I thought that time was invented so everything didn’t have to happen at once. Of course in ICU nursing it usually does anyway. 
Oh, and my thanks to Grey, QED,& MC for taking the side trip to answer my question. I will seek out the recommended reading.
Regarding the Planck Scale;
There is a measurement called the Planck Mass which is 10^-11 gram(kilogram?) which is NOT the quantum of mass…indeed, anything smaller than molecules weigh less than this.
Mass/energy is apparently continuous.
Space/time, being a non-substance, is even more so.
The Planck scale only reflects the limits of measurement with our present understanding og Relativity and Quantum Mechanics.
Og Relativity?
Og no like Relativity!
OG SMASH!!
The Planck mass is actually 2.1767 × 10[sup]-8[/sup] kg.
And don’t tell the quantum guys that energy is continuous, they’ll have to throw all their stuff out.
Other than in bound states energy is continuous and can take any value. When talking about photons energy equals Planck’s constant times the frequency, so for a specific frequency you only have one value of energy, but again, other than in bound states, the frequency can be anything, and therefore so can the energy.
Also, nature seems in many respects to be scale dependent. In other words properties can be continuous at one scale and discontinuous at another.
i don’t understand why the speed of light should be able to diverge if time were quantised. how can a physical process occur in places that do not exist (i.e. between two adjacent time quanta)? if time were quantised, wouldn’t that mean that the speed of light can not fall between two time quanta, but has to settle for an eligible speed which then CAN be measured?
speed is a function of time and distance. both time and distance are quantised in this theory, so their product has to be quantised as well. if you multiply integer numbers, the outcome will always be integer, never decimal. (excuse my clumsy use of terminology… i’m sure i used some terms wrong, please correct me.)
in any case, has the speed of light ever been measured down to where planck time stands in the way?
C= Planck Distance/Planck Interval
IANAPhysicist either, but here’s what I thought the previous poster had meant:
Let’s suppose that there are Planck units for time. Let’s also suppose that light travels 3 microKeeves (mK for short) in 1 Planck Time Unit (PTU). That would suggest that the speed of light is exactly 3 mK/PTU.
That means that light travels 6 mK in 2 PTUs.
Now, I ask you, how long does it take light to travel five mK?
The correct answer cannot be 1 2/3 PTUs, because you can’t break up a Planck Time Unit. If you round it to 2 PTUs, then you’ve done one or the other of two possibilities:
– (1) You’ve said that the speed of light in this case was actually 2.5 mK/PTU, which means that the speed of light is not constant; or
– (2) If you insist that the speed of light remains constant, then at 5 mK, our photon was both 5 and 6 mK away from the starting point, which is absurd.
I can see one case where all the above calculations would work out okay, and that is if a Planck Time Unit is defined as the length of time it takes light to traverse one Planck Distance Unit. Could that be what the article said?
Simulpost! Thanks, Enola!
Now I think I am missing something here.
How does Planck time equate to quantizing time?
First off I seem to recall Chronos and maybe Ring or a few others around here saying that the Planck anything is not necessarily the smallest (whatever it is you’re measuring) you can get. It is merely the limit at which humans can hope to measure anything.
Secondly, I thought Planck Time was merely the measurement of time it takes light to cross the Planck Length. Where is the quantized time or speed of light here? Light runs at a constant speed and time and the speed of light are related (not sure how to put that in physics terms but I mean that altering one affects the other in equations). So we can’t measure a shorter time than Planck Time but I son’t see how that implies a quanta of time.
Did I miss something here?
Well since the microKeeve is shorter than the Planck length I think it’s a meaningless question.
maybe the universe.exe would crash or something.
you can say that at the given time the probability of the photon’s defined position hasn’t reached 1 yet. kinda like electrons behave (though a little different). they don’t “are” neither at 5mK nor at 6 mK, but neither at somewhere in between. they spray a probability cloud around those two positions.
a different approach: light particles would behave like electrons in the double slit experiment. some will settle for 5mK while others will jump to 6mK.
That’s incorrect. The limit has nothing to do with our inability to come up with a way to measure. It’s a fundamental aspect of reality. I’ve read (I think in one of Hawking’s books) that “even God can’t know.”
Einstein disproved this classical concept with his black-body radiation paper, thus paving the way for “The New Physics.” If energy were free to exist in any quantity it wanted, black-bodies (such as iron) would glow blue at all temperatures.
I’m reading “The End of Time” by Julian Barbour - will probably start a GD thread soon.
Very well put. Somehow I forgot that we’re talking quantum physics here. Thanks.
I love the imagery of “They spray a probability cloud around those two positions.” Just sounds so dirty!
My dear Ellis Dee I suggest you look up the quantum mechanical difference between a bound state and a free state.
The separable solution of the “Time dependent Schrodinger Equation” (TDSE) for a bound state is the “Time Independent Schrodinger Equation” (TISE) which is an eigenvalue equation:
H(psi) = Lambda(psi)
Where H is the Hamiltonian operator and Lambda is the energy eigenvalue. In these states, and only these states, energy is quantized. For all other states and as a general rule energy is a continuous variable.
Ring is correct. To explain/solve the blackbody radiation problem, all you need is to accept that energy is quantized into discrete packets (photons). The energy of each photon can be anything.