The biophysics tag has no wiki summary.
17
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1answer
285 views
Why can Hiroshima be inhabited when Chernobyl cannot?
In Hiroshima, atomic bomb was dropped, but today, there are residents in Hiroshima. However, in Chernobyl, there is no resident living today (or very few). What made the difference?
4
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1answer
43 views
What is the minimum pressure difference for your ears to pop?
I'm assuming the answer to this largely varies from person to person. Assuming you could instantly change the pressure around your head by amount $\Delta p$, what is the minimum $\Delta p$ for your ...
1
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0answers
56 views
Concentration of Proteins
You release a billion protein molecules at position $x = 0$ in the middle of a narrow capillary test
tube. The molecules’ diffusion constant is $10^{−6} \ cm^2 s^{−1}$. An electric field pulls ...
5
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2answers
163 views
Effects of a very large magnetic field on the human body
Ever since reading about the NHMFL I have always wondered about this and asked several people without getting a good satisfactory answer. My question is, considering the simplest case let's say a ...
-1
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0answers
44 views
Does darker skin color make it easier to live under sun? [migrated]
I have always thought darker colors absorb more heat from the sun, so if you are wearing a white T-shirt you will be cooler under sun than wearing a darker T-shirt, or a black piece of steel will be ...
16
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2answers
652 views
Why can't Humans run any faster?
If you wanted to at least semi-realistically model the key components of Human running, what are the factors that determine the top running speed of an individual? The primary things to consider would ...
4
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2answers
544 views
A quantitative explanation of EM coherence domains in liquid with DNA
I've been looking with interest at a recent biology paper claiming that DNA molecules give off electromagnetic signals which can cause the same types of molecules to be reconstructed at a remote ...
0
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1answer
82 views
Atoms in our body
Our body of course exchanges some atoms with environment every day however are there some of atoms which stay with us a life time?
4
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2answers
97 views
Do viruses suffer from quantum de-localization?
Consider some microscopic life form. It should obviously be localized in space, in the quantum-mechanical sense, if it is treated as a single particle (though it is composite). If its characteristic ...
0
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0answers
32 views
RNA piece and force pulling it
RNA piece can be in two states, folded (energy E) or unfolded(enegry E1)? If you fix one side of the RNA, and pull on the other side with f that is constant... How will the force affect the energies ...
7
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3answers
670 views
What's the source of electricity for the human brain?
I keep hearing that there's always electrical activity taking place inside the human brain. Our heart and various other organs function because it receives electrical signals called impulse. But, ...
10
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5answers
592 views
Octave equivalence: biological or more?
I'm a graduate student in mathematics doing a bit of research in signal processing and Fourier analysis and I've come across a question that could probably be better answered by a physicist:
Is the ...
14
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2answers
2k views
How does space affect the human body (no space suit, no space craft)
How does "outer space" affect the human body? Some movies show it as the body exploding, imploding or even freezing solid.
I know space is essentially a vacuum with 0 pressure and the dispersion of ...
5
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1answer
2k views
Newton's color Disk
How does Newton's color disk work?
Newton's disk - Take a circular white color disk, make 7 equal intersections and paint section with respective VIBGYOR colors, now when you spin the disk in certain ...
5
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1answer
1k views
Adverse Health Effects of Strong Radio Waves
A while ago, I was hiking near the Hollywood Sign in Los Angeles. When I got to the sign, I found out it was fenced off; with several signs and a security camera promising prompt enforcement. As I was ...
2
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2answers
694 views
Why can you see a light in the location that the light source just left?
This is my first question on this site so forgive me for the awkward wording of the question. Basically, my question is why does light from, say, a sparkler, seem to remain where it just came from to ...
4
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1answer
130 views
Radiation exposure to a child who was briefly in the presence of an adult who had received a 18FDG PET scan
I am a physician who thought she was good at math, but apparently am not as I cannot figure out this mathematical/physics question. (My background is obviously NOT nuclear medicine!) A family friend ...
0
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1answer
24 views
Measuring life through radiation
Dramatic title, I know. But it's shorter than Measuring a person's effective mass through radiation and comparing it to their weighed mass and I figured this would get people's attention.
I just ...
4
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2answers
922 views
How efficient is the human body?
This question sort of comes to mind when hearing how efficient an internal combustion engine is turning chemical energy in mechanical energy (something like 20-40%) with lots of excess heat. As an ...
6
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1answer
692 views
What are the characteristics of the magnetic field surrounding a human brain?
The human brain is said to produce a magnetic field resulting from the action potentials released inside the brain. What's the nature of such a field in terms of size and strength, and what is the ...
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0answers
41 views
Recommended (bio)polymer physics book? [closed]
I am looking for a recommended introductory book on polymer physics.
I do not have sufficient time to learn the whole field. I am specifically interested in physics of biological polymers, and even ...
1
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2answers
68 views
Was the early Earth radioactive?
I've been reading of the (surprising) fact we are uncertain on whether there is nuclear fission in the center of the Earth or not (yet we know so much detail on structures at the other end of the ...
35
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7answers
1k views
Cyclist's electrical tingling under power lines
It's been happening to me for years. I finally decided to ask users who are better with "practical physics" when I was told that my experience – that I am going to describe momentarily – prove that I ...
2
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2answers
122 views
Computing microstate probabilities based on Boltzmann distribution for chemical systems - Is it rigorous?
One approach to predicting the folded structure of a polymer (DNA, RNA, protein) is to compute the probability that any particular part of the polymer $x_i$ is "paired" with another part of the ...
1
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1answer
255 views
What is physics of a normal jump?
What is the physics behind a normal human jump ?
when a normal human wants to jump.
First, some energy is stored in their thighs and The elastic tendons Just like a spring.
In mechanics and ...
1
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2answers
124 views
How much time can I power my laptop by eating one dessert?
Random question that popped into my mind after a 4-hours power outage. Let us assume that I am eating an extra dessert (250 kcal) and that I am using a bike and a generator to power my laptop (it ...
0
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2answers
238 views
How neutrinos can be harmful?
What are the circumstances in which neutrinos can harm humans or even kill them.?
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0answers
79 views
How can I measure the calories consumed in daily activity? [closed]
From a nice question here:
How are the calories in food calculated?
I can roughly understand how people provide the data of calories in certain food.
However, I am still confused about 2 things.
1) ...
-1
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1answer
126 views
How do photo mosaic work from eye and image processing perspective? [closed]
Hello fellow investigators
I have two question about optical illusions
1) A photo mosaic is something like this http://i.stack.imgur.com/Pzplp.png
What are the optical principles behind our eye ...
3
votes
1answer
367 views
How does a stronger magnet affect the MRI image quality?
In which ways is a stronger magnet better for magnetic resonance imaging? I read that:
The field strength of the magnet will influence the quality of the MR image regarding chemical shift ...
2
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4answers
1k views
Is it only red, green and blue that can make up any color through additive mixture?
I'm reading about color vision and have some trouble understanding the motivation for why the trichromatic theory was suggested in the first place. The book I'm reading ("Psychgology: The science of ...
2
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2answers
153 views
Can wireless power transfer harm organic life by anyway?
Now, humanity can beam 50-60 watts power through 10 centimeter-thick concrete block. Can such wireless power transfer harm us by anyways?
0
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1answer
174 views
What is the difference between “in-plane shear modulus” and “shear modulus”
In the wiki it is article only about shear modulus and it is written that it's unit is Pascal.
At the same time in all researches about Red Blood Cells shear stresses, authors write "in-plane shear ...
0
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1answer
223 views
How is tritium illumination possible without negative health effects?
Turns out there's tritium illumination - a tiny very strong plastic tube will be covered in phosphor and filled with tritium. Tritium will undergo beta decay and a flow of electrons will cause the ...
0
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0answers
179 views
Climbing stairs two at a time vs. one at a time. Which one is more efficient? [closed]
What is the more efficient way to climb stairs? Taking two steps at a time is almost twice faster, but how much energy does it take compared to taking one step at a time?
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0answers
52 views
Visualise the sound intensity
I'm studying Biophysics and my current subject is sound. One of the properties of sound is intensity. From my notes I can see the following definition:
Intensity Formula is: $(I = w*m^{-2})$ or $(I = ...
3
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1answer
115 views
Why do beverages taste different based on how cold they are? [closed]
Why does temperature effect the taste of beverages?
Specifically, how does the temperature for example mask certain tastes ie filtered vs unfiltered water taste very similar at colder temp and Is ...
0
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0answers
69 views
How and where is the information which constitutes memories stored in our brain? [closed]
I am wondering if the information was stored as in computers, with a sort of condensators system, but this would imply a certain discretization, and seems to be too restrictive.
Therefore, how the ...
13
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4answers
2k views
What does Peter Parkers formula represent?
Okay, so the trailer for the new Spider Man movie is out and appearently our friendly physicist from the neightborhood came up with something. However I can't find out what this is.
...
0
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1answer
119 views
Dynamic Light Scattering
In the Dynamic Light Scattering experiment, how is the intensity distribution plotted against time, keeping in view the multiple scattering of photon particles in laser ?
2
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2answers
101 views
Is metabolic rate the amount of heat given off?
The Basal Metabolic Rate is intuitively expressed as "the amount of energy you consume just sitting around." In some places it seems to be equated with the amount of heat that you give off.
Is this ...
2
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1answer
158 views
Examples of piecewise smooth dynamical systems [closed]
I have recently been studying continuous dynamical systems whose phase space can be divided into a number of regions. Inside each of these the flow is smooth, but there is a discrete jump in the flow ...
4
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2answers
191 views
Why don't massive water-borne animals crush under their own weight when they're in water?
If you take a giant whale out of the water and put it on land for long enough, it will crush itself under its own weight. Why doesn't the animal get crushed under its own weight when it's in water?
0
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3answers
553 views
What are brain waves? [closed]
I watched a documentary showing that humans could alter the results of an experiment by thinking about it, and the data these people collected supported their hypothesis.
And the reason these people ...
3
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2answers
325 views
Human perception of distance
When we see things around us, distant objects look smaller to our eyes than nearby objects do.
Is there any physics-related reason why our eyes or brain perceive things like this?
Or if this is ...
8
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5answers
865 views
What happens to light after it enters an eye
What happens to the light [energy] after it enters an eye and hits the rods and cones? I presume the energy becomes electrical, and it must be near 100% perfect, else our eyes would heat up? Or am I ...
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2answers
629 views
Why the pressure of atmosphere doesn't crush you when you e.g. walk outside?
Why the pressure of atmosphere doesn't crush you when you e.g. walk outside? I mean the density of air is $1.26 kg/m^3$, so with $100 km$ above us, it exerts much pressure on you when you walk ...
6
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2answers
923 views
Are regular light bulbs better for the eyes than CFLs or “tube lights”?
I've heard that regular light bulbs with a filament are better for the eyes. Is the spectrum of one worse than the other? If so, are there any regulations for their use in industrial settings for ...
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7answers
3k views
Why does holding something up cost energy while no work is being done?
I read the definition of work as
$$W ~=~ \vec{F} \cdot \vec{d}$$
$$\text{ Work = (Force) $\cdot$ (Distance)}.$$
If a book is there on the table, no work is done as no distance is covered. If I ...
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0answers
32 views
Is energy applied by the muscle when it holds a body in the air? [duplicate]
Possible Duplicate:
Why does holding something up cost energy while no work is being done?
We all know the following Newtonian formulas:
PotentialGravitationEnergy=m*g*h
Kinetic Energy = ...
