Selasa, 22 Desember 2015

Importance of Physics: Fundamental Science in Our Everyday Lives



Importance of Physics: Fundamental Science in Our Everyday Lives
Unless you’re a trained physicist or an engineering program graduate, chances are you don’t realize how much this important science impacts our everyday life. Even reading this article wouldn’t be possible without the physics-based ideas that played a huge role in the creation of computers and the internet. Every time you get in your car, you’re taking advantage of yet another benefit of what is often considered the most fundamental of all science fields.

We’re going to go in-depth on these subjects and more to help you understand just how amazing and interesting physics truly is. Really understanding a science like physics will require some math skills in the long run, so make sure to brush up on your algebra with this course if it’s something you’d like to continue learning about.

Maintaining Our Health
Ever gotten your blood pressure checked at the doctor’s office or local pharmacy? Chances are you have. Blood pressure is one of the most basic measures of good health and when it’s high, it serves as a warning for some pretty serious medical problems. But did you realize that physics is what made that test possible? There’s even a distinct branch of the science that deals specifically with medicine, known as medical physics.
Broken bones are found with x-rays, which are also a product of physics. If you’re ever seen or gotten an ultrasound that shows a developing child in the womb, you were actually watching physics in action. Ultrasounds are crucial for getting an idea of a newborn baby’s health and diagnosing any complications before birth.
One of physics’s other creations, the defibrillator, can literally be the difference between life and death for a patient suffering from cardiac arrest. The science is very important in anything radiation related, including radiation therapy, one of the more viable cancer treatments available. And physics also deals heavily with lasers, which includes things like laser eye surgery. And these are just a handful of the tons of incredibly important developments physics has contributed to medicine.

Providing Energy
Physics is absolutely huge when it comes to any and everything that we use for energy. Oil for fuel is extracted and processed largely through physics-based ideas. It’s key for mining coal and using it power massive factories.
It’s also essential in the research and implementation of cleaner and more environmentally friendly energy sources. Everything from nuclear power plants to solar powered cars require physics. Even windmills.
Not to mention the electricity in homes that is considered a basic necessity in our current day and age. Physics is largely responsible for the systems that allow it to be harnessed, controlled, and used to power everything from your laptop to the little light in your refrigerator.

Helping Us Communicate
Did you know that physicists are largely credited with the creation of the internet? So not only would your laptop not have power without physics, you wouldn’t be able to access this article, Udemy, e-mail, or any of the other sites you browse daily – and neither could anyone else. Imagine how much different life would be without the ability to communicate information across the world within seconds.
I supposed we’d have to go back to phones. Unfortunately, your smartphone would not be possible without physics. And actually, neither would your basic land line – not even the old rotary dial in your grandma’s dining room.
From electromagnetism to quantum optics, physics is simply indispensable to nearly every aspect of the way we currently communicate. Without it, we’d probably still be stuck with horse messengers delivering our mail and news.

Transporting People and Goods
We already talked about physics’s importance in mining and using fuel, which powers our planes, trains, and automobiles. Without it, they simply wouldn’t move. But the role of physics in both our personal transportation and shipping goes even deeper than that.
It’s our understanding of the science that allows us to build planes that can fly in the first place. This is something that people figured was impossible until not so long ago in history because of the many factors and forces that come into play when trying to master flight. Today, we sometimes forget what an amazing accomplishment it is that there are thousands of huge hunks of metal carrying people through the sky and around the globe every day.
Not only does it make all our different vehicles possible, we’re continually improving how fast, efficient, and safe they are. Engineers in all fields rely largely upon physics when creating the contours of a sports car or designing a bullet train. And don’t even get us started on the complicated but fascinating field of space travel.

Developing Consumer Electronics
Remember when we talked about how physics gave us the power and internet to use our computers? We’re just getting started. Many of the main components of desktops and laptops needed an understanding of physics to be created. This includes the screen, the processor, and the hard drive or solid state drive – the things that make a computer a computer, basically. If you find yourself a little confused about what these parts actually do in the first place, this course on building your own computer will help fill you in on what they are and how they work.
Now, if this is true for your laptop, you can also assume that the screen on your TV was created with the same technology. And the processor in your smart phone. And the memory in your tablet.
If you were paying attention, you’ll also recall our comments about lasers and how they relate to physics. In electronics, that means CDs, DVDs, and BluRay players, which use lasers to read the media from the disc they’re written on. Lasers are also used to print, copy, and fax documents, among other things.

Constructing Buildings
How does physics apply to building design and architecture? Let’s see. First of all, it helps determine the entire basic structure of a building. The best ways to support weight and keep everything stable and standing.
It helps us understand which materials are most affected by heat, light, and water. By studying how vibrations affect different structures, we’re able to design buildings that can withstand natural disasters like earthquakes and hurricanes. Imagine a city full of skyscrapers collapsing from a minor earthquake – then take a second to thank physics that they don’t.
The science is largely responsible for our ability to push the limits and create the magnificent structures we see all around us today while keeping them safe to live and work in.

Stimulating the Economy
As you can probably already from all of the things we just told you, physics helps create a lot of jobs for a lot of people. Engineers, electricians, pilots, physicists, and the like land jobs directly based on the science. Just check out this blog post on all the different types of engineers. And that doesn’t even include all the careers made easier by physics, like doctors.
Beyond job creation, physics helps the economy grow in so many other ways. Oil is obviously a very big and valuable commodity around the world, not only as an export but to help fuel our own industries and keep costs low. Energy from coal and nuclear plants is also critical in providing power for the many other sectors that make up our economy.
Speaking of exports, you can’t trade without transportation. And as we’ve covered, we wouldn’t have the same fast and efficient options for getting from point A to B without physics.
How effective would today’s businesses be without cell phones, conference calls, and e-mail? Plus, consider how much the internet has shaped our economy. Some of our biggest companies are based entirely online and nearly every business relies on it for a good chunk of their marketing and sales. Many of the most famous entrepreneurs and businessmen of our time – Bill Gates, Steve Jobs, Mark Zuckerburg – might not even exist without the technology made possible by physics.
For a better understanding on how these things fit into the bigger picture of the economy, check out this course on economics.

Physics is Amazing
I think by now you probably get the picture on just how crazy important physics is for the things we use everyday. From the house you live in to your fancy smartphone or a jumbo jet, the influences of physics can be seen literally everywhere you look. And there’s still plenty of things we missed – like cooking! Our life would certainly be a lot harder and less comfortable without all the great things we’ve gotten from its study.
If you’re interested in learning more about physics by traveling even deeper down the rabbit hole into quantum physics, this course will serve as an excellent introduction into some of it’s more basic concepts.

Kamis, 10 Desember 2015

KISI DIFRAKSI

Aplikasi Kisi Difraksi

Salah satu fitur keamanan kartu kredit, surat izin mengemudi, dan lainnya adalah hologram yang berubah ketika gambarnya ketika kartu dimiringkan. Hologram dibuat dengan membuat sinar laser berpencar dari satu objek menjadi emulsi. Sekali hologramnya terbentuk, bayangan objeknya dapat diciptakan dengan menerangi hologramnya dengan cahaya laser yang sejenis. Bayangan yang terbentuk akan sangat menarik karena memiliki kedalaman sehingga dapat dilihat dengan berbagai perspektif atau sudut pandang atas hologramnya.
Gambar 3: Fitur keamanan kartu kredit berupa hologram
 
Hologram dianggap sebagai penangkal pemalsuan yang ideal untuk kartu kredit dan jenis kartu pribadi lainnya. Tetapi hologram ini memiliki beberapa kelemahan  yaitu bayangan holografik dapat menjadi jelas jika dilihat dalam cahaya laser, yang koheren dan datang dari satu arah saja. Tetapi bayangannya kabur apabila dilihat dengan cahaya yang biasanya pada pertokoan. Cahaya yang terbaur merupakan cahaya yang tidak koheren dan datang dari segala arah. 2 hologram mudah dipalsukan karena hologram merupakan foto objek yang sesungguhnya. Pemalsu cukup membuat model objeknya dan menempelkan hologram pada kartu kredit palsu
Umumnya kartu kredit berisi grafik variable optics ( optically variable graphic – OVG) yang menghasilkan bayangan melalui difraksi cahaya terbaur oleh kisi yang ditanamkan dalam alatnya. Kisi ini mengirimkan ratusan bahkan ribuan orde yang berbeda. Seseorang yang membuat kartu tersebut akan menangkap sebagian orde dan cahaya yang bergabung menciptakan bayangan maya seperti pada logo kartu kredit.

 

Gambar 4: (a) Kisi titik a di permukaan perangkat OVG mengirimkan cahaya kepada pemirsa di orientasi A, menciptaka citra virtual tertentu. (b) Kisi pada titik b mengirimkan cahaya kepada pemirsa di orietasi B, menciptakan virtual yang berbeda.
Sumber: Halliday, Resnick
            Pada gambar 1 terlihat kisi pada titik a menghasilkan bayangan titik tertentu ketika si pengamat berada pada orientasi A, pada gambar b kisi pada titik b menghasikan bayangan yang berbeda ketika si pengamat berada pada orientasi B. Gambar ini terang dan jelas karena kisinya telah dirancang untuk dilihat dalam cahaya yang terbaur.
OVG sangat sulit dirancang karena ahli teknis optic harus bekerja dalam arah terbalik dari grafik. Ahli teknik harus menentukan sifat kisi pada OVG jika gambar tertentu harus dilihat dari sejumlah sudut pandang yang berbeda. Pekerjaan yang demikian butuh pemrogaman canggih pada computer. Sekali dirancang, struktur OVG sangat rumit sehingga juga sulit untuk dipalsukan.

Rabu, 09 Desember 2015

Listrik Statis



LISTRIK STATIS
Listrik statis secara sederhana muatan listriknya tidak mengalir. Muatan listrik adalah karakter intrinsik dari dasar-dasar partikel yang menyusun benda. Artinya muatan listrik merupakan properti yang secara otomatis hadir bersama partikel-partikel tersebut dimanapun partikel tersebut berada. Muatan listrik itu sendiri terdiri atas muatan proton (positif) dan muatan electron (negative). Muatan dalam jumlah besar terdapat pada peralatan rumah tangga yang biasanya tidak tampak karena muatan positif dan negatifnya sama besar. Keseimbangan tersebut dapat dikatakan netral.
Terlihat pada gambar sehingga dapat diketahui secara umum yaitu
1.      Benda terdiri atas atom-atom sejenis
2.      Setiap atom terdiri atas sebuah inti yang dikelilingi oleh satu atau  lebih electron.
3.      Inti atom bermuatan positif, electron bermuatan negatif
4.      Inti atom terdiri atas proton yang bermuatan positif dan neutron yang tidak memiliki muatan.
Sudah dijelaskan seperti di atas benda atau materi pada umumnya mempunyai jumlah proton yang sama dengan elektronnya sehingga dapat dikatakan benda tersebut keadaan netral. Jika keseimbangan antara jumlah proton dan jumlah elektron terusik yaitu adanya pengurangan ataupenambahan muatan elektron, maka benda tersebut dikatakan bermuatan listrik. Bendaakan bermuatan listrik positif bila kekurangan elektron dan benda bermuatan negatif apabila kelebihan elektron.
Partikel-partikel penyusun suatu atom:
Elektron → bermuatan negatif
Proton→ bermuatan positif
Neutron→ tidak bermuatan
Inti atom terdiri dari proton dan neutron, sementara elektron bergerak mengelilingi inti atom dalam lintasan tertentu.

1.      Benda Bermuatan Listrik
Listrik statis merupakan listrik yang dihasilkan jika benda digosokkan antara benda satu dengan lainnya.

Bahan-bahan
Hasil
Proses
Kaca - Kain Sutera
Kaca (+), Sutera (−)
Elektron dari kaca berpindah ke kain sutera
Mistar plastik - Kain wool
Mistar plastik (−), Kain wool (+)
Elektron dari kain wool berpindah ke mistar plastik
Sisir - Rambut Manusia
Sisir (−), Rambut Manusia (+)
Elektron dari rambut manusia berpindah ke sisir
Penggaris/mistar plastik - Rambut manusia
Penggaris (−), Rambut Manusia (+)
Elektron dari rambut manusia berpindah ke penggaris
Balon - Kain Wool
Balon (−), Kain Wool (+)
Elektron dari kain wool berpindah ke balon
Ebonit - Kain Wool
Ebonit (−), Kain Wool (+)
Elektron dari kain wool berpindah ke ebonit
Salah satu penjelasan diatas yaitu ketika kita menyisir rambut, electron dari rambut pindah ke sisir sehingga sisir mendapatkan muatan listrik statis. Jika sisir didekatkan kepotongan kertas tersebut akan menempel ke sisir, kemudian lama-lama listrik pada sisir akan berkurang sehingga kertas kecil akan jatus