Is Everything Really Half Its Original Size?

One morning, this SOB showed up and told me that every dimension of everything had shrunk to half of its original size overnight. He's been bugging me with the same statement ever since.

I think this SOB has been lying, but I haven't been able to come up with rigorous proof to refute him.

Would you help me refute this SOB and shut the **** him up for good?

I think I know what you are suggesting but I'll play along. First, tell me exactly what you mean by dimensions?

There is no way to prove your friend wrong. However, such a transformation is not really meaningful. Constants with dimensions are not fundamental; they are a result of our choice of units, and that is all. You could not detect any sort of change to a dimensionful constant in any way at all. The statement "everything is half as big today as it was yesterday" is exactly equivalent to "we are now using units which are twice as big as yesterday." It's not a real change.

On the other hand, changes to dimensionless constants (like the fine structure constant) would be very noticeable.

- Warren

Earlier I was considering the change in cross-sectional area as it is related to strength versus a changing volume. I hadn't considered any fundamental change in mass yet.

Actually I think I'm probably missing something and am curious as to what that might be. Anyway,

If you take an object, say a plank or board, and reduce all if it's dimensions by one half, the cross-sectional area of the board is reduced by one fourth, and the volume is reduced by one eighth. In this case mass would also be reduced by one eighth. The strength of the board is reduced by one fourth since strength is directly proportional to cross-sectional area. So we have a board which is supporting one eighth the mass but is only reduced in strength by one quarter. Proportionally, the board is twice as strong as the one twice the volume.

If mass were to change by one half per unit volume as well, this means that when the original board shrunk to half it's original dimensions. The mass would be again, half as much (1/16th the original mass) and the proportional strength of the object would be double that of the original case; four times as much. Conversely, if an object were to increase in size and mass in this manner, wouldn't a change be noticeable?

Originally posted by Jimmy
I think I know what you are suggesting but I'll play along. First, tell me exactly what you mean by dimensions?

size.

Well, there are square-cube relationship issues that need to be resolved. Scaled down humans would be much stronger per weight since strenght is proportional to size squared, and weight is proportional to size cubed.

If you halve my size (linearly), I weigh \frac{1}{8} but my capacity for lifting is only \frac{1}{4}. That means that I can lift twice as much, relative to my body weight.

Of course, if the physical constants of the universe also change accordingly, then there is no problem.

This type of question is really more philosophical than physical in nature unless it makes predicitions that differ from the typical physical ones. If this theory does not make new predictions, then it falls only to Occam's Razor - which is a pragmatic argument.

Why not just ask the SOB how he or she knows all dimensions are half size.

Heres where you nail him. First pin him down to exactly what has changed, if he sticks to his changing length . You can show him that if the sides of a cube are reduced by .5, its volume is reduced by by a factor of .125. Since only the lengths changed its mass must remain the same, therefore its density has to change.

Of course there has been no change in the density of any material, therefore he is wrong.

Originally posted by Julian Solos
size.

Size as used in every day language.

"Everything" seems to suggest things at sub-atomic level changed too. (I don't know if that makes any difference.)

If just size has changed (length, width, height), then you would definitely notice a change.

http://www.faqs.org/docs/Newtonian/Newtonian_37.htm

I'm not really sure about changes at the sub-atomic level. How would changes in the size of electron orbits affect atoms? Would electrons have to be more massive to orbit closer to the nucleus? How would the other constants have to be scaled to make unnoticeable changes?

chroot wrote: On the other hand, changes to dimensionless constants (like the fine structure constant) would be very noticeable.

Now a really sneaky SOB might have said "all the fundamental constants got shrunk overnight, to half the values they had yesterday". Of course, you could immediately tell, as Warren says, he (SOB, right? not DOB) was lying.

But what if he said "half the fundamental constants got changed"? Could you still tell?
https://www.physicsforums.com/showthread.php?s=&threadid=12882

Not only will the mass-density change as integral suggested, but the charge density would change as well, and I'm pretty sure that would change things on the sub-atomic level.

Like people have been saying, if ALL the physical constants changed overnight, (the relative mass of an electron as well as th universal gravity constant, etc.), there would be no way to detect it, but if it is only the size of things, it would become quite obvious.

I suppose this might explain why my paycheck was cut in half

Seriously, though, I find this somewhat interesting, as it seems to imply that it is theorectically possible(though obviously improbable) for certain types of catastrophic universal change to occur without being detectable.
Wow. Now that deserves another beer.

Originally posted by Julian Solos
One morning, this SOB showed up and told me that every dimension of everything had shrunk to half of its original size overnight. He's been bugging me with the same statement ever since.

I think this SOB has been lying, but I haven't been able to come up with rigorous proof to refute him.

Would you help me refute this SOB and shut the **** him up for good?

That is a meaningless statement since size only has a meaning when one is comparing the dimension of one thing to that of another. So if all things change size its not only unverifiable but it's meaningless.

Tell him that he's right but that this morning tiny angels stretched everything back to its normal size.

Originally posted by pallidin
I suppose this might explain why my paycheck was cut in half

Seriously, though, I find this somewhat interesting, as it seems to imply that it is theorectically possible(though obviously improbable) for certain types of catastrophic universal change to occur without being detectable.
Wow. Now that deserves another beer.

Prosecco, mio amico, prosecco (not beer).

Change anyone of the 26 by 50% and you'd cease to exist, and the SOB couldn't have told you anything (he'd have been blown out of existence within a nanosecond of making the change). That's obvious for some (e.g. mass of the electron), somewhat less obvious for others (e.g. which one of "the U(1) coupling constant, the SU(2) coupling constant, the strong coupling constant" hides the fine structure constant?), and I really don't know for several (e.g. "the mass of the tau neutrino, 4 numbers for the Maki-Nakagawa-Sakata matrix, the cosmological constant").

Change all 26 by 50%? You wouldn't be around to know. Why?

26

It's great to see that someone learned believes in 26

Originally posted by Julian Solos
One morning, this SOB showed up and told me that every dimension of everything had shrunk to half of its original size overnight.

I originally thought only "size" (including the distance between objects) changed. Does the shrinkage of everything in "size" change time (the rate of flow, etc.)?

Originally posted by Julian Solos I originally thought only "size" (including the distance between objects) changed. Does the shrinkage of everything in "size" change time (the rate of flow, etc.)?

Back to what chroot said, if all your friend has done is changed the definition of 'second', nothing physical has changed. Of course, you could read in yesterday's astronomy textbook that the Earth rotates on its axis in ~24 hours, and your new watch says it's ~12 hours (or 48), then you would know what the SOB had done.

Back to the 26 - where is 'time' among these?

If the three physical spatial dimensions were all cut in half, you most certainly would notice. For starters, you'd way four times as much as you did before...

Back to the 26 - where is 'time' among these?

It states in the Green, Schwarz and Witten book, vol.I that there are two timelike dimensions in the 26. But do not ask me anything more about that!

Originally posted by Julian Solos
He's been bugging me with the same statement ever since. ... Would you help me ... shut the **** him up for good? [/B]

Tell him if he doesn't quit bugging you then you'll do it agian! And if he really pisses you off then next time you'll only shrink his *****!

Originally posted by Julian Solos
One morning, this SOB showed up and told me that every dimension of everything had shrunk to half of its original size overnight. He's been bugging me with the same statement ever since.

I think this SOB has been lying, but I haven't been able to come up with rigorous proof to refute him.

Would you help me refute this SOB and shut the **** him up for good?

this discussion is similar to one we had on PF back around May 22 of last year,
https://www.physicsforums.com/showt...12&highlight=baez standard model&pagenumber=1

The discussion was begun by wolram asking a similar question to yours and I remember I linked to the same John Baez page that Nereid has seen more recently cited by Ambitwistor---about the 26 dimensionless constants.

--------to respond directly, though, to Solos question-----
Solos, it sounds like you are imagining that the PROPORTIONS between things stay the same

that is, all the pure dimensionless numbers----the ratios like pi and so forth-----are unchanged.


there is an issue about what "sizes" you are saying get halved
if linear size shrinks by a factor of 2 then area shrinks by a factor of 4. So the SOB must specify which set of independent dimensions (is it just length time and mass?) he says have shrunk

but not to quibble.
Nereid posted a link to a list of 26 pure numbers (ratios) on a John Baez page. I have linked to that page several times at PF myself. for instance back last May in the "four fundamental forces thread". My understanding is that when he says mass of this, mass of that he means

the ratio of the mass in question to the Planck mass

So if both the Planck mass and the mass of a certain quark are reduced by a factor of 2 then the ratio does not change.

In fact, if the SOB is right (once his specifies what he means in a way that is consistent) NONE of these 26 numbers can have changed.

The are all like the number pi in the sense of being pure dimensionless.
He was not talking about chopping the number pi in half, presumably, only the sizes of things---quantities----with ratios staying unchanged.

I suspect that there is no physical observation by which the SOB can be refuted-----his statement (with terms defined so that the statement is logically consistent) cannot be falsified by experiment.
Therefore his statement is scientifically meaningless. Tell him this and see what he says.

--------incidentally here's a quote from my May 10, 2003 post----
...I wish I could mentally bridge between the practical experimentally useful constants
that are used in perturbative (power series/successive approximation) calculation with Feynman diagrams and the 26 REAL constants of the Standard Model summarized here:
http://math.ucr.edu/home/baez/constants.html
In this brief exposition Baez seems not to be talking about constants that "run" but about 26 definite dimensionless numbers. His list does not include 1/137, for instance, because it is calculable from four numbers he calls theoretically more basic.
I expect or hope that the "running" of 1/137 is also calculable from these four theoretically basic numbers...

I believe you would notice a change even if it was in all dimensions and physical properties simultaneously. If the change was quick, say overnight, wouldn't it result in movement exceeding the speed of light to accomplish the change? Think about it. If a star more than 4 light years away is reduced to a distance of only about 2 light years away in an instant, its movement toward you would be far exceeding the speed of light, and therefore impossible.

Originally posted by Artman
... If the change was quick, say overnight, wouldn't it result in movement exceeding the speed of light to accomplish the change?...

a curious thought---having the transformation be gradual
I cannot imagine how it could be gradual
it is hard enough to picture it as an instantaneous discontinuity
(the supreme being, a small man sitting on a toadstool, winks at us and presto things are changed but it all looks the same)

the star is still 4 lightyears away (because the year is shorter too)
so it never moved
bizarre stuff
dont think it could really happen

but as for distances between things changing faster than the speed of light, they do do that (according to the mainstream cosmology picture) so it is not, as you suggest, impossible at all

look up Tamara Davis and Charles Lineweaver's 2003 article called
"Expanding confusion"
they dispell some popular misconceptions about the expansion of space

google probably has it under the keyword Lineweaver
or i can get a link

Originally posted by marcus
a curious thought---having the transformation be gradual
I cannot imagine how it could be gradual
it is hard enough to picture it as an instantaneous discontinuity
(the supreme being, a small man sitting on a toadstool, winks at us and presto things are changed but it all looks the same)

the star is still 4 lightyears away (because the year is shorter too)
so it never moved
bizarre stuff
dont think it could really happen

but as for distances between things changing faster than the speed of light, they do do that (according to the mainstream cosmology picture) so it is not, as you suggest, impossible at all

look up Tamara Davis and Charles Lineweaver's 2003 article called
"Expanding confusion"
they dispell some popular misconceptions about the expansion of space

google probably has it under the keyword Lineweaver
or i can get a link

This would still require a physical movement of stars, planets, nebulas, everything (or else it could be detected), we would be talking about the distance that light travels in 4 years being reduced to say 4 hours. Could this occur without mass becoming infinite (rather than shrinking)?

As was mentionned at the beginning of the thread, only quantities dependant on the same power of length would stay constant relative to each other. If right now you can lift your weight, and the length of everything was shrunk by a factor of two, you could now lift twice your weight. Also, light would take less time to travel between two known points.

I still think that the idea that the matter that produces the light would have to move at a rate of approximately 1,486,848,000 miles per second in order to move to the proper distance to be half as far away in 4 hours is pretty good evidence that it didn't happen.

if you drop a ball off a building the previous day, and drop it off the same building after the change has occurred, the ball will take half the time to fall as it did the previous day because no matter what size of the object, it will fall at the acceleration of gravity.

at the atomic/subatomic level, we have to consider attractive and repulsive charges. you cannot eg half the orbital distance in atomic shells and their nuclei withou t consequences..
you cannot half planks length without entering into issues such as quantum jitters ..
if you extrapolate it to string theory . a change in the length of the string would disrupt mass and charges...

Thankyou for your input vyvyanne and goldsax but if you note the date of the posts (recorded just above their name) you will see that this thread is 7 years old and thus is dead. Thread closed.