-
Posts
25528 -
Joined
-
Last visited
-
Days Won
133
Content Type
Profiles
Forums
Events
Everything posted by Strange
-
It does apply, just not in the simplistic way you imagine it does. At one level, models are tested and if they give the wrong results they are changed or discarded. At another level, individual bits of science that are used to build the models are tested and either included to build better models or rejected. For example, the basic physics of CO2. Or the effects of dust in the air (acting as nucleation centres for clouds). Or ... They are very reliable. There is a popular (mis)conception that they are often wrong, mainly based on confirmation bias I suspect. Short term forecasts (24 hours) have accuracies of 80 to 90%, I believe. This falls off for longer term forecasts, which is why you don't see forecasts for more than 1 weak or so. They are tested. Against past events and against the current climate. So that's fine then. There are models and it is all based on sound science. Your attempts to sow doubt about this aren't going to work. It's fine. My hypothesis is that there is no son and no teacher.
-
They are.
-
Does General Relativity pertain to more than effects in light?
Strange replied to captcass's topic in Speculations
What is the “continuum of quantum physics”? Can you provide any mathematics or (quantitative) evidence to back this up? (I guess the answer is no, in which case I expect the thread will soon be closed.) -
Indeed. It seems to me that religion only provides a post-hoc justification ("god") for the morality that people in a society would have developed anyway.
-
They may be (hopefully are) using logic to rationalise their belief. So, yes, logic can answer the question. But that doesn't mean the answer is correct.
-
Does General Relativity pertain to more than effects in light?
Strange replied to captcass's topic in Speculations
What are the "two directions" you are referring to? What do you mean by "evolution"? -
Well, at least one school is taking action by banning .... backpacks. /facepalm http://6abc.com/education/high-school-banning-backpacks-in-effort-to-make-school-safer/3133684/
-
Does General Relativity pertain to more than effects in light?
Strange replied to captcass's topic in Speculations
I don't even know what that means. What "two directions"? What "evolution"? If you mean, "does GR describe how the movement of things through space-time is altered by the presence of mass-energy", then the answer would be yes. But you seem to be denying this is the case. I wrote a long response to your previous thread which was lost when it was shut down. I will summarise it here as: 1. The stress-energy tensor is an essential part of the equations of GR. 2. One component of the stress-energy tensor is mass. 3. The equations describe how the components of the stress-energy tensor (including mass) change the curvature of space time. It is, basically, as simple as that. To add a bit more detail: http://math.ucr.edu/home/baez/einstein/ -
And not all of them claim to be the one true religion.
-
At best, one could be correct.
-
I can’t see how. Can you show this logic?
-
I’m not really sure what you expect. There are obviously models because they are used by climate scientists. But these are probably not something you will be able to get hold of. They are complex simulations of the behaviour of the atmosphere, land and oceans consisting of millions of equations to be run on supercomputers. What you might be able to find are some of the (relatively) simple equations describing specific bits of behaviour. I already mentioned the basic physics of CO2. You may also find some information on how temperature affects water content of the atmosphere and cloud formation. But then it starts getting congrats located. Clouds reflect sunlight (a cooling effect) but also trap heat (a warming effect). But none of these are much use by themselves because they all interact. Because of this the simplistic “falsification “ idea doesn’t really apply. The models are tested to see how accurately they recreate past climate and then used to predict what might happen in future. So climate modelling is not itself a theory to be tested but is using underlying scientific theories (which are well tested) to try and model the behaviour of the world. The problem is that climate models cannot be reduced to a single equation. It is simulation of complex interactions of a very complex system. I guess you don’t think weather forecasts exist either? (I’m beginning to wonder about the existence of this “teacher”)
-
Well, that is obviously untrue. There are models of the climate. The problem for a high school project is that the climate is a very complex thing and therefore the models are very complex. If you think the teacher is a "denier" then this may be a trick question: "well if you kids can't produce a model of this incredibly complex thing in term project, then obviously thousands of scientists working for decades with access to masses of data and the world's fastest supercomputers must be lying". A simpler thing to look at is the basic physics of how CO2 absorbs infra-red radiation. This has been known for about 200 years and is relatively straightforward. Other things you could look at are the basic correlations between rising CO2 levels and average temperature (and other measures of climate change). Or the similar correlation of economic activity (which correlates with CO2 production) and temperature. And then, because correlation doesn't mean causation, you would also want to look at the [lack of] correlation between solar activity and temperature change (and whatever other excuses the deniers use). Which is why that is a terrible example.
-
Because, when discussing solutions to a problem that causes a large number of deaths one needs to consider the possible dangers (as well as any potential benefits).
-
Has anyone predicted that? Or is this a silly straw man. Is it? Really? Are you confusing "identifying possible risks" with "prediction"?
-
Well, it is true that both gravity and gravitational waves are caused by the changing geometry of space time, but they are different things. Gravity is caused by a (relatively) static curvature of space time. So if we look at a masses falling towards the Earth, it is "falling down a slope" but there are no waves involved. And, you can have gravitational waves travelling through empty space where there are pretty much no gravitational forces (in the vast distances between galaxies, say). It is a bit like the difference between water flowing down hill and waves on the sea. They both involve water but are completely different phenomena. Correct. Because they are ripples in the field and the field is space-time which exists everywhere! That is probably a reasonable (but crude) summary. Luckily, I don't.
-
There is not obvious connection between gravitational waves and virtual gravitons. Gravitational waves would be quantised as (real) gravitons in the same way that light waves are quantised as photons. Virtual gravitons carry the gravitational force (not gravitational waves). Space time curvature and virtual gravitons are different descriptions of the same thing, in the same way that the magnetic field and virtual photons are different descriptions of the same thing.
-
It will eventually reach the temperature of the surrounding space.
-
“Virtual particle” is a name for the explanation. (See the link above for more details. And https://profmattstrassler.com/articles-and-posts/particle-physics-basics/ for even more) Virtual photons (ie the electromagnetic field) carries the force between charg s and magnets. Virtual gravitons (ie the space time field) would carry the force between masses.
-
It will lose energy until it is in equilibium with its surroundings. After that there will be no net loss of energy
-
Wikipedia? For physics related stuff: http://hyperphysics.phy-astr.gsu.edu/hbase/index.html
-
What could possibly go wrong... https://www.twincities.com/2018/02/05/maplewood-police-officers-gun-fires-at-school-no-injuries-reported/
-
I was under the impression that was almost unique to the Abrahamic religions.
-
Because it worked. At the time it was seen, by Planck, as a mathematical "trick" to get rid of the infinities. But the quantisation was later confirmed by Einstein's work on the photoelectric effect. Where would that infinite energy come from? Torch batteries wouldn't last long if the were the case! If it doesn't "manifest" how can you say it is there? You seem to be invoking magic as an alternative explanation Theoretically? Please show the maths and evidence that supports this claim. Otherwise it is not "theoretical," it is just nonsense.