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4 views

Effects of light wavelength on the Lindblad equation of the FMO complex

Recently, I have been interested in the energy transfer within the FMO complex. I was wondering, how could the wavelength of the light that excites the complex affect the energy transfer efficiency. ...
0
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0answers
25 views

Material with incredibly small young's modulus [on hold]

I'm looking for a material with a Young's modulus of less than 100 Pa. I've looked at elastomers, but I haven't had any luck. Thanks for your help, I appreciate it.
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0answers
58 views

Why is it harder to stand still than to walk? [closed]

I can walk for miles, but I'm exhausted after an hour of standing. I think it is not psychological. Is there any explanation according to physics?
2
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0answers
19 views

Why our cells don't merge, when their phospholipid membranes touch each other? [migrated]

Membranes of our cells consist of lipid bilayer (with some other components mixed in). Why wouldn't those lipid bilayers glue to each other and our cells won't merge? If you suppose that it's due to ...
3
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3answers
167 views

Size of black hole so large that I could pass event horizon without dying from tidal forces?

Were I to fall towards a typical black hole, the tidal forces would rip me apart well before I got to the event horizon. However, if a black hole were big enough, I could enter the event horizon ...
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3answers
82 views

Can higher level animals have lower entropy than the food they consume?

If there is plant source of energy 100Cal and an animal source of energy 100Cal for a human being, where the animal derived that energy from a similar plant source, can we say for sure that the animal ...
4
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1answer
54 views

What, if anything, makes primary colours distinct?

I've recently become interested in the primary colours; red, green and blue. In my capacity as a computer programmer I'm well aware of how these colours are used practically, and of how varying ...
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3answers
70 views

Why do our ears pop?

Have you ever been on a train going through a tunnel or plane and your ears pop?I was wondering why this happens and I know it relates to pressure but don't know exactly the reason
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2answers
67 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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0answers
48 views

What is the difference physiologically between running uphill vs. downhill? [closed]

In pure potential energy terms a person needs positive energy (work) to lift their body to a higher gravitational potential. When they turn around and run back down, the same transaction is reversed ...
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2answers
674 views

Does energy expenditure require movement? [duplicate]

In every formula I've seen that involves energy, I've also seen a distance element. Is there nothing that doesn't involve movement? For instance if I hold my arm out parallel to the ground with a ...
0
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0answers
30 views

Chromatic aberration in human eye [duplicate]

A lens focuses the different colours of white light at different points. Since our eye has a convex lens there should also be such an aberration but we see objects clearly with normal eye. I want to ...
0
votes
1answer
123 views

What would happen to the human body if we went almost at the speed of light? [duplicate]

If we were to travel almost at $299\,792\,458~m/s$, or the speed of light, what would happen to the human body? Would the human body stay the same or would there be consequences that would harm the ...
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0answers
17 views

My microwave oven disrupts my bluetooth connection even when I'm 12ft away. Should I be worried? [duplicate]

I often wear bluetooth headphones that connect to my mobile phone. I work on my laptop in my dining room approx. 12ft away from the microwave oven and my mobile phone is usually in my pocket; ...
0
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1answer
46 views

What happens when a bird lands on a power line?

I know that when a bird is sitting on a high-voltage power line, virtually no current flows through the bird because there is (almost) no voltage drop between its legs, the two points are ...
-3
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3answers
83 views

If radiation didn't exist, would everything live longer? [closed]

I recently noticed that dying of old age is similar to a death by radiation - hair loss, weakened immune system etc. and I was wondering - Does background radiation limit our lifespan, or that of any ...
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2answers
165 views

Why do we (3 dimensional creatures) see in 2 spatial dimensions? [closed]

Why do us humans, as 3-dimensional (in terms of space) creatures, see everything in 2 dimensions? Is it because the surface of every 3-dimensional object is 2 dimensional? Or because light enters our ...
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4answers
148 views

Is the hard problem of consciousness an obstacle to finding a physical theory of everything? Why or why not?

I do not understand how, without understanding the mind and how (physical) neural interactions within the brain give rise to consciousness, one can have a definitive theory of everything. There will ...
2
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0answers
46 views

Understanding quantum coherence in biological processes (Magnetoreception)

Moved my questions to the top. Context below. Why is the strength of the electric field and the coupling constant being compared to the inverse coherence time? What is the inverse coherence time? Is ...
1
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1answer
58 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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1answer
1k views

How long would it take for a smelly object to evaporate?

This question is a follow on from this deleted one: http://physics.stackexchange.com/q/177894/26076 as I was writing what I thought to be a valid physics answer to it. Version 1 of this question ...
0
votes
2answers
39 views

How can plants rooted on the ground become charged?

According to a quote on the physics forum "Plants are usually charged negatively and emit weak electric fields." Reference However this seems to contradict the fact that plants are grounded and any ...
0
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1answer
78 views

Why does the sky look blue rather than violet? [duplicate]

Sky looks blue because because our eyes are sensitive to blue colour. But when viewed through a camera why don't we see violet of the sky even though we can see violet colour of other pictures taken ...
0
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1answer
39 views

Factors affecting pain of static electricity shock

Referring to How to avoid getting shocked by static electricity?, someone I knew suffered much pain from static electric shocks when touching door knobs or car doors where I didn't feel anything doing ...
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2answers
77 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
1k views

Why is pale coloured skin said to absorb more UV?

Many resources state that light skin/pale skin absorbs more UV than dark-colour skin. Doesn't black absorb maximum radiation? For an example, see this article: Natural selection therefore ...
1
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1answer
75 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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2answers
72 views

Laser tattoo removal

I would like to know if someone could please briefly explain how laser technology of tattoo removal works? And second, could there possibly be any dangers to cells, specially on bones?
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6answers
1k views

Why do we lift our feet when we walk?

I'm not sure if this is a good question for here- albeit if I asked it somewhere else I'd want the physical argument. Why do we lift our feet when we walk, as opposed to doing something like ...
-1
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1answer
54 views

Top speed for a human

What is the fastest that a human being of average weight could possibly travel, and what is the most widely held theory for how this might be achieved (assuming this person is impervious to all forms ...
0
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0answers
21 views

Frequency resonance of Bones, and other parts of the human body [duplicate]

Today in class we were learning about states of matter. I found out that in a solid the atoms are vibrating. This caused me to think about how crystal glass will break if an opera singer sings high ...
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2answers
310 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 ...
7
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4answers
3k views

Can the brain detect the passage of a neutrino?

On a few occasions either in bed or sitting around a fire, with my eyes closed, I rarely but sometimes see a very quick fast flash of white and then, with my eyes still closed, the flash disappears ...
5
votes
4answers
170 views

How would swimming in low gravity work?

Sorry I know very little of actual physics, I'm not looking for hard and fast numbers just a general idea of how the mechanics would work. For the sake of argument, say you were on a planet or moon ...
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0answers
43 views

Will increased air pressure increase efficiency of solute diffusion into a membrane?

Biophysics question: I have a container with a biological tissue inside of solution where the solute slowly diffuses across the membrane and binds inside of the tissue. If I were to put this unsealed ...
2
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2answers
357 views

What are the main issues that are preventing a human mission to Mars? [closed]

Is it just because it'd be very expensive? Or are there serious problems that need to be dealt with, studied and solved? If so, what are they?
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4answers
65 views

Using formula for work with distance of 0m [duplicate]

Consider this: Wind is pushing a huge rock towards me at with massive force at 2m/s. I push against the rock at equal force so the rock stays still. I am clearly "working" very hard, using a lot of ...
0
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1answer
27 views

a question regarding Fourier transform in electron microscopy

I have recorded a micrograph of a 2-D array at a magnification of 43,000x on my DE-20 digital camera, which has a 6.4 μm pixel size and a frame size of 5120 × 3840 pixels. This magnification is ...
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1answer
70 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
57 views

What is one human power? [closed]

some time ago I was asked what the HP equivalent of a human was, looking into this apart from in the creation of steam engines the power definition 1 Horse power was set at the work of two of the best ...
0
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0answers
23 views

A simple derivation of the generalization bounds for the classical perceptron model

I'm basically referring to the great work of Elizabeth Gardner in this matter. I find that her work is often overlooked in the field of neuroscience, arguably because it is too difficult to understand ...
0
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3answers
70 views

Work power and energy

When you push your bicycle up on an inclined the potential energy of the bicycle and yourself increases. Where does this energy come from?
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0answers
59 views

How much energy does it take to hold a bag? [duplicate]

I'm holding a bag with some mass $m$. The force required for not letting it fall is equal to its weight $m \cdot g_L$ (where $g_L$ is the local gravity, assuming Earth this is $\approx 9.8 \; \text{m} ...
6
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1answer
349 views

Why do I hear a deep rumble when I cover my ears?

Probably a trivial thing but a simple google search didn't show anything relevant about it. If I cover both of my ears with my hands, I hear a very deep rumble. If I slowly move my hands away the ...
2
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0answers
80 views

What biology knowledge can be applied in physics? [closed]

After asking a commensurate question in Biology.SE (What physics knowledge can be applied to biology of organisms and ecosystems?), I wonder about the reverse direction: What biology knowledge can be ...
1
vote
1answer
155 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 ...
3
votes
2answers
2k views

Does staring at a bright LED light damage your eyes?

According to this article it seems that it is the UV part of the spectrum from the Sun that causes damage to the eye. Would it therefore be "safe" to observe directly an equivalent energy density LED ...
0
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0answers
63 views

Can high osmotic in nerve, intracellular concentration, lead to 'pumping up' nerve cells, strongly increase internal pressure, myelin sheath broken?

On: http://biology.stackexchange.com/questions/6916/can-in-the-case-of-multiple-sclerosis-ms-a-too-high-osmotic-pressure-in-the-n I read a question: Can in the case of multiple sclerosis (MS), ...
0
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1answer
63 views

A parameter to quantify instability in flight

Suppose I have plotted the body angles of a flying aeroplane.I have two such plots. One of a normal plane, and the other plot in which a primary sensor of the aeroplane is removed. So with the absence ...
-1
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1answer
133 views

Possible dangers of power lines radiation, wi-fi and gsm technology [closed]

I'd like to know more about the topic mentioned in the title. I have 3 questions. I'd be happy to hear your thoughts on any of those. So if high voltage power lines can cause harm to a human in some ...