The quest to prove Einstein right
Here’s an entertaining documentary on Einstein. It focuses on the efforts of others to prove whether Einstein’s general theory of relativity was correct by photographing the sun during an eclipse in order to see whether it bends the light of stars. It wasn’t easy.
Give it a go, if that interests you:
Too wowy-zowy and insufficiently technical. If you know some math, Leonard Susskind’s the Theoretical Minimum books are a good introduction, although a bit light on the experimental history that did much to drive developments at the time.
As a small note, IIRC, Einstein’s initial calculation of light bending by gravity was the same as Newton’s, off by a factor of two 🙂 How did Newton make the calculation, you ask? He assumed light consisted of particles, and the mass cancelled out, essentially an assumption of the equivalence principle that left only acceleration behind.
Me!?!?!, I get lost in my own closet!
It’s interesting that physicists still test and try to prove Einstein wrong, but we use his theory (I forget whether it’s Special or General) for our phones to work with satellites. Because time differs by minute milliseconds between being on earth or in orbit.
Science is never settled. Except for climate change computer models.
In science, an experiment never PROVES an hypothesis is correct. It can only DISPROVE an hypothesis.
Pass enough experimental tests, and your hypothesis advances to theory if it explains a lot of things.
The bending of light had been observed but never explained. Then Einstein offered an explanation of gravity bending space-time. An experimental observation was performed and Einstein’s theory was close enough to the data to show that he had not been disproved.
A subtle difference but like rbj1 noted above, the science is never settled, only getting better at explaining and predicting.
Someone might want to send a note to Anthony Fauci….
EXCELLENT comment, there, from Joseph Somsel: In science, specifically scientific theory, nothing is ever regarded as having been proven. Science, via the Scientific Method, operates by RULING THINGS OUT based on EVIDENCE. That which has not been ruled out by evidence remains possible. It is true that some things are more probable than others–but that is not the same thing as having been proven.
@Joseph Somsel:Pass enough experimental tests, and your hypothesis advances to theory if it explains a lot of things.
I know we all heard about this in middle school, but it’s not right. Hypotheses cannot be “promoted” to theories any more than a brick can be promoted to a house. A theory is a large conceptual framework which explains a large number of observations and constrains the kind of hypotheses that can be generated. A hypothesis is very specific.
Einstein’s general relativity is not a specific hypothesis and explains much more than the bending of light.
Interestingly there had been noticeable discrepancies in Mercury’s orbit that led 19th century astronomers to postulate a planet between Mercury and the Sun, which was usually called “Vulcan”, and every time there was a solar eclipse they would try to catch it in transit across the Sun. The same approach had led to the discovery of Neptune, after all. They never did find Vulcan, and Einstein’s general relativity accounts for Mercury’s orbit without requiring an undiscovered planet.
That’s one of the differences between “theory” and “hypothesis” right there. A theory can be used to generate hypotheses, or to exclude them from serious consideration, and these hypotheses may have nothing whatever to do with the problem that motivated the first developers of the theory.
Finding a planet Vulcan big enough to perturb Mercury’s orbit would be very challenging for Einstein’s theory to explain and might require throwing it out–or more likely, very large changes to it.
Another example of how theory and hypothesis are completely different categories. People had various hypotheses about what Saturn’s rings were made of. In 1859 James Clerk Maxwell applied the theory of Newtonian mechanics to the problem and showed that the rings needed to be made of individual solid lumps in order to match observations. And so he was able to exclude any of the other hypotheses about them being fluid, or some huge solid ring-shaped object. And what we’ve learned from our satellite fly-bys has been consistent with that.
He also developed the classical theory of electromagnetism, which generated the hypothesis that light is specifically an electromagnetic wave. Einstein’s special relativity was mostly a different interpretation of Maxwell’s theory of electromagnetism, which was fully compatible with special relativity before anyone ever thought of it.
https://en.wikipedia.org/wiki/Gravitational_wave
I felt that it was unlikely that this would ever happen in my lifetime. Quite an acheivement.
I admit I glossed over the difference between a theory and an hypothesis since that was not the main point of my comment and I think it is a difference without much substance re the topic at hand of “proof.”
My notion is that an hypothesis is the specific prediction that one tests with an experiment or observation. That result hopefully gives you a pass/fail on your hypothesis (some don’t and are a waste of time.) A theory makes sense of a bunch of prior tests of hypotheses or it can spin off new hypotheses to test the theory.