How Big is the Universe?

Space is too huge that humans find it difficult to sense it’s humongous size. The units to measure earthly distances wont quite works for cosmic distances. Distance within Solar System is often measured in Astronomical Unit (AU). It is the distance between Sun and Earth. Even AU becomes less helpful when the distances get much larger. In that case, the unit Light Year, comes to the rescue. (Parsecs are also used. 1 Parsec is 3.26 Light years) Light Year is the distance, light travels in a year. Remember, light travels 299,792,458 metres in a second. These are mind boggling distances, completely foreign to our day-to-day experiences, making it hard to grasp the size of this vast Universe. The easy way to tackle this is to make an analogy for the large distances with smaller ones that we can easily relate. Here’s a trick,

1 light year = 5.879 x 10¹² miles

1 AU = 9.296 x 10⁷ miles

5.879 x 10¹² miles / 9.296 x 10⁷ miles = 63242.25

That implies, 1 light year equals around 63242 AU.

And 1 Mile comprises, 63360 inches.

Thus we can take inch - Mile analogy for AU - lightyear relation.

With this relation, you can get a better grasp on the distances of the vast Celestial objects. Now lets consider, Sun and Earth are 1 inch apart, then a light year would be exactly 1 mile. Then Jupiter would lie 5.2 inches away and Pluto around 40 inches away. In this analogy, the nearest star, Proxima Centauri is roughly 4.2 miles away. The star Vega would be 26 miles away, Orion Nebula 1340 miles away, and the globular cluster M15 some 25,000 miles distant (about three times the diameter of the Earth).

On this massively compressed scale, the diameter of the Milky Way Galaxy itself would be about 100,000 miles. And to prove human’s miserable sense of scale, the radius of the observable universe would be 46.6 billion miles. Still finds it hard to imagine huh?

Puny humans!!

Credits : Wikimedia commons / Dave Jarvis

Star Gazing for Beginners - Part III

Eyes on the Sky

If you haven't gone through the first and second parts, please have a look on it, Star Gazing for Beginners - Part I, Star Gazing for Beginners - Part II

Transcript:

Hi I’m David Fuller from the “Eyes on the Sky” video series. In this last Stargazing Basics video, we’ll learn how to easily measure distance in the sky, so you can find constellations or objects more easily either naked eye, with binoculars or telescopes. In our first video, we learned that a line called the meridian splits the sky into equal halves, from north to south. If we were to place a giant protractor in place of that line, it would appear as if the sky was 180 degrees from horizon to horizon. Although space is actually infinite, our eyes make the night sky appear like a “half sphere,” so for all practical purposes, it’s easier to think of the sphere. And though a sphere should technically be measure in radians, degrees is a concept people understand more readily and works for our purposes. So horizon to horizon is 180 degrees – that’s easy enough. And if we measured another large distance, from horizon to zenith, that would produce a right angle, or 90 degrees. Still pretty simple, right? But to measure smaller angles than that, we need a measuring tool. A ruler doesn’t work, because that would be for linear measurement, and holding a protractor to our eyes is a bit impractical. So what to do? Easy: Use your hands!

Check this out: Hold out your hand at arm’s length. Now spread your thumb and pinky as far away from each other as possible. If you look across your thumb and pinky, that distance is approximately 25 degrees. Don’t worry – this works for almost everyone. Don’t believe me? Look for the Big Dipper in the night sky. See the last two stars in the “Bowl” of the dipper? Draw a line through them, from the “bottom” of the bowl towards the top. Now hold your hand at that top star, along that line. The other side of your outstretched hand should be near Polaris, the north star, because that distance is NEARLY 25 DEGREES. But sometimes we need to measure smaller distances than 25 degrees. This time, hold up your forefinger and pinky, and stretch them out. The distance across them is about 15 degrees. This is about the distance from Orion’s belt to the star Aldebaran – this way – or the star Sirius, going this way. You can find these stars in the winter sky.

Img Credits : squarespace.com

For another smaller tool, hold up your fist. Across the top of your fist from side to side is about 10 degrees of sky. We can ‘calibrate” that by looking at FIND A GOOD CIRCUMPOLAR CALIBRATION. Two split that in half, now hold up these three fingers – this approximates 5 degrees of sky. Those two stars at the end of the Big Dipper are about 5 degrees from each other. Hold up your hand and see if your fingers match that. And lastly, the one degree tool. Simply hold up your pinky! This one amazes many people, because the actual angular distance across the Full Moon is only half of a degree. So holding your pinky at arm’s length, you can cover the WHOLE Moon! Of course, mixing and matching these can help you find even more – two hands like this can measure halfway across the 90 degrees of horizon to zenith, approximating 45 or 50 degrees or so. Use other combinations to create 30, 35 or 40 degrees, just by using two hands. 

But how will you know how far an angle is in the sky from a star chart? The declination lines will tell you degrees, but only in that direction. Try downloading the “Skymaps” all sky star charts each month. These charts are about 180 millimeters across. Though not terribly useful at the edges, as the sky diagrams are “stretched” there, you can use a simple ruler with millimeters on it to measure approximate angular distances in the sky, helping you “hop” from bright stars or well known constellations, to dimmer ones. Give it a try – it’s really easy, and works for just about everyone. Thanks for watching; I’m David Fuller. Keep your eyes on the sky and your outdoor lights aimed down by using dark sky friendly lighting fixtures, so we can all see, what’s up. 

What's inside an Atom?

In the early 1900’s, the atom was considered the ultimate, indestructible unit of matter. They believed, atoms of the then known elements, such as oxygen, nitrogen, hydrogen and others, could not be broken down into anything simpler. But later, certain experiments like ionic dissociation and the cathode ray tube, indicated the existence of subatomic particles. These and other experiments lead to the knowledge of the proton, electron and neutron as the basic subatomic particles.

Proton: charge = +1, mass = 1.67 x 10^-24 kg

Electron: charge = -1, mass = 9.11 x 10^-27 kg

Neutron: charge = 0, mass = 1.67 x 10^-24 kg

Physicists thus have discovered that atoms are not solid and that electrons rotate around the nucleus and complex orbits. But the understanding of atoms stopped with the electrons, protons and neutrons? The answer is No. 

Modern physics examines particles at the sub-atomic level. Some of the smallest particles are called Quarks. Quark Theory has been around since the mid-nineteen sixties. But a Quark has never been isolated. No one has ever seen a Quark. So you might ask how do scientists know they exist? The answer comes from data collected at high-energy particle accelerators.  Particles are accelerated to nearly the speed of light around the long distant underground tract and smashed together. By studying the patterns made by the new particles that are created in the collisions, scientists are able to determine the properties of the particles and their interactions. The tests have been repeated and the results have been duplicated with enough experiments to convince us that quirks are real and just as fundamental today, as the familiar electron, proton and neutron, were once thought to be. Quarks come in three paired types, that physicists call flavours. They are,

Up and Down

Charm and Strange 

Top and Bottom

Up and down were named based on components of their spin. Strange quarks were given the name, strange because they were observed in particle decays that had slightly longer lifetimes than they should have done. The charm quark was given the name because of it's fascination. The way that it fascinated the physicists at the time. Bottom and Top quarks were chosen by a famous physicist named Haim Harari. He chose the names because they were the logical counterparts of the up and down quark. 

These Quarks are bind together with the help of Gluons. Gluons are hypothetical massless subatomic particle, believed to transmit the force binding the quarks together in a hadron. Gluons mediate the strong force. They have no mass and no electric charge.

Star Gazing for Beginners - Part II

Eyes on the Sky

If you haven't gone through the first part, please have a look on it, Star Gazing for Beginners - Part I

Transcript:

Hi I’m David Fuller from the “Eyes on the Sky” video series. Let’s look at another aspects of Stargazing Basics, this time, magnitudes of various objects. Magnitude is just a fancy way to describe the difference in brightness of objects we see in the night sky. And it’s not too hard to learn how it works, but let’s start with some history. The Greek astronomer Hipparchus developed the magnitude scale back in the 2-nd century BC, when he assigned the brightest stars a magnitude of “one” and the dimmest stars that of “six,” the in-between stars of 2, 3 , 4 and 5 magnitude assigned according to brightness. He assumed that the difference in brightness of stars was 2.512 times brighter than the next dimmest one. Taken across that full 6 magnitude scale, this meant that the brightest stars – the first magnitude ones - were 100 times brighter than the dimmest, 6-th magnitude ones. It also allows for a fairly easy way to determine other brightness differences: The difference from first to third magnitude is 6.3 times; first to fourth, 15.8, first to fifth , about 40 times.

This worked just fine until Galileo turned a telescope towards the heavens, and humans discovered there were a LOT more stars out there than just the first through sixth magnitude ones they could see naked eye. But what they did was just extrapolate the scale further. So much like golf or ERA in baseball, the lower the number, the brighter the star, and the higher the number, the dimmer the star. 11-th magnitude is 100 times dimmer than 6-th magnitude, and that 11-th magnitude star would also be 10,000 times dimmer than a first magnitude star. In the other direction, we have some objects that are brighter than first magnitude stars. Hipparchus actually fudged the numbers a bit; the star Sirius in the winter sky is definitely brighter than most other bright stars, and it shines at magnitude negative one point four. The planet Jupiter is brighter than that, often appearing at around magnitude negative 2, and Venus brighter still, typically around negative four. When objects are bright, they are denoted on star charts with larger dots; dimmer stars are usually given smaller dots. This helps us locate brighter objects in the sky more easily. But beyond the stars’ magnitudes is that of the Moon and Sun. 

The full Moon in the night sky shines at magnitude negative 12.7, and the Sun at magnitude negative 26.7! Those are both bright compared to starlight, but also a huge difference, even between themselves, as the Sun is 400,000 times brighter than the full Moon! Now everything we have discussed has been “visual magnitude,” meaning how bright or dim objects appear to our location on Earth. Another concept is “absolute magnitude,” used by astronomers to compare the relative brightness of objects when placed the same distance. But that is more complex than what we need to know for simple stargazing purposes. However, for visual magnitude, it helps to understand how it relates to other objects besides stars. Stars are point-like objects in the sky, so it is easy to assess their magnitude and brightness. But galaxies, star clusters and nebula are not quite as easy. So we look at their “integrated magnitude.” That’s a way of saying that the same magnitude is now spread out over a larger area. For small objects, that can mean it is something that will look brighter to us in telescopes. If the area if very large though – such as the galaxy M33 or the nebula M1, those objects may look very dim, relatively speaking. If possible, try to look for the surface brightness of an object; objects above a surface brightness of 11 or 12 can be very difficult to find from light polluted areas. 

That’s a quick overview of the magnitude scale, and how to understand it. Just remember the Sun and Moon have negative magnitudes and are the brightest visual magnitude objects, and lower numbers are dimmer stars and objects, and you’ll be in good shape! Thanks for watching; I’m David Fuller. Keep your eyes on the sky and your outdoor lights aimed down by using dark sky friendly lighting fixtures, so we can all see, what’s up. 

Star Gazing for Beginners - Part III

Everything you need to know about the newly discovered Elements

Img Credits : wired.co.uk

The International Union of Pure and Applied Chemistry (IUPAC) announced that four new elements will be joining the other 114 on the periodic table of elements. The addition of elements 113, 115, 117 and 118 means, the seventh row or period is now complete! They still don’t have proper names yet, they’re just called by their numbers. So where did these as yet unnamed elements come from? Scientists from Lawrence Livermore National laboratory in California and the Riken institute in Japan, smashed atoms together in particle accelerators and these new elements were created when the two nuclei fused. But the new elements existed only for a fraction of a second. Then they decayed into isotopes of other elements.

Element 113, the one created in Japan, exists for less than a thousandth of a second before it decays into other isotopes, so it’s unlikely you’ll run into this element anytime soon. So alright, sweet new elements. While cool, it probably won’t mean much for your daily life, yet. Unless you have to memorise the entire table in chemistry class, sorry 10th graders. But for science, it could be huge. Scientists have been searching for the elusive “Island of Stability," which according to a theory by Nobel laureate Glenn Seaborg is a stable element with just the right number of protons and neutrons. And these new elements might be getting scientists closer to the island of stability.

Img Credits : iflscience.com

You see, most heavy elements, ones with more than 113 protons like these new ones, only exist for a short amount of time. That’s because the force of the positive charges of their protons is too strong and the nucleus is pushed and pulled apart in a fraction of a second. But just like atoms become stable when their outer electron shells are full, some researchers, like Seaborg, believe that if a nuclei has a certain number of proteins arranged in just the right way, the element would be stable, it could last. If we can create this theoretical stable element it could be used to build things we haven’t even imagined yet! Even the effort of doing so, teaches scientists "a tremendous amount of just basic nuclear physics." According to Seaborg, the magic number to hit is 114 protons and 184 neutrons. 

And after  years of trying, Seaborg’s mentee Ken Moody finally hit the sweet spot by slamming together plutonium and calcium which briefly created a new element. Unfortunately, while the element, now called flerovium, or Fl has 114 protons it doesn’t have the needed 184 neutrons, and so it fell apart too quickly. Element 117, has been heralded as a possible “shore to the island of stability”. Five years ago, A U.S.–Russian team first created it at the Joint Institute for Nuclear Research in Dubna, Russia. Described in a journal Physical Review Letters, this new element has a half-life of about 50-thousandths of a second. Which means in that short of a time, half the element will decay into other isotopes like lawrencium-266, which had 103 protons and 163 neutrons, a combination never seen before. This lawrencium-266 even lasted a long time for an isotope, with a half life of 11 hours. Because of this, one of the lead authors said “Perhaps we are at the shore of the island of stability.” 

So, maybe, science is one step closer to creating a new element which we could use in ways we haven’t even dreamed of. And though we’re not there yet… we’re getting closer. It’s clear more research is needed. There’s no theoretical limit to how big elements can get! One day scientists might just start filling out the elusive 8th row! So don’t change your shower curtain just yet.

Credits : DNews

Know the Constellation - Orion

Orion, often referred to as The Hunter, is a prominent constellation located on the celestial equator and visible throughout the world. Orion got its name from Greek Mythology. The story says, Orion was a giant hunter whom Zeus Placed among the stars as the Orion Constellation.

The brightest stars in Orion are Rigel and Betelgeuse. 

Located in the constellation Orion, Rigel is a Pulsating Variable Star. It is the brightest object in Orion,Rigel is approximately 863 light-years from earth. The sky location for Rigel is : RA 05h 14m 32s, Dec -09°47' 54"

Know the basics of sky gazing, Sky Gazing for Beginners - Part I

Betelgeuse is a Semi-regular Pulsating Star with distinctly reddish-tint. It is the second brightest star in Orion. It is also known by Betelgeuse's Bayer designation Alpha Orionis and is the ninth brightest star in the night sky. It is approximately 498 light-years from earth. Betelgeuse marks the upper right vertex of the Winter Triangle and center of the Winter Hexagon. Betelgeuse is expected to explode as a type II supernova. The sky location for Betelgeuse is : RA 05h 55m 10s, Dec +07°24' 26"

Credits : astrobob.areavoices.com

You can locate Sirius, the brightest star in the night sky, by using the belt of Orion. The belt points South East directly toward Sirius. Sirius is in the constellation of Canis Major and it is the fifth-nearest known star with a distance of just 8.7 light-years from earth.

What is Evolution?

Stated Clearly

Transcript

What is Evolution?

In Biology, the theory of Evolution doesn’t tell us exactly how life began on earth, but it helps us understand how life, once it came into existence, diversified into the many incredible forms we see now and in the fossil record. It also helps us make sense of the way in which modern creatures continue to adapt and change today. In biology, evolution can be defined as any change in the heritable traits (those are physical traits like fur color in mice, spots on the wings of butterflies, or instinctive traits like the way in which dogs greet their friends with a sniff) within a population, across generations . This definition can be a bit confusing so let’s see how it works.

All healthy living things, from single celled amoebas, to flowers, to dolphins: are capable of reproduction. We have children, we make copies of ourselves. We do this by duplicating our DNA and passing that DNA on to future generations. DNA is a chain like chemical stored inside each one of your cells, which tells them how to grow and function. Your DNA contains coded information on how to build you. The information in your DNA is different than that of, say, a daffodil’s DNA which is why you look and function differently than a daffodil. The information in your DNA is slightly different than that of Elvis Presley, which is one of many reasons you don’t look or act quite like he did.

Single celled amoebas (and other simple creatures) reproduce by copying their DNA inside their guts, moving both copies to either side of their body, splitting in two right down the middle, and then growing back to full size. If all goes well, the two new amoebas will be exact copies of each other, but in nature, things aren’t always perfect. When DNA is being copied, errors can occur which modify the DNA code. This is what we call a DNA mutation. These mutations (which happen completely on accident and randomly to any part of a DNA strand) can produce variation in the body shape and function of the creature who inherits the modified DNA.

In this case, our new little friend has an arm that stretches extra long. If he survives to grow and reproduce, that extra stretchy arm (which is now coded for in his DNA) will be passed on to his children. Evolution, any change in the heritable traits within a population, across generations, has officially occurred. As you know, reproduction for Dolphins and badgers and people, is a little more complicated. We have to find ourselves a partner. When two badgers get together and... ya know, fall in love, a sperm cell from the father (which contains a copy of half of his DNA - ONLY half), combines with the egg cell of the Mother (which contains half a copy of her DNA). The result is a new cell with a complete set of DNA instructions, all the information needed to divide and grow up into a brand new badger.

The new child matures to be similar to her parents but also unique because she developed some traits from her mother’s DNA and some from her father. Her new combination of traits can be passed to her children and again, evolution, any change in the heritable traits, within a population, across generations, has officially occurred.

Besides the unique recombination of her parents traits, she might also have developed some completely new traits due to DNA mutations. Maybe extra hairy ears for example. If she survives long enough to have kids of her own, her DNA will combine with the DNA of her partner, and she’ll pass on those extra hairy ears to at least some of her children. This of course, is also evolution. So there you have it, evolution is really pretty simple. Scientists and normal folks everywhere, witness evolution happening all around them  

Small changes like the ones we’ve seen here can add up over multiple generations to create dramatic changes.

If you were to go back in time just a few thousand years, you’d find that all dogs for example, originally evolved from an ancestral group of gray wolves. The evolution of those wolves, from generation to generation, was guided by humans. People were selecting wolves with traits they liked, letting them breed, and then only keeping the puppies with the most desirable traits. As time went on, different breeders preferred dogs with different features, some selected for large size, some for small size, some for brains, others for braun. Today, wolves have branched out into hundreds of dog breeds, very few of which look and behave much like their ancestors.

A massive amount of observable evidence from many of different fields such as Genetics, Chemistry, Paleontology and Mathematics, overwhelmingly suggest that just like all dogs share a common ancestor, all living things; me; you; puffer fish; banana trees; if you go back far enough, also share a common ancestor. We are literally related.

We don’t know what the first life form was or exactly how it came to be, but the simple process of reproduction with variation over billions of years looks to be responsible for all the diversity in of life we see today. Now you might be saying: “Wait a minute! Hold on here. Isn’t evolution random? To do something functional like turn a wolf into an adorable mini poodle, random evolution had to be guided by a dog breeder. Researchers say all mammals evolved from an ancient shrew like creature but the difference between a shrew and an elephant is far greater than that of a wolf and a poodle. Who guided that process? Who was the breeder?”

In the mid 1800s two men, Charles Darwin and Alfred Russel Wallace independently discovered, that a breeder is not necessarily needed. There is another force capable of guiding random evolution to produce order and complex function. They called it Natural Selection which happens to be the entire topic of our next video, but before you move on let’s recap what we have learned so far.

Biological evolution is any change in the heritable traits within a population across generations. All healthy living things can make copies of themselves, but they do so imperfectly. Small variations can add up over time to create dramatic differences in body form and function. Evidence overwhelmingly suggests that all living things are related.

So remember, next time you invite family and friends over for a holiday feast, you’re actually just inviting family. That includes the turkey and the pumpkin in the pumpkin pie.