Random musings on scale
- Thread starter ddrueding
- Start date
timwhit
Hairy Aussie
Aren't these the same thing?
ddrueding
Fixture
We think of them differently. At least I do. The fun concept that I heard the other day is that due to the rate of expansion becoming greater the further you are from anywhere, there are parts of it that are accelerating away from us faster than the speed of light that are lost to us forever no matter what we do.
Bozo
Storage? I am Storage!
The 'Time Line' was great!
Bozo
Storage? I am Storage!
I didn't think anything went faster than the speed of light.
ddrueding
Fixture
I'm about halfway through a Stanford lecture series on Quantum Entanglement by Leonard Susskind which is amazingly good (despite the video quality). The reason it is taking me so long is that I have to keep going back to Khan Academy to learn the math required.
AFAIK shortly after the big-bang (10^-43 sec to 10^-35 sec) the universe expanded 40-50 orders of magnitude, AKA "inflation". Space itself expanded faster than the speed of light. It's the horizon problem. The observable universe is ~14 billion light years across while the actual universe is about ~ 85 billion light years. And our "universe" may just be a bubble along with hundreds? billions? of other bubble universes within the multiverse.
Of course relativity seems simple when compared to quantum mechanics.
Chewy509
Wotty wot wot.
In addition to what snowhiker mentioned, the current theory is that the amount of energy to accelerate something with mass increases as you get closer to the speed of light (or more correctly, the speed of a photon in a vacuum, as the speed of a photon can change depending on the medium it travels through).
However Feinberg in the late 60's released a paper on the possibility of particles that can move faster than a photon, these were termed tachyons. The theory with tachyons however is that the more energy the possess, the slower the travel (inverse to matter), so a tachyon with little energy moves faster than one with more energy... ( http://en.wikipedia.org/wiki/Tachyon for the basics )
Wikipedia also has a summary of FTL as well: http://en.wikipedia.org/wiki/Faster-than-light
However Feinberg in the late 60's released a paper on the possibility of particles that can move faster than a photon, these were termed tachyons. The theory with tachyons however is that the more energy the possess, the slower the travel (inverse to matter), so a tachyon with little energy moves faster than one with more energy... ( http://en.wikipedia.org/wiki/Tachyon for the basics )
Wikipedia also has a summary of FTL as well: http://en.wikipedia.org/wiki/Faster-than-light
They've measured quantum entanglement and the information transfer seems to run at least 10,000x faster than light.
ddrueding
Fixture
From my understanding, there is no information transfer in quantum entanglement. The orientation of the second entangled bit is determined the instant the first is measured (as near simultaneously as we can measure) regardless of distance, but there is no information that can be extracted from that determination. The person at the first bit knows what just happened at the second, but the person at the second has no way of finding out (without measuring themselves) unless that information is sent using some other method.
What you seem to be describing is that the results are pre-destined (no information transfer need occur, so the results can happen instantaneously regardless of distance because it just is) as opposed to being determined during measurement (If it is determined during measurement, then the results of that measurement needs to transfer to the other particle). Instantaneous, regardless of distance, is much faster than the speed of light! The problem, of course is that if the state is predetermined before measuring then the particles/waves would behave differently than what is observed before measurement. As I said, Quantum Physics gets really strange really quick and I do not understand to the point of feeling unfathomable. Time and space seem simple in comparison.
Mercutio
Fatwah on Western Digital
It's difficult to wrap your head fully around most theoretical physics because you very quickly wind up dealing with units with deeply unintuitive and possibly absolute properties.
Also, if anyone who is NOT a physicist is talking to you about quantum mechanics, it's a safe bet that you can ignore every single other thing they say to you.
Also, if anyone who is NOT a physicist is talking to you about quantum mechanics, it's a safe bet that you can ignore every single other thing they say to you.
ddrueding
Fixture
Of course, Merc is right, but I'm going to keep going with this as well
From what I understand, the only property that two entangled particles have is that they are opposite. This is a property that the particles have before either has been measured or moved apart. My brain tries to keep hold of this thought by arguing that the binary nature of our measurements of spin is the result of some deficiency in our methods of measurement. That it is in fact possible for the particles to be opposite in all axis simultaneously, and that our measurements simply reveal a property that was there all along. I'm fairly certain that there isn't a way to describe how a particle could have the "opposite" property on all axis simultaneously, so they model this "action at a distance" thing because it is easier and explains the observations. So long as they can produce a model that is able to consistently describe real-world experiments, I'll take their word for it.
Stereodude
Not really a
I'm sorry, were you saying something? :erm:
Mercutio
Fatwah on Western Digital
To return to the original question, time has, within the realm of human understanding, a start point (The Big Bang) and can be thought to have an end point as well; the heat death of the universe, when all all energy has been evenly distributed between all existing particles, at which point all motion will cease. Humans mostly have a pretty tenuous understanding of time outside the scale of a few lifetimes anyway; we have a hard enough time contemplating the world we're going to leave for our grandchildren, let along comprehending a geological epoch.
Matter has a similarly enormous but finite bound. There are only so many hydrogen atoms. Some of them are alone and surrounded by vast gulfs of emptiness on all sides, but on an atomic scale EVERYTHING is surrounded by vast gulfs of emptiness on all sides anyway.
Distance is probably the closest property to being infinite; we only have a finite amount of time in which to travel and there's a fixed upper boundary on our speed. In functional terms, that means that space is almost completely filled with "You can't get there from here." Putting aside the fact that it's ridiculously difficult for us to get off the rock we live on, we can only make something move at the tiniest fraction of light speed, and even at that speed, we can only travel some finite distance within the span of time remaining in our universe.
So... space.
Matter has a similarly enormous but finite bound. There are only so many hydrogen atoms. Some of them are alone and surrounded by vast gulfs of emptiness on all sides, but on an atomic scale EVERYTHING is surrounded by vast gulfs of emptiness on all sides anyway.
Distance is probably the closest property to being infinite; we only have a finite amount of time in which to travel and there's a fixed upper boundary on our speed. In functional terms, that means that space is almost completely filled with "You can't get there from here." Putting aside the fact that it's ridiculously difficult for us to get off the rock we live on, we can only make something move at the tiniest fraction of light speed, and even at that speed, we can only travel some finite distance within the span of time remaining in our universe.
So... space.
ddrueding
Fixture
Apparently there are no limits on the movement/expansion of space-time itself, only stuff in it.
Neat video.
ddrueding
Fixture
I'm planning in my head a lesson on scale, using scientific notation, to 3rd graders.
I'm thinking of using inches. Starting with 1 inch, picking an example item, and then going up and down from there as far as their imagination can go before jumping to planck length (6.3629892 × 10[SUP]-34 [/SUP]inches) and observable universe (3.40153434 × 10[SUP]28[/SUP] inches). Of course, units only really matters for the smaller factors, but inches gives me the most range with reasonable examples I think.
1 Inch - ?
10 - Pencil
100 - floor to ceiling
1000 - distance to playground
10000 - distance across school
100000 -
Still thinking of examples both ways as far as I can. Just thoughts at this point.
I'm thinking of using inches. Starting with 1 inch, picking an example item, and then going up and down from there as far as their imagination can go before jumping to planck length (6.3629892 × 10[SUP]-34 [/SUP]inches) and observable universe (3.40153434 × 10[SUP]28[/SUP] inches). Of course, units only really matters for the smaller factors, but inches gives me the most range with reasonable examples I think.
1 Inch - ?
10 - Pencil
100 - floor to ceiling
1000 - distance to playground
10000 - distance across school
100000 -
Still thinking of examples both ways as far as I can. Just thoughts at this point.
Mercutio
Fatwah on Western Digital
Do third graders get the metric system? I think you should at least try to communicate this in metric since it lends itself better to scale.
Stereodude
Not really a
Is this something you really need to do or is it a random thought exercise?
time
Storage? I am Storage!
The vast majority of people never really 'get' this, so the best of luck with your hypothetical 3rd graders.
Actually, I think psychologists would say that no-one really gets this; it's just a question of understanding the limitation within oneself - simple really ...
Actually, I think psychologists would say that no-one really gets this; it's just a question of understanding the limitation within oneself - simple really ...
Howell
Storage? I am Storage!
The story is about scale not units. You could make up a unit for all the kids care. Does the comparison have to be length as opposed to count? I would think that would be relatable for sure.
Btw, a quarter is about an inch.
Btw, a quarter is about an inch.
ddrueding
Fixture
My mother is a 3rd grade teacher. I used to go in as a guest and teach one lesson a year, about an hour max. In the past I've done model rockets (not allowed to anymore - no incident, just paranoia) or other neat chemistry demos.
ddrueding
Fixture
That is the part I'm struggling with. What party trick or other excitement could be understood once you grasp this concept?