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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2answers
34 views

Physics of exercise/movement [closed]

I am a Pilates teacher and a student asked me why an exercise (ie the Pilates 100) is more difficult when your legs are suspended off the edge of an apparatus (more distance to the floor)as opposed to ...
1
vote
0answers
39 views

Is light spectra different for all living bodies? [closed]

As we know that honey bees can see lots of different colours, is it possible that the light spectra is different for them? My main question is that is light spectra different for all living organisms?...
3
votes
1answer
93 views

How does eating a cold ice cream actually heat up your body? [closed]

The question is the title itself. During winter one of my friend told we'll have an ice cream. And rest of us where like are you nuts. He was like cold ice-cream actually heats up your body. Even I ...
0
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0answers
29 views

Mikrotubule growth and master equations

I am looking for a description of the growth of mikrotubules governed by a set of master equations. I have problems with proper derivation and the boundary conditions. Model: The mikrotubules can ...
15
votes
4answers
328 views

Why don't hexapods gallop?

I haven't observed any terrestrial hexapods that gallop like agile tetrapods(cheetahs/horses). Instead, I've observed that all of them scuttle which constrains their maximum velocity. And after ...
10
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0answers
762 views

Is the amount of the soil reduced when plants grow? [migrated]

According to the principle of mass conservation I think the amount of the soil should be reduced when plants grow. But this reduction is not observable so much. For example, some trees (big trees) ...
0
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0answers
40 views

Why human body is not affected on magnetic field?

Electric-current easily cause shock to human body. But magnetic fluxs through human body do-not cause any perceptible change, as-well no invisible-impacts/ health impacts are well-known. We, when hold-...
34
votes
4answers
5k views

Why is the efficiency of human cells less than the efficiency of an Otto engine?

I always used to think (I don’t know why!) that the efficiency of human (and animal and plant) cells should be equal to or near the efficiency of a Carnot engine or at least should be the highest ...
-1
votes
1answer
29 views

How can I get the sensitivity of some eye cone at a specific wavelength?

The following graph shows the sensitivity for eye cones and rods, but I want to know e.g. what is the red cone sensitivity for a wavelength of 500 nm? How can I find an answer for questions like this?...
0
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2answers
35 views

Work and energy example [duplicate]

The normal definition of Work, as far as I have read, is: Energy is transferred through work. But I just heard an educationist state this example, where there is a weightlifter who keeps up a huge ...
-1
votes
1answer
82 views

Are all radioisotopes equally dangerous? [closed]

I'm currently writing an issues investigation on the radioisotope plutonium-239. It's difficult to talk about the dangers of the radioisotope itself, since information on the internet is mixed. ...
0
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2answers
57 views

A dead body floats with its head immersing in water . Why?

I found this question in my practice book . I want to know about it .
2
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1answer
44 views

Why does our eyes see red when exposed to too much light? [closed]

When I looked into my projector when it was on the blue screen it left a red spot in my vision. I should not have tried it but all the colors left a red spot. Why not a blue or yellow spot was left?
0
votes
2answers
226 views

Can we write the wave function of the living things? If yes then how? [closed]

In quantum mechanics we studied that everything has a wave function associated with it.My question is can we write down the wave functions of things. Then how we can write down the wave functions of ...
5
votes
2answers
112 views

How does electrical energy develop by concentrating ions on one side of a biomembrane?

In biology there is a topic called oxidative phosphorylation. In the first step of this process substrates such as isocitrate is oxidised and the electrons are transferred to coenzymes NAD+ or FAD ...
0
votes
1answer
70 views

What are the problems in the idea that a person would freeze to death in outer space?

It is said that the body would freeze to death, if left in outer space, which is true, since the temperature is around $3$K. But what are the flaws in this theory, in terms of thermodynamics (if we ...
3
votes
1answer
463 views

Can we use radiation pressure to push/levitate a human?

I want to know, at least in theory, are there any safe em wavelength that could affect human body as net force and do no harm? To put it bluntly I want to know is it possible for levitate a human on ...
3
votes
2answers
37 views

Is a folded protein's conformation subject to thermal fluctuations?

In biology class we learn that proteins are folded, and that the shape the protein takes affects its bioactivity. Typically we don't go much further into protein shape from that, at least not at the ...
1
vote
2answers
48 views

What causes anything to smell?

We all know that we can see anything because of Light Absorption and all. We can hear things because of caused vibrations. But what makes an object smell? I read somewhere about the presence of ...
0
votes
1answer
34 views

Why is resting membrane potential or a membrane depolarisation localised to the membrane?

Why would a membrane depolarisation be localised to one part of the membrane? If adjacent areas have a more negative potential shouldn't the difference in potential cause charge to flow into the ...
0
votes
1answer
62 views

Why is standing still easier than walking? [closed]

Both the works basically push force into the ground.So why does walking require more work?
0
votes
1answer
109 views

Why does holding an object cost energy while no work is being done? [duplicate]

I was reading the discussion here: Why does holding something up cost energy while no work is being done? I feel as though the question is being avoided. Suppose instead of holding an object by hand ...
1
vote
1answer
70 views

Could I pick up a human with a strong enough magnet? [duplicate]

Could I pick up a human with a strong enough magnet? Humans contain magnetic materials, such as iron.
-1
votes
3answers
103 views

How do Calories (kcal) relate to watts?

In thinking about exercise and "burning calories" it occurred to me that there should be some fairly intuitive correlation between the biological energy conversion going on in a person's body with the ...
0
votes
0answers
31 views

How do inverse of Kirchoff matrix of a polymer possess the information for its mobility?

In Normal Mode Analysis of polymers like proteins, I have seen that mobility (measures like root mean squared fluctuations) can be found from the eigen values and eigen vectors of inverse of Kirchoff ...
-2
votes
1answer
61 views

Humans Voice Frequency? [closed]

Do all human beings have a different voice frequency like they have different finger prints? as all of us are unique so probably our vocal folds make different vibrations while saying a same word that ...
3
votes
2answers
90 views

Why do some people support more electricity than others?

There is a game where people hold by their hands and two of them touch the electrodes of a shock box, then an electric current flows through them. I understand that since they are all making a single ...
1
vote
1answer
26 views

Decompression sickness

In decompression sickness why does nitrogen gas come out as bubbles? Is it because under high pressure the nitrogen gas was converted into liquid nitrogen and during the process of coming to the ...
2
votes
1answer
93 views

Confusion over plant's “magnetic field” being used to reduce wastage of pesticide

As far as I am aware, a plant does not have a magnetic field of any significant magnitude. What I wonder is, is there any electromagnetic related basis for the crop spraying technique outlined in ...
1
vote
1answer
48 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 ...
-4
votes
1answer
59 views

How to shield myself from the LTE radiation coming from my phone while working on my Laptop? [closed]

I am connecting to the internet with the tethering option on my phone. I wonder if there is a way to shield myself from the LTE radiation (Long-Term Evolution, commonly marketed as 4G) as I am exposed ...
3
votes
1answer
59 views

Physiological Significance of Superposition

To what extent is the concept of superposition appropriate to physiology? In other words, can organisms "actually" exist in a state of superposition?
0
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0answers
23 views

Can we define a whole body thermodynamic model for human?

we can consider human body as a thermodynamic system and an energy exchange system, so we can investigate efficiency, entropy, exergy, is there any thermodynamic model for whole body?
0
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0answers
44 views

Why does the lack of pressure in outer space affect what's inside our bodies?

I have read multiple similar questions on this site, but none answer specifically the thing I am having trouble understanding. I have read repeatedly that a lack of pressure will cause the fluids ...
3
votes
1answer
45 views

How much ionizing (carcinogenic) radiation is one exposed to on a commercial flight, what are the sources, and how could exposure be minimized? [closed]

I don't know if this is the best place to ask this question, but I figure a physics-based answer would be the most satisfying. I'd be happy to be convinced I'm being paranoid about protecting an ...
4
votes
2answers
80 views

Why is it harder to situp on solid floor?

When I situp on solid floor it is harder for me to lift my body upwards versus on a soft/foamy floor which I can do a lot.
-7
votes
1answer
78 views

If a being was able to swallow itself, where would it go physically? [closed]

if a being was made from a special type of material that allowed it to stretch and was very flexible, if it were to swallow itself, where wold it go. I mean the physical aspects of it since it wont be ...
0
votes
1answer
40 views

Voltage homogeneity across cell membrane

During respiration, individual cells produce a relatively large potential difference ($\sim 100$ mV) between the inside and outside, using energy to pump $H^+$ out of the cell to the liquid ...
-1
votes
1answer
210 views

Why it's more difficult to walk in an inclined plane than in a causal road [closed]

my question is about something very casual , but when i tried to solve that , it was not easy at all . My question is : "Why when we walk in an inclined plane we get tired more than when we walk in ...
0
votes
3answers
95 views

Lifting and putting down a weight

A man in a gym lifts a weight and then puts it down where it was before. 1) What can be say about the work done by the man to the weight? 2) Can it be equal in absolute value to the work made by ...
1
vote
1answer
21 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 ...
1
vote
0answers
17 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 ...
0
votes
3answers
59 views

According to the second law of thermodynamics, would life be possible on an Earth always facing the sun?

Suppose the Earth was making one complete rotation around its polar axis every year. Will life develop, or will there be a constant flow of energy from the Sun through and around the Earth? Will a ...
-4
votes
2answers
108 views

Do animals defy gravity? [closed]

I am a beginner and trying to understand the concept of gravity Do animals defy gravity? If yes, which animal defies and in what way it does? Sorry had I asked something wrong
2
votes
2answers
81 views

Why was it difficult to walk in the same direction the train's acceleration, and easier the other way around?

The other day while I was walking in the same direction that the train was accelerating. Then I came across this question. Please if would answer it, I am very curious to know. But when I walked the ...
1
vote
2answers
287 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 ...
0
votes
0answers
48 views

Deriving an upper limit to the information in a human brain

For this question I am presuming that the human brain works deterministically and all information in a human brain is, once you get down to the lowest level, stored through the arrangement and other ...
6
votes
1answer
61 views

What happens at the point of welding iron?

What is the physics behind welding iron? It is obviously the electricity that causes the two metal parts to fuse but what is the role of the welding rod and why is it said to damage your eyes when you ...
3
votes
1answer
151 views

How do snails avoid being cut while crawling over a razor blade? [closed]

This YouTube video shows a snail crawling over the edge of a razor blade without being harmed. The author claims that: To us, slug and snail slime is gooey and gross but the mucus is one of ...
0
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0answers
21 views

Hydraulic conductivity and flow rate

I have several sources that have the following equation relating the change of volume in a cell to the hydraulic conductivity (permeability coefficient) $L$ and pressure differential $\Delta P$: $$ \...