Country Boy
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According to Wikipedia, "Epigenetics most often denotes changes that affect gene activity and expression, but can also be used to describe any heritable phenotypic change" so, yes epigenetic changes affect genes and can be passed on to off spring. However, "working out" and "eating lots of nutrient dense food" are NOT "epigenetic". They are phenotypic, do not affect genes, and are NOT passed on to offspring.
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Dead end in radical simplification?
Country Boy replied to ScienceNostalgia101's topic in Mathematics
It doesn't have to be prime- as long as a number is not a perfect square or divisible by a perfect square, you cannot continue. For example to simplify the square root of 216, I can observe 216= 2*2*2*3*3*3= 2^3 3^3 (that's its "prime factorization"). Since I want the square root, I look for squares- powers of 2: (2*2)(2)(3*3)(3)= 4(2)(9)(3). "4" and "9" are "perfect squares", 2 squared and 3 squared. [math]\sqrt{216}= \sqrt{4(9)(2)(3)= \sqrt{4}\sqt{9}\sqrt{2(3)}= 2(3)\sqrt{6}= 6\sqrt{6}[/math]. "6" is not prime but it is not a perfect square either. Notice that 2*2*2= 8 and 3*3*3= 27 are "perfect cubes", $2^3$ and $3^3$ so its cube root: [math]\sqrt[3]{216}= \sqrt[3]{2^3(3^3}= 2(3)= 6[/math]. -
Originally Newton tried to define the derivative as "dy divided by dx" where dy and dx are "infinitesmals" but was not able to give a rigorous definition of "infinitesimal". The Bishop Berkeley famously satirized them as "ghosts of vanished quantities". Later people like Cauchy redefined the derivative in terms of limits. But recently Abraham Robinson and others resurrected "infinitesmals" by extending the real numbers to include both "infinite" and "infinitesmals" in "non-standard analysis": https://en.wikipedia.org/wiki/Non-standard_analysis.
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Please clear my doubt about acceleration.
Country Boy replied to Shahroze's topic in Classical Physics
When an object is sitting on the ground there are two forces- the force of gravity pointing downward and the force due to the pressure the ground is exerting on the object. Those are "equal and opposite", they cancel and one could, as well, say there is no (net) force. If an object is sitting on a frictionless tilted surface such as a wedge there is the force of gravity but now the force due to the surface is not directly opposite to gravitational force and we may have motion along the surface. In "real life", with friction, the friction force is parallel to the surface so we can think of this as three forces- the vertical force of gravity, the pressure force due to the surface which is perpendicular to the surface, and friction which is parallel to the surface. -
Do you not know how 'google' works? I entered "parts working together for one purpose" in Google and immediately got "system".
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Help Please: Weight, Space, Mass,Volume, Ratio
Country Boy replied to DJL's topic in Analysis and Calculus
If the weight of herbs alone is "m" and the weight of herbs and vodka is "M" then the weight of vodka alone is M-m so that the ratio of "herbs to vodka" is m/(M- m). -
Yes, but a cramp can cause a muscle strain. I thought that was what the question was asking.
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Are you asking if the universe was created by a sentient, reasoning, being?
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That is a "cramp". A "spasm" is only momentary.
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Computing inverse of a 4*4, 5*5 matrix.
Country Boy replied to prashantakerkar's topic in Linear Algebra and Group Theory
If someone else has done the tedious work of programming the computer! -
Reaction between Tin and Nitric Acid lab discussion Help
Country Boy replied to kratious's topic in Homework Help
Didn't your teacher, or text book, explain what a "mole" is? One mole of any substance contains "Avogadro's number" of molecules of that substance and that number is chosen so that the mass of one mole of a substance, in grams, is equal to that substance's molecular weight. For example, carbon-12 has a molecular weight of 12 atomic units (au) (Any form of carbon has 6 protons. The isotope, carbon 12, also has 6 neutrons which have the same weight as the protons. Since an electron's weight is negligible, the "atomic weight" of carbon 12 is 12 au [and that's where the "12" in the name comes from]) so one mole of carbon 12 weighs 12 grams. A methane molecule is made from one carbon atom and four hydrogen atoms. Since we don't want to worry about isotopes here we take the average atomic weight of all isotopes of carbon, 12..011 au, and the average weight of all isotopes of hydrogen, 1.008 au, which makes the atomic weight of methane 12.011+ 4(1.008)= 16.043 au. One mole of methane has mass 16.043 grams. -
Can someone explain details of this seawater car ?
Country Boy replied to Externet's topic in Engineering
"Conservation of energy": you can't get energy out of something that does not already have energy already in it. Oil, and gasoline, have energy "trapped" in its molecules. So does wood or anything that burns. Water, even seawater, does not. As for a "chemical soup", isn't that what oil is? -
Draughts or Checkers game.
Country Boy replied to prashantakerkar's topic in Linear Algebra and Group Theory
Odd number of sides or odd number of squares on each side? -
The Collatz Conjecture has been proved. What next??
Country Boy replied to Antony Howard Stark's topic in Applied Mathematics
You mean people didn't rush to bow before you? -
The Collatz Conjecture has been proved. What next??
Country Boy replied to Antony Howard Stark's topic in Applied Mathematics
Back in July, you started a thread saying that you had proved the Collatz conjecture. Want happened to that? Why are you starting a new thread saying the same thing? -
[tex]\frac{f(x+h)- f(x)}{h}[/tex] is the "difference quotient". Geometrically, it gives the average "slope" of a graph between the points (x, f(x)) and (x+ h, f(x+h)). That is the slope of the straight line between those points. Taking the limit as h goes to 0, if it exists, gives the slope of the tangent line to the graph at (x, f(x)). (The graph has a tangent line at that point if and only if that limit exists.) In some textbooks the "derivative" of f at that value of x is defined to be that limit and then that is shown to be the slope of the tangent line. In other textbooks the derivative is defined as "the slope of the tangent line" and that formula derived.
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Free fall Experiment, Second Law of Motion. (Help)
Country Boy replied to TheDragon's topic in Classical Physics
What results did you get from that experiment? -
Yes, and a constant Yes, and a constant acceleration, with no "change in acceleration" is a change in velocity requiring that inertia be overcome.
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resistance to change of velocity.
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Projectile Motion: Kinematics: Finding maximum height
Country Boy replied to TheDragon's topic in Homework Help
How you would approach this depends upon what you know. If you know a little Calculus then you can start from the fact that there is no horizontal acceleration while the vertical acceleration is that of gravity, -g or approximately -9.8 m/s. That horizontal acceleration is the derivative of the horizontal velocity function: dvx/dt= 0 so vx is a constant. You are told that, initially, the speed is "20m/s at an angle of 50° above the horizontal" so that constant is 20 sin(50). The horizontal velocity is the derivative of the horizontal position, x, so the horizontal position, taking the point at which the ball is kicked to be x= 0, is x(t)= 20 sin(50)t. The vertical acceleration is the derivative of the vertical velocity function: dvy/dt= -g so vy= -gt plus the initial vertical velocity which is 20 cos(50). vy= -gt+ 20 cos(50). The vertical velocity is the derivative of the vertical position, y, so taking the point at which the ball is kicked to be y= 0, y(t)= -(g/2)t^2+ 20 cos(50)t. If you have not learned any Calculus, you probably have just learned that "x(t)= vx(0)t+ x(0)" and "y(t)= -(g/2)t^2+ vy(0)t+ y0" where vx(0), vy(0), x(0), and y(0) are the initial values put in above. The question asks for the highest point the ball reaches. Again, there are several ways of doing that. If you know a little Calculus, you know that a maximum of a differentiable function is reached where the y derivative is 0. If not the you probably realize that, at the highest point, the vertical velocity, vy, is 0. Or, since the vertical position function is quadratic, its graph is a parabola with vertex at its highest point- you can simply "complete the square" in the quadratic formula for the height. -
Split from Is Our Universe Too Perfect to be Random?
Country Boy replied to Brian T. Johnston's topic in Speculations
Darn! If I could just remember where I put my time machine! -
Split from Is Our Universe Too Perfect to be Random?
Country Boy replied to Brian T. Johnston's topic in Speculations
I would like to know what the OP means by "perfect". "Perfect" for what? Certainly NOT "perfect" for life! Almost all of the universe is terribly hostile to life. If the earth is "perfect" for life that is because life has evolved to fit it.