Faster Than Light

             As we already know speed of light is 299 792 458 m/s. The speed of light 'c' is an absolute physical constant. No matter where you are in the universe or how fast you are moving relative to something also the speed of light in vacuum is always the same.
Why is it finite?, what came it to move?, it always move in a straight  line, no matter the frame light is in. Why is that? Is it possible to travel faster than light( FTL)? Of course ,as you have already seen FTL in many tv series( star trek) or science fiction movies. They go faster than the speed of light every show and travel into the past like it's a trip to Disneyland. It is fun to think about and enjoy in science fiction, truly going faster than light is not that possible.
Actually, there are some hypothetical ways and natural phenomenon which allows FTL. It is possible to travel faster than light, but not faster than speed of 'c'. Let me explain, there is difference between faster than light and faster than 'c'. Even light can't travel faster than this, what if you strapped a torch to the front of a moving rocket or train, wouldn't the light coming faster than the 'c'.
When light travel through material or medium, its effective speed is reduced. Where the effective speed of light is c/n and in some material other particle can travel faster than c/n. Because of this it is possible to break the light barrier in a material while still traveling less than 'c'. One example of this is our sun. In the sun light is produced in it's core through nuclear fusion. Traveling at the speed of light, it should be just a two or three second journey to the surface of sun. But the sun interior core is pack so densely with charged particles that light can't simply travel in a straight line. Imagine photon trying to leave the sun but getting bounced in a random direction every cm. It is scattered in random direction, this random walk of a photon through the Sun actually takes about 20000 to 150000 years to travel from the Sun's core to it's surface. But in case of sound wave, it can travel through Sun faster than light because sound wave propagate in different way, they are pressure waves. As a result they are not hampered by ions in the core. Sound waves can travel through Sun faster than light. This may appear to travel faster than light but this do not convey any object or mass.
Another phenomenon which actually convey mass faster than light is the rate of cosmic expansion. The way our universe is expanding as measured by red shift, the more distant a galaxy is the greater it's apparent red shift and thus the faster is appear to be moving away means that distant galaxies are traveling away from us faster than nearby galaxies. Because of this if you consider two points in space far enough apart they will be moving away from each other faster than the speed of light. A galaxy about 16 billion light years away is moving away from us faster than light, but that galaxy isn't defying relativity, relativity requires that nothing can move through space faster than speed of light 'c'.
Another hypothetical way to go faster than light is 'closing speed'. The rate at which two objects in motion in a single frame of reference get close together is called mutual or closing speed. Imagine two fast moving particles approaching each other close to speed of light, the closing speed would be the rate at which the distance between two particles is decreasing from the point of view of an observer standing at rest relative to reference frame, the rate will be slightly less than twice the speed of light. This may be seems faster than light but in special relativity, it is impossible to accelerate an object to the speed of light. However it might be possible for an particle to exist which move faster than light, the hypothetical elementary particle called tachyon. A tachyon would always move faster than light so it would not be possible to see it. Most physicist think that faster than light particle can not exist because they are not consistent with the known law of physics. Experiments have been conducted to search the evidence for the existence but there is no evidence that this particle exist.

          A possibility predicted by general relativity is the famous traversable wormhole of science fiction which would create shortcut between arbitrarily distant points in space but this have disadvantage that this need negative energy and exotic matter to keep open and as with the alcubierre drive, this also need region of high negative energy, which we don't know how to create. It also have other problem such as that this might destroy everything at it destination when it slows down.
It still far beyond we could do and it is straight forward to create device which allow FTL travel but that's because relativity forbid the transfer of information or object through space at a speed of greater than that of light in vacuum and if any theory which permit's true FTL travel also has to cope with time travel, pretty much interesting, what if one were to go back in time and kill one's own grandfather before one's father conceived?
 In special relativity it is impossible to accelerate an object to the speed of light or for a massive object to move at the speed of light . According to relativity 'c' is the maximum speed all matter and information in the universe can travel, because faster something travel, the more massive it get's, and the more time slows until you reach the speed of light at which time stops altogether and if time stops, well then so does speed and so nothing can travel faster than the speed of light.

Indian Traditions

Indian Traditions

         This post is about our Indian tradition, which follow in our country and the science(pseudo science) behind them.

1. Namaste

                            According to our tradition we greed someone by joining both palms to show respect or honoring them. However scientifically speaking, joining both hands ensures joining the tips of all fingers together, we exerts pressure at the tip of the figures to activate pressure points, which are nerve endings, that directly connected to eyes, ear and mind, helps us to remember that person whom we might not meet for a long time and no germs since we don’t make an physical contact.

2. Throwing coin in the water

                            In ancient times, mostly currency used was made of copper unlike the stainless steel coins today. Copper is a vital metal very useful to the human body, so people used to throw copper coins in drinking well to make sure there were adequate amount of copper in drinking water. Don’t believe in that dumb shit of making wishes by throwing coins.

3. Start with spice and end with sweet

The significance of this eating practice is that eating spicy things activate t he digestive juices and acids and ensure that the digestion process goes on smoothly and efficiently, sweets or carbohydrates pulls down the digestive process.

4. Why do temple have bells

                                              People who visits the temple will ring the bell before entering, where the main idol is placed. The reason behind bells is that the composition of temple bell is such that when you strike it, it create frequency of sound that creates a unity in the left and right parts of our brain. Their rings clear our mind and helps us stay sharp and keep our full concentration on devotional purpose. When we ring the bell, it produces a sharp and enduring sound which last for minimum of 7 seconds in echo mode. This results in emptying our brain from all negative thoughts.

5. Why do we apply mehendi/henna on hand and feet

           Mehendi or henna is known for it’s medicinal purpose. It has a cooling effect that aids in soothing stress, headaches and fevers. It also protect from any viral diseases before wedding.

During a wedding the application of mehendi calms you down from being tense.

6. Fasting

                 This ancient Indian medical system help us to cure many diseases as accumulation of toxic materials in the digestive system. As explained by Ayurveda, the human body is composed of 80%  liquid and 20% solid, like the earth, the gravitational force of the moon affects the fluid contents of the body. It cause emotional balance in the body, making some people tense, irritable and violent. It also lowers the acid content in our body which helps people to retain their sanity.

7. Why married women apply sindoor or vermilion

                            The application of sindoor by married women carries a physiological significance. This is so because sindoor is prepared by mixing turmeric-lime and metal mercury. Due to it’s intrinsic properties, mercury besides controlling blood pressure also activates sexual drive. For the best result, sindoor should be applied right up-to the pituitary gland where all our feelings are concentrated.

8. Why do we go to temple

                                                           In India ancient temples are located strategically at a place where the positive energy is abundantly available from the magnetic and electric wave distribution of north/south pole thrust. The main idol is placed at the core center of the temple, this is place where earth’s magnetic found to be maximum. Scientifically, it is the positive energy that we all require to have a healthy life.

9. Why do Indian women wear bangles

                                                                      Normally the wrist portion is in constant activation on any human. Also the pulse beat in this portion is mostly checked for all sorts of ailments. The bangles used by women are normally in the wrist part of ones hand its constant friction increases the blood circulation level.

10.                  Why you should not sleep with your head towards north

                        Because human body has its own magnetic field and Earth is a giant magnet, when we sleep with head towards north, our body’s magnetic field become completely asymmetrical to the Earth’s magnetic field. That cause problems related to blood pressure and when we sleep in this position, iron from whole body starts to congregate in brain. This can cause headache, cognitive decline, Alzheimer diseases.

                                                        

                                                

The Known Universe

The Known Universe

Universe, what is it, who created it, where do we exist, couple of questions always puzzle my mind. I asked my teachers, friends and read some books, and this is what i knew about universe.

     According to Big Bang theory our universe concentrated into a single point which have infinite density and zero volume. Early time it was so hot and according to Lambda CDA, universe age is 13.7 billion years (that’s so big, very very big). Our general relativity says that at the beginning of the Big Bang, was a singularity, it showed that the universe could have had a singularity, a beginning of time. According to general relativity gravity is always attractive by this fact scientist showed star that collapse under its own gravity is trapped in a region where boundary eventually shrinks to zero size. This mean that all the matter in the star will be compressed into a region of zero volume, so the density of matter and the curvature of space time become infinite. In other words, one has a singularity contained within a region of space time known as Black Hole, but that’s a different topic first you should know what is singularity- it’s a location where the quantities that are used to measure the gravitational field become infinite in a way that does not depend on coordinate system(seems interesting).              

Nobody knows where it came from?, who created it?, why should the universe have begun at the Big Bang? And why was the early universe so hot?

God (creator) caused the Big Bang, he made it happen, perfectly reasonable answer. This seems to help many questions with unsatisfying prospect of an event without a cause. But problem is that from where did the creator of universe come? If the answer is- he always existed then we have situation that is no more satisfying than a universe that come out from Nothing. A Creator that has always existed is an entity that somehow exist without a cause.

                                             Actually we can’t predict anything beyond the time of Big Bang because itself time had a beginning at the Big Bang. Time and space had a finite beginning that corresponds to the origin of matter and energy. If there were events before Big Bang, then they could not affect what happened at the present time. Their existence can be ignored because it would have no observational consequences.

          We can’t predict what would come out of the singularity because predictability would break down at the Big Bang. Event before Big Bang have no consequences according to Stephen Hawking. All the known laws of science would break down at such a point(that were the bad news for some scientist).

In order to predict how the universe should have started off, one needs laws that hold at the beginning of time or space time singularity. So if you are intelligent enough to suggest laws that hold at the singularity then you can answer, from where did the universe come

In other words our universe looks like this

No matter how good our telescopes and technology, we can’t see through that infinitely small hole into The Before.

          Earlier I thought that universe is expanding in  a infinite space. As I studied that matter occupy space, so that was normal to think that( for me ), there is already a infinite space and universe is expanding in it. Actually Big Bang is not a explosion of matter moving outward to fill an empty space. Instead, space itself expand with time everywhere and increasing the physical distance between two co-moving points. According to theory, Big Bang is not a explosion in space but rather an expansion of space.

Before the twentieth century no one had suggested that the universe is expanding or contracting. It was generally accepted that either had existed forever in a unchanging state. In 1992, Edwin Hubble observed that wherever you look, distant stars are moving rapidly away from us. Every single one galaxy is moving away from us and farther the galaxy is, the faster it is moving. In other words universe is expanding. This mean that earlier time objects would have been close together and this proves that there is a singular point in the universe, at a time, the distance between neighboring galaxies must have been zero. The discovery that universe is expanding one of the great revolution of the twentieth century

In particular, it might seem that as we must be at the center of the universe and universe also looks the same in every direction as seen from any other galaxy(roughly on a large scale).

The situation is rather like steadily blowing up a balloon which has a number of spots painted on it, as the balloon expands, the distance between any two spots increases but there is no spot that can be said to be the center of the expansion and also farther apart the spots are, faster they will be moving apart. Similarly speed of which two galaxies are moving apart is proportional to the distance between them.

     According to Friedmann model, that the universe is not infinite in space, but neither does space have any boundary. Gravity is so strong that space is bent round onto itself, making it rather like the surface of the Earth, if one keeps

 travelling in a certain direction on the surface of the Earth, one never comes up against an impassable barrier or falls over the edge.

       It’s like, when one try to reach at the end of the Earth but eventually comes back to where one started. According to Stephen Hawking the idea that one could go right around the universe and end up where one started makes good science fiction, but it doesn't have much practical significance because it can be shown that the universe would re-collapse to zero size before one could get around. You need to travel faster than light in order to end up where you started before the universe came to an end, and that is not possible, our theory doesn't allow it.

We can also determine the present rate of expansion by using Doppler effect, so all we know is that the universe is expanding by 5 per cent and 10 per cent every thousand million years.

     Is it enough to halt the expansion of universe or it will expand forever. First we need to know the present rate of expansion and present average density. If the mass density of the universe is greater than the critical density, it would become denser and hotter again, ending with a state similar to that in which it started- A Big Crunch.

If the density in the universe is equal to or below the critical density, the expansion would slow down but never stop. Stars formation would cease with the consumption of interstellar gas in each galaxy stars would burn out leaving white dwarf, neutrons stars and black holes. The average temperature of the universe would asymptotically approach absolute zero- A Big Freeze

The present evidence therefore, suggests that the universe will probably expand forever( Don’t bank on it ).

Still now less than 5% of all matter and energy is directly detectable, we have to discover a lot so don’t forget to keep looking Up.

 The Universe is yours to Discover.