What Does PDT mean? does it have to do with time?
610440
pacific daylight time
645936
Delta simply means "change in".  It is used to indicate a change over a given period of time.  If you are looking for an "average" value, you use "delta N over delta t".\n\nThe "d" as it is used in your question refers specifically to a change over an infinetessimally small period of time.  If you are dealing with a specific point in time, in other words an "instantaneous" value, then "d" is used rather than delta.
219704
Do you mean that it is behind the time?\n\nIf so it just offsets the time. It does not keep you at work longer.
1012693
I'm not sure what he means by his explanation, but he's not totally off to think there would at least be a possibility of the longest 'day' not being adjacent to the shortest 'night'.\n\nAs measured from the Sun's local zenith to the next local zenith, solar days are not the same length of time (24 hours is just the average amount of time to get from noon to noon).  It takes longer to get from local noon to the next local noon at the solstices when the Earth is tilted directly toward or directly away from the Sun.  The shortest solar days (noon to noon) should be at the equinoxes.  (In other words, if there are more total seconds in the solar day at the solstice, then having the most daylight seconds doesn't necessarily mean having the shortest night time seconds).\n\nAdditionally, the Earth's orbit is slightly elliptical.  At perihelion (closest point to the Sun), the Earth is traveling faster and sweeping out a bigger angle per second.  That means the Earth has to rotate further to get back to noon the next day.  Solar days near perihelion are longer while solar days near apohelion (furthest from Sun) are shorter.  This is where your dad's argument starts to break down.  The Earth is at apohelion around the first week of July and at perihelion the first week of January.  In other words, there are more seconds in a solar day in the winter than there are in the summer.  The tilt of the Earth is more significant, so there are still more seconds in a solar day near the summer solstice than either equinox, even if the longest solar day (noon to noon) isn't in the summer.\n\nThe biggest reason his argument breaks down is sheer magnitude.  The variation in the length of a solar day is in seconds/day while the difference in the amount of daylight/darkness can be minutes/day (the amount of variation depends on a person's latitude)\n\nFor 2006, the longest daytime period will be on Jun 21, with the shortest nightime period being Jun 20 or 21 (the Naval Observatory's charts only list hours and minutes).
156038
That means they change wih time. I do not understand your question. \n\nSuppose I measure the electric field at some location, X=10. If I move a charge close to X=10, say to X=9, then away to X=1, then back to X=10, then the electric field varies with time as I move the charge closer and then farther. It is a time varying electric field.
269676
Is that 3 a.m. GMT? E.S.T? Swatch time? Spirits often get confused by time zones. I was once visited by a sprit who thought it was 3 a.m. but it turned out to be jetlag.\n\nCome on... don't believe that religious hocus pocus. Probably your mind has set up some kind of internal "alarm clock" for any number of reasons. It'll go away eventually - spirits or no spirits.
280410
Are you sure you have the correct PD number? Here is the listing by index of all PDs.... hope this helps
1096313
The word bardo literally means "an interval between two things." Bar means 'interval' and do means 'two'. We can think of this interval in a spatial or temporal way. If there are two houses, the space between them is a bardo. The period between sunrise and sunset, the interval of daylight, is a bardo. A bardo can be of long or short duration, of wide or narrow expanse.\n   To a large extent our experience is made up of intervals between one thing and another. Even in the case of the momentary thoughts that arise in our mind, there is an interval between one thought arising and fading and the next thought appearing. Such a gap, even if infinitesimal, is part of every process. Everything we experience has this quality of intervals between states.
406985
Its to make more evening time ( time before lights on ) available to office workers. In UK they even had double-DST during wwII
914748
The funny looking S thing is an integral sign, the p stands for pressure and the dV stands for a little change in volume.\nIt sounds like the work performed by something expanding at constant pressure.  The work is the amount of energy used.
629015
Its not that the times are different in different countries, it has to do with time zones. There are 16 (I think) different time zones around the world, so that no matter where you are in the world, the time will be about the same to where the sun is.\nTo learn more try the link
395749
"The change to Daylight Saving Time (not Savings!) allows us to use less energy in lighting our homes by taking advantage of the longer and later daylight hours."\n\nAs an aside, my birthday is on one of the last days in October, meaning that sometimes I have a 25-hour birthday... at least until 2007, when the time change back from DST will be pushed to the end of November.
213340
PST is -8:00 GMT\n\nPST= Pacific Standard Time\nGMT= Greenwich Mean Time
58166
its a time in pacific standard time
231203
term is used mostly in lab practicals, it means the lag between the time at which a certain thing happens and the time at which you react to it e.g. suppose using a stop watch you are noting the time taken by a ball to roll down an incline, say 'x' is the time at which the ball reaches bottom and as soon as you 'see' (ur eyes transfer a signal to brain) that the ball has reached bottom  (ur brain 'reacts' and signals hand to stop the watch) you stop the watch at say 'y' this little time lag i.e. y-x is reaction time, the time which you took to react to the stimulus.
122485
Time has to pass means that, in order for change to occur, one must allow time.  Times are changing means that the customs of a particular period are altering into something more relevent to the current period.
415387
It is a relative term.  \n\nFor the Marine Corp drill Sgt who has just given a command...2 seconds.\n\nFor a student, concerned that the teacher will ask a him a question he can't answer...5 minutes\n\nFor a woman who has just found out she's pregnant...9 months.\n\nFor an old man...the next 5 years are longer than the last 80.\n\nFor anyone looking at ages....15 years older or younger\n\nFor a historian....a century or two\n\nFor a geologist....a millennium