Jump to content

PaperBoy

Members
 View Profile  See their activity

  • Posts

    35

  • Joined

  • Last visited

 Content Type 

Blog Entries posted by PaperBoy

  1. PaperBoy

    Big, Empty Space

    By PaperBoy,

    Something that baffles scientists today is a strange situation called the Fermi Paradox, named after Italian physicist Enrico Fermi.
    The basic conundrum is that there's an incredibly high probability that alien life forms not only exist in the universe, but nearby Earth. The reason for this statement is the radically large number of solar systems in our galaxy alone. With so many stars in the observable universe, billions are similar to our Sun. The likelihood that many of these stars have Earth-like planets is therefore quite high. Assuming Earth is a typical planet, intelligent life must have developed on many of these planets. Our planet has existed for about 4.5 billion years in a 14 billion year old universe, so there should have been plenty of time for countless organic lifeforms to develop space travel and begin exploring our galaxy, since humans have come thus far in only 200,000 years. Finally, with rough estimates based on current hypothesis for interstellar travel (which may in fact be very slow and inefficient) the Milky Way Galaxy could be traversed in only about a million years, and totally colonized in about two million.
    So, scientists wonder, where are all the aliens? Why, if life in our galaxy has had so many chances to exist, do we have such little evidence of extraterrestrials? Well, there are several different hypotheses.
    One idea concerns filters. This idea states that life has many difficult to pass barriers which make its existence incredibly difficult. We've passed some already, such as the still undiscovered process through which life originates, mutually assured destruction, and extinction events. Perhaps the universe was actually incredibly hostile and dangerous for any life until only recently, making humans some of the first ever. And, there are great filters in our future as well, such as irreversible climate change. Maybe there's some impassible filter we don't know of, and won't for a long time, that no life form has yet to defeat. Plenty of people have already assumed that nuclear bombs and the Large Hadron Collider would destroy the Earth, maybe someday they'll be right.
    There's also the idea that other life forms are preventing this interaction. Maybe some incredibly advanced life form from far away has advanced enough that they can control the entire galaxy, and they don't want other life forms to advance to the point where they pose a threat. Maybe they physically prevent interaction in order to stop the spread of ideas, and prevent any further development. Or, perhaps they act as a filter themselves, and annihilate and race that begins to get too far.
    Or, maybe we're actually just alone. We could be the first life ever to exist, the only, and the last once we eventually kick the bucket. Any way it works out, scientists still don't really have an answer to the Fermi Paradox, and with good reason. This question is a very confusing, scary, and difficult one to answer. So, for now, all we know is that either there's no evidence of life on Earth, or the government took it.
  2. PaperBoy
    My last blog post mentioned the Fermi Paradox, that no evidence for extraterrestrial life exists despite plentiful chances. I talked about one proposed solution being a race of super aliens which control their galaxy. According to Nikolai Kardashev, Russian astrophysicist, this civilization would be classified as a Type III, the final form of existence. In 1964 he invented his Kardashev Scale for measuring a civilization's progress towards perfection. It currently has three different classifications, types one through three. The three types are organized based on how well they control their available energy sources.
    Type I civilizations can utilize and store the readily available energy from their nearby star. Humans are currently approaching a type I civilization, and are about a .724 on the scale. The main reason for this is that humans have only begun to access renewable energy in the past century, and we have yet to efficiently use fusion and antimatter towards energy production. Some suggest humans may reach type I statues in the next few centuries.
    Type II civilizations can harness the total potential energy of their nearby star, and even other solar systems' stars. One of the most popular current theories for reaching type II is the Dyson Sphere. This idea consists of many satellites which orbit a star nearby its surface, forming a shell totally encapsulating the star, which absorb and transmit back to Earth the entire energy output of the star. Its inventor Olaf Stapledon considered this idea a necessary and probable approach to the ever increasing energy demands of an expanding race of beings.
    Type III civilizations can harness the energy of their entire galaxy. To our current age, any type III aliens would seem like gods, or at least like Galactus. Type III species would use mainly the same processes as type II's, but on a much wider scale. And, theoretically, they would also be able to access the power of the supermassive black holes thought to exist at the center of all galaxies, as well as gamma ray bursts, quasars, and white holes.
    Since his initial proposal, other scientists have added on to Kardashev's idea, even adding types IV and V. Others have creates subtypes based on how well the aliens can use the power, or what they can accomplish genetically. As for, type IV's, they can harness their entire universe's energy, and even the mysterious dark energy. Type V's can even harness the power of multiple universes, stretching into the multiverse. It seems the sky's the limit for this idea, and personally I don't mind it either. What if there is some super-race of aliens out there somewhere, bending the laws of space time? I think it'd be pretty sweet. Maybe I'll invent my own types. Type VI: the aliens can control the multiverse even after the universes die out or Big Crunch to death. Type VII: the aliens are the corporate bosses of other type VI's. I could go on!
  3. PaperBoy

    Inductance

    By PaperBoy,

    Along with capacitors, inductors still make up a very important part of modern day circuitry. Often, the two are used in conjunction to great effect.
    Inductors usually consist of an electric current passing through a coil of wire. The coil may be in a circular or straight shape itself. The purpose of an inductor is to store voltage via a magnetic field in the coil, according to Faraday's Law of electromagnetic induction.
    Nowadays, inductors are often used to remove the mains hum of an AC current. This hum can vibrate the circuit, obstructing power lines, and can usually be easily heard, so the inductor coupled with a capacitor reduces the hum. Similarly, they can be used to reduce electromagnetic interference. EMI is the interference outside sources of electromagnetic power exert on a circuit, and can ruin a good circuit rather easily. Inductors help to negate this interference so that the electricity can pass normally and the circuit will function Inductors can also convert AC current to DC.
    Sadly, inductors are now being phased out due to their various side effects over extended use. However, one can't deny their important contribution to modern circuitry!
  4. PaperBoy
    We all know that insulators carry charges much better than conductors. This is because conductors have much freer electrons than insulators, allowing electrical currents to form.
    However, these two types of materials aren’t exclusive. In fact, one can rather easily turn an insulator into a conductor. This process is known as dielectric breakdown, and concerns a variable known as the dielectric strength of a material.
    The dielectric strength of a material is the constant maximum electric field that a pure form of that material can withstand before it breaks down. When a material breaks down, it now becomes a conductor. In today’s circuitry, engineers have to be careful they don’t exceed the dielectric strength of the insulators they are using, or else the circuit may be in serious danger of overheating or simply functioning incorrectly.
    Dielectric strength can also be altered. The factors which affect the strength are the thickness of the material sample, the temperature of the material, the humidity (for gases), and the frequency. For insulators, one can imagine, this strength is very high. However, it can be exceeded. Air has a strength of 3.0 MV/m, or 3,000,000 V/m. When an object’s strength is exceeded, it can often be seen with electrical sparks trailing off of it.
    Below I’ve included an example of power lines exceeding air’s dielectric strength. Very visible electricity can be seen arcing through the air. That’s definitely something you don’t want to mess with!
     
     
  5. PaperBoy
    Lots of people have heard the word “superconductor.” But, not too many people really know what they are or how they’re made.
    A superconductor is an occurrence of exactly 0 internal resistance to electrical charges and the removal of interior magnetic fields, known as the Meissner Effect. During this change, all magnetic flux within the material is transferred to the outside, greatly multiplying the outside field. Super conductance was discovered in 1911 by Dutch physicist Heike Kamerlingh Onnes. And, it’s actually a phenomenon of quantum mechanics.
    Superconductors are made when a material is cooled to below that material’s critical temperature. And, they can break down once the magnetic field around them grows too great as well. There are currently two classes of superconductor based on how they break down. Type I superconductors abruptly stop conducting in this way if the field breaches a certain threshold value. Type II superconductors begin to accept magnetic flux back into the material above the threshold point, but retain their 0 resistivity. It is because of these quirky effects that superconductors cannot simply be seen as perfect, or ideal, conductors, but rather entirely separate phenomena.
    Scientists still study superconductors and their applications in depth today. In 1986 ceramic materials were shown to have very high critical temperatures, ones that were theoretically impossible, and were dubbed high-temperature superconductors.
    Nowadays superconductors are used in particle accelerators and mass spectrometers due to their incredible power as electromagnets. However, they have all kinds of fascinating circuitry and quantum mechanics applications. Feel free to investigate yourself, but for now, enjoy a video of a superconductor floating above a magnet, known as quantum levitation.
     
     
     

Terms of Use

The pages of APlusPhysics.com, Physics in Action podcasts, and other online media at this site are made available as a service to physics students, instructors, and others. Their use is encouraged and is free of charge. Teachers who wish to use materials either in a classroom demonstration format or as part of an interactive activity/lesson are granted permission (and encouraged) to do so. Linking to information on this site is allowed and encouraged, but content from APlusPhysics may not be made available elsewhere on the Internet without the author's written permission.

Copyright Notice

APlusPhysics.com, Silly Beagle Productions and Physics In Action materials are copyright protected and the author restricts their use to online usage through a live internet connection. Any downloading of files to other storage devices (hard drives, web servers, school servers, CDs, etc.) with the exception of Physics In Action podcast episodes is prohibited. The use of images, text and animations in other projects (including non-profit endeavors) is also prohibited. Requests for permission to use such material on other projects may be submitted in writing to info@aplusphysics.com. Licensing of the content of APlusPhysics.com for other uses may be considered in the future.

APlusPhysics Books

APlusPhysics Books

×
×
  • Create New...