Related disciplines

Mechatronics is an engineering discipline which deals with the convergence of electrical and mechanical systems. Such combined systems are known as electromechanical systems and have widespread adoption. Examples include automated manufacturing systems, heating, ventilation and air-conditioning systems and various subsystems of aircraft and automobiles.

The term mechatronics is typically used to refer to macroscopic systems but futurists have predicted the emergence of very small electromechanical devices. Already such small devices, known as micro electromechanical systems (MEMS), are used in automobiles to tell airbags when to deploy, in digital projectors to create sharper images and in inkjet printers to create nozzles for high definition printing. In the future it is hoped the devices will help build tiny implantable medical devices and improve optical communication.[31]

Biomedical engineering is another related discipline, concerned with the design of medical equipment. This includes fixed equipment such as ventilators, MRI scanners and electrocardiograph monitors as well as mobile equipment such as cochlear implants, artificial pacemakers and artificial hearts.

Computers

Computer engineering deals with the design of computers and computer systems. This may involve the design of new hardware, the design of PDAs or the use of computers to control an industrial plant. Computer engineers may also work on a system's software. However, the design of complex software systems is often the domain of software engineering, which is usually considered a separate discipline. Desktop computers represent a tiny fraction of the devices a computer engineer might work on, as computer-like architectures are now found in a range of devices including video game consoles and DVD players.

Instrumentation

Instrumentation engineering deals with the design of devices to measure physical quantities such as pressure, flow and temperature. The design of such instrumentation requires a good understanding of physics that often extends beyond electromagnetic theory. For example, radar guns use the Doppler effect to measure the speed of oncoming vehicles. Similarly, thermocouples use the Peltier-Seebeck effect to measure the temperature difference between two points.

Often instrumentation is not used by itself, but instead as the sensors of larger electrical systems. For example, a thermocouple might be used to help ensure a furnace's temperature remains constant. For this reason, instrumentation engineering is often viewed as the counterpart of control engineering.

Telecommunications

Telecommunications engineering focuses on the transmission of information across a channel such as a coax cable, optical fiber or free space. Transmissions across free space require information to be encoded in a carrier wave in order to shift the information to a carrier frequency suitable for transmission, this is known as modulation. Popular analog modulation techniques include amplitude modulation and frequency modulation. The choice of modulation affects the cost and performance of a system and these two factors must be balanced carefully by the engineer.

Once the transmission characteristics of a system are determined, telecommunication engineers design the transmitters and receivers needed for such systems. These two are sometimes combined to form a two-way communication device known as a transceiver. A key consideration in the design of transmitters is their power consumption as this is closely related to their signal strength. If the signal strength of a transmitter is insufficient the signal's information will be corrupted by noise.

Signal processing

Signal processing deals with the analysis and manipulation of signals. Signals can be either analog, in which case the signal varies continuously according to the information, or digital, in which case the signal varies according to a series of discrete values representing the information. For analog signals, signal processing may involve the amplification and filtering of audio signals for audio equipment or the modulation and demodulation of signals for telecommunications. For digital signals, signal processing may involve the compression, error detection and error correction of digitally sampled signals.

Signal Processing is a very mathematically oriented and intensive area forming the core of Digital Signal Processing (DSP) and it is rapidly expanding with new applications in every field of electrical engineering such as communications, control, radar, TV/Audio/Video engineering, power electronics and bio-medical engineering as many already existing analog systems are replaced with their digital counterparts.

Although in the classical era, analog signal processing only provided a mathematical description of a system to be designed, which is actually implemented by the analog hardware engineers, Digital Signal Processing both provides a mathematical description of the systems to be designed and also actually implements them (either by software programming or by hardware embedding) without much dependency on hardware issues, which exponentiates the importance and success of DSP engineering.

The deep and strong relations between signals and the information they carry, makes signal processing equivalent of information processing. Which is the reason why the field finds so many diversified applications. DSP processor ICs are found in every type of modern electronic systems and products including, SDTV | HDTV sets, radios and mobile communication devices, Hi-Fi audio equipments, Dolby noise reduction algorithms, GSM mobile phones, mp3 multimedia players, camcorders and digital cameras, automobile control systems, noise cancelling headphones, digital spectrum analyzers, intelligent missile guidance, radar, GPS based cruise control systems and all kinds of image processing, video processing, audio processing and speech processing systems...Just to mention a few of the possibly much more.

Microelectronics

Microelectronics engineering deals with the design and microfabrication of very small electronic circuit components for use in an integrated circuit or sometimes for use on their own as a general electronic component. The most common microelectronic components are semiconductor transistors, although all main electronic components (resistors, capacitors, inductors) can be created at a microscopic level.

Microelectronic components are created by chemically fabricating wafers of semiconductors such as silicon (at higher frequencies, compound semiconductors like gallium arsenide and indium phosphide) to obtain the desired transport of electronic charge and control of current. The field of microelectronics involves a significant amount of chemistry and material science and requires the electronic engineer working in the field to have a very good working knowledge of the effects of quantum mechanics.

Electronics

Electronic engineering involves the design and testing of electronic circuits that use the properties of components such as resistors, capacitors, inductors, diodes and transistors to achieve a particular functionality. The tuned circuit, which allows the user of a radio to filter out all but a single station, is just one example of such a circuit. Another example (of a pneumatic signal conditioner) is shown in the adjacent photograph.

Prior to the second world war, the subject was commonly known as radio engineering and basically was restricted to aspects of communications and radar, commercial radio and early television. Later, in post war years, as consumer devices began to be developed, the field grew to include modern television, audio systems, computers and microprocessors. In the mid to late 1950s, the term radio engineering gradually gave way to the name electronic engineering.

Before the invention of the integrated circuit in 1959, electronic circuits were constructed from discrete components that could be manipulated by humans. These discrete circuits consumed much space and power and were limited in speed, although they are still common in some applications. By contrast, integrated circuits packed a large number—often millions—of tiny electrical components, mainly transistors, into a small chip around the size of a coin. This allowed for the powerful computers and other electronic devices we see today.

Control

Control engineering focuses on the modeling of a diverse range of dynamic systems and the design of controllers that will cause these systems to behave in the desired manner. To implement such controllers electrical engineers may use electrical circuits, digital signal processors, microcontrollers and PLCs (Programmable Logic Controllers). Control engineering has a wide range of applications from the flight and propulsion systems of commercial airliners to the cruise control present in many modern automobiles. It also plays an important role in industrial automation.

Control engineers often utilize feedback when designing control systems. For example, in an automobile with cruise control the vehicle's speed is continuously monitored and fed back to the system which adjusts the motor's power output accordingly. Where there is regular feedback, control theory can be used to determine how the system responds to such feedback.

Power

Power engineering deals with the generation, transmission and distribution of electricity as well as the design of a range of related devices. These include transformers, electric generators, electric motors, high voltage engineering and power electronics. In many regions of the world, governments maintain an electrical network called a power grid that connects a variety of generators together with users of their energy. Users purchase electrical energy from the grid, avoiding the costly exercise of having to generate their own. Power engineers may work on the design and maintenance of the power grid as well as the power systems that connect to it. Such systems are called on-grid power systems and may supply the grid with additional power, draw power from the grid or do both. Power engineers may also work on systems that do not connect to the grid, called off-grid power systems, which in some cases are preferable to on-grid systems. The future includes Satellite controlled power systems, with feedback in real time to prevent power surges and prevent blackouts.

Sub-disciplines

Electrical engineering has many sub-disciplines, the most popular of which are listed below. Although there are electrical engineers who focus exclusively on one of these sub-disciplines, many deal with a combination of them. Sometimes certain fields, such as electronic engineering and computer engineering, are considered separate disciplines in their own right.

Tools and work

From the Global Positioning System to electric power generation, electrical engineers have contributed to the development of a wide range of technologies. They design, develop, test and supervise the deployment of electrical systems and electronic devices. For example, they may work on the design of telecommunication systems, the operation of electric power stations, the lighting and wiring of buildings, the design of household appliances or the electrical control of industrial machinery.[29]
Satellite communications is one of many projects an electrical engineer might work on

Fundamental to the discipline are the sciences of physics and mathematics as these help to obtain both a qualitative and quantitative description of how such systems will work. Today most engineering work involves the use of computers and it is commonplace to use computer-aided design programs when designing electrical systems. Nevertheless, the ability to sketch ideas is still invaluable for quickly communicating with others.

Although most electrical engineers will understand basic circuit theory (that is the interactions of elements such as resistors, capacitors, diodes, transistors and inductors in a circuit), the theories employed by engineers generally depend upon the work they do. For example, quantum mechanics and solid state physics might be relevant to an engineer working on VLSI (the design of integrated circuits), but are largely irrelevant to engineers working with macroscopic electrical systems. Even circuit theory may not be relevant to a person designing telecommunication systems that use off-the-shelf components. Perhaps the most important technical skills for electrical engineers are reflected in university programs, which emphasize strong numerical skills, computer literacy and the ability to understand the technical language and concepts that relate to electrical engineering.

For many engineers, technical work accounts for only a fraction of the work they do. A lot of time may also be spent on tasks such as discussing proposals with clients, preparing budgets and determining project schedules.[30] Many senior engineers manage a team of technicians or other engineers and for this reason project management skills are important. Most engineering projects involve some form of documentation and strong written communication skills are therefore very important.

The workplaces of electrical engineers are just as varied as the types of work they do. Electrical engineers may be found in the pristine lab environment of a fabrication plant, the offices of a consulting firm or on site at a mine. During their working life, electrical engineers may find themselves supervising a wide range of individuals including scientists, electricians, computer programmers and other engineers.

Practicing engineers

In most countries, a Bachelor's degree in engineering represents the first step towards professional certification and the degree program itself is certified by a professional body. After completing a certified degree program the engineer must satisfy a range of requirements (including work experience requirements) before being certified. Once certified the engineer is designated the title of Professional Engineer (in the United States, Canada and South Africa ), Chartered Engineer (in India, the United Kingdom, Ireland and Zimbabwe), Chartered Professional Engineer (in Australia and New Zealand) or European Engineer (in much of the European Union).

The advantages of certification vary depending upon location. For example, in the United States and Canada "only a licensed engineer may seal engineering work for public and private clients".[20] This requirement is enforced by state and provincial legislation such as Quebec's Engineers Act.[21] In other countries, such as Australia, no such legislation exists to practise engineering, however it is a mandate that if an engineer is to sign off or seal an engineering document or drawing then that person must be registered as a Certified Practising Engineer (or CPEng).[22] Practically all certifying bodies maintain a code of ethics that they expect all members to abide by or risk expulsion.[23] In this way these organizations play an important role in maintaining ethical standards for the profession. Even in jurisdictions where certification has little or no legal bearing on work, engineers are subject to contract law. In cases where an engineer's work fails he or she may be subject to the tort of negligence and, in extreme cases, the charge of criminal negligence. An engineer's work must also comply with numerous other rules and regulations such as building codes and legislation pertaining to environmental law.

Professional bodies of note for electrical engineers include the Institute of Electrical and Electronics Engineers (IEEE) and the Institution of Engineering and Technology (IET). The IEEE claims to produce 30% of the world's literature in electrical engineering, has over 360,000 members worldwide and holds over 3,000 conferences annually.[24] The IET publishes 21 journals, has a worldwide membership of over 150,000, and claims to be the largest professional engineering society in Europe.[25][26] Obsolescence of technical skills is a serious concern for electrical engineers. Membership and participation in technical societies, regular reviews of periodicals in the field and a habit of continued learning are therefore essential to maintaining proficiency.[27]

In countries such as Australia, Canada and the United States electrical engineers make up around 0.25% of the labor force (see note). Outside of these countries, it is difficult to gauge the demographics of the profession due to less meticulous reporting on labor statistics. However, in terms of electrical engineering graduates per-capita, electrical engineering graduates would probably be most numerous in countries such as Taiwan, Japan, India and South Korea.[28]

Education

Main article: Education and training of electrical and electronics engineers

Electrical engineers typically possess an academic degree with a major in electrical engineering. The length of study for such a degree is usually four or five years and the completed degree may be designated as a Bachelor of Engineering, Bachelor of Science, Bachelor of Technology or Bachelor of Applied Science depending upon the university. The degree generally includes units covering physics, mathematics, computer science, project management and specific topics in electrical engineering. Initially such topics cover most, if not all, of the sub-disciplines of electrical engineering. Students then choose to specialize in one or more sub-disciplines towards the end of the degree.

Some electrical engineers also choose to pursue a postgraduate degree such as a Master of Engineering/Master of Science (MEng/MSc), a Master of Engineering Management, a Doctor of Philosophy (PhD) in Engineering, an Engineering Doctorate (EngD), or an Engineer's degree. The Master and Engineer's degree may consist of either research, coursework or a mixture of the two. The Doctor of Philosophy and Engineering Doctorate degrees consist of a significant research component and are often viewed as the entry point to academia. In the United Kingdom and various other European countries, the Master of Engineering is often considered an undergraduate degree of slightly longer duration than the Bachelor of Engineering.[19]

History of electrical engineering

Electricity has been a subject of scientific interest since at least the early 17th century. The first electrical engineer was probably William Gilbert who designed the versorium: a device that detected the presence of statically charged objects. He was also the first to draw a clear distinction between magnetism and static electricity and is credited with establishing the term electricity.[2] In 1775 Alessandro Volta's scientific experimentations devised the electrophorus, a device that produced a static electric charge, and by 1800 Volta developed the voltaic pile, a forerunner of the electric battery.[3]
Thomas Edison built the world's first large-scale electrical supply network

However, it was not until the 19th century that research into the subject started to intensify. Notable developments in this century include the work of Georg Ohm, who in 1827 quantified the relationship between the electric current and potential difference in a conductor, Michael Faraday, the discoverer of electromagnetic induction in 1831, and James Clerk Maxwell, who in 1873 published a unified theory of electricity and magnetism in his treatise Electricity and Magnetism.[4]

During these years, the study of electricity was largely considered to be a subfield of physics. It was not until the late 19th century that universities started to offer degrees in electrical engineering. The Darmstadt University of Technology founded the first chair and the first faculty of electrical engineering worldwide in 1882. In 1883 Darmstadt University of Technology and Cornell University introduced the world's first courses of study in electrical engineering, and in 1885 the University College London founded the first chair of electrical engineering in the United Kingdom.[5] The University of Missouri subsequently established the first department of electrical engineering in the United States in 1886.[6]
Nikola Tesla made long-distance electrical transmission networks possible.

During this period, the work concerning electrical engineering increased dramatically. In 1882, Edison switched on the world's first large-scale electrical supply network that provided 110 volts direct current to fifty-nine customers in lower Manhattan. In 1887, Nikola Tesla filed a number of patents related to a competing form of power distribution known as alternating current. In the following years a bitter rivalry between Tesla and Edison, known as the "War of Currents", took place over the preferred method of distribution. AC eventually replaced DC for generation and power distribution, enormously extending the range and improving the safety and efficiency of power distribution.

The efforts of the two did much to further electrical engineering—Tesla's work on induction motors and polyphase systems influenced the field for years to come, while Edison's work on telegraphy and his development of the stock ticker proved lucrative for his company, which ultimately became General Electric. However, by the end of the 19th century, other key figures in the progress of electrical engineering were beginning to emerge.[7]

[edit] Modern developments

During the development of radio, many scientists and inventors contributed to radio technology and electronics. In his classic UHF experiments of 1888, Heinrich Hertz transmitted (via a spark-gap transmitter) and detected radio waves using electrical equipment. In 1895, Nikola Tesla was able to detect signals from the transmissions of his New York lab at West Point (a distance of 80.4 km / 49.95 miles).[8] In 1897, Karl Ferdinand Braun introduced the cathode ray tube as part of an oscilloscope, a crucial enabling technology for electronic television.[9] John Fleming invented the first radio tube, the diode, in 1904. Two years later, Robert von Lieben and Lee De Forest independently developed the amplifier tube, called the triode.[10] In 1895, Guglielmo Marconi furthered the art of hertzian wireless methods. Early on, he sent wireless signals over a distance of one and a half miles. In December 1901, he sent wireless waves that were not affected by the curvature of the Earth. Marconi later transmitted the wireless signals across the Atlantic between Poldhu, Cornwall, and St. John's, Newfoundland, a distance of 2,100 miles (3,400 km).[11] In 1920 Albert Hull developed the magnetron which would eventually lead to the development of the microwave oven in 1946 by Percy Spencer.[12][13] In 1934 the British military began to make strides towards radar (which also uses the magnetron) under the direction of Dr Wimperis, culminating in the operation of the first radar station at Bawdsey in August 1936.[14]

In 1941 Konrad Zuse presented the Z3, the world's first fully functional and programmable computer.[15] In 1946 the ENIAC (Electronic Numerical Integrator and Computer) of John Presper Eckert and John Mauchly followed, beginning the computing era. The arithmetic performance of these machines allowed engineers to develop completely new technologies and achieve new objectives, including the Apollo missions and the NASA moon landing.[16]

The invention of the transistor in 1947 by William B. Shockley, John Bardeen and Walter Brattain opened the door for more compact devices and led to the development of the integrated circuit in 1958 by Jack Kilby and independently in 1959 by Robert Noyce.[17] In 1968 Marcian Hoff invented the first microprocessor at Intel and thus ignited the development of the personal computer. The first realization of the microprocessor was the Intel 4004, a 4-bit processor developed in 1971, but only in 1973 did the Intel 8080, an 8-bit processor, make the building of the first personal computer, the Altair 8800, possible.[18]

Electrical engineering

Electrical engineering, sometimes referred to as electrical and electronic engineering, is a field of engineering that deals with the study and application of electricity, electronics and electromagnetism. The field first became an identifiable occupation in the late nineteenth century after commercialization of the electric telegraph and electrical power supply. It now covers a range of subtopics including power, electronics, control systems, signal processing and telecommunications.

Electrical engineering may or may not include electronic engineering. Where a distinction is made, usually outside of the United States, electrical engineering is considered to deal with the problems associated with large-scale electrical systems such as power transmission and motor control, whereas electronic engineering deals with the study of small-scale electronic systems including computers and integrated circuits.[1] Alternatively, electrical engineers are usually concerned with using electricity to transmit energy, while electronic engineers are concerned with using electricity to transmit information.

Masa Depan Bumi Saat Matahari Berevolusi (1)

Perubahan iklim dan pemanasan global yang terjadi akhir-akhir ini menjadi salah satu efek yang sangat signifikan dalam perubahan kondisi Bumi selama beberapa dekade dan abad ke depan. Namun, bagaimana dengan nasib Bumi jika terjadi pemanasan bertahap saat Matahari menuju masa akhir hidupnya sebagai bintang katai putih? Akankah Bumi bertahan, ataukah masa tersebut akan menjadi masa akhir kehidupan Bumi?

Milyaran tahun lagi, Matahari akan mengembang menjadi bintang raksasa merah. Saat itu, ia akan membesar dan menelan orbit Bumi. Akankah Bumi ditelan oleh Matahari seperti halnya Venus dan Merkurius? Pertanyaan ini telah menjadi diskusi panjang di kalangan astronom. Akankah kehidupan di Bumi tetap ada saat matahari menjadi Katai Putih?

Berdasarkan perhitungan yang dilakukan K.-P. Schr¨oder dan Robert Connon Smith, ketika Matahari menjadi bintang raksasa merah, ekuatornya bahkan sudah melebihi jarak Mars. Dengan demikian, seluruh planet dalam di Tata Surya akan ditelan olehnya. Akan tiba saatnya ketika peningkatan fluks Matahari juga meningkatkan temperatur rata-rata di Bumi sampai pada level yang tidak memungkinkan mekanisme biologi dan mekanisme lainnya tahan terhadap kondisi tersebut.

Saat Matahari memasuki tahap akhir evolusi kehidupannya, ia akan mengalami kehilangan massa yang besar melalui angin bintang. Dan saat Matahari bertumbuh (membesar dalam ukuran), ia akan kehilangan massa sehingga planet-planet yang mengitarinya bergerak spiral keluar. Lagi-lagi pertanyaannya bagaimana dengan Bumi? Akankah Matahari yang sedang mengembang itu mengambil alih planet-planet yang bergerak spiral, atau akankah Bumi dan bahkan Venus bisa lolos dari cengkeramannya?

Perhitungan yang dilakukan oleh K.-P Schroder dan Robert Cannon Smith menunjukan, saat Matahari menjadi bintang raksasa merah di usianya yang ke 7,59 milyar tahun, ia akan mulai mengalami kehilangan massa. Matahari pada saat itu akan mengembang dan memiliki radius 256 kali radiusnya saat ini dan massanya akan tereduksi sampai 67% dari massanya sekarang. Saat mengembang, Matahari akan menyapu Tata Surya bagian dalam dengan sangat cepat, hanya dalam 5 juta tahun. Setelah itu ia akan langsung masuk pada tahap pembakaran helium yang juga akan berlangsung dengan sangat cepat, hanya sekitar 130 juta tahun. Matahari akan terus membesar melampaui orbit Merkurius dan kemudian Venus. Nah, pada saat Matahari akan mendekati Bumi, ia akan kehilangan massa 4.9 x 1020 ton setiap tahunnya (setara dengan 8% massa Bumi).

Setelah mencapai tahap akhir sebagai raksasa merah, Matahari akan menghamburkan selubungnya dan inti Matahari akan menyusut menjadi objek seukuran Bumi yang mengandung setengah massa yang pernah dimiliki Matahari. Saat itu, Matahari sudah menjadi bintang katai putih. Bintang kompak ini pada awalnya sangat panas dengan temperatur lebih dari 100 ribu derajat namun tanpa energi nuklir, dan ia akan mendingin dengan berlalunya waktu seiring dengan sisa planet dan asteroid yang masih mengelilinginya.

Jembatan Terpanjang di Dunia

Liputan6.com, Shanghai: China tidak hanya memiliki warisan sejarah seperti tembok Cina yang terpanjang di dunia. Namun negara Tirai Bambu ini ternyata juga memiliki jembatan terpanjang di dunia yang membelah laut dan menghubungkan Pantai Hangshou di Shanghai ke kepulauan kecil Yangsan.

Jembatan sepanjang 36 kilometer ini untuk sementara masih bisa disebut jembatan terpanjang di dunia. Bukan tanpa sebab Cina membangun jembatan yang bisa ditempuh satu jam dari Pantai Hangsou ini. Ini tak lain adalah untuk investasi.

Cina dikenal sebagai salah satu tempat investasi di asia yang cukup aman. Tidak heran pertumbuhan ekonomi negeri ini bisa mencapai 11,5 persen sepanjang masa sesudah 1994. Di pulau seluas 1,5 juta meter persegi ini untuk sementara dibangun terminal peti kemas. Berbeda dengan pelabuhan pada umumnya di Indonesia, pemerintah Cina sangat tegas untuk urusan pungutan liar sehingga dalam waktu dua tahun pelabuhan ini terus berkembang dalam jumlah bongkar muat.

Mirip Tank, Fosil Mamalia Purba di Andes

WASHINGTON, RABU - Pegunungan Andes di Chili di zaman purba pernah dihuni mamalia yang memiliki bentuk tubuh mirip sebuah tank mini. Bagian leher hingga ekornya diselubungi perisai keras, seperti armadillo, namun perisainya menempel di tubuhnya dan tidak dapat dilepas.

Hewan yang diberi nama Parapropalaehoplophorus septentrionalis ini merupakan versi primitif Gyptodon, mamalia berperisai dan berekor lancip yang hidup hingga 10.000 tahun lalu. Jika Gyptodon seukuran VW kodok, berukuran panjang tiga meter dan berat tiga ton, hewan ini hanya sepanjang 76 centimeter dan berat 90 kilogram saja.

Kedua makhluk dikelompokkan ke dalam familia yang dinamai glyptodon. Asal-usulnya dari Amerika Selatan, namun kemudian menyebar hingga Amerika Utara setelah dua lempeng benua menyatu sekira 3 juta tahun lalu.

"Ia kelihatan berbeda daripada apapun yang hidup di darat saat ini. Sungguh tidak ada sesuatu yang mirip dengannya saat ini terutama dilihat dari bentuk tubuhnya," ujar john Flynn dari Museum Sejarah Alam Amerika di New York, AS, salah satu yang menelitinya.

Sosok mamalia yang mirip tank ini terkuat dari fosil perisai, rahang, kaki, dan tulang belakangnya yang ditemukan pada tahun 2004. Lokasi penemuan fosil berada pada ketinggian 4200 meter yang mengandung udara tipis, jarang air, dan suhu dingin. Namun, hewan tersebut tidak hidup pada lingkungan semacam itu.

Para ilmuwan yakin kawasan tersebut mengalami pengangkatan sejak Parapropalaehoplophorus septentrionalis hidup sekira 18 juta tahun lalu. Saat hewan tersebut hidup, kawasan tersebut mungkin berupa savana terbuka pada ketinggian 900 meter dari permukaan laut dan berisi rumput-rumputan yang diselingi pohon.

Di dekatnya ditemukan fosil-fosil hewan lainnya, misalnya hewan-hewan berkuku, hewan pengerat, dan opossum (sejenis tupai). Ttidak ditemukan jejak predator. Para peneliti memprediksi hewan berkantung yang mirip anjing dan burung raksasa yang tidak dapat terbang adalah pemangsanya.

Pilot Berhasil Desain Gitar Lipat

Stockholm, 29 Juli 2004 11:26
Seorang pilot Swedia yang juga musisi amatir, cukup kreatif mendesain gitar yang bisa dilipat, sehingga dapat ditempatkan di kokpit, tanpa harus memakan tempat.

Fredrik Johansson (41) pilot Scandinavian Airlines itu, sejak lama ingin melakukan desain ulang instrumen musik favoritnya tersebut, agar bisa dibawa ke berbagai tempat yang ia kunjungi saat bertugas.

Desain kreasi Johansson itu merupakan modifikasi dari badan gitar elektrik asli, yang ukuran dan bentuknya mirip Fender Telecaster. Tapi bagian leher gitar itu bisa dilipat ke depan badan gitar. Senar gitar ditarik menggunakan sebuah roller, mirip roller untuk melipat gorden jendela.

Begitu dilipat, panjang gitar menciut jadi 50 sentimeter, atau setengah dari ukuran gitar enam senar normal.

Ia berhasil membuat tiga gitar prototip, dengan banderol masing-masing 26 ribu dolar AS. Uniknya, Johansson mengklaim bahwa pengguna tak perlu menyetem gitar, meski baru dilipat.

"Anda hanya perlu mengencangkan senar-senar, yang hanya memakan waktu sekitar 20 detik," ujar Johansson, sebagaimana dikutip situs CBC News. "Lalu, mainkan."

Gitar kreasi baru itu telah dipatenkan di Swedia tahun ini atas namanya. Sebuah grup musik Swedia, sudah menggunakan gitar kreasi Johansson pada sebuah pertunjukan musik di Stockholm, Juni lalu.

"Mereka terkejut dengan gitar lipat ini. Suaranya yang keluar sangat bagus," puji Johansson, yang berencana membawa gitar desainnya ini ke sebuah pameran di AS.

Lima Senjata Kimia Paling Berbahaya

Ini dia lima jenis senjata kimia paling berbahaya yang menjadi momok yang menakutkan dalam pertempuran yang dapat menimbulkan efek yang mengerikan, jika diterapkan pada rudal, rocket, bom, granat, pecahan senjata dan ranjau darat:

1. VX: racun berbahaya dalam bentuk cair dan uap, dapat menyerang sistem syaraf pusat. Bahan kimia ini dianggap 100 kali lebih beracun melalui sentuhan terhadap kulit daripada syaraf, dan dua kali lebih berbahaya melalui pernafasan. VX dapat menyebabkan kematian beberapa menit setelah terkena. Bahan kimia itu mematikan dengan menyerang otot yang dikendalikan dalam keadaan aktif sehingga otot lelah dan tidak dapat bernafas lagi.

2. Sulfur Mustards: Gelembung dan unsur perantara alkali. Bahan kimia ini tak berwarna dalam keadaan murni, namun secara umum berwarna kuning hingga coklat dan sedikit berbau mustard atau bawang putih. Sulfur Mustards menyebabkan luka pada kulit, mata dan saluran pernafasan. Tidak ada penawar racun atas keracunan sulfur mustard, satu-satunya cara efektif yaitu dengan mengurangi kontaminasi semua daerah yang terkena. Sepuluh miligram bahan kimia itu dapat menewaskan korbannya.

3. SARIN:
Komponen yang sangat beracun baik dalam bentuk cair atau pun gas, menyerang sistem syaraf pusat dan dapat menimbulkan kematian beberapa menit setelah terkena. Bahan ini memasuki tubuh melalui pernafasan, pencernaan, mata dan kulit.

4. CHLORINE:
Gas kuning kehijauan dengan bau tajam yang lebih berat dari udara. Bahan ini bereaksi dengan berbagai bahan organik, menimbulkan api dan ledakan keras. Menimbulkan efek korosif pada mata dan kulit. Penyebaran melalui udara menyebabkan kesulitan bernafas dan edema paru-paru. Tingkat terkena yang tinggi dapat menyebabkan kematian.

5. HYDROGEN CYANIDE:
Sangat mudah terbakar, tidak berwarna dalam bentuk gas ataupun cair. Dalam keadaan terbakar menyebarkan racun dan dapat memicu ledakan. Dapat menimbulkan iritasi mata, kulit dan saluran pernafasan. Bahan ini dapat menyerang sistem syaraf pusat sehingga sirkulasi tidak berfungsi.

Pesawat tercepat didunia

[U]LONDON - Sekumpulan teknisi asal Inggris Selasa lalu mengumumkan pada publik mengenai rencana penerbangan dari Eropa ke Australia kurang dari lima jam.

Pesawat A2, didesain oleh perusahaan teknik Reaction Engines yang berbasis di Oxfordshire, Inggris Selatan. Pesawat tersebut mampu membawa 300 penumpang dengan kecepatan hampir 6.400 km per jam, atau lima kali lebih cepat dari kecepatan suara.

A2 mempunyai panjang 143 meter, sekira dua kali lipat lebih panjang dibandingkan jet terbesar saat ini. Tidak hanya itu, A2 mempunyai kemampuan terbang non-stop sejauh kurang lebih 20.000 km.

"Pesawat ini dapat beroperasi hingga 25 tahun mendatang," ujar Vice President European Space Agency sekaligus Project Officer The Long-Term Advanced Propulsion Concepts and Technologies (LAPCAT) Alan Bond pada Guardian Daily, yang dikutip AFP, Rabu (6/2/2008).

"A2 direncanakan akan meninggalkan Airport Internasional Brussels terbang via Atlantik Utara melewati North Pole kemudian bantaran Pasifik lalu berakhir di Sydney," jelasnya mengenai rute penerbangan A2.

Penerbangan ini akan memakan waktu 4 jam 40 menit. "Hal itu memang sulit dipercaya. Tapi, kita berada di generasi masa depan, tidak ada yang tidak mungkin untuk melakukan perjalanan sehari ke Australasia," imbuhnya.

Tarif yang akan diberlakukan untuk pesawat A2 sekira 3.500 pounds atau kurang lebih [B]Rp64 juta[/B]

Ponsel Dengan 3 SIM Card? Ada di MyG 820?

Ponsel 2 kartu sudah biasa, tapi bagaimana dengan yang 3 kartu? Ya, model ini bisa dibilang baru pertama kali di luncurkan brand lokal di tanah air. Adalah MyG 820, ponsel yang sanggup mengkoneksi pada 3 kartu sekaligus dan ketiganya aktif ini merupakan hal baru dipasar seluler indaonesia..

Tiga kartu yang dapat dikoneksikan berupa, 2 GSM dan 1 CDMA. Dan untuk mengakses masing-masing kartu, MyG menanamkan tiga tombol khusus yang ada di jajaran tombol navigasi.

Dari sisi disain, MyG 820 sepintas mirip Nokia N82. Mulai dari karakter disain, Candy Barnya. Di pasaran, ponsel ini dihargai Rp 2,3 jutaan.

Spesifikasi:
TV Player, Call Recorder, Triple SIM Card (CDMA, GSM, GSM), LCD 3″, 262k TFT Color, Video Recorder, FM Radio, Bluetooth, Camera 1,3MP, 4x Digital Zoom, 2nd Camera VGA, Touch Screen, External Memory, MP3 / MP4 Player, USB Connector, 3D Sound Stereo Speaker, GPRS/WAP/MMS, Java