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Mass is relative, measured by a standard object of arbitrary mass to which we've given a value. What we consider a "kilogram" is determined by one specific obj
by Zikes 13y ago
Mass is relative, measured by a standard object of arbitrary mass to which we've given a value. What we consider a "kilogram" is determined by one specific object sitting in a vault somewhere, and if that object were to be halved or doubled without us realizing it, then the official value of the kilogram would be similarly halved or doubled.
Since we determine the mass of things by comparing them against that object, if everything in the universe changes mass in precisely the same way at precisely the same rate then we would have no way of knowing. All we can do is compare them with each other, and relative to each other the masses would remain the same.
- contingencies 13y agoIf time is relative, and mass is relative, and space is relative ... then what's the point of science?
- ollysb 13y agoCould you give an example of something that can be measured absolutely?
- chimeracoder 13y agoI'm not sure if this is the answer you're looking for, but degrees/radians are considered dimensionless in that they're defined by the ratio of two lengths. There's no way for the value of 1 radian to magically 'double' without causing π radians to magically amount to a full circle, which would seriously warp Euclidean geometry as we know it.
- onezeno 13y agoI didn't understand this part of the article. We can measure the mass difference because, according to the theory, that is what we are measuring when we see a redshift. Should we not be able to measure the redshift in a laboratory, given equipment of high sensitivity and a large enough time delta for the change to register? Edit: Looks like Le_SDT beat me to it :)
- Zikes 13y agoI would imagine so, that part confused me as well. It's possible that the level sensitivity required is just too extreme, and would be subject to too much local interference. There's one such test [1] that I find interesting that suffers from similar problems. It tries to detect gravitational waves traveling through the universe by pointing a laser at a mirror at the end of a 4km tunnel and measuring any changes in the total distance. [1] http://en.wikipedia.org/wiki/LIGO http://en.wikipedia.org/wiki/LIGO
- roc 13y agoWhat about astronomical objects that are distorted by gravitational lensing? Even if the mass of everything is increasing, couldn't we still note any otherwise-anomalous universal change in the presentation of many such systems?
- dllthomas 13y agoThis seems to make assumptions about a relationship between mass and gravity that may or may not hold as "mass changes" in this way, but it's certainly something to look at.