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Wednesday, June 6, 2018

Why do things get darker when wet?

Why do things get darker when wet?

Why do things get darker when wet?

Posted: 05 Jun 2018 02:05 PM PDT

What happened to acid rain? I remember hearing lots about it in the early 90s but nothing since.

Posted: 06 Jun 2018 04:56 AM PDT

Does dust affect space telescopes such as Hubble?

Posted: 06 Jun 2018 05:19 AM PDT

There must be a huge amount of isolated dust particles in Space, particularly around Earth's atmosphere. I was wondering if dust gets stuck to Hubble's (and other telescopes') lenses or even damages the lenses due to the velocity it travels at? How do Space agencies deal with this issue?

submitted by /u/WonderfulMud7
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Why isint Rubidium more conductive than Copper?

Posted: 06 Jun 2018 04:14 AM PDT

Title. They both form a 1+ ion (mainly) but Rubidium has less attraction towards it's outer electron than copper, because of electron shielding and atomic radius, suggesting that it's valence electrons should be more mobile than copper, hence Rubidium should be more conductive. This however is not the case - why not?

submitted by /u/InProx
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Companies making washing detergent have been launching new and improved products for years. So what's the difference between a detergent sold in 1978 and one on sale today?

Posted: 06 Jun 2018 03:58 AM PDT

If each neutrino flavor has a different mass and this phase shifts their wave packet as they move causing oscillation, why isn't the wave packet stretched over long distances?

Posted: 06 Jun 2018 06:34 AM PDT

I'm trying to understand how neutrinos oscillate and I read that because each flavor has a different mass (the sum of all 3 is less than 1 millionth of an electron's mass) this causes their wave packet to phase shift but wouldn't this stretch out the wave packet over long distances so when the neutrino is in its heaviest form it would slow down? I guess mass can't change so how does this work?

They found a 4th neutrino that's apparently heavier and sterile which is what got me thinking about this: https://science.slashdot.org/story/18/06/05/2036233/scientists-may-have-discovered-a-new-fundamental-particle-sterile-neutrino

submitted by /u/redditor100k
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Can you get muscle cancer?

Posted: 06 Jun 2018 05:45 AM PDT

I heard cancers from everywhere from testicles to brain, but i have never once heard of muscle cancer.
Can you have cancer in your biceps for example?

submitted by /u/Baji25
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How do our bodies know when to wake up? What stops us from sleeping forever?

Posted: 05 Jun 2018 01:43 PM PDT

Does the general theory of relativity predict that the universe is expanding?

Posted: 06 Jun 2018 01:08 AM PDT

Have their been any more gravitational wave detections?

Posted: 05 Jun 2018 09:10 PM PDT

Can you catalyze the aluminum - gallium - water reaction?

Posted: 05 Jun 2018 12:18 PM PDT

I've read that the reaction is good at producing hydrogen, yet the limiting factor is that it produces it very slowly. Does anyone know of any research done into accelerating this reaction?

submitted by /u/Rideron150
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What's the difference between the South and North pole of a magnet?

Posted: 05 Jun 2018 10:04 AM PDT

An expirmental physicist is magically teleported to another planet. The physicist has access to any instrument or piece of equipment they desire EXCEPT a magnet or compass from Earth (and its magnetic field) with the poles labeled "North" and "South." How could they tell which pole of a magnet is which?

submitted by /u/SingularityIsNigh
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Why is SHA256 not a good hash for passwords?

Posted: 05 Jun 2018 10:19 AM PDT

I've read that for password hashing, hash functions such as Bcrypt or PBKDF2 are preferable because they are much slower to calculate. SHA256 was not good because it was very fast to compute. However, just as people recommended to have multiple iterations of hashing for Bcrypt, couldn't I have multiple iterations of SHA256 hashing for each password? What makes a SHA256 password hashed 1 million times iteratively worse than a Bcrypt password hashed 1000 times?

submitted by /u/Dueling7
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How does a device keep it’s hostname?

Posted: 05 Jun 2018 08:25 AM PDT

When a device with a hostname is disconnected and reconnected to a network, how is it reassigned the hostname given by the network?

submitted by /u/Worgencyborg
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Why are Rivers Uneven and as a Result Turbulent?

Posted: 05 Jun 2018 12:46 PM PDT

I am currently studying lithosphere, hydrosphere and physical geography topics and understand erosional and depositional features along with differential erosion. We do not study rivers as much as I thought we would. As a result I have a few questions which extend from my first:

Why are not all river beds flat? Where I live the rivers have ledges of the same rock which I assume is what causes turbulence and localised white water- what causes the rock to be deformed like this? Is it correct to assume that this is how turbulence solely arises?

I do know some rivers are flat and merely run along the path of least resistance.

Any further reading or recommendations to textbooks would be appreciated.

submitted by /u/MythicalGeology
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Tuesday, June 5, 2018

If light doesn't dissipate with travel distance and the universe is infinite, why isn't the night sky bright?

If light doesn't dissipate with travel distance and the universe is infinite, why isn't the night sky bright?

If light doesn't dissipate with travel distance and the universe is infinite, why isn't the night sky bright?

Posted: 04 Jun 2018 11:49 PM PDT

I read that in vacuum light doesn't dissipate so it travels infinitely. If the universe is infinite as well though there should be an infinite amount of stars visible on the night-sky or if you want to amount for light pollution, there should be when you're watching from Space.

I have a few theories why it could be (finite amount of light spread too thin, infinite amount of planets/asteroids getting in the way...) but let's hear it from someone who actually kbows their shit :)

submitted by /u/SuperSchweinchen
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When a water filter (e.g. Brita filter) is past its expiration date, is it just not filtering very well anymore, or is it actively making the water worse?

Posted: 05 Jun 2018 07:10 AM PDT

What causes a plane to make that "divebombing" sound when it nosedives towards the ground?

Posted: 05 Jun 2018 04:50 AM PDT

How does a pop-fliter for a microphone work?

Posted: 05 Jun 2018 12:01 AM PDT

Why does water that is sitting in a metal water bottle have a metallic taste?

Posted: 05 Jun 2018 06:53 AM PDT

I just drank out of my metal water which had water sitting in it for about a week, it tastes metallic. Why? What is the mechanism ?

submitted by /u/didujustcthat
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What breaks objects, the force, or the energy?

Posted: 04 Jun 2018 06:33 PM PDT

Given a scenario where i have a ceramic tile and a rock, when i place the rock onto the tile it doesn't break, but when i drop the rock from a height it does, but in the scenario the force(weight) doesn't change, the only thing that does is its height and therefore its gravitational potential energy.

submitted by /u/mikey10006
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Why do proteins contain only the L isomers of amino acids and not the D?

Posted: 05 Jun 2018 07:21 AM PDT

Is there a universal unit for measurement of mass?

Posted: 05 Jun 2018 05:55 AM PDT

Time can be measured by 9,192,631,770 cycles of the radiation from a cesium atom. This should be essentially the same no matter where you are in the universe. This is something that in the far future, no matter where you are from (e.g. another planet) the measurement remains the same.

Mass on the other hand is measured in kg or lbs. These are relative to the Earth's gravity, thus not a "universal" unit of measurement.

My thoughts would be something along the lines of a gravity well displacement or a measurement of Higgs field interaction? These would not rely on understanding of our home planet's gravity well, but would allow for description of an object at any size or density.

If it doesn't exist, how would you go about calculating a new unit of measurement??

submitted by /u/ignanima
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Can you donate your blood once you're dead much like you can your organs--or can it not be used?

Posted: 04 Jun 2018 05:51 PM PDT

How can something be strong and brittle like tungsten, isn't that contradictory?

Posted: 05 Jun 2018 04:46 AM PDT

Like I hear so much that "tungsten is strong" but it's also brittle like how the hell is that possible?

submitted by /u/RamboCreativity
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Why do forklifts use propane as fuel as oppose to another fuel?

Posted: 04 Jun 2018 01:33 PM PDT

At work, we have multiple forklifts that use propane as the fuel. They run out of fuel quite often and I have only heard of propane being used for cooking. What properties make it ideal for forklifts? Does is burn differently that other fuels?

Thank you.

submitted by /u/Schiffty5
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Was Earth's orbital period always the same through it's history?

Posted: 05 Jun 2018 07:36 AM PDT

We know that around 1.4 billion years ago day used to last only 18 hours or so. What about Earth's orbital period, was it always the same length of time or it also changed through history. If yes, how big of a change was it from beginning of Earth to now and do we even know?

submitted by /u/Marcipanas
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How do spiders spin up a really long horizontal web between two bushes?

Posted: 04 Jun 2018 03:06 PM PDT

Whenever I've hiked along a trail and torn apart a spiders web, I've always wondered that to myself. Often times it's just a single strand. How does a spider manage to cross two bushes with a web, seemingly building a bridge between them?

submitted by /u/225millionkilometers
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Does hormonal birth control affect fecundity in later life after cessation, since they prevent ovulation which leads to more eggs in the ovaries?

Posted: 04 Jun 2018 07:15 PM PDT

Are the two electrons in the Helium atom in the same energy state?

Posted: 05 Jun 2018 05:00 AM PDT

Are the two electrons in the same energy like two non-interacting electrons in a hydrogen atom (hypothetical) where the groundstate is degenerate due to spin? Or are the two electrons in different energy levels due to Coulomb repulsion?

submitted by /u/MaoGo
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How do scientists know Mars' (and other planets) air and soil's compositions, air pressure, etc.?

Posted: 05 Jun 2018 04:58 AM PDT

A few days ago, a small asteroid burned up in the atmosphere; what happens to the matter?

Posted: 04 Jun 2018 07:03 PM PDT

Does it just settle to earth? Or is it somehow ejected back into space?

submitted by /u/popegonzo
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What device could I use to measure both Electric and Magnetic Fields?

Posted: 05 Jun 2018 03:20 AM PDT

May be an odd question but I'm looking for a device that would be able to measure up to 10,000V/m and up to 1,000uT.

I have a device that can do both but it maxes at at 2000V/m and 100uT.

Any help would be massively appreciated!

submitted by /u/CamsGraphics
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How does salmonella cause homeostatic imbalance?

Posted: 05 Jun 2018 03:05 AM PDT

My teacher in class was talking about homeostasis and she gave an example of salmonella as something which causes homeostatic imbalance. How is this so, since salmonella only stays in your digestive system, or does it spread to other body systems as well?

submitted by /u/nk7gaming
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Can we estimate where the barycenter of the universe is?

Posted: 04 Jun 2018 10:11 AM PDT

Could volcanic eruptions eventually deplete the Earths core?

Posted: 04 Jun 2018 08:29 PM PDT

Why is New York colder then London in the winter even though London is a lot further north and New York is on the same latitude as Spain?

Posted: 04 Jun 2018 01:50 PM PDT
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Monday, June 4, 2018

Why are there so many volcanic eruptions recently? Are they somehow connected or is it a coincidence? Or is it just new media coverage?

Why are there so many volcanic eruptions recently? Are they somehow connected or is it a coincidence? Or is it just new media coverage?

Why are there so many volcanic eruptions recently? Are they somehow connected or is it a coincidence? Or is it just new media coverage?

Posted: 04 Jun 2018 04:42 AM PDT

Why do quantities like brain-structure-mass-to-neuron ratio affect animal cognition?

Posted: 04 Jun 2018 07:03 AM PDT

Hi AskScience,

I've been reading about Dr. Herculano-Houzel's brain soup method after following some popular science articles. It appears that in various brain structures, the mass-to-neuron ratio for primates deviates from other groups of mammals and presumably that is at least one factor which causes increased cognition (though I could be wrong, so please let me know if so!). Why should that be the case?

As a side question, have any studies been done on other mammals such as whales and dolphins? A quick google search didn't yield anything in that realm.

Thanks!

submitted by /u/themeaningofhaste
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Can high solar activity affect Contactless communication (RFID type in payment cards or smartphones) ?

Posted: 04 Jun 2018 04:20 AM PDT

Is WISE 1828+2650 habitable at all?

Posted: 04 Jun 2018 08:17 AM PDT

I just found out recently, via a temperature of the universe info graphic, that WISE 1828+2650 has an surface temp of 80F/27C.

Is there a maintainable orbit where the radiant temp would be appropriate for human living conditions? What about the surface directly? Other than lack of oxygen, is there anything inherently toxic about the environment that would need to be overcome?

submitted by /u/keef0r
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What is the density of dark matter?

Posted: 04 Jun 2018 06:11 AM PDT

I saw in book that the observed density of dark matter is round about 4 eV per KMH-Photon. What does KMH-Photon mean? Never saw that unit. Neather could I find any more information about the density of dark matter. How exact do we know the density?

submitted by /u/Spac3junkie
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Does old blood get phased out of circulation after a certain amount of time or does it circulate until a laceration?

Posted: 03 Jun 2018 05:29 PM PDT

Why are tardigrade so resilient and how CAN they be killed?

Posted: 03 Jun 2018 03:41 PM PDT

How do we know what an animal’s field of vision looks like? I.e. how can we tell that rodents see in yellow hues and that certain insects can see UV light?

Posted: 03 Jun 2018 04:32 PM PDT

Can Pilot Wave Theory be expanded to incorporate relativity? What are the current barriers to its expansion?

Posted: 03 Jun 2018 02:00 PM PDT

Why does gold have a smaller atomic radius than lead?

Posted: 03 Jun 2018 04:54 PM PDT

So, just from a discussion, I was thinking about Gold being denser than lead, to which I figured it largely has to do with atomic radius and bond lengths. Now I could be wrong here, only having an advanced high school level understanding of chemistry, but I remember being taught that generally radius decreases across a period due to a stronger nuclear effect. Is this incorrect or is there something else at play here causing this? I assume this question occurs elsewhere on the table, but gold and lead were just the notable examples here.

submitted by /u/NYbeast
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If a box made of mirrors is filled with photons that bounce forever, is the box heavier than if it was empty? If so, why?

Posted: 03 Jun 2018 01:48 PM PDT

What happens to bullets shot straight up into the air?

Posted: 03 Jun 2018 08:50 PM PDT

Do they go up into space or eventually come back down? Where would they land?

submitted by /u/vl1234567890
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What is the Structure at the Center of the Tevatron?

Posted: 03 Jun 2018 06:37 PM PDT

My understanding was that the beam only had functions around the outside of the circle. What is the purpose of the tower at the center of the Tevatron? I did some searching but was unable to find details on it. Not a great image but here's a link to maps.

https://goo.gl/maps/2rqcALKR1JA2

submitted by /u/cjgroh
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How are proteins in our body powered?

Posted: 03 Jun 2018 11:34 AM PDT

I was watching this video by Veritasium and I'm mind-blown by the complexity.

The proteins that move; How do they do it? What is making them move and how is the energy they use distributed to them?

The proteins that create for example microtubules; How do they get the "building blocks" they use?

submitted by /u/Lord_Banzai
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How has a tardigrade survived at -273 Celsius when (I assume) most elements reach their freezing/boiling/melting point at those temperatures?

Posted: 03 Jun 2018 05:11 PM PDT

How does lightening "know" what it "wants" to hit?

Posted: 03 Jun 2018 01:44 PM PDT

From what I understand lightening hits things that offer the least resistance, but how does lightening know to hit those things? (Sorry to personify) When I was looking this is up the Internet kept saying things about positive lightening too, which I've never heard of. Please, someone explain the mystic workings of the Big Sky Fire to me.

submitted by /u/lizzardlass9000
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Why can we see satellites orbiting the earth?

Posted: 03 Jun 2018 10:36 AM PDT

It doesn't seem like they would have bright lights on them.

submitted by /u/buy_one_get_one_jk
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Helium has a melting point of -272 degrees Celsius, and boiling point of -269: how is this possible?

Posted: 03 Jun 2018 08:03 AM PDT

Seems odd to me that a gas would have a melting and boiling point very close to each other, at a near extreme cold - how?

submitted by /u/PsychMarketing
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What is the smallest possible size of a nuclear fusion reactor?

Posted: 03 Jun 2018 05:00 AM PDT

Obviously it couldn't be the size of Tony Stark's Arc Reactor but how small could we make a nuclear fusion reactor, at least with modern technology?

submitted by /u/The-Author
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Do CT scans increase the risk of cancer noticably?

Posted: 03 Jun 2018 07:50 AM PDT

Doctors often say not to do them unneccesarily due to the radiation involved, but is there a noteable increase in the risk of cancer after having one and if so how long does that increase stay noticable?

Wasn't quite sure what to flair this as...

submitted by /u/WhiskersCleveland
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Why do they specifically swab your nose and groin when screening for MRSA?

Posted: 03 Jun 2018 05:47 AM PDT

What specifically about these areas makes them the place to swab, does MRSA have some affinity for the Nose/Groin? And if so, why? The two areas don't seem to share that much in the way of common characteristics.

submitted by /u/NewbieWithARuby
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