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Sunday, March 18, 2018

Durban, South Africa. Are these different colors due to the Umgeni river or the difference in temperature that affects plankton?

Durban, South Africa. Are these different colors due to the Umgeni river or the difference in temperature that affects plankton?


Durban, South Africa. Are these different colors due to the Umgeni river or the difference in temperature that affects plankton?

Posted: 18 Mar 2018 06:13 AM PDT

https://i.pinimg.com/originals/68/cb/d4/68cbd4ef6dfe679f329cb1bf38b82a8c.jpg

Couldn't find much info, maybe when they release the dam it carries more sediment because in the pictures I found the river is not so brown.

submitted by /u/JohnnyFriendzone
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Could you use jet engine with, ramjet and than sramjet in series?

Posted: 18 Mar 2018 04:38 AM PDT

Consider that jet engine would be at the front and would have turbine cappable of reducing speed bellow mach 1 and keeping temperature in save level.

submitted by /u/davcrt
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How is a fighter jet engine different from a commercial jet engine?

Posted: 18 Mar 2018 06:03 AM PDT

Why does salt increase rusting in a metal when it doesnt take part in the reaction. Is it a catalyst? If so how?

Posted: 17 Mar 2018 07:01 PM PDT

Can we use nuclear weapons for good? Elon Musk said we can use them to melt Mars's ice caps. Are there any other positive uses?

Posted: 18 Mar 2018 05:23 AM PDT

I've been fascinated by ball lightning for a long time. Has a reasonable theory emerged as to what causes it or is it still a mystery?

Posted: 17 Mar 2018 05:14 PM PDT

Does the heat released in a chemical reaction affect the rate of the reaction?

Posted: 17 Mar 2018 07:30 PM PDT

Every single reaction is either exothermic or endothermic and the temperature the reaction happens in affects the rate constant k and therefore the equilibrium of the reaction, so does, for example the heat released from an endothermic reaction affect the rate constant of that reaction, increasing the rate? this would mean that any calculated rate constants and equilibrium constants are only correct for a very short period time would it? Or is the heat released somehow accounted for in the rate constant?

submitted by /u/mlop098
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Is There a Relationship Between Standard Candle Stars and Stars on the Main Sequence of the Hertzsprung-Russell Diagram?

Posted: 18 Mar 2018 06:01 AM PDT

Physicists sometimes talk about symmetry or "supersymmetry", but they seem to use it in a different way than in normal conversation. What does it mean in this context?

Posted: 17 Mar 2018 02:21 PM PDT

What's actually going on in double-jointed people?

Posted: 17 Mar 2018 11:17 AM PDT

Where is the flaw in my reasoning?

Posted: 18 Mar 2018 02:52 AM PDT

This page poses a question:
If it takes 5 machines 5 minutes to make 5 widgets, how long would it take 100 machines to make 100 widgets?

My solution:
If it takes 5 machines 5 minutes to make 5 widgets then 5 machines produce widgets at a rate of 1 widget/min. That means 1 machine produces widgets at a rate of 0.2 widgets/min. So 100 machines would make 50 widgets a minute. Therefore, it would take 100 machines 2 minutes to make 100 widgets.

But the page suggests that the answer is 5 minutes. Where is the flaw in my reasoning?

submitted by /u/foxneZz
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What happened to Apollo 16 Lunar Module?

Posted: 17 Mar 2018 05:06 PM PDT

After the ascent, it was intended to crash on the Moon.

But I've read it did stay on orbit for over a year... How? and How it crashed if on the Moon there is no atmosphere to drag it down like on Earth??

submitted by /u/rBeowulf
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Why can insects survive so long after receiving wounds that would instantly kill a human or other animal?

Posted: 17 Mar 2018 09:40 AM PDT

When you are in a coma, do you go through sleep stages like REM or deep sleep?

Posted: 17 Mar 2018 06:15 AM PDT

My Dad is currently in hospital at the moment and is in a medically induced coma and I was wondering whether or not when people get put into a coma, induced or not, whether they go through the three stages and following from that. Do they dream?

submitted by /u/ep123pearce
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The bennu asteroid has a 1 in 2,700 chance of striking Earth on September 25, 2135. How are odds of an asteroid impact calculated? How are they adjusted over time? What don't we know that makes them measured by chance?

Posted: 17 Mar 2018 08:52 AM PDT

I keep seeing articles about the bennu asteroid having a 1 in 2,700 chance of striking Earth on September 25, 2135. I'm curious about what factors into how these chances are progressively changed over time.

submitted by /u/eastarcadia
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How can we tell the make-up of exo-planets from light alone?

Posted: 17 Mar 2018 01:45 PM PDT

Was watching a YouTube video the other day of cool planets (i.e planet made of diamond etc)

Now from my understanding (and I may have this completely wrong) is the only way we can 'see' exo-planets is when they pass infront of the star.

So how can we, from just the shadow predict the make up of these planets? Is there other tests I do not know about or do we just know how light 'passes-by' these planets?

TIA

submitted by /u/kingkornish
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How accurate is our measurement of great distances in space?

Posted: 17 Mar 2018 05:02 PM PDT

This is a two part question:

Given that the Earth orbits the Sun on an ellipse, does the Astronomical Unit change on any given day when trying to determine the distance of celestial bodies?

If parallax is only effective for objects within a certain distance, how do we measure the distance of bodies that are really far away?

Thank you!

submitted by /u/Jak03e
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Approx what percentage of the Universe is visible in the famous “Pale Blue Dot” photo?

Posted: 17 Mar 2018 06:44 PM PDT

I understand this photo is an astronomically small portion of the universe but I was wondering if there is a rough estimate as to what fraction of a percent of the universe it shows? Trying to really wrap a friends head around how small earth is in the universe.

submitted by /u/chudleyjustin
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How did umbilical cords work before modern surgery, lets say the stoneage? Did they just fall off? Did humans just have pieces of gut dangling for a while?

Posted: 17 Mar 2018 09:42 AM PDT

Like bruh what did their belly buttons look like

submitted by /u/fabbez98
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Saturday, March 17, 2018

Could I have a bag of neutrons? And if so, what would it look like, would they be reactive?

Could I have a bag of neutrons? And if so, what would it look like, would they be reactive?


Could I have a bag of neutrons? And if so, what would it look like, would they be reactive?

Posted: 16 Mar 2018 08:40 AM PDT

Why do nuclear power plants have those distinct concave-shaped smoke stacks?

Posted: 17 Mar 2018 06:07 AM PDT

Were superconductors theorised first or discovered?

Posted: 17 Mar 2018 05:49 AM PDT

The title say it all really.

Were they mathematically predicted first or just discovered by accident or similar?

submitted by /u/ChakMlaxpin
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Does having only one testicle affect testosterone, muscle growth, etc?

Posted: 16 Mar 2018 11:08 PM PDT

Google wasn’t clear on this, but how is the brain able to throw a object or catch a object and predict when, where, etc etc. All on its own? It’s like advanced trig near instantly?

Posted: 16 Mar 2018 09:03 PM PDT

When I read an article on my phone, do I drain my battery significantly faster when I scroll a little as I read each line of text, compared to only scrolling once I've read a whole screen of text?

Posted: 16 Mar 2018 09:58 PM PDT

Does lightning really form from the ground up?

Posted: 17 Mar 2018 12:48 AM PDT

so ive heard that lightning form from the ground and go up. It doesen't seem like it when you see a still image of the way it branch out.

submitted by /u/Divide-By-Turtle
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How fast do clouds move in relation to the earth? What factors are there when measuring the speed of clouds?

Posted: 17 Mar 2018 12:14 AM PDT

Just looking at clouds on the chair lift this morning and during conversation with my friend we were discussing like what needs to be understood to know how fast clouds are moving.

submitted by /u/jbmac77
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What makes noble gases inert?

Posted: 17 Mar 2018 08:10 AM PDT

What I've been taught is that it's because their valence shell is fully filled and they follow the 2,8,8 octet rule. But beyond argon, that explanation doesn't fully show why the other noble gases are inert.

submitted by /u/aelin_farseer
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Why do we refer to radio frequencies in terms of frequency, not wavelength? We refer to everything from IR to UV in wavelength, and media from before the 50's or so tends to use wavelength. Why did we switch?

Posted: 16 Mar 2018 04:28 PM PDT

How is a completely flat surface created?

Posted: 16 Mar 2018 08:51 PM PDT

How is a completely flat surface created? As in, what process took place to turn materials from the environment into completely flat objects (which could then be used again to create flat objects)...

submitted by /u/0100011001001011
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How does classical information arise from quantum building blocks?

Posted: 16 Mar 2018 09:57 PM PDT

How does classical information arise from quantum building blocks? How could I build (or approximate) a bit that is copyable and a non-reversable NAND gate from purely quantum operators?

submitted by /u/rotuami
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How does LSD effect Fetal Development ?

Posted: 16 Mar 2018 09:47 PM PDT

Saw a similar post earlier on r/morbidquestions and did a google search. Nothing too in depth but I wasn't able to find anything conclusive or even close to it in terms of reliable studies and the most in depth one I could find was from the 70's. Would love to hear if anyone on this sub has any knowledge or theories about positive or negative side affects. Should go without saying that I'm not advocating it but from what I was able to find it didn't have any harmful side affects physically. The article I read seemed kind of contradicting in that it stated their was chromosomal damage and yet it wasn't a terogen. Thoughts?

submitted by /u/JoeSchmohawk
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Is land usage for beef increasig or decreasing (production/land area) Anyone have data resource globally or country per country?

Posted: 17 Mar 2018 05:56 AM PDT

Meat production increased the last 30 years, but i suspect land area usage decreased due to more effective farms ect. Who knows? I would like to know!

submitted by /u/Memohigh
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[chemistry] Do electrons ever switch places within the same atom?

Posted: 16 Mar 2018 04:24 PM PDT

Why we can't get the integral of sin(sin(x))dx ?

Posted: 17 Mar 2018 05:22 AM PDT

Are there any other planets in the solar system which, when viewed from their surface, their moons appear to be exactly the same size as the sun?

Posted: 16 Mar 2018 04:43 PM PDT

I watched the eclipse with my friends last summer, and it occurred to me, "Hey, the moon is just exactly the right diameter, and distance from the Earth, that when you look at it from the Earth, it appears to be exactly the same size as the sun." Is this just a coincidence, or is there a good reason for this?

Are there other planets in the solar system where their moon(s) appear to be the same size as the sun? That is, you could watch an eclipse from the planet, and it would look like it does on Earth, where you can see the halo, or corona, of the sun, around the moon?

submitted by /u/wam235
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Does the rotation of the earth's magnetic field (either around the poles or around the sun) generate an electric field?

Posted: 16 Mar 2018 03:49 PM PDT

Does there exist a dielectric that would lower the capacitance between two plates instead of raise it?

Posted: 16 Mar 2018 08:37 AM PDT

we keep finding all these examples of humans interbreeding with other hominids, are there any modern animals that successfully interbreed with different species?

Posted: 16 Mar 2018 08:10 PM PDT

How porifera (sponges) life-cycle, reproduction and longevity is affected by its environment and life in colony?

Posted: 16 Mar 2018 02:54 PM PDT

Hello, i'm developer for educational aquarium game/simulator, we're implementing poriferas, and i have some niche questions for someone with experience/expertise in tropical/salt-water sponges. I did my search, looked through Google Scholar and Books, and unfortunately could not find conclusive answers, so i would be very thankful if any of r/AskScience marine biology scholars/students would be able to spend 30 minutes for answering questions below.

All questions are about average/most common species of porifera phylum. I understand there are extremities and notable differences between species, but i will refer here as "sponge" to the average/most often documented behaviour, or the specie You are most comfortable to answer about.

1) Does every sponge reproduce? If there is colony of sponges, is there some kind of "monarch" that reproduces more often? Does sponge age affects it fertility? If sponges reproduce annually, can something break the cycle? Do they reproduce every year until death? What environmental mechanism regulates whether sponge reproduces in K/r strategy, does it only vary between species and is independent of available resources?

2) What is the reason for sponges dying "of old age" if there are no organs to fail? Do sponge cell replication mechanism is limited by telomers length like in other animals? Is sponge in colony individual organism that lives and dies on it's own "cycle", or is part of one single organism, similar to fungi? Does sponge live as long as the colony, and dies only due to environment change/depletion of resources, or do they just die-off more or less in order of being born?

3) In the rare case of sponges that reproduce by budding (and for the species that are hermaphrodites and germinate without other specimen) - is the sponge heir a perfect clone of parent, or does random minuscule mutations happen in the process of reproduction noticeably more often than in case of normal sponge cell replication? Is there some time threshold (linked to annual reproduction cycle) after which sponges capable of self-germination do it?

I would be very glad if anyone can at least partially clarify those topics, or forward me to someone who would find time to do it. Thank You very much.

I've also posted this in r/marinebiology, if it's not okay to repost that - i apologize, and please remove this post

submitted by /u/Koksny
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What properties and characteristics of transition metals allow it to act as a catalyst for organic reactions?

Posted: 16 Mar 2018 04:20 PM PDT

Friday, March 16, 2018

Do electrical cables have a jerk effect, similar to a water hose, would the voltage/throughput matter?

Do electrical cables have a jerk effect, similar to a water hose, would the voltage/throughput matter?


Do electrical cables have a jerk effect, similar to a water hose, would the voltage/throughput matter?

Posted: 15 Mar 2018 03:05 PM PDT

AskScience AMA Series: I am Jessica Pierce, a bioethicist who has recently focused my work on animals. AMA!

Posted: 16 Mar 2018 04:00 AM PDT

Jessica Pierce is a bioethicist who has extensively written about bioethics and animals. Bioethics is a field of research that sits at the crossroads of biomedical sciences and ethics, and bioethicists explore ethical issues in the biomedical sciences.

Jessica has authored or co-authored more than 30 articles in peer reviewed journals, and writes for many publications including The New York Times, The Wall Street Journal, and Scientific American. Her recent article, "You Love Dogs? Don't Clone Them" makes a case against cloning pets. Jessica also publishes a blog on Psychology Today. Here is her blog.

Her published works include Run, Spot, Run: The Ethics of Keeping Pets which discusses moral ambiguities in pet ownership, The Last Walk: Reflections on Our Pets at the Ends of Their Lives which discusses caring for pets in the end of their lives, and Wild Justice: The Moral Lives of Animals, which discusses prosocial behaviors in pets.

More information about Jessica can be found on her website. She'll be joining starting at 3:30 ET (1930 UT)!

submitted by /u/AskScienceModerator
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What is a Lagrangian? What is the action? Why does the principle of least (stationary) action work?

Posted: 15 Mar 2018 11:02 PM PDT

I've gone through the procedure in class. I've gone through it again watching Leonard Susskind's online lectures. Newton's equations pop out... or whatever correct equations we're looking for ... and I have no idea why.

Why should this procedure work? Please help me- I feel like I'm a wizard invoking spellcraft.

submitted by /u/TwirlySocrates
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Why are the oceans salty and where does the oceans salt com from?

Posted: 16 Mar 2018 04:30 AM PDT

Bosons have integer spin (such as 1, 2 or 3) whereas fermions have half-integer spin (such as 1/2, -1/2, 3/2, 5/2). In what situation does a boson have for instance spin 3, and a fermion spin 3/2?

Posted: 16 Mar 2018 06:28 AM PDT

Since neutrinos DO interact with particles if they get lucky, such as atomic nuclei, do neutrinos interact with the strong force, or weak force?

Posted: 15 Mar 2018 02:24 PM PDT

What does Particle Horizon growth mean to observer?

Posted: 16 Mar 2018 05:17 AM PDT

I've read this title

https://www.reddit.com/r/askscience/comments/4msj5s/do_we_suspect_there_are_galaxies_were_already/d3yxrw5/

Still I can't get this: "Note that the particle horizon grows over time. So more and more galaxies become visible until the end of time." So as for now these galaxies out of PH or inside?

Yes, there are galaxies will never see at all, specifically those galaxies beyond a co-moving distance of about 65 Gyr.

Does it mean we can find galaxy in a distance between 32 (the most distant galaxy we see already) & 47 (PH) Gyr NOW but in a future we would be able to find something closer than 65 Gyr? So 65 Gyr boundary isn't increasing in time? So in infinte perspective PH is limited by 65 Gyr?

submitted by /u/stout_sigma_penguin
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Would the impact of a very big meteor like the one causing the dinosaurs extinction be noticeable around the world?

Posted: 16 Mar 2018 06:43 AM PDT

Does using a graphics card create "wear and tear" on the GPU?

Posted: 15 Mar 2018 08:53 AM PDT

Take a graphics card that is run 24/7 for two years as part of a crypto mining operation. Assume that heat is never an issue because it's sufficiently cooled and that its undervolted like most miners do. What kind of "wear and tear" is applied to the GPU and ram chips through constant use?

submitted by /u/spooed
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Is it possible that we could discover some place deeper than Challenger's Deep?

Posted: 15 Mar 2018 12:43 PM PDT

What prevents carbon from forming four bonds with another carbon atom?

Posted: 15 Mar 2018 11:39 AM PDT

NASA's Kepler Space Telescope is running out of fuel. What type of fuel does it use and why does it need it?

Posted: 15 Mar 2018 12:54 PM PDT

When I look at picture of Kepler, I can see solar panels. Is the power coming from those panels insufficient to keep the telescope in orbit?

Could a future telescope run entirely off of solar or will a fuel source always be required?

Relevant article: https://www.nasa.gov/feature/ames/nasa-s-kepler-spacecraft-nearing-the-end-as-fuel-runs-low

submitted by /u/banedon
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Why are observatories on hills and mountains? Does this extra height help?

Posted: 15 Mar 2018 01:05 PM PDT

How many atoms are being split in an atomic bomb? What would happen if they did a bunch of them (like 5x the amount or more) Would it have any effect on the size of the explosion?

Posted: 15 Mar 2018 07:06 PM PDT

Can low energy beta radiation emitted from a tritium vial damage plant seeds?

Posted: 15 Mar 2018 06:49 PM PDT

How long does it take for a new island to get colonised by plant and animal life?

Posted: 15 Mar 2018 10:26 PM PDT

This is in the context of either islands formed due to the resurfacing of an older land mass or the eruption of volcanoes.

submitted by /u/justfor_hasya
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Do sunspots have antipodal sunspots?

Posted: 15 Mar 2018 05:44 PM PDT

I just learned that sunspots are a result of magnetism (forgive me if I get the phrasing wrong). This idea came from the fact that celestial bodies, for the most part have magnetic fields. (Assuming that if sunspots do have antipodal sunspots, they don't necessarily have to be equal in size, they merely have to exist)

submitted by /u/__Kev__
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When transmitting RF, how do electrically long and electrically short lines affect your transmission?

Posted: 15 Mar 2018 05:26 PM PDT

Is compensation needed in either case? Is the 'ideal' line length equal to 1/4λ ?

submitted by /u/AbsoluteZero_
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Is there anything that won't be a solid at absolute zero?

Posted: 15 Mar 2018 05:59 PM PDT