|Light reflected off of objects is the result of electrons giving off photons. Presumably, under normal circumstances, not all the electrons are in sync; i.e. they don't all simultaneously give off photons: they are staggered. But what about when you turn on a light in a totally pitch black room? It is known that the eye is slow to react to such changes, but might part of the resulting brightness be a result of the initial combined barrage of all the exposed electrons giving off photons? I suppose the ideal answer to this would be to get a really super-sensitive light meter and try it.
|Why are there curbs next to sidewalks? Why not just paint the edge of the sidewalk where necessary?
|When you're traveling faster than the speed of sound, and you slow down, do you hear your own sonic boom?
|Why is "Dvorak" pronounced [dvorjak]?
|How do leaves get stuck under windshield wipers?
|Why won't CDs copy 1:1? I.e. why can't 1s and 0s get read from the original and put in the same place on the copy? Why do some CDs copy and others not?
|Why do car windshields have a blue-tinted stripe at the top?
|Why do cars with manual transmissions burn oil when traveling over 55mph in neutral?
|Why is freeway noise louder on some days than others?
|Why does February have only 28 days?
|Why is it that when I open the windows in my home on a warm day, only cold air comes in?
|What compels a cockroach, when it dies, to crawl out to the middle of the floor, flip upside-down, and then explode?
|(1-2-12) Do electronic devices really present a hazard to an airplane? Why am I allowed to turn them on above 10,000 feet?
|I'll answer myself, because I get asked it all the time. There are two reasons here:
1) Below 10,000 feet, during the taxi-out and takeoff and departure, and again during the arrival and landing and taxi-in, are considered "critical phases of flight." This is the time, statistically speaking, when accidents are most likely to occur. If there were an emergency, you don't want to be distracted or burdened by your shiny device - you want to exit the aircraft as quickly as possible, with your hands free to help yourself climb out of the airplane. If you're seated in an exit row, everyone else on board is putting their life in your hands. So if you find yourself with some extra leg room, I personally would prefer that you not only stay awake, but don't even read. Just be ready to open that door.
2) An airplane's electrical system and avionics are tested and guaranteed to work with all of the airplane's electronics on and functioning. It is NOT tested or guaranteed to work with a bunch of other electronic devices powered up. On the ground and parked, I've held my cell phone within a couple feet of the compass and watched the compass card spin around madly. I've also heard the most annoying buzzing in the speakers, and have been unable to communicate on the radios as a result. Granted, passengers don't sit that close to the compass or radios, but there are wires running all along the sides, floor, and ceiling of the fuselage, along the entire length of the airplane. There are antennas located all along the top and bottom of the airplane. Any electronic device puts out a small electrical field. For proof, try holding up a light bulb within 10 feet of a high-voltage power line: it lights up. That's an extreme case, but you get the idea. One could argue that a particular devices is "probably" safe, but do you really want to risk your life and the lives of everyone else on board on "probably?" No one can afford to test the millions of different devices ever made on every model of aircraft ever made. There are some exceptions to this policy, like pacemakers, oxygen concentrators, and electric shavers, because those devices have been tested, and they're safe.
|(5-23-98) Has anyone converted "Descent I" levels to "Descent II" levels? And if so, where can I get them?
|Sort of. If you have the original files, you can install the "Rebirth" mod from http://www.dxx-rebirth.com. (or you can grab it here)
A mod for "Descent II" is also available, both at that site and here.
|(12-7-02) How did "Uncle Sam" get his name?
|Common folklore holds origins trace back to soldiers stationed in upstate New
York, who would receive barrels of meat stamped with the initials U.S. The soldiers jokingly referred to it as the
initials of the troops' meat supplier, "Uncle" Samuel Wilson, of Troy, New York. The 87th United States Congress
adopted the following resolution on September 15, 1961: "Resolved by the Senate and the House of Representatives
that the Congress salutes Uncle Sam Wilson of Troy, New York, as the progenitor of America's National symbol of
Uncle Sam." A monument marks his birthplace in Arlington, Massachusetts, and a monument marks his burial in
Oakwood Cemetery, Troy, New York.
Another theory suggests that Uncle Sam was a creation by Irish immigrants to the US who used the Gaelic acronym, SAM, or Stáit Aontaithe Mheiriceá, which is the translation for United States of America, as a nickname for their new host country. Unfortunately, however, the precise origin of the term may never be proven.
|Why is it "Lock and load" when you have to load first, then lock?
|You have to push and "lock" the magazine in place before pulling the charging handle to "load" the round.
|I think it comes from a time when rifles were single-shot breech-loaders. To load a new shot you open the breech (lock) and load in the new shot. This goes for both rifles and artillery pieces. I assume you know that the frase "Rock 'n' Roll" is often used instead?
-Henrik G Ewald
|(11-5-97) When a star goes supernova, does the matter travel slower than, at, or faster than the speed of light?
|Slower than. The speed asymtotically approaches c for smaller particles on the wavefront during the initial stages of the explosion. My guess.
|(1-8-98) A black hole sucks in light. Does that light travel faster than the speed of light?
|Again, no, in this case by definition :-) AFAIK it would just "seem" like steadily increasing gravity all the way in, and you'd never hit anything. Well, the academic question of "what when you get to the center" involves waiting longer than the expected life of the universe due to time dilation as you speed up. Even at or inside the Schwarzschild radius I personally go for the theory that nothing special happens to an observer, there's no red line saying "point of no return".
|(4-18-98) If you travel away from earth close to or faster than the speed of light, then come back at a similar speed, it is theorized that you will have aged less than the people you left behind. If you travel far enough, and fast enough, will you eventually return before the time you left? If so, will you see yourself? Before you left in the first place, will you have been able to see yourself returning?
|No. There will always be positive elapsed time. You can slow to timespeed zero by traveling at the speed of light, provided you can endure infinite acceleration while expending infinite energy to get
that :-) So in real life your bussard ramjet will take a few sidereal years to reach an appreciable fraction of the speed of light, and at that point relativistic effects become obvious and your local time starts noticeably slowing down wrt to your twin on earth. Eventually (barring accidents, and assuming your ramjet can handle it) you will get close enough to the speed of light that wandering round the galaxy would become practical, and you could even live to see the heat death/big splat. Where I get confused is the local terms/external terms thing. To me, you're traveling "at" c, but to you time is slowed down, so you would seem to you to be exceeding the speed of light. I'm not sure if this is correct, as it seems to violate the idea of frames of reference.
|(6-8-98) What is "ain't" a contraction of? "Doesn't" is a contraction of "does" and "not"; "isn't" is a contraction of "is" and "not". So is "ain't" a contraction of "ai" and "not"? If so, then what does the verb "to ai" mean?
|Perhaps Ain't is a derived from Aye + Not (as in Aye Captain)
|I have always taken the contraction Ain't to Replace the phrase Am I Not, and it has always seemed to fit alright, As far as for me, Am I not Is what Ain't means, but hey...I'm not right about everything, Amn't I?(just a [very] little humor there, ok I'm done for now...no more from me....promise...last word..ok I've gotta sign my name....)
-Tyler Harms (aka "Eggy")
|Regarding your question below. I'm not a native speaker, but I've always
assumed that ain't was short for "have not". 'You ain't seen nothing yet'.
Fits the uses I know and seems a reasonable sound migration.
|(5-17-98) How come "ain't" is considered a double-negative, but a "no-no" isn't?
|"Ain't" is not considered a double negative. However, "ain't not" is so considered. But it blows my mind that someone thought "ain't" is considered a double negative. Where on Earth did he
or she get that notion? "Ain't" is slang, but it's just a contraction
of "isn't" and has never been felt to be a double negative.
|(10-21-98) I've heard the follwing question so many times, that I felt it was time to explain it to the world: Why do airlines make you keep your seatbelt on while the plane is moving very slowly on the ground, but let you take it off while in the air?
|If something were to give the airplane such a jolt as to absolutely require your being restrained, you may not want to live through the long drop anyway. As far as I can tell, the only reason airlines require passengers to wear seatbelts while in the air is to exempt them from being sued. "I'm sorry about your daughter's decapitation ma'm, but there's nothing we can do. She did willfully refuse to obey the captain's fasten seatbelt order." As far as I know, no-one has ever been injured during normal flight. The ground is a different story. We all know how bad parking-lot accidents are in cars. Now imagine that car is on stilts. Now this accident would not only involve whiplash, but also a short, violent drop. Not enough to kill anyone, but you get the idea.
|(6-22-98) Why are there curbs next to sidewalks? Why not just paint the edge of the sidewalk where necessary?
|This is to help keep cars from going onto sidewalks when the driver loses controll. I also warns the driver when he's too close when he's trying to park alongside a sidewalk.
-James "Dewback" Davis
|(6-6-00) When the Spanish were exploring California, did they ever report earthquakes?
|The answer is a big yes.
|(10-23-98) Why is the speed of light the end-all and be-all of speed barriers? How is it that different from the speed of sound?
|Technically it is not the speed of light which is a barrier, it is the speed of a "massless" object in a vacuum. The speed of light can be altered quite drastically by the medium it is traveling through. In fact recent experiments have slowed light down to 1.6km per hour... (see here). and others have sped it up to 300 times "the speed of light" (see here). Now if terms of getting an massed object to exactly the speed of light, traditional physics states that you would require an infinite amount of power. (the power required to approach the speed of light grows asymptotically)... an interesting note is that once you exceed the speed of light, it would appear the same amount of power is required to slow you back down. It is also reported that mathematically, it is possible to sidestep the problem by creating a "warp bubble". (see here). Abstract: I show how a minor modification of the Alcubierre geometry can dramatically improve the total energy requirements for a `warp bubble' that can be used to transport macroscopic objects. A spacetime is presented for which the total negative mass needed is of the order of a few solar masses, accompanied by a comparable amount of positive energy. This puts the warp drive in the mass scale of large traversable wormholes. The new geometry satisfies the quantum inequality concerning WEC violations and has the same advantages as the original Alcubierre spacetime. The two big problems to be resolved are:
1) how do you get an object inside a warp bubble?
2) What happens to the object when the warp bubble collapses?
Sound is the propagation of wave compression though the medium its in. It cannot travel through a vacuum. Since air can compress and uncompress only so fast, that restricts how fast sound can travel. Incidentally sound also travels at different speeds based on the physical medium (e.g. faster through solid objects)
|(8-2-99) Why is the phrase "slept like a baby" used to refer to a good night's sleep? I've never heard of a baby sleeping through the entire night.
|"Sleeps Like a Baby" refers to the un-troubled sleep of one with no worries. And yes, babies do sleep through the night sometimes. Young children even more so. Remember those childhood days when you fell asleep and then the next thing you know it's morning?
last modified 30 June 2017