Human Definition and 895 Threads

For zebrafish and Xenopus, are there currently any effective gene knockout strategies? From literature, these two organisms have effective gene knockdown strategies in practice. Thanks for any help.

I have a question: can the human body be expressed mathematically? If so, how would you even go about starting to map out the algorithmic structure of something that's living (which would include molecular function, cellular function, etc. etc.)?

I have a school assignment about the physics of the human heart, primarily about the pressures in the ventricles and atriums, what causes the valves to open and what makes blood flow from the atrium to the ventricle, what is the pressure and where? I already know how what makes the heart beat...

Why does a voltage tester (that looks like a screwdriver) turn on even when you are "heavily" insulated from the ground e.g. sitting on a wooden chair. Is it the result of capacitance between the human body and the ground? (i.e. the body and the ground act as conductors, whereas the insulated...

I spoke to someone that said that the reason we know humans originated from evolution is because there is no other scientifically possible explanation. I originally thought the reason we knew humans originated from evolution because we had explicit evidence of human evolution. Although now that...

Tom Cruise's Oblivion got me thinking: can human clone reproduce naturally? what are the pros and cons of clones reproducing themselves?

How much of a human's body can be replaced with mechanical devices / non organics before the human is no longer considered human? Which parts of a human's body must remain organic for a human to still be considered human?

Hello, I would like to understand what exactly is meant by "calories" when we read for example that a chocolate bar has 300 kcal. I understand what is a (kilo)calorie. What I do not know is whether the written values are the raw values in calories or if they are the values our body can...

Apparently, from what I heard, it's illegal in the US to sell headsets that block sound in the 1k Hz to 2k Hz frequency range. The problem is that human speech is in that range and I want to block human speech so I can study. Normally, the product description reads something like this...

How would you think natural human flight would be possible?

Hello - I'm having a difficult time finding this answer anywhere else on Physics Forums. I'm curious if anyone knows, or can figure out, the smallest difference in wavelength that the human eye can notice. For example: Can the human eye detect if a light changes from 568nm to 570nm?

I'm aware my following thoughts are highly speculative at best, i just wish to be explained, are they total magic, do they have anything common with reality, what can be their Mohs scale level? I thought about a story, where people fused their brain with nanobots, while they still think like...

"The Human Genome" vs a person's genome Is "genome" a term that applies both to a species and to individuals of that species? What's the difference between "The Human Genome" and Eddie Ledesco's genome? For example, quoting from this article...

Hey guys, I’m interested in knowing if there are any known implications of quantum theory in the macroscopic scale, regarding randomness. Small particles behave probabilistically, but that has any consequence in the macroscopic or in the microscopic (but higher scale than those particles –...

How would I store human DNA for decades, at room temperature, blood samples and not too invasive methods available. It needs to be 100% undamaged and usable for genome mapping.

Greetings folks, I'm new to this forum and to physics in general so apologies if I come off like a greenhorn or if I am posting these questions in the wrong place. I have an Arts background and have never really "gotten" science, but my interest in post-Enlightenment philosophy has led me to a...

Okay it's been well established that objects with momentum exhibit wave like properties. Hence, electrons being observed forming interference patterns when scattering off of crystal lattices. Also I recently read this webpage. At the bottom it mentions performing a double slit experiment with...

I always wonder about our human body in space without any suits. I don't know exactly what happens but i want to know which has been a interesting question to me right from my past. What will happen when a human body is exposed to space without any space suits?

Lawrence Krauss says that We evolved as human beings a few million years ago on the Savanna in Africa and we evolved to escape tigers, or lions, or predators. You know, how to throw a rock or a spear or how to find a cave and we didn't evolve to understand quantum mechanics. How correct is the...

I want to build a fun, but potentially dangerous toy - a human slingshot (into a lake). I'm trying to figure out the physics of a contraption like this but it's been 20 years since I took a physics class. The formulas I'm finding online are giving me some unrealistic numbers, so I know I'm...

Hi, every time I hear any website/TV program/person mention the percentage water composition of the human body it varies tremendously. 90,80,85,70,53. What is it? any help appreciated. Thanks

Suppose a human could live for two hours (120 minutes ) unclothes in air at 45 F . How long could he live in water at 45 F ? how do the thermal conductivities of water and air compare ? Air : k = 0.0251 W/mC , water = k = 0.597 W/mC my answer now for conduction we will say that...

"Unlike our close genetic relatives - chimps - all humans have virtually identical DNA. In fact, one group of chimps can have more genetic diversity than all of the six billion humans alive today." When humans faced extinction By Dr David Whitehouse 6/9/2003 What are they talking about when...

I am trying to design an optimal colormap for display interval data. I would like to create a scale that is linear in perceived luminance while adding a hue component to help mitigate the simultaneous contrast effect. However, I am confused on what hue to pick. The longest curved path I...

Is the Hayflick limit an absolute limit for the human lifespan or is it just the average limit of the human lifespan just like there are average heights and weights? Based on the maximum number of times the cells divide which is 50 according to Hayflick's experiments, how can the maximum...

Would someone help me to understand what would happen in this situation. w→ x→ (y)→ z Photon emitter is at point w emitting photons one at a time. Double slit is at point x. Screen is at point z. There is a detector at point y (after photon has already passed through slits) which is capable...

I wasn't sure whether to post this question in biology or physics. I'm stumped on a couple experiments. Here are the basic experiments. I have people wash their hands and dry them off and then hold onto the probes of a volt meter. To my surprise some people give a reading as high as...

Carbon (18%) Hydrogen (10%) Nitrogen (3%) Calcium (1.5%) Phosphorus (1.0%) Potassium (0.35%) Sulfur (0.25%) Sodium (0.15%) Magnesium (0.05%) Copper, Zinc, Selenium, Molybdenum, Fluorine, Chlorine, Iodine, Manganese, Cobalt, Iron (0.70%) Lithium, Strontium, Aluminum, Silicon, Lead...

Homework Statement A) Under optimum conditions, the smallest black dot that can be seen subtends an angle of 2.3 x 10-6 rad. If a dot is viewed at a distant of 0.25 m, the near point of a normal adult, what is the smallest diameter it can have and still be seen? B) The maximum resolution is...

Let me remind you all how small we are :D not that most of you need to be told :P Credit for the photo belongs to Nick Risinger. Website credits in the bottom left hand side of the picture.

I was wondering how a uniform image is formed. If the eye is a point then I can visualize how an image is formed. But the eye isn't exactly a point. So don't light rays from all angles hit all spots on the retina? How is a uniform image formed? For example if we're looking in a plane mirror, we...

Hello everyone, long time lurker first time poster here. I've been wondering for a while about this: Let's suppose a newborn baby is placed in a spaceship capable of traveling at 0.95c. The baby travels from Earth to a (theoretical) planet 95 light-years away which is at rest relative to...

Take for example a human being inside a wooden crate. One can not see, taste, touch, smell or hear the human inside the crate, or whatever it is being tested against. We know roughly the outer dimensions of the crate giving an upper limit to the size of the human being within plus or minus a...

Definition of "View Angle of Human Eye"? I've been told (since high school I think) that "view angle" in a 2-dimensional plane is approximately (distance to the object/object's length). The assumption is that I'm viewing an object AB of length L, basically a segment in a 2-dimensional...

Hi, I am using a Human body model which I built for some simulation studies. I was trying to pass DC current through the Human body and though my Project completed the simulation successfully I got the below warning message. Can anyone please help me interpret it? The error log is as...

I'm posting this here because it's neither fully statistics or biology, and I have no technical knowledge of statistics. It's well known that humans have trouble behaving truly randomly. If a group of people is asked to choose a random number between 1 and 10, each person is very likely to...

Hello, I have trouble to get what work is. I find physics notions difficult to understand and I'm kinda bit astray like Rainman in that movie when he walks that moving walkway the wrong way, realizing he's not progressing. Could you, please, explain me with human words what work really...

Hi, I'm doing some research on developing a physics-based platform game and I want to see how the gameplay will feel if the environment and physics were made to scale as realistically as possible. Since one of the core features of a 2D platformer is jumping, I need some figures on how much...

This might be a bit off topic, but I am curious about cycles of evolution. What is the goal of human evolution and how does the process happen in sync to the enviornment? My thoughts: Wouldnt the evolution goal be control? Meaning control by having the forces of the universe bend to you and...

Preferably I would like to find a UV-VIS absorbance spectra of urine. I have found ones that focus on the deep UV range, and one that had fluorescence peak information. Any help would be appreciated.

Homework Statement The arm in the figure below weighs 37.1N. The force of gravity acting on the arm acts through point A. Assume that L1 = 0.0720m, L2 = 0.300m and α = 11.8deg. Point A is 0.300m away from the pivot point. Fs is unknown angle degree from the horizontal. a) Determine the...

Hello everybody. I am just a man who interest in physics. And with the question I concern above is the reason I join this forum. Nice to meet you all To the main point I want to know exactly that, Is energy of one person enough to generate hot air for lift balloon system and himself? By any...

My answer is that the 3Gigabits of base 4 memory in the human genome is equivalent to 750MB of binary standardised to 8 bits/byte. Once I have taken into account that there are two copies, evolutionary junk and repeated or copied areas, I am getting an estimate of around 30MB.

To find the respective torque that is need to bend the the arm at 180 degrees, 90 degrees and 30 degrees. The arm is not holding anything. Relevant equations and information τ=rFsinθ total arm weight =3.35kg upper arm length =19cm forearm length =28cm

From the wiki page on Hermann von Helmholtz: "an 1847 physics treatise on the conservation of energy was written in the context of his medical studies and philosophical background. He discovered the principle of conservation of energy while studying muscle metabolism. He tried to demonstrate...

This was described by Michael E. Mann,professor of meteorology at Penn State University. http://www.meteo.psu.edu/holocene/public_html/Mann/news/interviews.php Others have had readings that give similar results. "While scientists and environmentalists have used the daily milestone to...

Throughout history, people are always trying to keep certain sects of human beings from doing things, from being equal, from having rights... I just don't understand. From African Americans, gays, women, or even Christians being barred from this and that nowadays by the realm of political...

I'm designing a monitor and I've been getting various answers to this, seems to really depend. I've gotten everything from 10-120Hz.

HI, please do not get me wrong, I am trying to grasp and learn when HV capacitors get dangerous and I am confused right now. Your help is extremely appreciated. Caps discharge their energy very very quickly and said THERFORE to be dangerous, but a Van de graaf also discharge its energy...

Basically I have to make a comparison matrix of the bionic eye, the human eye and the camera. I want to sound scientific so I thought I would check what you guys think I should use as properties in the matrix?? Please thankyou :)