Friday, December 23, 2011

Deslandres and Pitatus Moon craters through astrochemistry telescope

Video by: Victor Lupu Optics: Celestron C8-Newtonian telescope, plossl 20mm, 2x Barlow Mount: CG5 (EQ5) Device: Sony CX105 Filter: No Date: 11/05/2011 Location: Baia Mare, Romania lupuvictor.blogspot.com astrofotografieluna.blogspot.com

New Bose V30

Wednesday, December 7, 2011

TwinStar Black 6" iOptron Computerized GPS Reflector Telescope

!9#: TwinStar Black 6" iOptron Computerized GPS Reflector Telescope

Brand : TwinStar / iOptron | Rate : | Price :
Post Date : Dec 07, 2011 15:34:14 | Usually ships in 1-2 business days


  • 150mm (6 inch) objective mirror, 1400mm overall focal length
  • Short tube design yields maximum 400x magnification
  • 25mm & 10mm Plossl 1.25" Diameter Eyepieces Included
  • iOptron SmartStar-G Computer Controlled GPS Mount
  • iOptron GoToNova Controller with 50,000 Celestial Object Database

More Specification..!!

TwinStar Black 6" iOptron Computerized GPS Reflector Telescope

Prices Thermos Carafes Lowest Price Pampers Sensitive Swaddlers Best Buy Brother 5370dw

Thursday, November 17, 2011

TwinStar White 4.5" iOptron Computerized GPS Reflector Telescope

!9# TwinStar White 4.5" iOptron Computerized GPS Reflector Telescope


Rate : | Price : | Post Date : Nov 17, 2011 17:00:18
Usually ships in 1-2 business days

This telescope is ideal for backyard astronomy enthusiasts or older children with space on the brain. Simply turn the telescope on, choose the object you want to see on the handheld controller and the computerized GPS mount does the rest. With a large 114mm (4.5 inch) primary mirror and a 500mm focal length, this fast F/4.4 telescope is the perfect large light-gathering instrument for wide-field and deep space astronomy. You can observe fabulous nebulae, galaxies, binary star systems and most of the famed deep-space Messier objects. Of course, with this telescope, you can see outstanding detail when viewing the moon and you can see the Rings of Saturn and the Moons of Jupiter. The iOptron SmartStar-G Alt-Azimuth Mount with GPS, a.k.a. The Cube, is probably the most functional and flexible unit on the market. Both axis motors are built into a small single unit. In addition, there are no "dead spots" -- so you can point your telescope anywhere above the horizon, whereas, other mounts block the telescope tube at certain points of rotation. This mount comes standard with AC connection, but also accepts 8 AA cell batteries for use at home or in the field (Batteries sold separately). The GoToNova computerized control system is by far the most technologically advanced automated tracking system available on the market today. With a database of 50,000 celestial objects, including all of the most famous galaxies, nebulae, star clusters, not to mention the planets, you'll be able to enjoy star gazing with the simple push of a button. There is no need to align the telescope, with GPS, it knows its location. The GoToNova Controller is much easier to use than other similar products. The hand controller is more intuitive with menu categories better organized. It also has a larger LCD screen with more lines of content compared with the competition. With the easy-to-use hand controller you can easily set up your telescope and select where you want to go.

Spalding Hoops Get It Now! Lg 60pk950 Order Goodyear Duratrac Buy Now

Thursday, November 3, 2011

TwinStar Silver 90mm iOptron Computerized GPS Cassegrain Telescope

!9# TwinStar Silver 90mm iOptron Computerized GPS Cassegrain Telescope

Brand : TwinStar / iOptron | Rate : | Price :
Post Date : Nov 03, 2011 08:19:37 | Usually ships in 1-2 business days


  • 90mm fully coated, achromatic objective lens
  • 1200mm focal length
  • Kellner 25mm Eyepiece; (1) Kellner 9mm Eyepiece included
  • Altazimuth Mount (Point & Shoot) -- Full Size Tripod
  • 45 degree angle prism -- images are seen right-side up

More Specification..!!

TwinStar Silver 90mm iOptron Computerized GPS Cassegrain Telescope

Canon Xl1 This Instant Low Cost Cyberpower Review Promotional Bob Revolution Stroller On Sale

Wednesday, November 2, 2011

3 Types of Telescopes - Know the Differences Or Risk Buying the Wrong One

!9# 3 Types of Telescopes - Know the Differences Or Risk Buying the Wrong One

[if ]
[endif]

There are 3 main types of telescopes and each one performs differently and may be used for different purposes. If you are thinking about buying a telescope to look at stars and deep space then you should know that this might not be possible if you live in a built up area with light pollution. If it is just the moon and the planets you want to look at then you should now that refractors are better than reflectors for this. If you are prepared to travel with your telescope then you should know which types are fragile and which ones give you the best performance from a smaller scope.

The three types of telescopes that exist for capturing light so that it may be magnified for viewing are Catadioptric, Newtonian Reflector and Refractor.

Refractor Telescope

The traditional long-tube looking telescope. The Refractor uses lenses to bend light and this causes the rays to meet at a point on the other end of the telescope. They are magnified by the eyepiece for viewing. There is a large lens on the front of the Refractor, which is the objective lens.

Pros

Requires little to no maintenance Excellent for planetary viewing

Cons

Color deviation in achromatic designs Not recommended for deep sky observation

Reflector Telescope

The Newtonian Reflector uses a primary mirror that is concave. This mirror sends light to a flat mirror which reflects the light out a side opening and to the eyepiece where it is magnified and focused.

Pros

Best for deep space observation - Great for looking at remote galaxies Delivers very bright images

Cons

Requires regular alignment Requires more complicated cleaning of mirrors than other types of the same design

Catadioptric Telescope

The last of the three types of telescopes and currently the most popular on the market. This type uses a series of lenses and mirrors that fold the light path and send it through to the primary mirror through a small hole. This allows the light to be magnified and focused for viewing. There are two types of Catadioptric telescopes - Schmidt-Cassegrain and Maksutov-Cassegrain. The Maksutov type has a concave and convex correcting lens where the light enters. The light hits the primary mirror, is sent back to the secondary mirror and finally sent to the opening in the back of the telescope.Pros

Portable and easy to use Versatile - good for deep space and planetary observation About the best for focusing Excellent optics

Cons

It does not look like a telescope to many people It is more costly than other Newtonians with the same size opening for light

Once you know what you want to look at and which of the types of telescope you should choose you need to think hard about how much you are prepared to carry around, telescopes can be bulky and your tripod and mount are essential bits of additional kit. Size determined, you are now ready to see just how much aperture you can get for your money. Don't concern yourself with magnification, it is not nearly as important as is touted and higher magnifications will cause images to be blurry because of air turbulence. The performance of a telescope depends on how much light gathering capability it has, the more light it can gather the better you will see, and this is aperture. As a general rule of thumb, once you know which of the types of telescopes is best for you, get the biggest aperture you can afford for your money.


3 Types of Telescopes - Know the Differences Or Risk Buying the Wrong One

Panasonic Wet Shavers Top Quality Brand New Kushies Ultra

Thursday, October 27, 2011

The Ten Cosmological Fallacies

!9# The Ten Cosmological Fallacies

[if ]
[endif]

A key question in modern cosmology, rarely asked, its answer usually assumed, is whether or not the Big Bang event actually created space and time, as well as producing or providing our supply of matter/energy that we observe all around us. The central foundation of the Big Bang event, apart from the observational evidence of an expanding cosmos, was that the Big Bang event somehow created time and space, out of nothing for apparently no reason, and thus, the often assumed answer is "Yes". But, there's no evidence for this (and if they did that would exhibit causality lacking in the standard Big Bang scenario). No laboratory has ever created time and/or space. There's no real even theoretical recipe textbook way of doing this.

What if one rejects that premise? So, what if the answer instead is "No"? What if the Big Bang was created out of something, and for a reason? Then it's a whole new ballgame! If time and space pre-existed the Big Bang event, 13.7 billion years ago, then that suggests that because time existed prior to the Big Bang event, that there was a chain of events (a cause) that led up to and included the Big Bang (an effect). In fact, I invoke the principle of causality (cause and effect) which is one of the, if not the, foundation upon which all science is based, to 'prove' (as far as that's possible, but which is as close to certainty IMHO as makes no odds) that the Big Bang event had a cause. Therefore, there had to have been a before-the-Big-Bang. Hells, bells, even "The Bible" attributes a cause to the origin of the Universe - 'In the beginning, God created...". Ditto that for all other major religions.

Faced with a choice between accepting a Big Bang event that had a cause, and a Big Bang event that had no cause, I'll accept the former (hands down) and consign the latter to the fantasy land occupied by such notables as Santa Claus, James Bond, Little Red Riding Hood, Rocky and Bullwinkle, the Tooth Fairy, Harry Potter, the Easter Bunny, assorted elves, goblins and the Loch Ness Monster! Anyone believing that all of time, space, matter and energy, were created out of absolutely nothing, for absolutely no reason, is living in that same fantasy land.

Now if space existed prior to the Big Bang, then clearly the Big Bang event had coordinates (a centre or defined place) where the event happened. Also, it suggests that our Universe is currently expanding throughout that pre-existing space. Until such time as cosmologists can actually explain in detail how the Big Bang event created space and time, I'll assume the opposite and follow the implications trail of that. But that's not the end to what I consider the cosmological fallacies, IMHO.

#1: The origin of our observable universe (and in fact the Universe) can be traced back to as close to time equals zero, and space equals zero, as makes no odds. However, astronomers can't really see beyond roughly 380,000 years after the Big Bang event. It's only then that the Universe would have cooled enough to allow for atoms to exist and for the Universe to become transparent enough to allow electromagnetic radiation to pass. The remnants of that are observed as the cosmic microwave background radiation, now cooled to a temperature of some 2.7 degrees Kelvin. It's like with the Sun. At the core, the Sun is opaque to photons. It's only when they worm themselves up to the solar surface that things are cool enough, and transparent enough, to race away into space. However, although there's no way we can observe any electromagnetic radiation at an earlier era, astronomers can, using their equations, extrapolate further back - in fact back to very tiny micro-seconds after the Big Bang when those equations break down. At such time, the universe would have been small enough that quantum physics ruled. But, just because one can theoretically extrapolate earlier than 380,000 years after the Big Bang, doesn't mean that such theoretical cosmology represents what actually happened - again because there's no observable evidence. At 380,000 years old, the Universe wouldn't have been a quantum universe, but a fully formed macro Universe. Perhaps something happened at an earlier stage but that something just wasn't within the realm of quantum physics. [It must be noted that the search is on for primordial gravity waves, which, if found, would be observations of an even earlier era. So far, no luck, but in fairness, gravity waves (past or current) would be very hard to detect. Stay tuned!]

Actually, in other words, it's not so much that I object to extrapolating back towards the beginning (time equals zero) but rather uniformly extrapolating the ever decreasing volume of the Universe to where it (for all practical purposes) vanishes or becomes quantum-sized. The contracting volume of the Universe IMHO gets to a finite (macro) volume where it then ceases decreasing further in volume, and that point is reached well before time equals (near) zero. That volume might be in the range of a stellar to galactic sized object. That might be a reasonable volume to cram the contents of the Universe down into. It's more believable than cramming the Universe into a volume less than that occupied by an atom!

#2: You can not squeeze, IMHO, all the matter/energy contents of our observable universe, far less the entire Universe, into a volume that is properly the realm of the quantum or micro-verse. That's just common sense. However, that's what apparently the standard cosmological model (the Big Bang scenario) calls for. Now if you really believe the Big Bang was a quantum-sized event, then I suggest you can also be easily persuaded to believe that politicians have first and uppermost our best interests at heart, and not their best interests at heart - especially around election time!

#3: And in a somewhat similar fashion, IMHO, singularities may not be micro (quantum realm) objects either. Firstly, it's common sense that a singularity can not have zero volume and infinite density. Therefore, a singularity must have a finite volume and a finite density. As one adds more and more stuff to a singularity, the volume may remain constant while the density increases. But, because density can not hit infinity, it must have a limit. When that limit is reached, the volume of the singularity must increase. It follows therefore that the size of a singularity will eventually reach macro dimensions and fall out of the realm of quantum physics.

There's another reason why a singularity can not have zero volume and infinite density. If gravitational attraction increases as the density of something increases (the Sun, compressed to the size of a bowling ball, would have a lot more pull than said ball). So, what would the gravity be for something of so-called infinite density (i.e. - a singularity)? Well, it would have to also be infinite. Clearly singularities exist (because Black Holes have been verified to exist) and clearly we're not being attracted to them by their infinite gravitational pull (gravity might decrease with increasing distance away from the source of that gravity in accord with the well known Newtonian formula, but any decrease in infinity (say infinity divided by two) still leaves infinity. Therefore, either singularities do not exist, or they aren't infinitely dense.

#4: Space is expanding, according to cosmologists, carrying the entire Universe's matter/energy along for the piggyback ride. Thus we see the expanding Universe. However, IMHO, that's nonsense. The Universe (matter/energy) is expanding all right, but expanding through already existing and static space. The oomph that's driving the expansion of matter/energy through existing space is the energy or force of the Big Bang event itself.

Part and parcel of that expanding space idea is the concept of inflation that happened either just before of after the Big Bang event. Inflation is proposed to explain various cosmological observations, and suggests that a very sudden, but very short lived period existed where our embryo Universe increased in size (or inflated like a balloon) dramatically, so dramatically in fact that I have a problem with the concept. The one problem I have with the inflation concept is that apparently, for the duration that inflation existed, space was expanding at faster than light speed. Now that in itself is not the problem. That's allowable. The problem is that if space carries matter/energy along for the ride, the piggyback scenario above, then that matter/energy must have been moving, for the duration, faster than the speed of light, and that's not allowed.

If there is any observational test that can, and has, been made, which distinguishes between galaxies being carried piggyback by expanding space, and galaxies moving through existing space, I'm not aware of it.

#5: Although cosmologists inform us that there is no actual centre or location within our Universe where the Big Bang happened, that's nonsense, IMHO. Assuming a Big Bang (of some sort), it did not create space and time. How can any natural process create space and time is beyond me. Space is nothing, albeit a flexible nothing. Space is a 100% perfect vacuum in which all existing matter/energy resides, including containing the matter/energy that is what we term the vacuum energy or quantum jitters*. Time is just a measurement of the rate of change we observe in matter/energy, changes which can vary according to the Relativity Theories*. If the Big Bang did not create time and space, then time and space pre-existed when that cosmological event happened. Therefore, it had a specific location (coordinates) in that space (and time) - assuming there was an intelligence around to provide them. We have given the Universe coordinates (a cosmic latitude and longitude) in order to know where to point our telescopes. So, why can't we point our telescopes at these Big Bang coordinates - this point of origin coordinates - and observe directly the remnants of the Big Bang? Well, consider the following as an analogy. Say we have a heated oven (the Big Bang) in an enclosed room (the Universe). Now we turn the oven off. After an hour, it would be still obvious where the heat originated and coordinates (in the room) of same. However, after ten days, the oven is the same temperature as the entire room, and it is no longer obvious where the point of origin of the heat came from. Alas, we're at the ten day point. Since the Universe as a whole is at a uniform temperature (the cosmic microwave background radiation), ditto wherever the Big Bang occurred. One set of coordinates is identical in appearance to any other set. We have no idea therefore where to point our telescope, and even if we did, it wouldn't enlighten us.

#6: Cosmologists and science writers when trying to explain our evolving and expanding Big Bang Universe to the great unwashed, often use an analogy of an expanding balloon with painted dot 'galaxies' on the expanding surface to represent our expanding Universe and the galaxies within, nearly all of which are receding away from each other in a precise mathematical manner. It's nonsense!

The expanding Universe is a three dimensional object - it has volume.

The expanding balloon is a three dimensional object - it too has volume.

So why one is asked to just believe or picture the expanding two dimensional outside surface of the balloon as representing our expanding three dimensional Universe escapes me!

That said, of course painted dot 'galaxies' on the balloon's expanding surface will all be moving away from each other in a precise mathematical relationship that mirrors the real galaxies recession from each other, but...

If you could imagine these painted dot 'galaxies' inside the expanding balloon (and not just on the surface), and if you can imagine the expanding space inside the balloon carrying these painted dot 'galaxies' in a piggyback fashion, then the painted dot 'galaxies' inside the balloon would also be getting further and further apart from one another in a precise mathematical relationship.

Another problem with the analogy is that we are taught that there's no preferred place or exact geographical location for the origin of the expanding Universe. Yet clearly, even in the two dimensional surface-only picture, there is a specific point or origin or location of the cause - the point where the air is being pumped in.

In either case, whether two dimensions or three dimensions, the balloon analogy is wrong in that expanding space isn't carrying the galaxies piggyback, but that the galaxies are moving through existing static space.

Ask yourself this question: Is the Andromeda Galaxy - which we can easily observe (or our own Milky Way Galaxy for that matter) on the surface of anything? The Andromeda Galaxy is not on the surface of anything! It is inside outer space, not on the surface of outer space. Outer space does not have a surface. The correct balloon analogy is that the Great Galaxy of Andromeda is inside the expanding balloon, not a dot on the surface of the balloon.

#7: There was absolutely nothing before the Big Bang event - no time, no space, no matter, no energy. Asking what happened before the Big Bang is akin to asking 'what's the shape of a square triangle?'! At least that's the standard spiel. Of course if space and time have existed for all eternity, then lots of things, happenings, events, etc. preceded our Big Bang, IMHO. Unfortunately, with respect to cosmology, I've locked myself philosophically into taking the point of view that there are no absolute beginnings or first causes. By crossing these concepts off from consideration from the first, it eliminates a lot of otherwise potential messy details, like how does one create from absolute nothing things like time, space, matter and energy? (I can just imagine some stereotyped 'mad scientist' in his basement laboratory creating these from first principles - that would really muck up the works, but then again, if Mother Nature could do it, shouldn't we be able to do it too - at least in theory?)

#8: The "Cosmic Coincidence" is just that - a coincidence - and coincidences don't require explanations, IMHO. For example, if someone in Canberra gets up at 7 am, has corn flakes for breakfast, wears a red tie to work, and has a wife and two kids, and someone in Sydney also gets up at 7 am, has corn flakes for breakfast, wears a red tie to work, and has a wife and two kids, that's pure coincidence and no explanation is required. Now the "Cosmic Coincidence" relates to the fact that the cosmological constant or dark energy or the vacuum energy responsible for the acceleration of the already existing expansion of our observable universe happens to be roughly equivalent in strength to the Universe's matter density. The former is forever constant despite the expansion while the latter is forever decreasing as matter (gravity) is being diluted due to that same expansion. Of course the two lines have to cross at some point in time; it's just that that time just happens to coincide with roughly a time that's compatible to our own existence. If cosmologists suspect some deeper meaning behind the crossing of those two events, and that we're simultaneously here to make note of it, then perhaps it should be termed something akin to a 'fortuitous cosmic happening' or 'fortuitous cosmic occurrence'.

#9: That there is only one Universe (ours) is often taken as a given (or for granted). But to repeat myself, if Mother Nature can produce one (our) Universe, then She can produce more than one. The Multiverse is quite a viable/reasonable hypothesis IMHO.

#10: That String or M-Theory will come to the rescue of and shortcomings in the standard cosmological (Big Bang) model. That, IMHO, is highly unlikely. After over two decades, despite the efforts of hundreds of physicists, and thousands of academic papers, String or M-Theory (including Branes) remains just a theoretical mathematical playground. It has no runs on the board, not one shred or iota of hardcore evidence as provided by any experiment to date. Thus, ideas akin to the Ekpyrotic Universe remain in the realm of science fiction - at least in the here and now.


The Ten Cosmological Fallacies

Similac Formulas Buy Now Crane Humidifier Buy Now

Wednesday, October 19, 2011

Celestron 21045 114mm Equatorial PowerSeeker Telescope

!9# Celestron 21045 114mm Equatorial PowerSeeker Telescope

Brand : Celestron | Rate : | Price : $96.34
Post Date : Oct 19, 2011 10:12:39 | Usually ships in 24 hours


Celestron PowerSeeker telescopes are a great way to open up the wonders of the Universe to the aspiring astronomer. The PowerSeeker series is designed to give the first-time telescope user the perfect combination of quality, value, features and power.

Amateur astronomy is a great family hobby that can be enjoyed year round, and Celestron’s PowerSeekers are the ideal choice for families looking for an affordable and high quality telescope that will provide many hours of enjoyment for children and adults alike.

PowerSeekers are quick and easy to set up – even for the novice. No tools are required for assembly!

More Specification..!!

Saving Fujitsu Snapscan S500 Promo Bob Duallie Revolution Stroller Bissell 76t8 For Sale

Saturday, September 24, 2011

How to Use a Telescope - Reflector telescopes introduction

!9# How to Use a Telescope - Reflector telescopes introduction

[if ]
[endif]

Telescopes consist of two main types - reflectors and refractors. The fundamental difference between the two types is the type of glasses used for light collection. Refractors use lenses while reflectors use mirrors. Let's go back to school physics, it is obvious that the light from distant bodies, like celestial bodies, comes to us as a parallel beam. This parallel light rays, reflector telescopes use parabolic mirrors.

Such a parabolic mirror focuses each ray of light,receives from the original parallel beam at a single site. Since this type of mirror, a reflecting telescope type is much more beneficial than a refractor. A very important point to note is that the spotlight is not chromatic aberrations, which are a common problem for refractors suffer. This is because, unlike refraction, the way in which different wavelengths are refracted, the mirror does not change affects all wavelengths.

A second advantageis that they are relatively expensive for the quality of the same magnification. In addition, because the light is reflected, only the reflective surface of a perfect finish. In the case of refractors, the light is formed on the one hand the objective of moving in the other, following which both have refractive surfaces polished to perfection.

Astronomers generally prefer mirror telescopes, but these are also some disadvantages. The most obvious of which is the difficulties faced in the rightAlignment of the mirrors. The reflectors have an open tube, so that the internal optical components require regular maintenance and cleaning. Without this treatment, the images at the end of the telescope and produced blurry blurry. There are also cases of question, the secondary mirror to focus light properly in some places. These secondary mirror may also have a negative impact on image quality.

The biggest drawback of both refractors and reflectors are facing, that the final image of an ISinverted image. A simple solution for this error is the placement of a relay or a prism in the passage of light so that image that is inverted into the eyepiece, the returns are made to produce a portrait image. This is because the relay or the prism as the case acts as a beam of light to an inverter in vertical position what the final image.

The above paragraphs will change to reflect the use of secondary reflectors in place of the fire light. These mirrors are smaller than the secondaryPrimary mirror. According to historical accounts, Sir Isaac Newton used a mirror that was flat and the oblique angle of 45 degrees secondary mirror. The purpose of this mirror was the reflected light to an eyepiece at the postponement of the top tube. This provision is now known to Newton as the design and find buyers.

There is another type of special project such as design Cassegrain reflecting telescopes are known. This gives the light the object of a specificIn order to better reflect the path to the main mirror. With this project you can position the eyepiece at your own convenience. Even modern telescopes, the Hubble space telescope such as the use of this great building, and for the benefits listed above, astronomers tend to spotlight, and not the refractor.


How to Use a Telescope - Reflector telescopes introduction

Mini Dv Camcorder Reviews Adjustable Dumbbells 50 Right Now Kaz Vicks Order

Friday, September 16, 2011

The early history of telescopes

!9# The early history of telescopes

[if ]
[endif]

A poll in early telescopes provides an interesting read. Figured in 1722 joined John Hadley, an English mathematician, a form of the reflector of the telescope mirror in the style of Newton was apparently a result. This tool is a great feeling, and now turns to other producers were Newtonian reflectors, according to Hadley Technology, which was to eliminate spherical aberration, as has been revealed by extra-focal diffractionRings to take a star.

Hadley then turned to a design by James Gregory in 1726 and has produced an instrument a little 'more than 2 "in diameter and 12" focal length. This proved so successful that the construction was carried out by others.

Among these was James Short, both Newton and Gregorian produced in large numbers, from about 1732 until the time of his death in 1768. Observers bought his greatest tools, a tribute to his ability, and the smallesthave been marketed primarily under the needle and amateur astronomers.

The main attraction of the project was in direct Gregorian image there, that for terrestrial use. This fact influences the advantage over Newton's, despite the fact that his paintings must be pretty boring. Up to 19 century, but the Gregorian ridden a wave of popularity that any type of telescope known until relatively recent years, overwhelmed byFlood of amateurs who have poured Newton-design.

Since the invention of the telescope and the amazing discoveries of Jupiter's moons and rings of Saturn, the interest in astronomy had something contagious. Each new discovery has been given maximum publicity, stimulating demand for learning among those first-hand on this win heavenly miracle. It was not practical for the average person or to his speculum, but many fictionadjust the lenses in tubes, just as Galileo did 150 years ago. This was one of the first of the first telescopes.

Those whose means permitted bought telescopes, and envied the gentleman who was one of three or four cm opening through an artist had "exclusive". Measured, but, by today's standards, many of these were tiny reflectors. There is an (unknown manufacturer) in the collection of the Fugger of Augsburg, just 1 "in diameter and 6" focal length, which washidden in a walking stick! Eyepiece 1 / 6 "focal length or less were not uncommon.

The metal was used in these early stages is an alloy of copper and tin, the usual volume of about 75 to 25, which could be given a nice polish. But the metal had to work very hard, and a huge amount of work was involved in sanding and polishing of the curve. To facilitate the work, which ensures slices thin enough to approximate the curve were thrown on the curveto give uniform thickness and the compensation of temperature effects. Grinding tools of iron-like radius convex done with sandpaper, and sometimes sand. Polishing was done on a round field with rouge.

Manufacturers typically build their own machines to do the job of sanding and polishing. As it was necessary to the highest perfection that seems to have made a great final part of a short variant of stroke in an attempt to focus on polishing without guidancethe center. Critical review, was issued in doubt because of its rare nature, so far only be performed on a star. In specula reflectivity was only about 60 percent more efficient, and surface finish in a hurry, causing more severe loss of light. This meant frequent polishing and polishing Refiguring say.

It 'interesting that the prices for telescopes in this period, in the second half of the 18 st Century has been asked to investigate. Below arePrices and trained by some of the Gregorian made by Short, selected from his catalog. Newton in a similar format were only slightly lower price.

Diameter (cm) focal length (mm) price increases (guineas) *
1.1 3 18 3
1.9 7 6 40
4.5 24 90-300 35
6,3 100-400 36 75
18144800300-1.200

* An English gold coin issued until 1813, amounting to 21 shillings, about five dollars.

Early telescopes were certainlygaining popularity in this period.


The early history of telescopes

Shop For Make Internet Radio

Wednesday, August 31, 2011

Celestron 127EQ PowerSeeker Telescope

!9# Celestron 127EQ PowerSeeker Telescope

Brand : Celestron | Rate : | Price : $119.94
Post Date : Aug 31, 2011 21:27:34 | Usually ships in 24 hours

21049 With Free Motor Drive: CES1071 Features: -Telescope. -PowerSeeker collection. -Color: Black. -Material: Aluminum. -127 mm (5'') Newtonian reflector. -3x Barlow lens triples the magnifying power of each eyepiece. -Quick and easy no-tool setup. -Slow motion controls for smooth tracking. -Erect image optics - ideal for terrestrial and astronomical use. -Fully coated glass optical components with high transmission coatings. -Enhanced image brightness and clarity. -Accessory tray for convenient storage of accessories. -''The Sky'' level 1 planetarium software with 10,000 object database. -Dimensions: 11'' H x 17'' W x 33'' D.

  • 3x Barlow Lens
  • German Equatorial Mount
  • 127mm Aperture
  • 1000mm Focal Length
  • Comes with aluminum tripod and accessory tray

Order Boker Knives

Tuesday, August 23, 2011

Celestron NexStar 130 SLT Computerized Telescope

!9# Celestron NexStar 130 SLT Computerized Telescope

Brand : Celestron | Rate : | Price : $339.00
Post Date : Aug 23, 2011 08:18:06 | Usually ships in 1-2 business days

The Celestron® NexStar® SLT Series 130 SLT reflector telescope showcases a computerized hand control and a 4000+ object database. With a touch of a button you can select the object catalog, change the slew speed, view fascinating information about an oject, or simply know if a desired object is visible in the sky. It comes equipped with a sturdy steel tripod, a StarPointer® finderscope, software, and more.

  • Computerized hand control with 4,000-object database
  • SkyAlign allows you to align on any 3 bright celestial objects
  • Motorized Altazimuth mount
  • Focal ratio: f5
  • Focal length: 650mm

Eau De Toilette Vs Eau De Parfum Buy Online Purchasing Sony Camera Slr Digital Shopping Dumbbell Powerblock

Sunday, August 14, 2011

What you should know before buying a telescope

!9# What you should know before buying a telescope

[if ]
[endif]

Telescopes are used for a variety of purposes. Both telescopes and binoculars are normally used for bird watching, night sky, and some other activities. If you are interested in buying a telescope for observation, some factors must be considered first. For example, you need to know, what are you going to use it. Larger telescopes is larger, sharper images, while the smaller more limited in what they are, users can see.

The job ofTelescope is to see one of the most important features. This refers to the materials and the way in which it is produced. Optical instruments of any kind must be engineering work correctly, the information is really important. Some will say that consumers should avoid shopping for telescopes in department stores, and attend instead to those who are certified in telescopes. These stores are people who have knowledge about them, and could explain the differences between individualModel.

Another attribute is taken into account in designing optical telescope. Several types are available, as refractors, Newtonian Reflector, Schmidt - Cassegrain and Maksutov Cassegrain.

What you should also think of the atmospheric turbulence. This refers to the way in which a telescope will show fainter objects. You must also decide how large you want the opening. The greater the degree to gather more light and the result is a sharper image. More opennessThis also means that the telescope is more expensive.

If you have little or no knowledge of telescopes and I'm not sure what to buy, try to ask others who have more experience. This could be someone in a store near you, or perhaps there is a club in your area that is about astronomy. There are forums and review sites online telescope, which are also useful. Most of these people has at least some knowledge and experience in dealing with the telescopes. Magazinesalso an excellent resource to get a telescope and help you be more of astronomy.

There are many different types of telescopes specially designed for specific purposes. That's why it is so important that research before buying one. Want to be your telescope in place, in a way that is suitable for your purpose to perform. Of course, you also decide how much you are willing to spend on one. In general, the most expensive model, theThe higher the quality.


What you should know before buying a telescope

Pamper Swaddlers Order

Thursday, August 4, 2011

Celestron 76LCM Computerized Telescope

!9# Celestron 76LCM Computerized Telescope

Brand : Celestron
Rate :
Price : $299.00
Post Date : Aug 04, 2011 14:24:22
Usually ships in 1-2 business days



All glass, fully coated optics reveal the depths of our solar system and the wonders of the Universe. Fully adjustable Tripod features a convenient accessory tray. Easy to use computerized hand control allows user to locate objects at the touch of a button

Promo Oxygen Concentrators Dutch Oven Tramontina Decide Now




Sponsor Links