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Wednesday, August 22, 2018

What happens to the 0.01% of bacteria that isnt killed by wipes/cleaners? Are they injured or disabled?

What happens to the 0.01% of bacteria that isnt killed by wipes/cleaners? Are they injured or disabled?


What happens to the 0.01% of bacteria that isnt killed by wipes/cleaners? Are they injured or disabled?

Posted: 21 Aug 2018 05:41 PM PDT

Will a conductive material attached to a insulating material (Like a copper plate attached to a glass plate) have a thermal conductivity equal to one of the materials, or an average?

Posted: 22 Aug 2018 07:09 AM PDT

As an example, if I bake cookies in a pan that consists of a bottom made of a typical metal sheet pan and a top made up of glass, with the cookies sitting on the glass, would the cookies bake the same as if they were in a glass pan?

submitted by /u/UCLLC
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Is cancer actually more common today in developed countries or are other causes of death just not as prevalent anymore?

Posted: 21 Aug 2018 12:19 PM PDT

Hi, it seems like the prevalence of cancer today is relatively high in developed countries. I don't have any figures but historically I'm not aware of it being a leading cause of death, whereas 3 of the top 10 causes of death in high income countries are related to cancer, according to the WHO. Is cancer actually becoming more common in developed societies due to pesticides, processed foods, air pollution, sedentary lifestyles etc. or are we simply eliminating other diseases which historically would have killed people at a younger age, and because people are living longer they are more likely to develop cancer over time? I'm not sure it's possible to answer this (unsure how reliable historical data relating to cause of death are, and also not sure how it would be possible to assess whether the child of a medieval peasant would have developed cancer later in life had they not died of childhood diseases), but if anyone has any insight into this I'd be really grateful!

submitted by /u/manuk85
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How does the diameter and width of a wheel affect the ability of it to move on a soft surface such as sand?

Posted: 22 Aug 2018 06:16 AM PDT

How does fabric softener work?

Posted: 22 Aug 2018 07:35 AM PDT

Why does rain fall in varying-size drops? Why is it not a uniform droplet size?

Posted: 22 Aug 2018 06:35 AM PDT

Sorry to sound like Forrest Gump, but why is there itty bitty stinging rain and big ole fat rain in the same temperate climate?

Thank you for any answers you have.

submitted by /u/IPretendToPlayGuitar
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What do people here mean with "laws of physics start breaking down"?

Posted: 21 Aug 2018 10:47 PM PDT

Are they talking about the laws of physics as we know them start being incorrect and faulty or is it physics itself becoming unpredictable and weird like in a blackhole?

submitted by /u/osxthrowawayagain
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At what speed does 2 deuterium nucleus has to collide for them to fuse into Helium-4?

Posted: 22 Aug 2018 12:42 AM PDT

According to the theory of relativity, do all observers agree on causality?

Posted: 21 Aug 2018 08:51 PM PDT

This is a question that I posed to my astronomy 101 teacher, but I don't think she understood my question. So, as I've heard relating to the theory of relativity, if observer A is on Earth, and observer B goes at ½c to the nearest star and back, observer B will have experienced far less time than observer A. But that's from the perspective of observer A. From the perspective of observer B, observer A is receding at ½c away from them, and so observer A should be experiencing less time. How is this resolved within the theory, or am I just not getting it?

submitted by /u/slimegoo
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How can electrical charge be detected in ionic solutions?

Posted: 22 Aug 2018 12:38 AM PDT

So today, I have a very complex question I need possible answers for, or to just brainstorm with other people on.

Background: So, dissolved solutions with ions, such as saltwater which we will use here, are proven to be great conductors; this is because when an electrical current is produced in salt water, the sodium and chlorine ions form bridge like paths that carry electrons.

My Question; Here is what I need help with; I need to know how to pick up these electrons from, let's say, salt water. Now normally this would be easy; a signal could easily be read say if lighting struck salt water. But here's the catch. I need to detect (or notice the presence of electrons) electrical currents at voltages in the nanovolt region without touching the item which is producing the voltage. In other words, I want to be able to detect the present of nanovolts in salt water in order to run them trough an amplifier to get readings for data, so images sticking a machine in a tank of salt water with a machine producing nanovolts in it and getting a reading on the magnitude of the voltage. Currently, I have thought about using slightly charged chemicals which could take up the free electrons and produce a chemical signal or something like that. I also don't want to spend to much money. I would love to hear peoples suggestions, it would really help me!

-Mbio

submitted by /u/Mbio33
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Does the smoke from forest fires meaningfully block UV rays?

Posted: 21 Aug 2018 08:47 PM PDT

Do people aboard the ISS experience astro-intestinal problems?

Posted: 21 Aug 2018 05:11 PM PDT

How large a role does gravity play in digestion?

submitted by /u/grau0wl
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What can you tell about a person from a DNA test?

Posted: 21 Aug 2018 04:53 PM PDT

I'm thinking about getting one some time in the future. I'm curious how it works, and I want to know as much as practically possible.

I'm guessing there's thousands of things, but as far as what you're told, what is there?

submitted by /u/Puzzleheaded_Stable
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How much C02 is released during a forest fire?

Posted: 21 Aug 2018 08:55 PM PDT

Take the current forest fires in California at present for example.

submitted by /u/burnerneveruse3000
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If two points determine a line, two parallel or intersecting lines determine a plane, then does two parallel or intersecting planes determine 3d space?

Posted: 21 Aug 2018 06:16 PM PDT

In 4d geometry.

submitted by /u/Catty-Cat
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Has a gravity assist/swing-by to pick up speed ever been done using the Earth itself? Could it help send probes to Venus and/or Mars?

Posted: 21 Aug 2018 05:43 PM PDT

Why hasn’t London been able to reduce its NO2 levels?

Posted: 21 Aug 2018 02:13 PM PDT

As shown by this graph, many cities across the globe have gradually reduced their NO2 emissions over the past 20 years. However, there are multiple outliers. In particular, London is demonstrating a slight upward trend in emissions. Why hasn't London been able to reduce it's NO2 emissions like other comparable cities.

submitted by /u/Luke-HW
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So I’ve seen posts asking about disease caused by cannibalism among humans and a few other animals, but is it common for other species to engage in cannibalism?

Posted: 21 Aug 2018 12:32 PM PDT

Are there many species which are NOT affected negatively by cannibalism, and if so, do any of those carnivorous/omnivorous species actively or willingly engage in cannibalism?

submitted by /u/chrisdip55
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Is Lightening a Threat to Airplanes?

Posted: 21 Aug 2018 04:36 PM PDT

Living near an airport, I see a lot of planes fly into storm clouds and it has me wondering - what's stopping these giant metal tubes from being struck by lightening?

submitted by /u/Scuilla
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Why do solar panels installed diagonal to the ground and not vertically facing the sun?

Posted: 21 Aug 2018 01:42 PM PDT

Is astronomy a predominantly western study? Are there any stars/planets/phenomenon discovered and named by Arabic/Eastern cultures?

Posted: 22 Aug 2018 02:55 AM PDT

Is it possible the Bootes Void is void of planets because an advanced civilisation(s) harvested them all?

Posted: 21 Aug 2018 09:12 PM PDT

How does hurricane modeling provide prediction on storm path?

Posted: 21 Aug 2018 12:13 PM PDT

Whether a hurricane will angle left or right as it proceeds? Or continue straight? When a hurricane departs much from a predicted path, is that considered highly aberrant?

submitted by /u/Markdd8
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What does the amount of blades do for a airplane or helicopter?

Posted: 21 Aug 2018 03:20 PM PDT

Tuesday, August 21, 2018

What's the cause for the extreme increase of Sargassum seaweed since 2011?

What's the cause for the extreme increase of Sargassum seaweed since 2011?


What's the cause for the extreme increase of Sargassum seaweed since 2011?

Posted: 21 Aug 2018 04:52 AM PDT

How does hail form? (Especially large sizes)

Posted: 20 Aug 2018 11:27 PM PDT

Why is the singlet-state gluon not allowed, instead of just being a non-strong-interacting particle?

Posted: 20 Aug 2018 11:27 PM PDT

How does half life work for individual atoms?

Posted: 20 Aug 2018 02:59 PM PDT

So I do know what half life means on a macroscopic scale. If you have an unstable substance with a half life of, say, a minute. It would mean that every minute, half of the atoms of that substance would decay in some other substance.

So when you start witb 120 unstable atoms with a half life of 60 seconds. Probably no more than a second after you start measuring there would already be one atom that has decayed. A minute later roughly 60 atoms will have decayed. The decay of the last atom, however, will probably be some minutes later.

Given that the decay of a single atom can be really close to t=0 and could also be really distant t=0 depending on the amount of atoms you start with. Why can some atoms 'hold on' longer than others. And why even more so when you start with more of those atoms.

Note: While typing this I realized that it is possible that every atom has the same probability of decaying at any given time and more atoms will decay when you have more rather than less. So half life is basically just the average rate of decay for individual atoms of that substance. This would translate into a macroscopic observation of halving every half life. Is this a correct way of seeing it?

submitted by /u/SyefufS
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Why are microplastics any worse than other small, inert particles like sand?

Posted: 20 Aug 2018 10:31 AM PDT

https://www.npr.org/sections/thesalt/2018/08/20/636845604/beer-drinking-water-and-fish-tiny-plastic-is-everywhere

Even though plastics get everywhere, shouldn't they just pass through the digestive systems of animals?

submitted by /u/darkbane
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If deserts form around 30° latitude due to global pressure belts, why aren't there deserts in Florida or Eastern China?

Posted: 20 Aug 2018 05:01 PM PDT

If I throw a ball straight up, how long does it remain perfectly still at its max height before beginning to fall? What factors, if any, affect this length of time?

Posted: 20 Aug 2018 02:21 PM PDT

Are dielectrics affected by external magnetic fields?

Posted: 20 Aug 2018 10:54 PM PDT

I understand they are only affected by constant or time-varying electric fields, but are they affected by constant or time-varying magnetic fields?

submitted by /u/9tothe9
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What is the del operator in the Schrodinger equation?

Posted: 20 Aug 2018 09:52 AM PDT

How are there storms and wind on the Mars, when there is no atmosphere?

Posted: 20 Aug 2018 09:46 AM PDT

Just saw "The Martian" and was wondering that.

submitted by /u/lassenym
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How high in latitude does water need to be to evaporate at room temperature?

Posted: 20 Aug 2018 10:20 AM PDT

Monday, August 20, 2018

What is the smallest size a fire can be?

What is the smallest size a fire can be?


What is the smallest size a fire can be?

Posted: 19 Aug 2018 10:44 PM PDT

When someone is sight reading a piece of music, what is happening in their brain? Has anyone ever monitored brain activity during sight reading? If so, Is it similar to when someone reads a language?

Posted: 19 Aug 2018 09:56 AM PDT

How do seeds determine where's the surface when planted underground?

Posted: 20 Aug 2018 02:36 AM PDT

I recently planted pea and was wondering if seeds have some kind of gyroscope or gravity sensor to determine in which way they must grow roots and stem. In case of "on the ground" it would be easy to guess that there are some chemicals which reacts in the contact spot with the soil, but underground there is soil everywhere.

submitted by /u/maaboo
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Was the fifth force discovered or not?

Posted: 20 Aug 2018 03:36 AM PDT

Below is an article about a possible discovery of a particle responsible for soem kind of new force (?).

https://www.nature.com/news/has-a-hungarian-physics-lab-found-a-fifth-force-of-nature-1.19957

Article date is at about 2016 and says that in a year some other labs would come with confirmation or not.

I'm not sure how to find this out but has there been any development and if possibly what exactly could this 5th force be responsible for?

Thank you very much.

submitted by /u/viksl
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What is the standard used to measure elevation on other planets that don’t have a “sea level?”

Posted: 19 Aug 2018 11:09 AM PDT

Can a dead person left in the sun get a tan?

Posted: 19 Aug 2018 09:45 AM PDT

A spinning magnet can induce a current in a conductor, this is how a generator work. But what is the average rotational to electrical energy efficiency of these generator?

Posted: 19 Aug 2018 09:36 PM PDT

What exactly is the dark side of the moon?

Posted: 20 Aug 2018 04:06 AM PDT

I mean, doesn't it rotate and revolve so all sides get light at some point?

submitted by /u/CormacN
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Can I just put a magnet (or a bunch of little ones) on my induction stove to adapt it for all cookware?

Posted: 19 Aug 2018 07:21 PM PDT

They sell converter disks, but I'm wondering if I could just use magnets.

What you say you science folk?

submitted by /u/lapret
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Why is gasoline sold and measured by volume, not mass?

Posted: 19 Aug 2018 04:45 PM PDT

As far as I know, gasoline's volume varies with temperature and air pressure, much like pretty much everything else. So why do we buy gas and measure fuel efficiency by volume rather than by mass?

submitted by /u/18BPL
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What makes plutonium and uranium so special?

Posted: 19 Aug 2018 04:42 PM PDT

In reactors or bombs, why do we use these specific elements rather than others?

Could you make a fission reactor that worked on carbon or iron or titanium? If it is possible, why don't we?

submitted by /u/AJollyRogering
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Why is it that both the stratosphere and mesosphere are cold while they’re between the troposphere and thermosphere which are hot?

Posted: 19 Aug 2018 10:25 AM PDT

How do microwaves heat food up?

Posted: 19 Aug 2018 02:34 PM PDT

So if microwaves have longer wavelengths and less energy than visible light, how do they increase the temperature and thus average molecular kinetic energy of its target (food)?

submitted by /u/The_Septic_Shock
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Are bubbles airtight? Does it change with different types of bubbles like dish soap bubbles, water bubbles, etc.

Posted: 19 Aug 2018 09:25 AM PDT

Does the electromagnetic interaction in molecular bonds have a frequency in the electromagnetic spectrum?

Posted: 19 Aug 2018 12:14 PM PDT

The question that I want to ask is actually broader than the one in the title. Do all the interactions that the fundamental force of electromagnetism regulates have a frequency? If not,then how can the photons responsible for the force be emitted without a frequency? I'm sorry if this is somehow a stupid question

submitted by /u/omniscientboner
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Why do sleepers and rails from the railway track need to be removed and replaced with new ones?

Posted: 19 Aug 2018 08:09 AM PDT

When people pass out from too much drinking, is that due to low heart rate or something else?

Posted: 19 Aug 2018 10:16 AM PDT

I ask because i had a drink tonight and after getting up to use the bathroom. I felt my heart rate slow down and my fitbit recorded it to be 25 to 30... i felt light headed and very dizzy. I had one drink lol

submitted by /u/Slayer_Tip
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Why does it take so long to name new elements?

Posted: 19 Aug 2018 05:30 PM PDT

Nihonium was first synthesized in 2003. Moscovium was first synthesized in 2003. Tennessine's synthesis was first announced in 2010. Oganesson was first synthesized in 2002.

They were given their present names in 2016. Why did the names take so long?

submitted by /u/Catty-Cat
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Pressure drops in Venturi's pipe vs Heat exchanger?

Posted: 19 Aug 2018 10:44 AM PDT

Hello to all,

my collegue recently came up with really interesting questions, which certainly seems like two chemical engineers should know by default, but we couldn't come up with definite answer...

so here it is, when Bernoullis equasion applies to Venturi's pipe, it says that when fluid flows throught narrower area its speed increase but pressure drops...but when it goes to wider area again, speed decreases and pressure increases.

If this is applied to heat exchanger ( with situation where there is some fouling in pipes of HE ), why doesn't pressure goes up again when fluid exits heat exchanger system into normal pipe again?

EDIT: in other words, shouldn't principle be the same in Venturi's pipe and pipe's in heat exchanger with some fouling?

Thank you very much

submitted by /u/dothakercro
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