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Willowz
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Do you know where this 'thought experiment' that cannot be put to test originated from? Was it Bertrand Russell?
DaleSpam said:If all of the universal lengths changed in such a way that none of the dimensionless constants were changed, then the change would not be measurable.
At the present time, the values of the dimensionless physical constants cannot be calculated; they are determined only by physical measurement. This is one of the unsolved problems of physics.
A dimensionless constant would be a ratio of dimensionfull constants that are measureable. Lengths can't be doubled without any other change occurring concurently and those other changes would be noticable. For instance, gravitational force is given by:Willowz said:On what basis can physicists suppose that there are dimensionless constants if they can only be calculated by physical measurement?
Willowz said:Do you know where this 'thought experiment' that cannot be put to test originated from? Was it Bertrand Russell?
You can always make a dimensionless constant by taking some dimensionful constants and combining them so that the units cancel. So the existence of dimensionless constants is not in doubt. Dimensionless constants are important because their value does not depend on your choice of units.Willowz said:On what basis can physicists suppose that there are dimensionless constants if they can only be calculated by physical measurement?
Jamma said:Yes, but we are assuming that all the other constants change accordingly. Obviously if this was not the case then things would be noticeably different (just think about the orbits of planets).
The original question just asked if everything doubled in size whether we could observe a difference, I think that the answer to that is yes we could by structures falling down as their mass cubed but supporting framework only squared. Even if you push a bit further and alter the density and strength of materials so that everything stays upright I think that things like the way waves break on a shore and ripples propagate would change (if you look at films with scale models of nautical disasters the sea always looks a bit wrong), all down to Reynolds number. If you want to push things to the limit and modify the laws of physics so that everything acts the way it did before you doubled it's size, I suppose that then you couldn't see a difference but what would be the point of the question?
The point is that that question, as stated, is incompletely specified. There are multiple ways that everything could double in size, some would be observable and some would not. The way to determine if a difference is observable or not is to determine if there is a change in any of the dimensionless fundamental constants.Jobrag said:The original question just asked if everything doubled in size whether we could observe a difference
Not necessarily.Jamma said:There are an infinitude of reasons why we'd notice a difference if simply all lengths were doubled in size...
Willowz said:On what basis can physicists suppose that there are dimensionless constants if they can only be calculated by physical measurement?
There are a few possible explanations for this phenomenon. One possibility is that there was a sudden and significant increase in temperature, causing materials to expand. Another possibility is that there was a sudden influx of air or gas, causing objects to inflate. It is also possible that there was a chemical reaction or growth process that occurred rapidly, leading to an increase in size.
No, it is not possible for living organisms to double in size overnight. Organisms have a set rate of growth and require specific conditions to grow and develop. While some may experience rapid growth, it is not possible for them to double in size in such a short period of time.
Yes, it is possible for a natural or man-made disaster to cause objects to double in size overnight. For example, a volcanic eruption or earthquake could cause the ground to shift and materials to expand. Additionally, a chemical spill or explosion could lead to sudden growth or inflation of objects.
Scientists can use various methods, such as measuring tools or imaging techniques, to accurately measure and study the change in size. They may also conduct experiments to replicate the conditions that caused the growth and gather data to analyze and understand the process.
It depends on the specific circumstances and objects involved. In some cases, such as with living organisms or structures, rapid growth could lead to instability and potential harm. In other cases, it may simply be a natural occurrence with no negative consequences. It is important for scientists to study and understand the cause of the growth to determine any potential risks or dangers.