Write a lecture on verb and verb agreement in 800 words

Welcome to this lecture on verb and verb agreement. In this lecture, we will discuss what verbs are and how they function in sentences, as well as how to ensure proper verb agreement in sentences.

Firstly, what is a verb? A verb is a word that expresses an action, occurrence, or state of being. Examples of verbs include "run," "jump," "sing," "exist," and "believe." Verbs are an essential part of sentences, as they allow us to convey actions and events.

Now, let's talk about verb agreement. When we use verbs in sentences, we need to ensure that they agree with the subject of the sentence in terms of number and person. This means that the form of the verb must change depending on whether the subject is singular or plural, and whether it is in the first, second, or third person.

For example, consider the sentence "I run every morning." In this sentence, the subject is "I," which is singular and in the first person. The verb "run" is also in the first person singular form, which agrees with the subject. If we were to change the subject to "we," which is plural and in the first person, the verb would need to change to the first person plural form "run."

Similarly, if we were to use the third person singular subject "he" in the sentence, the verb would need to change to the third person singular form "runs." Thus, the correct sentence would be "He runs every morning."

Let's look at another example: "The dogs bark loudly." In this sentence, the subject is "dogs," which is plural and in the third person. The verb "bark" is in the third person plural form, which agrees with the subject. If we were to change the subject to the singular form "dog," the verb would need to change to the third person singular form "barks." Thus, the correct sentence would be "The dog barks loudly."

It's important to note that sometimes the subject of a sentence can be more complicated than a single noun or pronoun. In these cases, we need to identify the main subject of the sentence and make sure that the verb agrees with it.

For example, consider the sentence "The group of students is studying for their exams." In this sentence, the subject is "group," which is singular. However, the phrase "of students" is modifying the subject, so we need to be careful not to confuse it with the main subject. The verb "is studying" is in the third person singular form, which agrees with the main subject "group."

It's also worth noting that certain verbs have irregular forms in different tenses or persons. For example, the verb "to be" has different forms for different persons and tenses. In the present tense, the first person singular form is "am," the second person singular form is "are," and the third person singular form is "is." Similarly, in the past tense, the first person singular form is "was," the second person singular form is "were," and the third person singular form is "was."

In conclusion, verbs are an essential part of sentences, allowing us to convey actions and events. When using verbs, we need to ensure that they agree with the subject of the sentence in terms of number and person. It's important to identify the main subject of the sentence and be aware of any modifiers that may affect verb agreement. Finally, it's essential to be aware of irregular verb forms in different tenses and persons. By following these guidelines, we can ensure that our sentences are grammatically correct and convey our intended meaning.

Amazimg Photographs Courtesy Discovery Channel

Swallowed by the Sea: Amazing Underwater Pictures

The Rainbow Warrior sunk after being bombed off Auckland harbor in 1985, and because Greenpeace demonstrators were using the boat as part of a protest of French nuclear testing, the French Secret Service was implicated in the bombing. Although there was an attempt to fix the ship, it was deemed beyond repair and was resunk in the ocean.

Image Credit: Amos Nachoum/CORBIS

All's Fair in Love and Germ Warfare: Bioterrorism Agents Pictures

This … is anthrax. No, not the thrash metal band -- the disease. More specifically, this is the Bacillus anthracis bacteria, which is the biological agent that causes the disease. This scanning electron micrograph shows a highly magnified culture of spores from the Sterne strain of the bacteria. Anthrax is the Abrams tank of germ warfare: tough, resilient, adaptable and deadly. And we're not just speaking hypothetically -- unlike many proposed bioterrorism agents, anthrax spores have already been used in the world of terrorism, to murder civilians and cause panic among a targeted population. To see more images of this infinitesimal assassin and other potential biological weapons

Image Credit: Discovery Channel

BLACKHOLE : THE MYSTERIOUS MEMBER OF THE UNIVERSE:

BLACKHOLE : THE MYSTERIOUS MEMBER OF THE UNIVERSE:

EVENT HORIZON:

The defining feature of a black hole is the appearance of an event horizon—a boundary in spacetime through which matter and light can only pass inward towards the mass of the black hole. Nothing, including light, can escape from inside the event horizon. The event horizon is referred to as such because if an event occurs within the boundary, light from that event cannot reach an outside observer, making it impossible to determine if such an event occurred.

As predicted by general relativity, the presence of a large mass deforms spacetime in such a way that the paths particles take bend towards the mass. At the event horizon of a black hole, this deformation becomes so strong that there are no paths that lead away from the black hole.

To a distant observer, clocks near a black hole appear to tick more slowly than those further away from the black hole. Due to this effect, known as gravitational time dilation, an object falling into a black hole appears to slow down as it approaches the event horizon, taking an infinite time to reach it. At the same time, all processes on this object slow down causing emitted light to appear redder and dimmer, an effect known as gravitational redshift. Eventually, at a point just before it reaches the event horizon, the falling object becomes so dim that it can no longer be seen.

On the other hand, an observer falling into a black hole does not notice any of these effects as he crosses the event horizon. According to his own clock, he crosses the event horizon after a finite time, although he is unable to determine exactly when he crosses it, as it is impossible to determine the location of the event horizon from local observations.

For a non rotating (static) black hole, the Schwarzschild radius delimits a spherical event horizon. The Schwarzschild radius of an object is proportional to the mass. Rotating black holes have distorted, nonspherical event horizons. Since the event horizon is not a material surface but rather merely a mathematically defined demarcation boundary, nothing prevents matter or radiation from entering a black hole, only from exiting one. The description of black holes given by general relativity is known to be an approximation, and some scientists expect that quantum gravity effects will become significant near the vicinity of the event horizon. This would allow observations of matter near a black hole's event horizon to be used to indirectly study general relativity and proposed extensions to it.

Simulated view of a black hole in front of the Large Magellanic Cloud. The ratio between the black hole Schwarzschild radius and the observer distance to it is 1:9. Of note is the gravitational lensing effect known as an Einstein ring, which produces a set of two fairly bright and large but highly distorted images of the Cloud as compared to its actual angular size.

Simulation of Gravitational lensing by a black hole which distorts the image of a galaxy in the background.

Artist impression of a binary system with an accretion disk around a compact object being fed by material from the companion star.

The jet originating from the center of M87 in this image comes from an active galactic nucleus that may contain a supermassive black hole.


Credit: Hubble Space Telescope/NASA/ESA.

 

 

If ultra-high-energy collisions of particles in a particle accelerator can create microscopic black holes, it is expected that all types of particles will be emitted by black hole evaporation, providing key evidence for any grand unified theory. Above are the high energy particles produced in a gold ion collision on the RHIC.

 

 

 

 

A simulated event in the CMS detector, a collision in which a micro black hole may be created.

 

Formation of extragalactic jets from a black hole's accretion disk.

by  Subhankar Karmakar

PHYSICS : ELEMENTARY PARTICLE subhankar karmakar

A fundamental question that haunts philosophers as well as physicists throughout the ages is nothing but the true essence of the behaviour and composition of matter. From ancient times different advanced human civilization have tried to reveal the intrinsic composition of matter, many philosophers had involved themselves to find out the true nature of matter. Ancient Greeks, Egyptian, Arabian, European philosophers tried to formulate a successful theory of matter.

All of us know that we exist in this world, ie in reality, but when some one asks about the true nature of reality, modern science has only partially correct theory to predict the outcome of an event in reality. Years ago I had seen a Hollywood science fiction named "Matrix". There was a scene in the movie, where Morpheus asked "Neo", "What is reality?" Does all the objects we see around us is real? If so, what is the difference between reality and virtual world. Can't we make a virtual world that would be indistinguishable from the real world? In Matrix, they had shown that the reality can be simulated, rather better say that by manipulating input signal we can simulate a reality which has all the characteristics of reality, but still it's not real in such a meaning.

Physics as a part of the general science was introduced to us when we were in class V. It was a love at first sight for me. Unbelievably I have found that the puzzles and queries I have, can be explained with the help of theories of Physics.Since then we know that the matter, which in reality, is looked like a continuous substance is in fact not continuous. We are told that every matter is composed of smallest unit of that matter, which is the building block of matter, and named as molecules. And for every different substances, their molecules are also totally different, distinct, and have different properties, physical as well as chemical. So, the next question that comes to our mind is about molecules itself! We, thus know the apparently continuous matter is in fact discrete, but that is beyond our perception too. So, matter is composed of molecules, but can a molecule be again divided into some more elemental forms of mass. As, the science progressed, our knowledge is exponentially burgeoning, and it is discovered that molecules are also divisible, they are not fundamental basic particles. So, our text book conveyed to us that a molecule is composed of one or more particles that may or may not be of same kind of substance. But, as we divide molecules into atoms, the matter loses it's properties, so molecules are the smallest unit of matter that can retain the properties. So, can we say an atom is the most fundamental particle? The answer is no, as the magnitudes of human conquest progressed exponentially in micro - nano domain, we came to know about relative voidness inside an atom. An atom has a core, aptly named as NUCLEUS. Later it was found that the core i.e. the Nucleus is made of two particles of nearly comparable mass and around them another types very very light particles are revolving, just like all the planets are revolving around the Sun. The two types of components those we have found as the key ingredients of the nucleus of an atom are named as Neutron and Proton, and it has been found that in addition to mass, another fundamental physical quantity named Charge. Where as the neutron is charge neutral, proton has a positive charge. The lighter particles orbiting the nucleus of an atom are named as Electrons. They have charge too, but unlike proton they have opposite kinds of charge, hence is named as negative charge. For a long time scientists used to believe these three kinds of particles as the most fundamental and basic particles and they are responsible for any kind of structure that are visible in this universe.

Due to the development of the atomic theory we could be able to reduce all the matters into different combinations of three types of sub atomic particles i.e. negatively charged electron, positive charged proton and charge neutral neutron. But as time passes by we have started to observe many physical phenomenon that can’t be explained by the “Atomic theory of matter” like the formation of atomic nucleus, radioactivity of heavy elements like uranium, thorium and plutonium etc.

But the main objection to this theory is the existence of "Nucleus" itself. As, we have observed that similar charges strongly repel each other, hence the protons inside the nucleus must repel each other and they should readily disintegrate. But, amazingly we have found that not only atomic nucleus is stable, but a fair amount of extra energy must be supplied if we want to disintegrate a heavy nucleus. It indicates that, there must be atleast one more kind of fundamental force other than Gravity and Electro magnetic force that binds the protons and neutrons together to form a nucleus of an atom.

                                                                                         to be continued............

NEUROLOGY : HOW WE SEE THINGS THAT MOVE

NEUROLOGY : HOW WE SEE THINGS THAT MOVE

by subhankar karmakar

How We See Things that Move:
A Hot Spot in the Brain's Motion Pathway
___________________________________________


Researchers have now traced the path of neural connections that make up the motion pathway and tested the responses of cells at different steps along this path.

Starting in the retina, large ganglion cells called magnocellular neurons, or M cells, are triggered into action when part of the image of a moving hand sweeps across their receptive field—the small area of the visual field to which each cell is sensitive. The M cells' impulses travel along the optic nerve to a relay station in the thalamus, near the middle of the brain, called the lateral geniculate nucleus.

Then they flash to the middle layer of neurons in the primary visual cortex. There, by pooling together the inputs from many M cells, certain neurons gain a new property: they become sensitive to the direction in which the hand is moving across their window of vision.

Such direction-sensitive cells were first discovered in the mammalian visual cortex by David Hubel and Torsten Wiesel, who projected moving bars of light across the receptive fields of cells in the primary visual cortex of anesthetized cats and monkeys. Electrodes very close to these cells picked up their response to different moving lines, and the pattern of activity could be heard as a crackling "pop-pop-pop" when the signals were amplified and fed into a loudspeaker.

The keystone of the motion pathway was discovered by Semir Zeki of University College, London, in an area of the cortex that lies just beyond the primary and secondary visual areas (V1 and V2), further from the back of the brain—a vast unexplored wilderness vaguely known as the "sensory association cortex."

"It was thought that somewhere in this mishmash of association cortex visual forms were recognized and associated with information from other senses, says John Allman of the California Institute of Technology. But studies in the owl monkey by Allman and Jon Kaas (who is now at Vanderbilt) and in the rhesus monkey by Semir Zeki revealed that the area was not a mishmash at all.

Instead, much of it was made up of separate visual maps, each containing a distinct representation of the visual field. In 1971, Zeki showed that one of these visual maps was remarkably specialized. Though its cells did not respond to color or form, over 90 percent of them responded to movement in a particular direction. American scientists usually call this map MT (middle temporal area), but Zeki called it V5. He also nicknamed it "the motion area."

"This very striking finding of this little hot spot, this little pocket, in which almost all the cells are sensitive for the direction of movement," says New York University's Anthony Movshon, was the impetus for many vision researchers to turn their attention to motion. Nowhere else in the visual cortex was there an area that seemed so functionally specialized.

The cells of this motion area, MT, are directly connected to the layer of direction-sensitive cells in the primary visual area, V1. And the two areas have a remarkably similar architecture. Hubel and Wiesel had discovered that V1 is organized into a series of columns. The cells in one column may fire only when shown lines oriented like an hour hand pointing to one o'clock, for instance, while the cells in the next column fire most readily to lines oriented at two o'clock, and so on around the dial.

Amazingly, MT has the same kind of orientation system as V1, but in addition the cells in its columns respond preferentially to the direction of movement.

"When you see that an area, like V1 or MT, has this highly organized columnar structure," says Wiesel, "you get a sense of uncovering something fundamental about the way the cells in the visual area work."

A JOURNEY THROUGH THE COMPLEXITY OF MY MIND

EMOTIONS AND THE BRAIN :

 

                                                                    by subhankar karmakar

 

Human emotions are abstract ideas that is different states of emotional conditions can be perceived by other material things, but emotions itself can not perceive other material bodies or abstract ideas. So, what is the physical basis of emotion? Can we relate some brain processes exclusively for an emotion? Where does the human emotion originates? Are they merely some kind of emergent behaviour? As well as consciousness is such a difficult things to handle that to understand this we have to go through some different kind of phenomenon regarding emotion and neurology.

While the autonomic nervous system regulates much of what happens in our body - especially with response to emotional situations, the brain has an important role to play. This goes back to the times of Shakespeare when it was asked "where is fancy bred in the heart or the head?" (Merchant of Venice)

Well, research now shows the head has a lot to do with it. In developing an understanding of the role that the brain plays in emotions, we must first recognise that the brain is not a single unit.

The human brain can also be examined from a number of viewpoints. When looking at the brain from the top, there is a deep crease that divides the brain into two almost identical halves, called the left and the right hemispheres. These are called the cerebral hemispheres. Below is a chart that shows the distinctions between these hemispheres:

Left Hemisphere : Systematic & logical Interpretation of information
Right Hemisphere : Auditory (sound) skills ,Visual (sight) skills ,Spatial skills

The surface of the brain is composed of so-called grey matter and has a wrinkled appearance. The area is called the cerebral cortex. It is a thin layer of cells that covers the entire surface of the forebrain. If spread out flat, it would cover an area about 18 square inches on each side. In order to fit in to our relatively small skull, the cortex is wrinkled and folded so it is easier to carry around and does not give us a huge head. The cortex itself is divided into four separate areas called lobes. Generally speaking, the cerebral cortex inhibits emotions. It modifies emotional reactions based on impulses from lower brain centres and directs emotional reaction and controls cognitive aspects of emotion by interpretation and memory of emotional events.