Posted: 26 Nov 2019 08:50 PM PST

How does CRISPR technology target one specific gene out of the roughly 30,000 genes in the human body? I just can't wrap my mind around how this is possible. And in my research and I can't seem to find a straightforward answer.

submitted by /u/nago7650
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If a object perfectly encircled a source of gravity, equidistant on all sides, would it ever fall in?

Posted: 26 Nov 2019 05:59 PM PST

I had this thought when reading about stellar constructs.

Say I build something like a Dyson sphere, if it encompasses the Star perfectly and on all sides was equidistant, if it started to drift, wouldn't the stars gravitational pull slowly correct it again to be equidistant?

submitted by /u/CrypticSympathy
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Why are the elements between polonium and actinium (84-89) so much less stable than heavier elements?

Posted: 26 Nov 2019 12:18 PM PST

It seems like there's a gap where isotopes with mass numbers around 210-220 where everything is ridiculously unstable. See this table and the circled area. What causes that massive dip in instability? It's like there should be some stable isotopes in this area but there aren't.

I'm guessing this has something to do with these being just after lead which has a closed proton shell in the nucleus. But if that is the case why is bismuth also (mostly) stable? And why does it not happen to elements after tin too?

EDIT: This answers the question https://www.quora.com/Why-are-elements-84-89-so-unstable-Uranium-and-Thorium-are-so-much-more-stable-despite-being-of-higher-atomic-number

submitted by /u/Quackmatic
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Does atmospheric pressure affect synaptic re-uptake of neurotransmitters?

Posted: 26 Nov 2019 02:41 PM PST

I've noticed a personal correlation between how I feel and the local atmospheric pressure reported on https://www.wunderground.com/. Low pressure seems to correlate with a high-energy, almost manic, state of mind, whereas high pressure seems to be often accompanied by lethargy.

This could simply be correlation and not causation, or some kind of placebo. But I was just curious whether there are any studies on the effects of ambient pressure on synaptic function.

submitted by /u/Shloosh
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Why doesn't plants seem to have an age limit?

Posted: 26 Nov 2019 09:41 AM PST

I have the impression that plants have no built-in age limit like humans and many animals. If perfect conditions persist indefinitely, it looks like plants can also live indefinitely. I am primarily thinking of trees, but I've read about herbaceous plants that can re-sprout annually, apparently without limits.

In humans I've been told that telomeres partly determine the life-span. They reduce in length every cell division, and when worn away, genetic material deteriorate from the edges of the chromosomes. Does plant chromosomes have telomeres? How is genetic material preserved in plants for such long time periods?

Does the age of (viable) seeds determine life-span of plants? Some seeds may stay viable for decades and longer, are there any notable differences between two individuals of a species who have sprouted from very differently aged seeds?

submitted by /u/MingoMash
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When birds migrate in a V formation, does the same bird always lead?

Posted: 26 Nov 2019 01:55 PM PST

If the moon was stationary, would it “fall” towards the Earth at 9.8 meters per second?

Posted: 26 Nov 2019 10:07 PM PST

A feather and a hammer fall at the same rate. Wouldn't this be false at larger scales?

Posted: 26 Nov 2019 09:48 PM PST

Galileo posited that objects fall at the same rate regardless of their mass. But if we were to scale this up to planetary size, for example; The Earth, The Moon, and an Asteroid, this shouldn't hold up.

If we "drop" the Moon onto the Earth from a standstill, shouldn't it hit the Earth quicker than an astroid dropped from the same distance, due to the fact that the Moon is also pulling the Earth toward itself?

submitted by /u/arod48
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What was the cause of the glaciation at the end of the Ordovican era?

Posted: 26 Nov 2019 12:53 PM PST

There isn't really a lot to add to the question. It's self explanatory. There was an ice age in the late Ordovican period. How did the ice age happen? Did the poles shift? Also did it continue throughout the early Sulurian era? How did it end?

submitted by /u/CoffeeSlutt
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What specifically is a dirac sea?

Posted: 26 Nov 2019 08:29 AM PST

Do Bones Get Stronger Through Constant Damage?

Posted: 26 Nov 2019 09:52 AM PST

I've seen Shaolin monks been stricken with sticks to strengthen their bones. Does this much damage actually promote bone growth when done multiple times a week, or does it do more harm than good? How much is overdoing it and does it work for muscles as well?

submitted by /u/HuronDorado
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I’m aware that radiation exposure can cause genetic mutations within animals and humans. However I’m unsure about plant life... can someone please tell me what sort of an affect high radiation exposure has on flora ?

Posted: 26 Nov 2019 02:23 PM PST

Are multivitamins effective at correcting vitamin deficiencies?

Posted: 26 Nov 2019 06:23 AM PST

Critical care RN and consumer here. Routinely, I give PO multivitamins (usually through a DHT/NG/OG/PEG) to my patients and take a "One A Day" vitamin myself. My question is, does the multivitamin actually work at correcting/maintaining adequate (healthy) levels in the body? I know that it's a supplement (not medication), therefore it's not regulated by the FDA and I know that problems with absorption/distribution can be a factor. But, I haven't been able to find any papers or reviews providing data on whether or not these multivitamins work in a perfectly healthy human. Is it worth taking these vitamins? Do they actually do anything?

submitted by /u/brian31b
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What's the difference between a Polypeptide, a Subunit, and a Protein Domain?

Posted: 26 Nov 2019 04:47 PM PST

I've looked through a few different textbooks, and they seem to use them interchangeably, but I've been told they're very different.

My understanding is that a polypeptide is a bunch of amino acids that are linked together, functional or not. When multiple polypeptides are combined to form a protein, each individual polypeptide is called a subunit. Where does Domain fall into this?

submitted by /u/bennettsaucyman
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Can a liver from an organ donor be shared and transplanted into two new recipients?

Posted: 26 Nov 2019 09:12 AM PST

How do computers know what to do with the ones and zeroes? And how are different computing languages implemented?

Posted: 26 Nov 2019 12:46 PM PST

Sunrise/sunset times: why don’t they get later at same rate as we approach the solstice?

Posted: 26 Nov 2019 07:21 AM PST

Where I live, sunset is now about as early as it's going to get, and sunrise will continue getting later right up to December 21st. Why the variance?

submitted by /u/MnstrShne
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