Pages

Wednesday, January 3, 2018

For humans, sea water is not drinkable due to its high salt content. How do whales, manatees, seals, and other sea faring mammals stay hydrated?

For humans, sea water is not drinkable due to its high salt content. How do whales, manatees, seals, and other sea faring mammals stay hydrated?

For humans, sea water is not drinkable due to its high salt content. How do whales, manatees, seals, and other sea faring mammals stay hydrated?

Posted: 03 Jan 2018 04:42 AM PST

Are there species with more than 2 sexes?

Posted: 03 Jan 2018 07:11 AM PST

In humans the X and Y chromosomes decides the biological sex. Are there any species where theres more than 2? I found previous discussions where birds were said to have 4 genders and 2 sexes, but I would guess its still only 2 chromosomes at play. I wanted to know if there can be more.

submitted by /u/Waifuranger
[link] [comments]

During the Cold War, how were ICBMs guided? Without GPS how do you accurately hit a city in the middle of Siberia from across the world?

Posted: 02 Jan 2018 01:19 PM PST

Does the temperature rise during a large fireworks display?

Posted: 03 Jan 2018 05:03 AM PST

We had a very overcast December 31st here in Copenhagen, Denmark but, of course, that did not stop anybody from launching TONS of fireworks during the course of the evening. This made me think about large, hour long firework displays (New Years, Chinese New Years, etc.) as to whether or not the ignition of the fireworks would give a noticeable rise in the local temperature? Would the mean daily temp in an urban location or city actually get warmer during that time period? of not, how many fireworks would it take before we would notice using regular methods of detection? Thank you all.

submitted by /u/svel
[link] [comments]

Ask Anything Wednesday - Economics, Political Science, Linguistics, Anthropology

Posted: 03 Jan 2018 07:07 AM PST

Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Economics, Political Science, Linguistics, Anthropology

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!

submitted by /u/AutoModerator
[link] [comments]

Why is liquid helium used to cool down superconducting magnets?

Posted: 03 Jan 2018 03:03 AM PST

This might be more of an engineering question now that I think of it. Liquid helium is used to cool down the superconducting magnets in the NMR machine in my lab. I figure, since it is so rare, can't we encase the magnets in a solid ice with a solid-liquid transition temperature below the superconducting temperature of the magnet? I figure the answer might have to do with transportation/and or handling, or maybe something more physics related, so can somebody shine some light?

edit: clarification

submitted by /u/tyeunbroken
[link] [comments]

What were the evolutionary steps for the blowhole on whales and dolphins?

Posted: 02 Jan 2018 09:23 PM PST

I'm watching a dolphin show live right now and I'm wondering, that if they're mammals, did they develop from an earlier form of gills? When in the chain of evolution might have it developed and are there any other mammals that have a vestigial remnant of this feature?

submitted by /u/Spystrike
[link] [comments]

How far are we from neural network based programs that will be able to generate speech from text based on provided voice records, that will be indistinguishable from real voice?

Posted: 02 Jan 2018 10:53 PM PST

This technology could provide a giant leap forward to video games, reducing time to record NPC text lines to basically... zero? Especially if neural network will be able to generate emotions too

submitted by /u/jstq
[link] [comments]

I'm short-sighted. Without my glasses, I can see through shutters way better than with my glasses on. Why? Do the holes in the shutter act as lenses?

Posted: 03 Jan 2018 03:51 AM PST

Has the salinity of the earth’s oceans changed over its history?

Posted: 03 Jan 2018 03:33 AM PST

Have the oceans gotten more salty over time due to more salty rocks being eroded and dissolving in the oceans? Are the rising sea levels affecting the salinity of the oceans?

submitted by /u/ManMan36
[link] [comments]

Can you track a radioactive golf ball with a Geiger counter?

Posted: 03 Jan 2018 05:03 AM PST

What type and level of radiation would you need to locate a lost radioactive golf ball with a Geiger counter (range at least 10 meters)?

submitted by /u/TheAntiSheep
[link] [comments]

Is negative absolute pressure possible?

Posted: 02 Jan 2018 10:59 PM PST

It seems that negative absolute pressure is a topic for debate. Many textbooks will tell you it's impossible to sustain a negative absolute pressure in a liquid, yet it's a common explanation for how trees can bring water to heights higher than the theoretical limit of 10m. I've also seen references to surface tension, which may or may not be related to this discussion. I figured the great minds on reddit would surely be able to sort this one out.

Inspired by this post:

https://www.reddit.com/r/todayilearned/comments/7nom4a/comment/ds49l4r?st=JBYOXE0W&sh=7fd87b62

In my opinion his answer in the video is still not totally explained. Negative absolute pressure in a liquid? I don't remember that one in my fluid mechanics class.

So you stretch the liquid out? How is that done? And cavitation (boiling) doesn't occur because... magically perfect tubes that won't allow vapor? What happens if someone chops into these tubes? Does that cause boiling to occur? Are these tubes at room temp?

Not saying it's wrong I just feel that these mechanics were identified as the driving force of this phenomena and should be more thoroughly discussed.

This article goes into some more detail but it still isn't too clear to me:

http://discovermagazine.com/2003/mar/featscienceof

Here's some forums where the topic is discussed:

https://www.physicsforums.com/threads/negative-pressure.428998/

https://physics.stackexchange.com/questions/65637/what-about-negative-pressure

And some scientific papers that I don't have access to:

https://link.springer.com/chapter/10.1007/978-1-4020-5872-1_24

http://iopscience.iop.org/article/10.1088/0953-8984/24/28/284110

https://www.nature.com/articles/278148a0

submitted by /u/m287ike
[link] [comments]

If water is continually flowing, does it decrease the freezing point, and if so, what is it?

Posted: 02 Jan 2018 11:21 PM PST

At what point would something like a waterfall freeze over, if it is continually flowing?

submitted by /u/Alsttr
[link] [comments]

Why does hot water freeze faster than cold water?

Posted: 03 Jan 2018 06:19 AM PST

Is there any evidence of a second super continent on the opposite side of the earth when Pangaea existed?

Posted: 03 Jan 2018 12:07 AM PST

It always looks odd to me that Pangaea existed as one land mass with the rest of the earth covered in ocean. Couldn't have another continent have existed which has disappeared beneath the plates? Have all the current land masses been largely above the water since Pangaea?

submitted by /u/imapassenger1
[link] [comments]

How small can transistors in CPUs possibly get? Is there a way to improve a CPU else than reducing the size of the transistors?

Posted: 02 Jan 2018 12:32 PM PST

Is it possible to create new elements with different baryons and leptons?

Posted: 02 Jan 2018 12:25 PM PST

Let my do a little clarification. Since elements are composed of protons and neutron cores (baryons) and elections (leptons). there are more types of baryon than just protons and neutrons. Let's pretend that we progressed technologically to the point where creating a synthetic element made of protons and neutrons was cheap and easy and creating other baryons was easy as well. Would it be possible to make new periodic tables of elements using different kinds and combinations of baryons?

submitted by /u/TheLastOne0001
[link] [comments]

Why is LSD so powerful?

Posted: 02 Jan 2018 11:35 AM PST

A normal LSD dose is about 100μg and it can cause hallucinations but the threshold is 25μg. How can such small quantities of this substance alter your mind? This has been for a long time one of my curiosities. Thanks for the answers.

submitted by /u/Arlkaj
[link] [comments]

Could a friction-less string tie a knot that remains tight when no external force is applied?

Posted: 02 Jan 2018 01:15 PM PST

Does a large diameter, cylindrical, standing body of water, perfectly level and still, slowly rotate on its own axis *inside* its container due to the motion of the planet?

Posted: 02 Jan 2018 12:17 PM PST

An observed phenomenon has not been easily explained and has caused much consternation and argument.

submitted by /u/ThePleasantLady
[link] [comments]

What happens to the photons of a light bulb when it us turned of ?

Posted: 03 Jan 2018 04:59 AM PST
vào lúc No comments:

Tuesday, January 2, 2018

What is the very worst case scenario in relation to the rise in water levels? Can Earth become an ocean planet?

What is the very worst case scenario in relation to the rise in water levels? Can Earth become an ocean planet?

What is the very worst case scenario in relation to the rise in water levels? Can Earth become an ocean planet?

Posted: 02 Jan 2018 05:05 AM PST

Is it at all possible that the earth can become an ocean planet? I've seen some rather extreme maps that show only a vast ocean with only narrow strips of land of both hemispheres but most maps seem to show only losing some coastal areas like London and NYC.

So, the simple question is, is there ANY scenario of the planet being taken by basically 90% ocean? Regardless of the likelihood, is there ANY scenario where humanity is forced to become a sea faring species?

submitted by /u/MaimedPhoenix
[link] [comments]

When it is crazy cold in the U.S. does that mean that the globe is likely colder overall at the moment, or is the distribution of cold and warm on the planet just distributed differently?

Posted: 02 Jan 2018 04:25 AM PST

How does the water supply network still remain liquid in cities even at very cold temperatures? Why don't the pipes freeze?

Posted: 01 Jan 2018 08:52 PM PST

[Human Body] Are 'fast twitch' muscle fibers anatomically larger in size than 'slow twitch' ones?

Posted: 02 Jan 2018 05:02 AM PST

In my limited understanding of the human skeleto-muscular system I am aware there are 2 types of muscle fibers.

Fast twitch: Develop from sprint-like exercise such as running sprints, 50m swimming races, lifting heavy weights close to your maximum limit etc.

Slow twice: Develop from endurance exercise such as long distance running and swimming, lifting light weights for prolonged periods/repetitions.

My question is because in the gymming and weight lifting community there is a consensus that muscle growth (size) occurs when the muscles are put under duress and they fatigue. I am told that fatigue is essential in muscle growth because it generates muscular repair and rebuilds the muscle larger than before.

Therefore lifting heavy weights is advocated because it puts the muscles under more fatigue and subsequently more growth. Growth of which is that of fast twitch fibers.

But is there any scientific difference in the composition of fast twitch and slow twitch fibers that makes them larger?

If a weight lifter were to lift only <5kg but for prolonged periods of 50-100 reps, that then fatigued the muscle, would the developing slow twitch muscle fibers be smaller than compared to fast twitch ones?

If the answer is no, why do people not commonly build muscle size through slow twitch fibers?

The answer may be obvious but it eludes me. Thank you.

submitted by /u/anotheraccount5001
[link] [comments]

Does doubling your computing power halve your processing time? Are 4 cores always 2x better than 2 cores of equal clock speed?

Posted: 02 Jan 2018 07:37 AM PST

Are magnetic materials stronger than they would otherwise be without their magnetic field?

Posted: 01 Jan 2018 03:12 PM PST

To clarify the title, does magnetic force within a magnetic object, like a natural magnet, contribute to its actual structural strength? Is say... a magnetized piece of iron stronger than a non-magnetized piece?

Would the magnetic force within the material hold the atoms more snugly together, or am I completely off-base in my understanding of this?

submitted by /u/beau101023
[link] [comments]

How do painkillers work?

Posted: 01 Jan 2018 08:22 AM PST

How dangerous is Chernobyl today?

Posted: 01 Jan 2018 11:45 PM PST

You can go on tours through the city? So I'm assuming short term, it's not that dangerous. Or are certain areas worse? Also, in the long term, is the risk of cancer what prevents rebuilding?

submitted by /u/mac60five
[link] [comments]

The angler fish attracts prey, but, does it attract predators too?

Posted: 01 Jan 2018 04:47 PM PST

I imagine angler fishes are easy to find in the deep ocean, and I don't think it is the biggest fish around, so, does it also attract predators?, how does it manage to attract prey more than it attracts predators?

submitted by /u/Frigorifico
[link] [comments]

Special Relativity Concept: n number of spaceships travel in a line, each with velocity 0.5c with respect to the one behind it. Is that possible?

Posted: 01 Jan 2018 09:44 PM PST

Is it possible for a spaceship to leave earth at 0.5c, then another smaller spaceship to travel ahead of the first one at 0.5c relative to the frame of the first spaceship? (And so on for any number of spaceships?).

My limited knowledge of relativity tells me that you could do this any number of times, and even after many spaceships they would still only be traveling something like 0.99c due to relativistic effects.... someone correct me if I'm wrong please!

submitted by /u/carnafillian113
[link] [comments]

Which explanation for aerodynamic lift is correct?

Posted: 02 Jan 2018 03:04 AM PST

So I'm currently studying for an aviation exam and I'm really struggling to find a good and somewhat simple explanation for aerodynamic lift.

The problem is that a lot of the explanations you find in aviation books (not physics books) are incorrect or incomplete.

I am really confused now so maybe you can help me out.

Also, apologies for language errors, I'm still practicing my English.

Here's what I figured out so far:

  1. The "longer path explanation" (air on the upper side of the airfoil travels a longer path in the same time) is incorrect. The air on top of the airfoils reaches the trailing edge long before the air beneath the airfoil.

  2. The specific shape of the airfoil/wing exerts a downward force onto the airstream above. According to Newton's third law, the surrounding air thus creates an upward force onto the wing.

  3. The air above the wing is accelerated and flows faster than the air beneath the wing. Faster flow means lower pressure (Bernoulli). Therefore, you have an area of low pressure above the wing and an area of high pressure. The resulting pressure gradient = lift.

  4. According to the Coanda Effect, the air follows the shape of the airfoil. Given that the upper half (of an asymmetric airfoil) has a somewhat circular shape, a centrifugal (centripetal) force is exerted onto the air molecules travelling along the upper half of the airfoil. The air is "stretched" and thus an area of lower pressure occurs. Lower pressure allows the air to flow faster (Bernoulli).

submitted by /u/mark01254
[link] [comments]

Is hearing loss like a noise gate (you can't hear quiet sounds), or is it like an overall volume reduction?

Posted: 01 Jan 2018 03:51 PM PST

Potentially stupid question: How do scientists calculate the length of a year?

Posted: 01 Jan 2018 05:01 AM PST

New Year's is around and it's time to write the date incorrectly for a few months. But how exactly do we know that the Earth has made its full circle around the Sun?

And another question: when our modern calendar was invented, how on earth did THEY know how long a year was?

Thanks for reading and have a great 2018 everyone :)

submitted by /u/xXReggieXx
[link] [comments]

In Everett's multiple worlds interpretation of quantum mechanics, do the other worlds already exist prior to splitting, or do they come into existence after?

Posted: 02 Jan 2018 12:00 AM PST

Wish I could get more information on this theory, but most of what comes up when I google it is critiques and the bio-doc with his son.

submitted by /u/middleupperdog
[link] [comments]

Biologically speaking, is there any difference between a genius and a ordinary person brain's?

Posted: 01 Jan 2018 02:46 PM PST

Sorry for any grammar error, english is not my first language.

Edit1: Yes, by genius I mean IQ.

submitted by /u/Marceloxdxp
[link] [comments]

MOSFET: Why do fixed oxide charges increase the flatband voltage?

Posted: 01 Jan 2018 03:43 PM PST

As shown in the link, how do oxide charges increase the flatband voltage? https://imgur.com/a/IZtBs

EDIT: Title should say MOS Capacitor

EDIT2: Is it because flatband voltage is negative?

submitted by /u/spacejockey8
[link] [comments]

Do any animals live at the extreme poles and how do they survive?

Posted: 01 Jan 2018 05:23 PM PST

I know of the animals that live near the poles such as penguins and polar bears. But this usually refers to the coastal parts of the polar surface (Coasts of Antarctica and the coast of the northern ice sheet). Do any animals live inland and actually close (say within 100 km) of the actual poles? How do they feed themselves without access to plants or sea?

submitted by /u/Sectiontwo
[link] [comments]

Does brain-training work to improve cognitive abilities, or only improve the exact tasks in the training-program?

Posted: 01 Jan 2018 05:47 PM PST

Do the results of the quantum eraser experiment imply that faster than light communication is possible?

Posted: 01 Jan 2018 11:59 PM PST

i recently finished watching a PBS space time video on the quantum eraser experiment and it got me interested (LINK: https://www.youtube.com/watch?v=8ORLN_KwAgs). So I did a bit of research and unless I am misunderstanding the experiment, do the results not imply that causality and information can travel backwards in time?

Say for example I set up an experimental apparatus where the photons which split through the prism land on a screen directly in front of me, whereas their entangled counterparts go off to a distance very far away (for example 10 light minutes away) to the quantum eraser. If I agreed prior to this experiment with an observer that is at the other end (by the quantum eraser) to either enable the quantum eraser or to disable it as a yes or no answer. Then can I not have instantaneous but binary communication?

If I am understanding the experiment correctly then the entangled photons arrive at the second detector AFTER those that arrive at the first screen but still retroactively influency the photons that hit the screen first. This seems to imply that I should see either an interference pattern or a particulate-like pattern before the entangled counterpart reaches the person I am trying to communicate to in my frame of time. And theoretically that individual could communicate an outcome to me, prior to it occuring in my timeframe.

Sorry if this is a jumble!

Thank you!

submitted by /u/Ledja
[link] [comments]

How exactly do benzodiazepines affect the brain?

Posted: 01 Jan 2018 05:15 PM PST

I am prescribed Ativan for panic attacks. When I take 1 mg, I am calmer and my heart rate goes back to normal. However, after taking 3 mg one day, I almost immediately fell asleep (I don't remember much of anything after taking the pills) for a long period of time, and I woke up very confused. I'm wondering how exactly benzodiazepines (more specifically Ativan) are able to produce a calming effect at a lower dosage but a sedative effect at a higher one?

submitted by /u/Throwaway101496
[link] [comments]

Why are heavy metals considered toxic?

Posted: 01 Jan 2018 04:55 PM PST

Sorry if I butchered the title. I'm asking about how heavy metals are toxic.

submitted by /u/GTSPKD
[link] [comments]

Is the sea the same “salty” in all oceans ?

Posted: 01 Jan 2018 03:03 PM PST

Is the salt concentration consistent in all oceans around the world? Or does it vary because of factors ? Of course we all know the Dead Sea is more salty, that's a given

submitted by /u/FireTrickle
[link] [comments]

How does heat travel? Does it need something to conduct it like sound and can it travel through vacuum?

Posted: 01 Jan 2018 02:46 PM PST
vào lúc No comments:

Monday, January 1, 2018

Is oxygen evenly dispersed across the planet?

Is oxygen evenly dispersed across the planet?

Is oxygen evenly dispersed across the planet?

Posted: 31 Dec 2017 02:59 PM PST

Is oxygen more prominent in the rain forest more so than the desert? Is there an area with the least and most oxygen? I mean low elevations of course.

submitted by /u/MAD_OR_NAW
[link] [comments]

What does mean sea level mean if you're thousands of miles from the sea?

Posted: 01 Jan 2018 07:59 AM PST

As I understand it, Mean Sea Level is defined by taking the time-averaged effective gravitational potential of the water-air boundary averaged over the world's oceans. Since sea levels are rising globally, we choose some datum and stick to that. This seems reasonably unambiguous.

If the summit of Everest is 8848m above MSL, does that mean it's 8848m directly above a point within the crust on that same equipotential, or does it mean it's on the equipotential defined by the average of all points 8848m directly above the sea? Or does it mean something else?

How much difference would there be?

To rephrase the question: if you hollowed out Everest and made tunnels (sealed against groundwater) connecting that cavity to the oceans, would the water find a time-averaged level 8848m directly below the summit?

submitted by /u/TheBobathon
[link] [comments]

Can gamma rays break apart small nuclei?

Posted: 31 Dec 2017 08:36 PM PST

If fully ionized (electron free) nuclei of elements like hydrogen or helium or oxygen are hit with an extremely high-energy gamma ray, what happens? Would it cause the oxygen to undergo fission? Would it even interact with the hydrogen? Assuming it does interact, what happens?

submitted by /u/_AUTOMATIC_
[link] [comments]

What better determines where lightning will strike: height, material, or some other factors?

Posted: 31 Dec 2017 02:06 PM PST

I know that cloud-to-ground lightning generally speaking strikes from the negatively charged portion of a cloud to the positively charged portion of the ground below the storm, and that it will find the path of least resistance there, which usually means something tall.

But does the material of the thing matter too? If the stepped leader is spreading out over an open field with an 80 foot metal pole vs a 100 foot wooden pole vs a 120 foot rubber pole near each other, does it just matter that it touches the rubber pole or wooden pole first, or would it still strike the metal one?

(I also know that if something is really tall then it will send out an upward leader that can cause a ground-to-cloud strike, but I'm less clear about how that works)

Thanks!

submitted by /u/DaystarEld
[link] [comments]

How can water go from being in a liquid state to being frozen by simply shaking it?

Posted: 31 Dec 2017 07:23 PM PST

If an object with a net force experiences a constant acceleration, why can’t it exceed the speed of light in a vacuum?

Posted: 31 Dec 2017 01:08 PM PST

What does the Maxwell term in the Ampere-Maxwell law physically represent?

Posted: 31 Dec 2017 12:45 PM PST

I'm trying to understand the Ampere-Maxwell law, in the form curlB = μJ + εμ ∂E/∂t [no subscript 0s on reddit]. I get how Ampere's law works for static currents, and I can also follow the mathematical steps that are used to add the Maxwell term. (The divergence of a curl is zero, so Ampere's law always results in the rate of change of charge density being zero. Then adding an unknown vector field to the original equation and rearranging everything using Gauss's law and the equation of continuity gives the Maxwell term of εμ ∂E/∂t.)

But even though I can follow the maths, I can't shake the feeling that it's like using the same information twice in one equation. The μJ term is the current density, so it represents the movement of charge. And the εμ ∂E/∂t term is the change in electric field, so it represents... also the movement of charge? I can't get my head around why the rate of change of electric field means something fundamentally different to the movement of charge, since electric field is defined by the location of charge to begin with.

I've tried doing research and looking for useful analogies and explanations. But I've found a lot of things talking about the displacement current, which all seems to lead to explanations about how electric fields can polarise a medium and cause a sort of opposing field - and I can't figure a way to relate that back to the Ampere-Maxwell law itself in any useful way.

Can anyone help me understand the physical meaning of the Maxwell term, and how the change of electric field means something physically different from the movement of charge?

submitted by /u/jayavery
[link] [comments]
vào lúc No comments:

Sunday, December 31, 2017

If the Niagara falls is frozen where does all the water go behind it? Does it just spill over and flood surrounding land

If the Niagara falls is frozen where does all the water go behind it? Does it just spill over and flood surrounding land

If the Niagara falls is frozen where does all the water go behind it? Does it just spill over and flood surrounding land

Posted: 31 Dec 2017 03:23 AM PST

Why is/was there a tendency for like minerals to collect together on earth?

Posted: 30 Dec 2017 08:20 AM PST

It seems that the original source for minerals was random and that they should be randomly, and relatively homogeneously spread over the surface of the earth. Yet minerals like iron oxide, sodium chloride, gold, silver, (and most others it seems) have had a significant tendency to be found concentrated in various areas, making mining them and collecting them a practical endeavor.

What has caused that to occur?

submitted by /u/mspe1960
[link] [comments]

If future data from the LHC and ILC suggest that our universe is metastable, what does that mean for the future of the universe?

Posted: 31 Dec 2017 05:01 AM PST

1) What does "metastable" mean in comparison to unstable and stable? Why is this related to the properties of the Higgs Boson and Higgs Field?

2) If it is metastable, what kind of event could cause it to suddenly want to seek a lower energy state?

3) How fast would this "new physics" bubble expand once it reached a lower stable energy level?

4) Would this be compatible with life chemistry as we know it? If the bubble hit Earth, would we just simply stop existing?

Bonus Question: If the Higgs Field were to simply disappear in an area of space, would W+, W−, and Z bosons become massless and completely change the weak force? Does this have anything to do with a vacuum metastability event?

submitted by /u/Stuck_In_the_Matrix
[link] [comments]

When heavier elements undergo fusion do they release more energy?

Posted: 31 Dec 2017 12:44 AM PST

Not actually sure if heavier elements can fuse without extreme conditions, but what would happen if heavier elements instead of smaller ones like hydrogen were fused? Since our sun releases energy this way could a star of heavier elements release more energy?

submitted by /u/Carconzo222
[link] [comments]

Since a particle that interacts with the Higgs Field only gets a portion of their mass from it, can there exist a particle that has mass but does not interact with the Higgs Field?

Posted: 30 Dec 2017 10:29 PM PST

Is their a limit to the amplitude of a light wave/ is their a limit to how intense a light source can be?

Posted: 31 Dec 2017 12:23 AM PST

Is there scientific backing to vibrational "healing"?

Posted: 30 Dec 2017 01:10 PM PST

I would love to see from a physics standpoint how vibrations/frequencies/waves from things like music or anything in general have a positive or negative effect on our bodies. I'm skeptical, but would be very interested to know if there is a connection.

submitted by /u/jennyo120
[link] [comments]

Is there a relationship between the amount of energy an isotope emits when it decays and its half-life?

Posted: 30 Dec 2017 05:20 PM PST

I spent a while trying to figure this out, but was unable to come to any conclusion. Different isotopes release different amounts of energy when they decay, and the amount of time it takes to decay can vary significantly, but is there a good way to estimate how radioactive something is with only knowledge of the half life OR energy emitted per decay? Elements with shorter half lives are pretty much always more radioactive than their longer lived counterparts, but that's entirely because the atoms are releasing energy much more frequently, rather than releasing more energy in total. Is it possible to have an isotope with an extremely short half life that is fairly safe because its radioactive decay releases very little energy?

I wasn't really sure if this is physics or chemistry, so I apologize if this was miscategorized.

submitted by /u/TheDubiousSalmon
[link] [comments]

The least-intuitive question in physics: how does gryoscopic precession work? (e.g. Helicopter Blades)

Posted: 30 Dec 2017 11:45 PM PST

This isn't a casual question for me, it's something I've tried to understand for some time now. Not sure what concept I'm missing.

But the outright weirdness of how gyroscopes work still bugs me, the fact that placing a torque on a gyroscope produces a force that is 90° off-axis is freaking bizarre, and I'm not the only one that thinks so!

Does anyone, anyone have a great explanation for how this concept works?

Here's a video by Veritaseum if anyone wants an introduction to the problem:

https://www.youtube.com/watch?v=ty9QSiVC2g0

submitted by /u/Anenome5
[link] [comments]

Why is there a critical spreading rate for epidemics in random networks while the spreading rate in scale-free networks are irrelevant for epidemics?

Posted: 30 Dec 2017 12:36 PM PST

Hi, Im a little bit confused after I read a paper* about the network topology and how they influence speading of diseases. My basic understanding was that there is reproduction rate (R) and the critical reproduction rate is 1. If R<1 then the disease will eventually die, but if R>1 then the disease will grow and eventually contaminate everyone in the network.

Can someone explain me why the spreading rate in scale-free networks is irrelevant, but relevant in random networks? I didnt quite understand the explaination by the authors.

Source: *Pastor-Satorras, Romualdo;Vespignani, Alessandro (2001): Epidemic Spreading in Scale-Free Networks, in: Physical Review Letters, 86 (14), 3200-3203

submitted by /u/Fotm_Abuser
[link] [comments]

(Stone) statue and radiation?

Posted: 30 Dec 2017 11:29 AM PST

Recently I took a tour of the UN in New York, and they had a statue (made of stone, I presume, but I'm not sure) on display that was in Japan during the Nagasaki bombing. The back part of it had melted off due to it. The statue was fully exposed, with no glass casing or anything, so I was concerned whether it was safe to display like that since it had been exposed to so much radiation. Would something like this contain/emit a harmful amount? (pic for reference)

submitted by /u/anacldgmz
[link] [comments]

What does the G tense in the Einstein field equation stand for and why does it have two other variables assigned to it?

Posted: 30 Dec 2017 08:52 AM PST

I recently encountered the field equations of Einstein as I was inquisitive about the expansion of the universe. Unfortunately for me I dont have an in-depth of physics (yet). I am a high school student. I was able to understand most of the variable components of the formulae but I have trouble understanding the G and T tenses of the formulae. Would love to get an explanation for this. Thank you for your time.

submitted by /u/the_rman
[link] [comments]

How does the falcon heavy have nearly double the payload to gto than the delta 4 heavy, a rocket just as big that doesn’t have to save feud in its first stage for a return trip?

Posted: 30 Dec 2017 11:35 AM PST

Why is the useful life of a smoke detector only 10 years?

Posted: 30 Dec 2017 08:00 AM PST

Given the half-life of the radioactive source is FAR greater than that, shouldn't these work for far longer (barring other causes of failure)? Or have smoke detectors been engineered to perform within specific tolerances for only 10 years (i.e. planned obsolescence)?

submitted by /u/psyop63b
[link] [comments]

How do marine mammals (especially whales) become trapped in seasonal polynyas?

Posted: 30 Dec 2017 04:45 AM PST

Having recently watched a sequence covering whales trapped in polynyas in an episode of the BBC's 2001 "Blue Planet" series entitled "Frozen Seas" I became curious to know how mammals (particularly whales) became trapped in them? Having searched online a bit I found little information about the development of this type of a situation.

submitted by /u/Creativation
[link] [comments]

Are there any theorized particles that existed only in the electroweak epoch?

Posted: 29 Dec 2017 09:33 PM PST

My current understanding is that at the beginning of the universe, at least two forces, the electromagnetic and the weak force, were under the right conditions to be considered a single force.

Are there are particles, akin to what a photon is to the electromagnetic force, that exist only in a merged electroweak force?

submitted by /u/Slayton101
[link] [comments]

Does thrust and acceleration affect the body (or other objects) in space?

Posted: 30 Dec 2017 07:23 AM PST

The question comes from a novel series I've read (the Expanse). In the series, they mention that at faster/higher thrust speeds, they have to have crash couches and drugs to handled the force of the thrust. When near a planet or star, that would make sense. But, if you're out in deep space with zero gravity, would you feel it if a ship had a sudden or constant acceleration? I would think in a zero gravity environment, you wouldn't feel the thrust. Or, you might feel an initial "bump" since the ship begins to travel before you do, but it would settle very quickly. Love the series, but that part bugs me when I read it.

submitted by /u/mal_reynolds_
[link] [comments]
vào lúc No comments:
Subscribe to: Posts (Atom)