Sriman Dutta

Brain cells are only formed once and they survive throughout the life. In case of their death, they are not replaced. So, beware to protect your brain !

I think we need to use sodium argentocyanide solution.

Oh I now see the its importance.

Neurons are the basic building blocks of the nervous system in large multicellular organisms. A neuron consists of three parts - dendrites, cyton and axon. Dendrites are thin thread-like structures arising from the main cell body of a neuron, connecting the neuron to other neurons. Cyton is the cell body, consisting of nucleus and other cell organeles (that I think you must know). An axon is a long chain spouting out of the cyton and continues as an elongated structure. This axon ends in axon terminals which join with other neurons via their dendrites. The whole axon is covered by a membrane called myelin sheath. An interesting fact is that the dendrites of one neuron and the axon terminals of another doesn't literally join with each other. Instead there is a small gap called a synaptic cleft.

Hi everybody, Can anyone tell me what is the actual purpose of the Lagrangian mechanics ? Lagrangian mechanics use a potential field to interpret Newtonian physics, but at the end of the day, it is just an approach to interpret Newton's laws in a different way. Why is this so ? Newtonian physics (as I think) is quite fine and can predict and define classical events. I understand how Lagrangian works but I don't know why it's needed ?

Are you clear now ??

Correct DimaMazin and that's because of the equation - observed frequency = sqrt[(c+v)/(c-v)].original frequency v is positive if both are approaching, else negative.

Hi Tim88, I know very little about GR as I can't seem to understand the concept of tensors in the EFE.

No. The same frequency is not going to reach you if the other person sends the signal. This is due to Relativistic Doppler Effect.

You must know that surface tension is correlated with the intermolecular force of attraction or the force of cohesion. If a liquid has a high cohesive force, then each of its molecules will exert a greater pull on the other molecules. The result is that the drop of the liquid will form a spherical shape. This phenomenon is known as surface tension. Mathematically, surface tension is the force exerted on the surface molecules per unit an imaginary line-length. T = F/l.

The process by which an electric current passes through an ionic compound, followed by the decomposition of the compound, is known as electrolysis. Any substance that undergoes electrolysis is known as electrolyte. A substance that doesn't undergo electrolysis ( i.e. the substance does not allow current to pass through it or doesn't get decomposed ) is known as a non-electrolyte. Most ionic compounds are electrolytes, whereas covalent compounds are mostly non-electrolytes. A good way to understand the process of electrolysis is to understand how an ionic compound dissociates into ions. Take, for instance, the electrolysis of sodium chloride (NaCl). When a current is passed through the NaCl solution, the charged ions migrate towards the oppositely charged electrodes ( cations move towards cathode and anions move towards anode). By this way, a current flows through the solution. But, there is a wide difference between the flow of current in a conductor and in an electrolyte.

Strictly speaking, E is not equal to SOMETHING. And as I have stated, by classical definition you can define energy of a system is equal to force times displacement. Energy spent by a system is the work done by it. Mathematically work is defined as the dot product of the vectors of force and displacement.

You haven't given any question. It's just a vague description of something.

You have to consider the spherical wave's two opposite wave fronts as two separate objects travelling at speeds c. So for any one of the observers, observed velocity = (c+c)/(1+c^2/c^2) = 2c/2 = c. That's how the system works ( as far as I have understood the concept, I'm a novice in this field).

+1.

George likes to play with marbles. He has got a jar full of marbles of different colours. One day, he started to pick the marbles out of the jar. In the first picking he took away 1 marble, in the second picking he took out 2 marbles, in the third he took out 3 marbles from the jar - each time picking up as many marbles as the number of picking. He found that after fifth and seventh picking, the number of marbles that were left in the jar was a perfect square. Now, can you find the number of marbles that was in the jar at the beginning?

The original length is what I assumed the length of the rod at the beginning of the situation. Yah, it's true that the rod's state of rest may not be the same for another observer, because according to relativity there is no absolute frame of reference.

Thanks Tim.

Hi friends, Once again I got this situation in my head. Let there be a metal rod of original length l, and the rod material has a coefficient of linear thermal expansion of a. Let this rod travel towards a star at a speed v, very near to the speed of light. Let the change in temperature of the rod be T. Then new length after thermal expansion l' = l(1+aT). But there is also length contraction. So the real length l" = l'/y = {l(1+aT)}/y , where y is the Lorentz factor. Am I right in this calculation ? Or, am I missing out some other factors ?

Different times has to do something with the energy of photon DimaMazin. If t' = ty, y is Lorentz factor => 1/t' = 1/ty => f' = f/y => hf' = hf/y => E' = E/y

A boson field is a field of particles that obey Bose-Einstein statistics.

Thanks Tim.... I think after such a long discussion, my concept of SR has improved a lot.

Hi friends, When we were kids and young, we all had some kind of misconceptions about the world around us that we see. I had several of such odd thoughts that I want to share with you all. When I studied in class 4/5, I was introduced to the concept how a electric energy lights a bulb (don't think it to be in detail, for we had only a simple diagram of a DC circuit). In the picture given in my book, there was a battery which was connected to a small bulb through two wires. As a convention two signs were given overhead the battery terminals ( + and - ). At that time, I presumed that + and - denotes the two charge types flowing through the wires. I guessed that protons flowed through the positive wire and electrons flowed through the negative wire. I would like to know if anyone else had such ugly childish misconceptions.

:eyebrow:It launched Sputnik on 4th October 1957.