![]() The historical prime meridian runs through a telescope established in 1851 by Sir George Airy at the Royal Observatory at Greenwich, England. Pre-GPS techniques actually responsible for the Greenwich shiftīy Stephen Malys, John H. ![]() He and his colleagues detailed their findings in the August issue of the Journal of Geodesy (opens in new tab).įollow us, Facebook & Google+. "It was fun coming up with conclusive evidence as to what really happened with the prime meridian, and why," Seidelmann said. "We found that each place had a different past value for their coordinates, probably based on how gravity caused a local deflection of the vertical." "We contacted friends who knew what their coordinates had been to go out with GPS receivers to take a reading to see whether there had been a change," Seidelmann said. With the aid of colleagues around the world, the researchers also found that the problem was not limited to Greenwich. The offset between these two kinds of verticals explains why the prime meridian now runs 334 feet (102 m) east of where it did, Seidelmann said. The verticals this strategy measures do go through the center of the Earth. ![]() In 1984, scientists began using satellites to precisely measure latitude and longitude coordinates on Earth's surface. This means the vertical there "did not go through the center of the Earth," Seidelmann told Live Science. ![]() Since Earth's mass is not spread out evenly, this means its gravity field is stronger in some places and weaker in others.Īt Greenwich, Earth's gravity field does not pull straight downward. Anything that has mass has a gravity field that pulls objects toward it, and the strength of this field depends on that body's mass. The problem with this strategy is that Earth's gravity field varies in strength over its surface. The act of "determining the vertical," or knowing which way was straight down, in turn depended on watching a basin of liquid mercury - gravity pulled the fluid downward so it was level with the horizon. These astronomical calculations depended on navigators knowing how their instruments might be tilted with relation to the positions of the moon and stars, explained study co-author Ken Seidelmann, an astronomer at the University of Virginia in Charlottesville. The apparent position of the moon and stars depends on where Earth is facing, and since Earth spins on its axis at a regular pace like a clock, knowing where Earth is facing can help navigators deduce their time and longitude. The prime meridian was used to establish Greenwich Mean Time, upon which all other time zones now depend.īefore clocks accurate enough to pinpoint longitude were developed, navigators gazed up at the night sky to determine time. Īfter inventors created timepieces accurate enough to help navigators calculate their longitude, an international conference in 1884 officially established the prime meridian through Greenwich. If navigators can know what time it is at a fixed reference point, such as the prime meridian, the difference between the time at that reference point and the time wherever the navigators are located can help pinpoint the distance of their ships from that fixed location, and thus determine their longitude. A line of longitude can be thought of not just as a marker of space but also of time - for instance, the eastern United States is an hour or more ahead of the western United States. In contrast, the key to calculating longitude is rooted in time. Latitude is relatively easy to calculate, using an instrument such as an astrolabe to measure the altitude of the sun or a charted star over the horizon. Britain once ruled the waves, and so the Royal Observatory at Greenwich near London ultimately became the reference point for longitude. However, the location of the prime meridian, which marks zero degrees longitude, is completely arbitrary - it could be located anywhere. In the case of latitude, the easiest place to start from and set as zero is the equator. In order to define a location in terms of latitude and longitude, one first has to have starting points both for the lines running north to south, known as meridians, and those running east to west, known as parallels.
0 Comments
![]() The website states that Business users get VIP support, but it doesn’t explain the difference between regular and VIP-just that help is available “whenever you need it.” As mentioned above, Enterprise subscriptions come with a dedicated account manager and onboard engineer. With 1Password, you’ll have access to 24/7 support via email. ![]() Your passwords are also protected with Secure Remote Password (SRP), which adds another layer of credential authentication. Beyond that, you’ve got your Emergency Kit, which includes a secure key you’ll need to use when logging in.ġPassword provides two-factor authentication with Authy and Microsoft Authenticator (opens in new tab), and it comes with security breath alerts, protection against keyloggers, and AES 256-bit encryption. Accounts are locked by a master password, which is never shared with 1Password or any third parties. (Image credit: 1Password) 1Password: SecurityġPassword uses a wide range of tools to keep your information as secure as possible. This is a highly responsive app, too, with changes on one device showing up on other devices almost instantaneously. It makes creating passwords easier – and speeds up categorization, too. You’re able to choose from more than two dozen security categories – from straightforward login and credit card details to medical records and passports – and each category collects different kinds of relevant information. In the main window you can see all your passwords, messages or alerts, and the search box – which is extremely fast.Īdding new passwords is simple and comprehensive. Here you’ll also find the Watchtower, which keeps track of security breaches, and lets you know if your details have been compromised. On the left-hand side there’s a navigation column that allows users to access their private or shared vaults, tutorials and their popular passwords. The latest version of the app adds support for the Apple Watch. ![]() Along with mobile apps for iOS and Android, the platform also provides desktop apps for macOS, Windows, Chrome OS, and Linux, plus a command-line tool and extensions for popular browsers including Chrome (opens in new tab), Edge (opens in new tab), and Firefox (opens in new tab). 1Password: Interface and performanceġPassword provides convenient access on virtually all devices. Changes are automatically synced across all devices, so you can use 1Password seamlessly on all your devices, including your computer, tablet, and phone. The setup process includes an option to create and download an emergency kit – a PDF with all the information needed to recover your account if you get locked out.Īfter creating an account, you can start adding items and vaults. 1Password doesn’t require credit card information during setup, so you can sign up without taking on any risk. These include setting a master password, which secures all of your information. You can start using 1Password after taking a few quick steps to create your account. (Image credit: 1Password) 1Password: Setup ![]()
![]() KScreen - KDE's screen management software.Disman - General screen management software for different compositors based on KScreen.Qtile - A full-featured, hackable tiling window manager written and configured in Python, now supports wayland.Weston - Reference compositor for Wayland.Vivarium - A dynamic tiling Wayland compositor using wlroots, with desktop semantics inspired by xmonad.Velox - Velox is a simple window manager based on swc, inspired by dwm and xmonad.Great starting place for compositor development. tinywl+ - A stacking wayland compositor based on tinywl.Sway - i3-compatible Wayland compositor.river - A dynamic tiling Wayland compositor.newm - A Wayland compositor written with laptops and touchpads in mind.Mutter - A window and compositing manager that displays and manages your desktop via OpenGL.labwc - A stacking Wayland compositor with look and feel of openbox.KWin - KDE window manager and compositor.Kiwmi - A fully programmable Wayland compositor.japokwm - A wlroots based dynamic tiling wayland compositor based around creating layouts.Hyprland - Hyprland is a dynamic tiling Wayland compositor that doesn't sacrifice on its looks.hikari - A hybrid stacking/tiling Wayland compositor.Cardboard - A scrollable tiling Wayland compositor.Cagebreak - A Wayland tiling compositor inspired by Ratpoison.wl-clipboard - Command-line copy/paste utilities for Wayland.copyq - CopyQ is an advanced clipboard manager with editing and scripting features. ![]() clipman - A simple clipboard manager for Wayland.Surfer - Simple keyboard based webkit2gtk browser.Qutebrowser - a keyboard-focused browser with a minimal GUI.Viper Browser - A lightweight browser using QtWebEngine.Crusta - Fast, modern and minimal desktop web browser with rich features.Tor Browser - Tor Browser Bundle: anonymous browsing using Firefox and Tor.Librewolf - An independent fork of Firefox, with the primary goals of privacy, security and user freedom.Firefox - For using Firefox on wayland just add MOZ_ENABLE_WAYLAND=1 to your environment variables.Wlsunset - Day/night gamma adjustments for Wayland compositors supporting wlr-gamma-control-unstable-v1.Gammastep - Day/night gamma modifier that adjusts the color temperature of your screen.No Wayland-specific requirements, so you can use your xorg solution of choice to control screen brightness, like brightnessctl, brillo, light, or just directly manipulate /sys/class/backlight. If you want to contribute, please read this. A curated list of Wayland code and resources. |