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Monday, November 26, 2018

Why is there no 1-methyl pentane?

Why is there no 1-methyl pentane?

Why is there no 1-methyl pentane?

Posted: 26 Nov 2018 02:46 AM PST

[ive got my answer now thanks guys:)]Can someone explain to me why 1-methyl pentane doesn't exist as a structural isomer of hexane? I've read a few explanations online but I don't understand them. Can you guys help? It's for a piece of work I'm doing on structural isomerism.(Im an a-level chemist who has just started work on isomers and biochemistry)

submitted by /u/commander_shortstop
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Would there be caves on other celestial bodies like there are on Earth?

Posted: 25 Nov 2018 07:06 PM PST

It would make sense that Mars would have caves, but would bodies like Europa, Io, Titan or Mercury have them? If so, why?

submitted by /u/edcamv
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Are there any organisms/living things that use magnets in any way?

Posted: 26 Nov 2018 04:11 AM PST

Apart from humans obviously

submitted by /u/fatoldarabguy
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How is the age of a star determined?

Posted: 25 Nov 2018 04:56 PM PST

Why does alcohol not cause dopamine resistance in the mesolimbic pathway like other drugs?

Posted: 26 Nov 2018 08:19 AM PST

I know with other drugs, you night end up feeling depressed because you can't achieve the same level of happiness, why does his not occur with alcohol?

submitted by /u/GforGENIUS
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If left alone, will all of the space debris eventually coalesce into a sort of artificial moon and how long would that take?

Posted: 26 Nov 2018 08:04 AM PST

Why do hydrogen atoms want to bind with other hydrogen atoms?

Posted: 26 Nov 2018 07:35 AM PST

If I am falling with an object (feet on it) and jump right before hitting the ground, could I survive a potentially fatal fall?

Posted: 26 Nov 2018 02:56 AM PST

How does the cabin in an airplane pressurize and maintain that pressure? Where does the oxygen come from as well?

Posted: 25 Nov 2018 03:32 PM PST

Why is weightlifting good for mental health?

Posted: 25 Nov 2018 03:22 PM PST

Why are people more likely to sing/talk to themselves while driving?

Posted: 25 Nov 2018 03:43 PM PST

The mechanics of gravity?

Posted: 25 Nov 2018 10:05 PM PST

Hi there, Science Reddit. I am curious as to how gravity works; is there a formula that links earth's volume and the constant of gravity? Could said formula standardize how strong an object's gravity is? And in the case of earth's gravitational force, what is the distance at which it begins to deteriorate and where it stops functioning altogether, and is there a formula for it as well?

submitted by /u/Dagdade
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What is assymetric magnetic coupling, and how will it affect our day to day lives if it proves practicable for use in consumer electronics?

Posted: 25 Nov 2018 06:44 PM PST

Can lasers be focused to reach an arbitrarily large intensity? (Optics)

Posted: 25 Nov 2018 02:03 PM PST

I saw this video on YouTube ( https://youtu.be/jdjTYlReE-I ), where a guy tries to focus a flashlight but cannot focus it to a greater intensity than the source due to conservation of entendue.

In the same video, he then claims he can focus his laser to heat an object to any arbitrarily large temperature, because lasers have negative energy states and can transfer energy to any material with positive energy states.

He shows how he can focus his laser with a magnifying glass to increase the speed of burning on wood.

However, I believe he is wrong. My hypothesis is this: The laser source is actually small, but the beam is widened in a collimator to produce a parallel beam. His magnifying glass merely focuses it back to its original intensity, thus still fulfilling the conservation of entendue.

Anybody know if this is true? Or can you indeed reach positive infinite kelvin with any home laser and proper focusing.

submitted by /u/Wormsblink
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Will a micro or nano scale aerofoil create lift?

Posted: 25 Nov 2018 08:38 PM PST

As long as there is some positive and negative pressure applied to an aerofoil shaped object, will lift always be generated?

submitted by /u/FineLite
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Is it possible to calculate how much force/ pressure is needed to make a solid material behave like a liquid/dough?

Posted: 25 Nov 2018 01:23 PM PST

Will scientists is future will find new elements as we explore our solar system and outer space more? Or every element is already discovered and listed in periodic table?

Posted: 25 Nov 2018 01:03 PM PST

Why are all the planets of the Solar System revolving on the same horizontal axis but not necessarily every objet of the Solar System. Why aren't all the celestial bodies of the universe on the same plane?

Posted: 25 Nov 2018 08:08 AM PST

In pills that are designed to be split into halves or thirds: how is it guaranteed that each part contains the same dosage?

Posted: 25 Nov 2018 02:51 PM PST

Say, a pill is designed to be split into thirds and contains 150mg of a specifig drug. How do pharma companies guarantee that each third contains 50mg?

submitted by /u/thscplgst
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What would the Sentinelese do with their dead?

Posted: 25 Nov 2018 11:50 AM PST

If the Sentinelese have lived on their island for approximately 55,000 years, what would they do with their dead over such a long time period?

I understand we know very little about them, but I'm curious what their after death rituals are such as burning the bodies, or possibly just burying them.

submitted by /u/inomark
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Sunday, November 25, 2018

What are the properties of an ion engine exhaust? Is it warm? Is the engine loud? What would happen to stuff that gets in the way of the exhaust?

What are the properties of an ion engine exhaust? Is it warm? Is the engine loud? What would happen to stuff that gets in the way of the exhaust?

What are the properties of an ion engine exhaust? Is it warm? Is the engine loud? What would happen to stuff that gets in the way of the exhaust?

Posted: 25 Nov 2018 05:06 AM PST

I have seen ion engines only in games or still images, and I am curious about the effects the exhaust has on stuff. Since it's electrically accelerated propellant, and such a low amount, it feels like it shouldn't affect a hand/other stuff in the exhaust, but I might be completely wrong.

submitted by /u/SimmeP
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The majority of drugs that work in mouse models are not successful in humans. Is the inverse also true, are there drugs that do not work in mouse models but do work in humans?

Posted: 25 Nov 2018 07:21 AM PST

Venn diagram version of question https://imgur.com/etQoR0N

submitted by /u/easy_pie
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Is a star’s luminosity dependant on ‘Big G’?

Posted: 25 Nov 2018 04:13 AM PST

I was reading 'Astro for people in a hurry' by deGrasse Tyson and he stated that 'if you do the math you can determine that a star's luminosity is steeply dependant on 'big G'." I don't remember any such relation - nor can I find it online with a very quick browse. I imagine he is right, since it's in a book, so where am I wrong?

Edit: dependent*

submitted by /u/Almyteacivil
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Does a black hole grow as it absorbs more mass?

Posted: 25 Nov 2018 05:00 AM PST

If two babies never exposed to language grew up alone on a deserted island, would they ever develop any form of language?

Posted: 24 Nov 2018 11:25 AM PST

Just wondering about how natural language is for humans. Would they be silent? Grunt at each other? Or would they naturally form a language full of nouns and verbs?

submitted by /u/tyler0351
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Why is boron classified as a metal and a non-metal on the periodic table?

Posted: 25 Nov 2018 07:18 AM PST

If 300 million years ago oxygen levels were 35%, why are they lower now?

Posted: 25 Nov 2018 12:53 AM PST

It is thought that 300 million years ago the oxygen concentration on Earth may have been as high as 35%. What I don't understand is why oxygen levels in the atmosphere aren't 35% now given the following logic:

​

Oxygen in the atmosphere is almost entirely a result of organisms doing oxygenic photosynthesis. Photosynthetic organisms split water yielding O2 (which is released to the atmosphere and thus increasing atmospheric O2 concentrations) and the reducing equivalents are used to reduce CO2 into sugars and other organic molecules. So for O2 levels to have been 35% in the atmosphere, a full 66% higher than they are now, then there must have also been 66% more reduced things somewhere else. So my question is where was that extra 66% stored back then, and why isn't it in circulation now?

​

I've only seen casual explanations for why oxygen levels were higher in the past, and nothing about the discrepancy of high O2 levels vs "reduced things" levels. I'm hoping someone knows of a rigorous article on the subject.

​

I can postulate 3 options but I'm not really in love with any of them:

Option 1: There could have been 66% more living things 300 mya. But that requires 66% more CO2 to have been reduced into organic molecules in living things. Where did that carbon go over the last 300 mya? For the hypothesis to work, as the quantity of life decreased from it's hypothetical peak 300 mya to now, the carbon would need to be released as CO2. But CO2 levels are thought to be lower now than they were 300 mya, even with the increased fossil fuel use in the last 200 years. Simply burying the life after it died, allowing it to ultimately become coal and oil, doesn't explain the discrepancy. Coal and oil still have the reducing equivalents in them, hence why we can burn them into CO2. So for this hypothesis to be true, some combination of forces was net emitting lots of CO2 then, and net removing CO2 out of the atmosphere now. Some combination of volcanoes vs rock weathering could explain this, but 300 mya is only about 6.6% the age of the Earth. Are these forces really so dynamic as to produce this result in a relatively short period?

​

Option 2: There was some slowly oxidizing material in the Earths crust that took an extra couple hundred million years to oxidize after the Great Oxygenation Event had oxidized everything else in the crust. In this theory the crust of the Earth was removing O2 out of the atmosphere more slowly than it was being produced for a short while, allowing oxygen to build up to 35%, above the equilibrium amount. Eventually photosynthesis became limited by whatever it's limited by and the O2 equilibrium amount of around 21% was reached, as it is today. But what material would be capable of this slow oxidation that would need to be quite abundant in the crust?

​

Option 3: After the Great Oxygenation Event the oxygen levels on Earth have been relatively constant around 21%, and simply our ability to measure it accurately is difficult because, you know, 300 million years have elapsed. Since I don't fully understand how the estimates are made I have no ability to really asses their validity. Therefore I'm inclined to trust the people who spend all their time arguing with each other about the estimates.

​

Edited for clarity

submitted by /u/sadddpanddda
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Can fabric and insulation (heat) be made from non-carbon-based materials?

Posted: 25 Nov 2018 06:21 AM PST

I'm working on a novel, and I'm wondering if there is a substitute for carbon-based materials to make clothes and heat insulation for houses. If so, what processes can be used to produce the carbon-free clothes and insulation?

submitted by /u/fanabomerro
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Is there a molecular or structural difference between cancer and metastatic cancer?

Posted: 25 Nov 2018 06:01 AM PST

Apart from the localization is there a molecular or structural difference between for example HER2-negative ER-positive breast cancer and metastatic cancer of the same type?

submitted by /u/Parallax_Effect
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Escape velocity of Earth is 11.186 km/s. Does rockets we launch goes upward with this speed?

Posted: 24 Nov 2018 10:30 PM PST

If someone resembles one parent in outward appearance does this mean they resemble that one parent "internally" e.g. propensity to heart disease, mental ability, propensity to breast cancer?

Posted: 24 Nov 2018 09:46 AM PST

So if you for example *look* like your dad do you have genetic similarities in the same proportions on things other than outward appearance.

submitted by /u/the_better_angels
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Does previous acclimatization make future acclimatization easier? (X/mountaineering)

Posted: 25 Nov 2018 01:43 AM PST

I was born and raised in a higher altitude/cold climate (Canadian Rockies) but have since moved to sea level in (warmer) Europe. I intend to climb Mont Blanc (French Alps) in a year or so and was wondering if it will be easier for me to acclimatize due to living at a higher altitude most of my life, or if the time spent at sea level will completely reset my system.

submitted by /u/wulfzbane
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Why do butterflies sometimes land on things and open/close their wings really slowly?

Posted: 24 Nov 2018 06:20 AM PST

Why are cro magnon not considered a subspecies but homo sapiens idaltu is when the anatomy of cro magnon seems to be more different to homo sapiens sapiens compared to idaltu?

Posted: 25 Nov 2018 12:51 AM PST

How does it make sense to talk about the volume of a given gas (as an inherent property of it), when gases always occupy the volume of the recipient they are in, and thus have variable volume?

Posted: 24 Nov 2018 12:31 PM PST

It might be too long since I took high-school level physics and I forgot, but declarations like "gas X has a volume of Y liters at standard temperature and pressure" don't currently make much sense to me because gases will expand to occupy the volume of whatever container they're put in.

Thanks for the clarification.

submitted by /u/Kelvets
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Is there much or any variation in size between different people's eyeballs?

Posted: 24 Nov 2018 03:18 PM PST

What is the proportion of the size of blackhole's event horizon compared to the volume of mass that created it?

Posted: 24 Nov 2018 07:18 PM PST

As in, how much bigger/smaller is a black hole than the star that it was born from (accounting for the lost mass during the super nova, if possible)

submitted by /u/SatanicOnion
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If light radiating from a star expands like a sphere in all directions, how is it that after many light years of expansion when that light finally reaches Earth such a small area of that sphere still seems to contain enough photons to blanket every square millimeter of our planet?

Posted: 24 Nov 2018 08:56 AM PST

Whats the difference between Centrifugal and Centripetal force?

Posted: 24 Nov 2018 10:20 AM PST

Is it possible to have planets orbiting a star in significantly different planes, similar to the Rutherford atomic model but with the star as the nucleus?

Posted: 24 Nov 2018 11:14 AM PST

How did laughing and the concept of humour evolve?

Posted: 24 Nov 2018 08:29 AM PST
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Saturday, November 24, 2018

Are there any known examples of domesticated mammals becoming extinct?

Are there any known examples of domesticated mammals becoming extinct?

Are there any known examples of domesticated mammals becoming extinct?

Posted: 23 Nov 2018 10:20 AM PST

Could a single celestial body be as large as the Milky Way galaxy? If not, what is restricting the size of it?

Posted: 24 Nov 2018 06:23 AM PST

How do ovums prevent excess sperm cells from entering them when they've already fused with one?

Posted: 24 Nov 2018 06:30 AM PST

How are mineral deficiencies even possible in adults? Minerals don't degrade or "break down" in enzymatic reactions (unlike many molecules), so can't the body completely stop excreting them if intake is low?

Posted: 24 Nov 2018 06:28 AM PST

Mineral deficiencies are possible in mammals when subjected to dietary restriction of said minerals.

Why are those deficiencies even possible, though? It is understandable why vitamin deficiencies are possible; Different vitamins (molecules) are used for X and Y, and then break down to useless molecules, requiring daily intake to keep a normal concentration.

The same does not apply to minerals. Magnesium, for instance; in the body, Mg2+ ions participate in 300+ enzymatic reactions, making Mg a major electrolyte required in large amounts in the diet. However, Mg2+ can't degrade or break down like molecules can (due to it already being a single atom/ion), so technically speaking, it could be recycled indefinitely in adults (children, but not adults, have rapidly growing bodies so it makes sense they would need it).

Yes, there's the fact that some endogenous chemicals require Magnesium to even function, like ATP, which is only active as Mg-ATP. That still doesn't defy my point - when Mg-ATP complex is broken down after it was used for energy production, the Mg2+ ion is released and can be reused for any purpose.

submitted by /u/SuperAgonist
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How old is Earth's oldest ice? What was going on when it froze?

Posted: 23 Nov 2018 09:45 PM PST

How did the tribal people of the Sentinel Island reached there in first place ?

Posted: 23 Nov 2018 10:34 PM PST

How the island got inhabited in first place thousand of years ago? The only way to reach there was through ships in past. But if they even don't know how to start fire or do agriculture, then reaching the island by boat for them is not an option.

submitted by /u/SupaComputah
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Was the development team of the first atomic bomb surprised by the size of the explosion or had they calculated how much energy would be released before the first explosion?

Posted: 23 Nov 2018 12:08 PM PST

Why is it that certain mammals carry a risk for rabies, but rodents do not?

Posted: 23 Nov 2018 08:59 PM PST

In the title I mean small indoor rodents, not necessarily larger ones like a groundhog or beaver.

I understand that certain animal populations pose a threat for this disease such as bats or raccoons (in the United States), and an experience with either of these would require urgent medical treatment.

However, I learned that small rodents (rats and mice) are almost never infected in the wild and have never transmitted the disease to humans in the US.

I went to see medical professionals a while ago because I had a small mouse in my living area at the time, it licked my foot but I had a sock on. I removed the sock shortly afterward and I'm pretty sure nothing got on my hands. I was just concerned (I deal with anxiety at times) even if in hindsight it was unnecessary. They told me not to worry and since there was zero risk, there is nothing that needs to be done.

Out of curiosity, why are small rodents capable of spreading certain other diseases, but never this one? If a small rodent was attacked by an infected carrier, would it die almost immediately? Appreciate all knowledgeable answers.

submitted by /u/IEatPastaFrequently
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Is there a material which giving energy (heat) makes it colder?

Posted: 24 Nov 2018 05:17 AM PST

I was reading through a physics class annotations and there was this statement:

"Generally, heat absorption results in an increase of temperature".

submitted by /u/iloveumariaxzz
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How do those flavor changing berries work?

Posted: 24 Nov 2018 12:05 AM PST

I think many people have heard about those berries that supposedly make sour things sweet and vice versa but how do they actually work?

submitted by /u/figgernaggotXP
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What happens when I jump inside a space centrifuge?

Posted: 23 Nov 2018 11:56 PM PST

Let's say it's a fairly low-acceleration centrifuge, so I'll be able to jump quite 'high'. I preserve angular momentum and velocity, but where do I land?

submitted by /u/Milo_Y
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What attracts flies to feces?

Posted: 23 Nov 2018 03:28 PM PST

Are there enough sugars, proteins and fats in shit to make a tasty meal for flies, that they can smell from a distance? Or are they being tricked somehow?

submitted by /u/ryuuhagoku
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Are tectonic plates moving faster in areas with frequent earthquakes?

Posted: 23 Nov 2018 09:39 PM PST

When describing tectonic plate movements, scientists say that they move at quite slow speeds, measured in millimetres per year. At the same time, in places where earthquakes occur, a single powerful earthquake can cause ground movement of multiple meters all at once, orders of magnitude faster than millimetres per year. Isn't this contradictory? Shouldn't the tectonic plate movement be actually faster, taking the earthquake movement into account?

submitted by /u/IndependentGuy
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Why aren't rotational kinetic energy and translational kinetic energy as fundamentally distinct from one another as angular momentum and linear momentum?

Posted: 23 Nov 2018 12:38 PM PST

Conservation of momentum and conservation of angular momentum each have, through Noether's theorem, their own associated fundamental symmetry of the universe: spatial symmetry and rotational symmetry respectively.

In (seeming) contrast, all different forms of energy -- translational, rotational, vibrational, nuclear, etc etc -- are lumped together in Noether's theorem, their collective conservation leading to (or being equivalent to) the universe's time symmetry. This makes sense, since you can convert any kind of energy into any other kind, so they are only conserved collectively.

But, rotational kinetic energy is directly associated with angular momentum (right?), and translational kinetic energy is directly associated with linear momentum (right?). So why are you able to convert between rotational and translational kinetic energies, but not between angular and linear momentums...momenta...?

submitted by /u/horacetheclown
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Did the dinosaur-apocalypse meteor's impact change the Earth's orbit or rotation?

Posted: 23 Nov 2018 05:45 PM PST

What are the numerous smaller pipes and gauges seen on rocket engines?

Posted: 23 Nov 2018 08:14 PM PST

I know the basics of how the Inert gas, fuel, Oxidizer and the turbines are fueled, but after many hours of looking I cannot find the use of all the other little pipes and gauges seen on the Space Shuttle or F1 engines... If anyone knows the answer of links that can be useful, please help, thanks in Advance! :)

submitted by /u/rancorjoy
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How do electrons or positrons come into existence during beta decay?

Posted: 23 Nov 2018 01:24 PM PST

How is it possible for an electron or a positron to just come into existence during beta decay? What happens to the quarks that were previously inside the nucleons? Like in beta positive decay, how is a positron and a neutrino just produced from the nucleus, I don't understand how these particles can just come into existence when the proton that "decays" does not consist of those particles....

submitted by /u/CommonAge0
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Do stars make noises? Would we be able to hear the noises or sounds they emit?

Posted: 23 Nov 2018 02:56 PM PST

What kind of animals inhabited north america before the native americans?

Posted: 23 Nov 2018 07:37 PM PST

How do perennials know when it's spring?

Posted: 23 Nov 2018 02:23 PM PST

In my experience, daffodils have always bloomed earlier than I expect due to receiving a couple warm days after a frost. How do perennials know when to bloom in warmer climates? And how exactly do bulbs know?

submitted by /u/fizicks11
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Are there any materials/metals that marine life (corals, barnacles, etc.) cannot grow on? If so, why?

Posted: 23 Nov 2018 09:34 PM PST

How is it possible to merge or split photons around a neutron star if photons are elementary particles/waves?

Posted: 23 Nov 2018 12:29 PM PST

According to this Wikipedia article , neutron stars' powerful magnetic fields can merge or split photons, but first of all, this makes about as much sense to me as splitting a quark -- you can't split something which is already the smallest possible unit of its kind. Second, how would it be possible to split or merge a photon if it has no mass?

submitted by /u/criostoirsullivan
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