The use of methods from the physical sciences to aid in the study of biological systems. Note that biophysics questions are only allowed if they are mainly about physics.

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128 views

What's Optimal About Six Legs According to Physical Laws? [closed]

In many respects the insects can be regarded as the most successful class of animals in evolutionary terms. And one of the most common features of insects is that they (mostly) all have six legs. Not ...
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2answers
793 views

What happens to body chemistry at the speed of light? [duplicate]

Assume that I'm traveling at the speed of light in one direction. My brain is also traveling at the speed of light in that direction. Presumably there is at least one receptor site in my brain that is ...
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1answer
163 views

Polonium tea emergency [closed]

Let's assume that I just realised that tea I drunk 30 minutes ago during meeting with a secret agent was doped with radioactive polonium. What should I do? What the doctors will do? Are there ...
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4answers
2k views

What is our estimated running speed on Moon's surface?

I was wondering if we have the chance to run on the Moon's surface, how would you expect it look like? I expect our velocity will increase for the same work we do on Earth, but not sure if this will ...
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3answers
622 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 ...
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2answers
275 views

How much more “work” (or energy) is required for short people to hike uphill?

Let's assume Short Person is 5 feet tall and the Normal Person is 5 feet and 8 inches tall. Let's assume the uphill hike has steps with 1 foot height. How much more work or energy does this require ...
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133 views

Singing for physicists: How to resonate by body cavities with my voice?

My body has various cavities, such as my throat, mouth, chest, and nose. This cavities have resonant frequencies. I also have a voice box, which creates sound. How do I create sounds at the resonant ...
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2answers
86 views

Does human body have a centre of mass?

According to this site, The center of mass of the human body depends on the gender and the position of the limbs. In a standing posture, it is typically about 10 cm lower than the navel, near the ...
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3answers
271 views

How much further can I throw a baseball (148 grams) than a grenade (453 grams)?

Question: Over a flat plane, how much further can I throw a Major League baseball than I can an M67 grenade? Major League baseball: 148 grams M67 frag grenade: 453 grams For a baseline of how ...
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448 views

Human Muscle Energy - Increases or Decreases by doing work?

When Human does some work, he gets tired. I will think he looses some energy. If he really loses energy by doing work how does he gain more strength to do more work later. His muscles become strong ...
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98 views

How do we represent 'smell' and 'taste' as signals?

I was wondering if we could represent 'smell' and 'taste' as signals like we do for audio. How do we mathematically represent them? Is there any research papers related to it? Can someone give me ...
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3answers
3k views

How do birds generate thrust?

I have been watching this video carefully and I want to know how the wings of birds generate thrust. This is because the wings are more or less flapping up and down --- generating the lift. But I do ...
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95 views

Safety of Polonium Isotope source

I saw a YouTube video by a guy demonstrating Geiger Counter use and one of his radioactive test sources was a disk with Polonium. He casually mentioned that this was the poison used to kill that ...
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1answer
62 views

Is (or why isn't) static charge as lethal as ionizing radiation?

Ionizing radiation, e.g. the "stuff" emitted by radioactive materials, is dangerous to humans since changes to the electron configurations (in the human body) causes the various molecules (in the ...
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2answers
381 views

Running: Determine how much more energy is needed per extra kilogram of weight

(I recently asked this on maths but was directed here) I have recently become a runner and having a keen interest in kinematics I'm very interested in the maths/physics of my running. Can someone ...
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2answers
52 views

The Balloon Model for Human Ventilation

The balloon model is often used to show how ventilation works in the human lungs. You pull on the diaphragm, expanding the volume of the container, and the balloon begins to fill up. My understanding ...
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2answers
115 views

What are good references for learning about Biophysics at graduate level?

I am graduating this year on both Physics and Mathematics and I want to pursue a career in research, more concretely I want to study Biophysics. I've been recommended Boal's Mechanics of the Cell and ...
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1answer
89 views

Why the visual system does not affect by the quantum zeno effect?

According to the quantum zeno effect, if a measurement is done on a sufficiently high frequency, the system remains stationary. In daily life, human see objects are moving. (i) Is the procedure ...
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1answer
322 views

Why am I not hearing frequencies of range 14 kHz-15 kHz? [closed]

Recently, a Radio Station (Red FM, 93.5) started a campaign called "RED FM bajao Machar Bhagao" (English: Play RED FM, scare away mosquitoes). In this, they claim to be broadcasting some frequencies ...
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122 views

What is the highest possible space dive free fall?

The world record is 136k feet but how high could it be without burning up. I know someone asked if u could jump from ISS which wouldn't be a free fall. Using any means of transportation. The record ...
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1answer
94 views

Kettlebell squats center of mass

I should, first of all, state that I have very limited knowledge of physics but as a fitness enthusiast the following question has puzzled me for a while. When I do squats on the gym holding a ...
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2answers
68 views

Brain and UV rays [closed]

I heard that brain can be switched off using ultra violet rays. I seek experts comments on this. Is it true? If it is so how it is possible to control brain by UV rays?
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1answer
5k views

How does the height of a jump change if the body is scaled down?

This is a physics question that appeared in the movie 'The Internship.' If you are reduced to the size of a coin and put into a blender what would you do? Apparently the answer was that with a ...
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2answers
7k views

Why does wet skin offer less resistance?

I know that water with salts is a good conductor-However wetting a hand only adds water to a not very conductive surface. How does water actually reduce the resistance of skin? The way I am seeing it ...
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1answer
37 views

Is it possible to fight tree height limit with centrifugal force?

I heard tree has some height limit because water cannot be pumped over some height (130m if I remember it right) which cap the limit of tallest tree possible on earth But there are centrifugal force ...
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1answer
25 views

What parameters could be considered to measure the coiling of a ring?

I want to draw a phase diagram to quantify the coiling of a ring inside my system and I was wondering what parameters could be use to precisely define how coiled the ring is. Currently I am modeling ...
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1answer
45 views

Have cosmic rays and the CMB affected Earth's history?

Do cosmic rays and the cosmic microwave background carry with them enough energy to have a macroscopic effect on events on Earth? The most obvious example I can think of is by giving animals cancer. ...
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2answers
45 views

What is the physical interpretation of Power Spectral Density (PSD) in optical tweezer?

For the calibration of an optical tweezer, the PSD of position values are plotted. If it follows a certain behavior having two regions - free diffusion and potential limited regions, then the trap is ...
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1answer
97 views

How much work can the human body do before dying of exhaustion [closed]

If we could assume: We don't increase our energy from absorbing food. Our human example in scope isn't starving or suffering from malnutrition. I mean how much work can we do until the body would ...
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2answers
58 views

Can we trap living cells in optical tweezers?

I read that optical tweezers work on the principle of radiation pressure caused due to momentum change of incident light due to refraction from a spherical object. For refraction to happen the object ...
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1answer
124 views

Physics involved in the DNA-structure discovery

In 1962 Francis Crick, James Dewey Watson and Maurice Hugh Frederick Wilkins won the Nobel Prize: For their discoveries concerning the molecular structure of nucleic acids and its significance for ...
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1answer
98 views

Molecular simulation applied to astrobiology

There is some research group which use molecular dynamics simulations to study the origin of life according to the hypothesis of abiogenesis? I'm just beginning to know this subject so I don't know ...
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1answer
48 views

Is electricity constant in standard ECG device? [closed]

I am reading the book Bioelectromagnetism by Malmivuo et al. I am thinking if you need to use Maxwell equations in electromagnetism of ECG device. I am not sure if you need to change the current ...
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1answer
54 views

Why is work not related to velocity?

A very simple question; why does it cost me more energy to very slowly lift a mass $m$ over my head compared to very fast? The definition of work does not state anything about velocity, only the ...
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3answers
745 views

How does a pressure suit work?

I recently learnt that a suit called pressure suit is worn by fighter plane pilots to prevent red-outs and black-outs. And it seems to be work by - "..applying pressure to selective portions of ...
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1answer
3k 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 ...
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2answers
2k views

How thin a filter to filter particles out of salt water to make salt for human consumption?

I have gathered some salt in the Death Valley and for the fun of it I would like to clean it and make it edible. The process I plan to follow is simple: Dissolve the salt in water. Boil water for ...
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2answers
3k views

How does length of the bar affect force on the muscles?

Fitness Model, Rob Riches, claims that doing bicep curls with Olympic bars is different than lifting with normal bars. Biceps have always been a favorite muscle group of mine to train, but ...
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43 views

Could I pick up a human with a strong enough magnet?

Could I pick up a human with a strong enough magnet? Humans contain magnetic materials, such as iron.
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1answer
12 views

how does voltage sensitive dye determine the membrane potential?

There are so many papers about VSDs and how to use them, but i can not find anything about what exactly is happening in the cell membrane that leads to the change in VSD's light intensity as a sign of ...
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0answers
16 views

Bimolecular and Isomerization reactions

Is it possible to describe a reaction of the $$ A+B \rightleftharpoons AB $$ exactly using the solution of an isomerization reaction? $$A \rightleftharpoons B$$ I just can not figure it out the ...
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0answers
30 views

What is the direction and orientation of the modulation frequency in AM when it uncouples in flesh? [closed]

Cancer research shows that dividing cancer cells could be killed with frequencies from 100 kHz to 300 kHz (Kirson Tumor Treating Fields or TFF). The early research used a monofrequency that was ...
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1answer
23 views

Is the range of frequency we hear dependent on the natural frequency of our ear?

Is the range of frequency we hear dependent on the natural frequency of our ear? (i guess the question is clear enough. Just writing to meet "quality standards".)
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0answers
35 views

Why do the vines change their spinning direction? [closed]

Look at the vines holding onto the lattice. The "vine springs" change their spinning direction in the middle. Why? And how do they achieve this? (I notice that some vines fail to get in touch ...
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0answers
19 views

How does it takes to deadlift a sports car? [duplicate]

In the movie Furious 7, Dom lift a Lykan HyperSport with bare hands. Given that in reality, how strong it has to be to lift a Lykan HyperSport(1,380 kg), says to 40 cm in one rear end, and hold it ...
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1answer
65 views

Cesium-137 From Fukushima Meltdown

I've been reading up on the Fukushima nuclear meltdown and its effects it had on the environment. The iodine-131 initially released from the incident decayed after 8 days, but other isotopes such as ...
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0answers
92 views

Why do our eyes only pick up electromagnetic radiation which has been classified as visible light?

My understanding: Electromagnetic radiation is carried via photons - which enter our eyes and activate receptors depending on the amount of energy the photons have when hitting them. At what point do ...
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0answers
39 views

Biological concept behind time dilation [duplicate]

What is the exact mechanism which makes aging process slow for persons travelling at higher velocity relatively. How does our body cells responds to gravity and undergo aging?
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1answer
40 views

Relation of Force and Energy, from a biophysics point of view

Considering us humans practically, does energy require force, ie we do apply some internal and external forces to do work, or does force require energy. ie we can only apply a force on an object if we ...
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13 views

Fluid motion videos [duplicate]

I am looking for references to papers and research problems involving fluid mechanics, and in particular animal/plant/bacteria locomotion, that could be illustrated by showing a video like these. It's ...