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Tag Archive for 'VI'

The Laser Elevator

Solar sails suck.

In a 2002 paper, Laser Elevator: Momentum Transfer Using an Optical Resonator (available at your local school/library, possibly electronically — J. of Spacecraft and Rockets 2002), Thomas R. Meyer et. al. talk about a neat way to get a lot more speed out of light reflection than with a regular solar sail. The basic physics are pretty simple, and it’s a fun subject to think about.

When a photon hits a solar sail, it gives the sail momentum. If the photon has momentum P and bounces off a stationary sail, it looks like this:

Think of where the energy is in this system. Before it hits, the photon has energy E. After it bounces, the photon still has roughly energy E. But the sail’s moving, so where did it get its kinetic energy? (Remember, energy — unlike momentum — has no direction.)

The answer lies in the word “roughly”. The photon loses a tiny fraction of its energy to Doppler shifting when it’s reflected, but only a tiny fraction. It is this tiny fraction that goes into pushing the sail. This is a phenomenally small amount of energy — far less than a percent of what the photon has. That is, not much of the photon’s energy is being used for motion here.

This is why solar sails are so slow. It’s not that light doesn’t have that much energy, it’s that it has so little momentum. If you set a squirrel on a solar sail and shone a laser on the underside, do you know how much power would be required to lift the squirrel? About 1.21 gigawatts.

This is awful. If we were lifting the squirrel with a motor, railgun, or electric catapult, with 1.21 gigawatts we could send it screaming upward at ridiculous speeds.

This is where Meyer and friends come in. They’ve point out a novel way to extract momentum from the photon: bounce it back and forth between the sail and a large mirror (on a planet or moon, perhaps).

With each bounce, the photon loses a little more energy and adds another 2P to the sail’s momentum. The photon can keep this up for thousands of bounces — in their paper, Meyer et. al. found that with reasonable assumptions about available materials and a lot of precision, you could extract 1,000 times the momentum from a photon before diffraction and Dopper shifts killed you. This means you only need 1/1,000th the energy to levitate the squirrel — a mere megawatt.

This isn’t too practical for interstellar travel. It requires something to push off from, and probably couldn’t get you up to the necessary speeds. It may, they suggest, be useful for getting stuff to Pluto and back, since (somewhat like a space elevator) it lets you generate the power any old way you want (a ground nuclear station, solar, etc). But more importantly, it’s kind of neat — it helped me realize some things about photon momentum that I hadn’t quite gotten before. It’s like Feynman says, physics is like sex — it may give practical results, but that’s not why we do it.

Now we’ll let things get sillier. I spent a while trying to brainstorm how to use this with a solar sail (that is, using the sun). I imagined mirrors catching the sun’s light and letting it resonate with a sail.

But you really need lasers for this — regular light spreads out too fast. Maybe a set of lasing cavities orbiting the sun …

Supplemented by a Dyson sphere …

And since by this point we’ll probably have found aliens …

Why settle for interstellar communication when you can have interstellar war? And we could modulate the beam to carry a message — in this case, “FUCK YOU GUYS!”

WCS Server!

I’ve set up a WCS server over at 202.60.93.58:27085 for you all to enjoy.

If you don’t know what WCS is, it is Warcraft: Source, It’s a modification for Counter Strike: Source.

Monkey, viBe, Chaos and Me are the admins!

Say that you come to my blog often and I might just give you some levelz!

Fancy Pants Adventure: World 1

Fancy Pants Adventure is a side scrolling platformer, like a cross between Sonic and Mario. This game is the first in the Fancy Pants series, and has been given the name World 1. Use the LEFT and RIGHT ARROW KEYS to move, press the “S” KEY to jump, and the DOWN ARROW to crouch. The UP ARROW is used to open doors. To go into a roll, either hold the DOWN ARROW on a steep slope, or hold it while mid air to land in a roll. Have fun playing this cool game!

[kml_flashembed movie="http://viewables.killcoder.info/games/fancypantsadventure.swf" height="480" width="700" /]

Why You Should Dump Internet Explorer

The time has come to dump Internet Explorer, period.

My argument is simple: the benefits of using IE are too few - and the faults too great - to put off the adoption of an alternative any longer.

Security

Just about everyone reading this has seen computers that have been beaten down with spyware - the evil junk that hijacks IE and renders a system virtually useless. How many times have you been called to a family member’s house to clean up their system? I get called multiple times a month! Or had to call your techie friend to come clean yours? It’s often quite awkward - the system slows to a crawl and every other mouse click conjures up some species of perverse, obscene image. What most people don’t realize, however, is that there is a very simple and powerful way to defend your system (and/or the systems of your loved ones) in one fell swoop.

Don’t use Internet Explorer.

What makes other browsers better than IE at protecting vs. spyware and other attacks? Well, it’s simple really - most other browsers don’t make it so easy to install malicious software on your system without you knowing about it. IE makes it relatively trivial through two features called ActiveX and Active Scripting. These technologies were designed specifically for the purpose of giving Web sites more control over a user’s computer. Unfortunately, as we have seen with exploit after exploit - that’s not always a good thing.

In addition to the spyware issues, IE in general has had a terrible track record when it comes to all types of serious security issues. For years now, it’s seemed like every time you turn around there is a new way to have your computer taken over via Internet Explorer. Put “internet explorer” and “allow an attacker to execute commands” (with the quotes) into Google and you’ll see what I mean.

In IE’s defense, many anti-Microsoft types will claim that it’s not possible to lock down IE at all. This is not true. It is possible - but if and only if you have a fair amount of technical know-how on the subject, and the time to do it. My personal view, however, is that tools such as Internet browsers should not require expertise and configuration time to be able to use them safely.

Standards

This is likely to get me in some hot water with my fellow security enthusiasts, but I find this issue to be of even more concern than that of IE’s security. The Internet works for one simple reason - everything at its core has been built on agreements that bind it together. Whether a computer is connected from California or Sri Lanka, it’s going to speak the same language and obey the same rules - the rules defined by standards. If this weren’t the case there would be no Internet at all. These agreements are forged by a body of people whose goal is nothing short of designing a better and more efficient Internet for everyone. Microsoft, for some odd reason, seems bent on breaking stride with these agreed-upon standards. Case in point: the next time you’re in a bookstore, head over to the technology section and pick up a book on XHTML or CSS. These are two major Web standards that deal with how Web pages are displayed to users, and within any book on the subjects you will find one common theme:

The absolute worst browser when it comes to supporting the standards is Internet Explorer.

Page after page in these books will reveal features supported in other browsers, but not in IE. Ask yourself why a company would choose not to support standards that benefit everyone? The way I see it, it’s for precisely one of two reasons - either they are unable to, or they don’t want to. Given the fact that they are a multi-billion dollar company (one of the richest on the planet), I can’t help but lean toward the second option. Without going into too much detail, they have their own plans, and those plans involve implementing their own standard and forcing it upon the world. Call me a geek/hippie, but the idea of a multi-billion dollar corporation snubbing its nose at agreed-upon standards is nothing short of infuriating.

Options

Lucky for us, we have alternatives. The good news is that the alternative browsers are actually as good or better than IE. There are many out there, but in my opinion the Mozilla products are the best. I personally prefer and recommend Mozilla Firefox. Not only does it keep your browsing sessions a lot more secure and spyware-free, but it also supports the standards religiously and has a wide range of powerful features. Arguably the biggest benefit to using a Mozilla-based product is something called tabbed browsing. I don’t care if IE 7.0 has it, mozilla does it BETTER. What this allows you to do is have multiple pages open within a single browser window. Rather than going from window to window in the taskbar, you can simply switch between clearly visible tabs, all within the same view. You can even do this and many other commands via the keyboard if you are into that sort of thing.

Using Firefox will not require any major shift in your daily browsing habits. It’ll import your favorites automatically, and you can benefit from the improved security starting the first time you open it. With the popup blocking enabled, you can breath quite a bit easier when browsing to unknown sites. Attempts to install garbage on your system that could have easily succeeded if you were using IE will simply be ignored by Firefox. Infact, it only notifies you that it’s happening if you want it too. The most annoying thing is that yellow bar coming up every time you change webpage in IE, Firefox doesn’t do that. Plus, the whole time you’re browsing you’ll know that you are doing your part to keep the soul of the Internet alive by choosing to use a browser whose developers actually care about standards.

Wrapping It Up

So, in closing, I leave you with two thoughts:

  1. Due to the combination of ActiveX, scripting, and its integration with the Windows operating system, Internet Explorer is more vulnerable to attack than many other browsers.
  2. The designers of Internet Explorer have purposely turned their back on the standards designed to benefit the Internet as a whole. They have done this for years, continue to do it today, and appear to have nothing but their own interests at heart.

I ask that you consider these points and pull down a copy of Firefox. Run it for a week and see how it feels. As mentioned above, I personally recommend Firefox due to its excellent development team and large user base. Once you have had some time to get to know your new on ramp to the Web, I think you’ll find that you’ll wish you had switched sooner. No longer will you have to worry about garbage clogging up your system because of your browser, or having to make a mad rush for a patch every time an IE vulnerability is released.

Finally, and most importantly - spread the word. It’s time now for us to put alternative browsers on the map and let it be known that we are aware of our choices. We need not settle for what we are being fed when there are better, more secure alternatives out there.

So do it:

You know you want to!

PowerLabs Can Crusher

Why crush a can yourself when you can get 22.7 Million Watts of electricity and a Magnetic field 260 thousand times the field of Earth to do it for you!

Over half a thousand US Dollars worth of equipment… The second largest semiconductor currently in production… 260 THOUSAND times the magnetic field strength of Earth… 22.7 MILLION Watts of electricity… Enough energy to kill a person 250 times over… Enough power during a single discharge to supply Adelaide… Several days worth of work… The ability to smash an aluminum can with no physical contact, and to do it so fast and heat it so much in the process that it sounds as though the can is exploding as the drink inside it boils off…
Why?
Simple…

BECAUSE I CAN.

(Sorry, couldn’t think of a better reason :)

See pictures and videos and vague instructions at PowerLabs

Power Supply

PowerLabs Power Supply

For the power supply, a bank of 20 inverter grade electrolytic capacitors, as seen above, 10 are Nippon-Chemi Com (the brown ones) and 10 Powerlytic (the blue ones). They are all arranged inside a clear Plexiglas box measuring 70×15x15 cm and weighting a total of 13.5kilos (some 24pounds). All capacitors are rated for 450V max and store a 1500uF charge. This amounts to 150Joules each, or, 3000Joules in total. The capacitors are interconnected using 2cm wide, 1mm thick copper buss bars (for low inductance) and, for this particular experiment, are connected as a 900V bank at 7500uF.
Above the capacitors is a Digital Multimeter reading the actual charge voltage (in this case 0volts). The multimeter is essential as it allows me to monitor the charging rate, the actual charge voltage, and any residual charge left in the capacitors after a discharge. It is also essential for safety. The box serves to insulate the capacitors from one another and prevent electrolyte from spilling out in the event of a capacitor failure. It is worth mentioning that such a capacitor bank is VERY LETHAL!

Do not operate with any metal near you or it you don’t want CRUSHED! PowerLabs is very power hungry…