By Ira Mark Egdall
My cousin sent me this quote from a religious site and asked me what I thought of it:
“Gravity is a theory, not a proven fact.
“The effects of gravity can be explained by other theories. An example would be the acceleration theory which asserts the earth is actually moving ‘upward’ at a constant rate of 1g (9.8m/sec^2). This produces the same effect as ‘gravity’.
“See there are different theories for the same phenomena – and none are facts, they are just theories.”
Oh boy. There is such misunderstanding on what a theory is and is not. First of all, a theory in physics is a “model” using mathematics to try to describe physical behavior. And no scientific theory is “proven”. You would have to test it against all possible scenarios, which are infinite in number. All you can do is rate the usefulness of a theory — how well its predictions agree with measurements and observations. The theory of gravity (here I assume they are talking about general relativity) is considered superb in its usefulness. Volumes of empirical data from a number of independent sources confirm its predictions to extraordinary accuracy.
As someone said; to say “it is just a theory” is like saying it is just science.
Per Einstein’s Equivalent Principle, acceleration produces the same physical effects as gravity. This is no doubt the source of the argument above. But the Equivalence Principle (EP) does not tell the whole story. A quick summary: the EP only takes into account the warping of time by a mass/energy. But mass/energy also warps space. So the effects of gravity and acceleration are not truly equivalent. Thus an accelerating Earth at 1g would not produce the exact same effects as gravity. Obviously, the writer has read some popularizations, but does not know the subtleties of the physics. (The Devil is in the details).
I didn’t know any of this until I did the detailed research for my book on Einstein and relativity. Sorry for the rant, but the quote above got me all excited. And these days, I get my thrills wherever I can find them.
Note: I read about rating the usefulness of physics theories in Roger Penrose’s book The Emperor’s New Mind, Concerning Computers, Minds, and the Laws of Physics, p. 152-155.
By Ira Mark Egdall
The scientific consensus is that global warming is caused by us. Apparently it’s all those fossil fuels we burn in our vehicles and power plants etc. The thing that scares me most is that if we don’t do something about it soon, the temperature increase may become self-sustaining. At least that’s what Stephen Hawking says.
So when regions of the world are inundated with massive droughts, record floods, super-hot summers, melting polar ice caps, vicious tornados, extensive crop-failures, mass starvation . . . yikes, these things are already happening!
Like most people, I don’t do enough to fight global warming. So I promise myself I am going to write to politicians at the state and national level to urge them to take action now. And to do more of the things recommended in the link below.
By Ira Mark Egdall
What’s in a name? That which we call a rose
By any other name would smell as sweet.
– Romeo and Juliet (II, ii, 1-2)
We live in a world of euphemisms — words or phrases respun to make them sound less offensive.
Fried food bad? Change the name to KFC. Nobody’ll remember that it stands for Kentucky Fried Chicken. Big Mac’s are selling, but fried chicken not so much? Call it crispy chicken. What’s the difference? Ah, none.
Filthy rich? Nasty label. (Wish I was one.) The Republican term is job creators. God forbid we raise taxes on job creators. Oh, excuse me, taxes is also an ugly word. So Democrats refer to them as revenue enhancements. My ever shrinking wallet must be enhancing somebody’s revenue.
If I die in the hospital, it’s a negative patient care outcome. Has such a lovely ring to it. Oh really? I’m still dead! A toilet is a rest room. When’s the last time you took a nap in one. (Don’t tell me, I don’t want to know.)
Even science has joined the club. Global warming? Too controversial. Proselytized by Al Gore — must be another big-government conspiracy. Let’s call it climate change. So much better. As though nature cares what we call it. The science still works the same. (Which is too bad for us, because we don’t seem to be doing much about it.)
I think I’ll put on my personal flotation device, get my full-figured body into my previously-owned vehicle, and drive off into the sunset!