61
Chemistry / Re: How does CRISPR/cas9 work?
« on: 17/05/2019 19:57:54 »
no
Show Posts
This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.
62
Physiology & Medicine / Re: guess-the-illness time! (rash, hyperpyrexia, hallucinations, short duration)
« on: 15/05/2019 13:48:47 »
The sudden onset, short duration, and extreme symptoms lead me to wonder whether this illness could have been caused by acute exposure to a toxin, rather than microorganisms.
Deadly nightshade (Atropa belladonna) grows wild in many parts of Europe. The tropane alkaloids it contains are known to cause, among other symptoms: vivid hallucinations, delirium, hyperthermia (especially in children), and rashes... ("red as a beet, dry as a bone, blind as a bat, mad as a hatter and hot as a hare")
Sound familiar?
https://en.wikipedia.org/wiki/Atropa_belladonna#Toxicity
Do you or your grandfather recall whether your pupils were dilated (it would not have been subtle). Before the hallucinations set in, was your vision blurry and eyes sensitive to light? Do you recall your heart racing, or losing the ability to walk straight, or stay balanced? Had you eaten "wild blueberries" while on your swimming adventure?
If, indeed, this is the explanation, you are very lucky. The dosage required for causing hallucinations is not much smaller than the fatal dose, especially for children.
EDIT: I see now that atropine poisoning was mentioned in the original post as a possibility...
Deadly nightshade (Atropa belladonna) grows wild in many parts of Europe. The tropane alkaloids it contains are known to cause, among other symptoms: vivid hallucinations, delirium, hyperthermia (especially in children), and rashes... ("red as a beet, dry as a bone, blind as a bat, mad as a hatter and hot as a hare")
Sound familiar?
https://en.wikipedia.org/wiki/Atropa_belladonna#Toxicity
Do you or your grandfather recall whether your pupils were dilated (it would not have been subtle). Before the hallucinations set in, was your vision blurry and eyes sensitive to light? Do you recall your heart racing, or losing the ability to walk straight, or stay balanced? Had you eaten "wild blueberries" while on your swimming adventure?
If, indeed, this is the explanation, you are very lucky. The dosage required for causing hallucinations is not much smaller than the fatal dose, especially for children.
EDIT: I see now that atropine poisoning was mentioned in the original post as a possibility...
63
Physiology & Medicine / Re: Can oxygen deprevation at night cause severe mind numbing headaches upon waking?
« on: 09/05/2019 04:40:40 »64
That CAN'T be true! / Re: Does Stokes' theorem equality produces the right results?
« on: 07/05/2019 23:23:07 »Stokes' theorem is equating a line integral with a surface integral. The result of the line integral is a length which is not equivalent to the the surface area of the surface integral which proves Stokes' theorem is mathematically invalid.Sorry. This only proves that you don't know what you're talking about. Multiple people have provided explanations or links to detailed explanations in an effort to educate you, while you have only repeated the same ridiculous straw man argument over and over. Please try to understand, or at least realize that you don't understand. This is the last post I will make in this thread.
65
That CAN'T be true! / Re: Does Stokes' theorem equality produces the right results?
« on: 07/05/2019 16:51:46 »The result of the Stoke's line integral is a length which is not equivalent to the the surface area of the surface integral.The integral of a function over a line is NOT the length of the line (HINT: it must relate to the function as well). Stokes' theorem does NOT equate a surface area with a length--which is what you appear to be claiming.
Please seek a better understanding of this topic before knocking it.
66
Complementary Medicine / Re: Can the brain distinguish between inhaling oxygen and hydrogen?
« on: 07/05/2019 04:05:06 »Am I the only one who is worried that by saying " He's more or less right- teh brain won't notice the lack of oxygen and kick in the panic reflex", we are effectively saying
"gases that are free from oxygen are a good way to top yourself"?
I really don't think we should be providing that advice.
I understand your concern here.
On the other hand, I'm not sure I have provided any real information that isn't available elsewhere (or by common sense). Other deadly inhalants include liquid water, chocolate syrup, and lava (this last one does elicit the panic response, but death is so very fast, I doubt it would matter).
Again, suicide is NOT recommended! https://suicidepreventionlifeline.org/
67
That CAN'T be true! / Re: Does Stokes' theorem equality produces the right results?
« on: 07/05/2019 01:59:52 »
This would be a good place to start: https://en.wikipedia.org/wiki/Stokes'_theorem
It does seem somewhat counterintuitive that the path integral of a closed loop would give any info about what is inside... but recall that it only applies in specific cases, ie. when looking at "smooth" and "orientable" surfaces (manifolds), which means that it is already limited to cases in which information about one specific point also has some bearing on its immediate neighbors (and their neighbors, and their neighbors, etc.)--thus information is somewhat delocalized.
The theorem proves that this type of delocalization ultimately allows limited (no pun intended) information about an n-dimensional manifold to be deduced by information gained by analyzing the n-1 dimensional boundary of that manifold.
It's been quite a while since I studied or used multivariate calculus, but I recall that some of the derivations of the theorem were pretty straight forward (at least in specific cases--I wouldn't even know where to start with the general form!)
It does seem somewhat counterintuitive that the path integral of a closed loop would give any info about what is inside... but recall that it only applies in specific cases, ie. when looking at "smooth" and "orientable" surfaces (manifolds), which means that it is already limited to cases in which information about one specific point also has some bearing on its immediate neighbors (and their neighbors, and their neighbors, etc.)--thus information is somewhat delocalized.
The theorem proves that this type of delocalization ultimately allows limited (no pun intended) information about an n-dimensional manifold to be deduced by information gained by analyzing the n-1 dimensional boundary of that manifold.
It's been quite a while since I studied or used multivariate calculus, but I recall that some of the derivations of the theorem were pretty straight forward (at least in specific cases--I wouldn't even know where to start with the general form!)
68
Physics, Astronomy & Cosmology / Re: How can we trigger expansion of materials?
« on: 29/04/2019 15:56:52 »Yeast.
I don't think yeast would be attractive for e.g. penis enlargement.
Neither would pH-responsive polymers (https://en.wikipedia.org/wiki/PH-sensitive_polymers), light-responsive polymers (https://onlinelibrary.wiley.com/doi/full/10.1002/marc.201700253) or Hg(SCN)2:
But you never mentioned penis enlargement in the original query...
69
Physics, Astronomy & Cosmology / Re: Could the universe be a simulation?
« on: 16/04/2019 20:35:56 »If we were living in a computer simulation then there would inevitably be bugs in the system. It is impossible to eliminate all computer errors. These would be detectable. So what 'bugs' do we have in our universe?Would they necessarily be detectable to the subprograms (us) within the major program? ie if the program is laggy and buffering, would we perceive a stop and start, or would it appear continuous and smooth within the running program?
70
Physics, Astronomy & Cosmology / Re: Why are there different sizes of stars?
« on: 16/04/2019 16:10:15 »
A few points:
Yes, there is a minimum size required, but that minimum also depends on the composition of the star. Stars that are only hydrogen and helium (primordial stars) must be much larger than stars that contain some carbon, nitrogen and oxygen (as our sun does).
Stars don't necessarily stop growing once fusion starts. If there is enough matter around, it will continue to fall in to the star and continue to add mass, even after the star has ignited.
There are also some maximum mass limits, which depend on the composition and temperature of the star.
Yes, there is a minimum size required, but that minimum also depends on the composition of the star. Stars that are only hydrogen and helium (primordial stars) must be much larger than stars that contain some carbon, nitrogen and oxygen (as our sun does).
Stars don't necessarily stop growing once fusion starts. If there is enough matter around, it will continue to fall in to the star and continue to add mass, even after the star has ignited.
There are also some maximum mass limits, which depend on the composition and temperature of the star.
71
Chemistry / Re: How can we remove a polar molecule from a solution?
« on: 15/04/2019 14:33:22 »
ooooh! I know this!
72
Physics, Astronomy & Cosmology / Re: Why water does not fall into space ?
« on: 12/04/2019 13:26:26 »Quote
Why water does not fall into space ?
Because space is "up" from where the water is.
73
Plant Sciences, Zoology & Evolution / Re: What does a chin do for us?
« on: 10/04/2019 22:47:26 »
I would guess that it might be related to the fact that we walk on two legs. The chin offers pretty good protection for our faces and heads as we learn to walk and run and jump (I say this having gotten 7 stitches in my chin as a 3-year-old).
74
Physics, Astronomy & Cosmology / Re: How (in)effficient is electrolysis for storing energy?
« on: 10/04/2019 16:27:30 »
Splitting water into hydrogen and oxygen using electrolysis is quite easy to do (and scalable), with reasonably efficiency. It doesn't necessarily have the same round trip efficiency as pumped hydro, but electrolysis also takes up several orders of magnitude less space than pumped hydro to store similar amounts of energy.
To alancalverd's point--hydrogen is annoying to handle, but can be reacted with CO2 to make hydrocarbon fuels. Alan mentioned methane, but it is also possible to use Fisher-Tropsch type chemistry to make essentially any alkanes with between 1 and 16 carbons.
These liquid or gaseous hydrocarbons are useful as portable forms of stored energy, but if we are just thinking of stationary power storage, then another way to avoid the hydrogen problem is to split something other than water. Zinc oxide is a leading contender: 2 ZnO → 2 Zn + O2
• No membranes required to keep the O2 and Zn separated, because one is a gas, and the other is a solid (a significant amount of the expense of water splitting devices is the membrane that keeps the O2 and H2 apart while allowing the ions to flow efficiently)
• Zinc metal has an energy density of about 38 MJ/L (40 kWh/gal), which is comparable to gasoline, while even liquified hydrogen only has an energy density of about 8.5 MJ/L (8.9 kWh/gal).
• Zinc is abundant, cheap, nontoxic, and easily recycled.
But zinc is also very heavy, so it would not work so well for powering vehicles...
To alancalverd's point--hydrogen is annoying to handle, but can be reacted with CO2 to make hydrocarbon fuels. Alan mentioned methane, but it is also possible to use Fisher-Tropsch type chemistry to make essentially any alkanes with between 1 and 16 carbons.
These liquid or gaseous hydrocarbons are useful as portable forms of stored energy, but if we are just thinking of stationary power storage, then another way to avoid the hydrogen problem is to split something other than water. Zinc oxide is a leading contender: 2 ZnO → 2 Zn + O2
• No membranes required to keep the O2 and Zn separated, because one is a gas, and the other is a solid (a significant amount of the expense of water splitting devices is the membrane that keeps the O2 and H2 apart while allowing the ions to flow efficiently)
• Zinc metal has an energy density of about 38 MJ/L (40 kWh/gal), which is comparable to gasoline, while even liquified hydrogen only has an energy density of about 8.5 MJ/L (8.9 kWh/gal).
• Zinc is abundant, cheap, nontoxic, and easily recycled.
But zinc is also very heavy, so it would not work so well for powering vehicles...
75
Physics, Astronomy & Cosmology / Re: Does the Neutrino flux thru a radioactive substance affect the decay rate
« on: 07/04/2019 17:58:18 »Indeed--that was a typo! Thank you for catching it. (I have corrected it in the original post). And yes, I suppose that would count as a nuclear reaction.There are other isotopes whose decay pathways are influenced by neutrino flux. Notably 39ClI think you mean 37Cl
But anyway, I'm not sure that counts as a "decay"- the rate of that reaction without the neutrino flux is zero.
It's a reaction. 37Cl is as stable as anything.
76
Plant Sciences, Zoology & Evolution / Re: Do all birds hop?
« on: 07/04/2019 01:35:14 »
(Off the top of my head) I think that birds that primarily live in the trees/bushes (parrots, sparrows, blackbirds etc.) hop, and those that live on the ground (ostriches, emus, turkeys, etc.) or in the water (ducks, geese, seagulls, etc.) do not.
77
Physics, Astronomy & Cosmology / Re: Does the Neutrino flux thru a radioactive substance affect the decay rate
« on: 07/04/2019 01:30:53 »
Funny--I was just talking about this with somebody earlier this week!
No, 14C half life is independent of neutrino flux, so it wouldn't matter how close we are to the sun, or what the solar weather is like, or if there are nearby supernovae.
There are other isotopes whose decay pathways are influenced by neutrino flux. Notably 37Cl (thanks for catching my typo) (https://iopscience.iop.org/article/10.1086/305343/pdf).
Apparently, there is some controversy over whether 54Mn does or not:
https://physicsworld.com/a/radioactive-decay-of-manganese-54-is-not-affected-by-the-seasons-says-physicist/
https://www.economist.com/babbage/2012/08/23/and-now-the-space-weather-forecast
http://blogs.discovermagazine.com/80beats/2010/08/26/scientist-smackdown-are-solar-neutrinos-messing-with-matter/#.XKlEletKh0s
No, 14C half life is independent of neutrino flux, so it wouldn't matter how close we are to the sun, or what the solar weather is like, or if there are nearby supernovae.
There are other isotopes whose decay pathways are influenced by neutrino flux. Notably 37Cl (thanks for catching my typo) (https://iopscience.iop.org/article/10.1086/305343/pdf).
Apparently, there is some controversy over whether 54Mn does or not:
https://physicsworld.com/a/radioactive-decay-of-manganese-54-is-not-affected-by-the-seasons-says-physicist/
https://www.economist.com/babbage/2012/08/23/and-now-the-space-weather-forecast
http://blogs.discovermagazine.com/80beats/2010/08/26/scientist-smackdown-are-solar-neutrinos-messing-with-matter/#.XKlEletKh0s
78
Physics, Astronomy & Cosmology / Re: Why do neutrons weigh more than protons?
« on: 05/04/2019 17:32:11 »
1) A neutron can decompose into a proton and an electron (also releasing a neutrino). It's actual mass is determined by the masses of the quarks and binding energy (a proton is made of two up quarks and a down quark, while a neutron is made of two down quarks and an up quark).
2) This is a very tricky question. We can use different models to account for the different speeds of light in different materials--one model essentially views the photon as being absorbed and re-emitted repeatedly, and one model just looks at the effective permittivities (both electric and magnetic), and uses that to calculate the speed of light. Both models predict the same speeds (as far as I know), but sometimes it is better to use one model than the other.
3) The free electrons stay in the plasma in a gaseous state. (overall the plasma is neutral, with an equal number of protons and electrons in it)
2) This is a very tricky question. We can use different models to account for the different speeds of light in different materials--one model essentially views the photon as being absorbed and re-emitted repeatedly, and one model just looks at the effective permittivities (both electric and magnetic), and uses that to calculate the speed of light. Both models predict the same speeds (as far as I know), but sometimes it is better to use one model than the other.
3) The free electrons stay in the plasma in a gaseous state. (overall the plasma is neutral, with an equal number of protons and electrons in it)
79
Physics, Astronomy & Cosmology / Re: Do electrostatic charges interact with magnets or electromagnetic fields?
« on: 03/04/2019 14:24:59 »
Yes. Magnetic fields exert a force on moving charges that is proportional to the velocity of the charge (relative to the magnetic field), the strength of the magnetic field, and the amount of charge that is moving. The force is perpendicular to both the magnetic field lines and the instantaneous velocity of the charge.
see: https://phys.libretexts.org/Bookshelves/University_Physics/Book%3A_University_Physics_(OpenStax)/Map%3A_University_Physics_II_-_Thermodynamics%2C_Electricity%2C_and_Magnetism_(OpenStax)/11%3A_Magnetic_Forces_and_Fields/11.3%3A_Motion_of_a_Charged_Particle_in_a_Magnetic_Field
see: https://phys.libretexts.org/Bookshelves/University_Physics/Book%3A_University_Physics_(OpenStax)/Map%3A_University_Physics_II_-_Thermodynamics%2C_Electricity%2C_and_Magnetism_(OpenStax)/11%3A_Magnetic_Forces_and_Fields/11.3%3A_Motion_of_a_Charged_Particle_in_a_Magnetic_Field
80
Physics, Astronomy & Cosmology / MOVED: How do we measure the energy of a photon?
« on: 30/03/2019 19:03:06 »
What initially appeared to be an interesting question regarding quantum epistemology has turned out to be (or transformed along the way into) the original poster trying to proselytize a new theory that is outside generally accepted science--thus I have moved the entire thread to the "New Theories" section, where this discussion may continue.
You may find it here: https://www.thenakedscientists.com/forum/index.php?topic=75960.0
You may find it here: https://www.thenakedscientists.com/forum/index.php?topic=75960.0