# Physics and science, just man made idea?

1. Sep 9, 2009

There are many people out there who assert that physics and science is just a man made invention, made by convention. They say a bunch of people just decided and agreed to say that the laws of physics are what they are and that since it was all just made up arbitrarily, this means it may not be true. These types usually have a religious motive for taking such a stance on science. So what are your thoughts on this? how do you respond to this kind of reasoning?

2. Sep 9, 2009

### Feldoh

Well all of our theories are man-made essentially, but that's not to say that they are arbitrary or false.

Our theories approximate physical phenomena to varying degrees of accuracy. As scientists we make sure the theories fit with empirical data. Without these theories we wouldn't really have any of the stuff we have today. No computers, tv, electricity, etc...

While the theories are not 100% absolutely true they do approximate everything to a high degree of accuracy.

3. Sep 9, 2009

### Monocles

I'm not sure if this question could even be answered by science outside of semantic arguments.

4. Sep 9, 2009

Saying they are 'just' man made does a disservice to them. They are among man kind's greatest creations of all time.

They are made up somewhat arbitrarily, but as Feldoh says - if they dont jive with observation (at least to some extent) they are thrown out. In this fashion these 'mere man made' theories have provided more descriptive and predictive power than any other philosophy in history.

5. Sep 9, 2009

### 27Thousand

Many non-religious Philosophers of Science believe the same thing.

Throughout history, philosophers have been saying we can't have absolute truth, but only relative truth. Looking at history, Science always changes with new evidence that comes in. How do we not know it'll do the same thing in the future, even if it's a further refined explanation/law?

Well, there's quantum physics and Einstein didn't think it was absolute truth.

Was Newton's equations for gravitation absolute truth or man made, and some sort of relative rather than absolute truth? Are the equations we have now going to be the same exact in a thousand years? Newton said gravitation is a force, and no one thought that was man made at the time, but rather real. Then Einstein said gravitation is the bending of space and time, implications very similar but what it is means something quite different.

There are many who talk about what in Science is not directly observable (ex. gravitation, electrons, x-rays, plate tectonics - yes we can observe movement but no time machine for millions of years ago). Some of them point out that the unobservables are only instruments in making predictions, but not necessarily real.

But then, you can point out that most scientific theories which are well tested most of the time only get replaced by something which is the same exact plus or minus a few minor details; most which are completely replaced by something else never made it off the ground in the first place. When something's well tested and does happen to get completely replaced, it usually keeps most of its implications (Newton's gravitation being a force for example).

6. Sep 9, 2009

### 27Thousand

Saying it's willy nilly wouldn't be correct. In Science you go with the best explanation for the evidence. Some call it the best fit for the evidence, or explains the most amount of facts using the lease amount of assumptions. We could say no one has observed electrons with an electron microscope, and some could claim that aliens are causing our experiments to go a certain way. However, that requires more assumptions and doesn't explain as many facts.

In a court of law, "beyond reasonable doubt" doesn't mean it's been proved, but no doubt which is reasonable. Since the jury wasn't there, there can't be proof, but just no reasonable doubt from the evidence. Even "clear and convincing evidence" is good evidence.

7. Sep 9, 2009

### byronm

Isn't god just man made? The "laws" of nature happen regardless of humans ability to classify our understandings of such. We've simply just progressed enough technologically and academically that we can convey our understanding of the universe through math & Physics.

8. Sep 9, 2009

### junglebeast

Without a doubt some of the most theoretical branches of physics are largely dictated by rational opinions of a few (very smart) people that hold clout.

However, as a whole, to claim that science and physics are arbitrarily made up is such an ignorant statement that it could only be made by someone who has such a dismal understanding that trying to explain otherwise would be like trying to argue with a dining room table without first teaching it how to speak English.

9. Sep 9, 2009

I would say the scientific method will never ever change. It is the best truth finding procedure possible. But what likely will change are the current "best" theories produced by this method as new evidence is collected...

so if it's "man made", then it cant be a "real" or true theory?, but if its not man-made, then it must be "Real" or "true"? So what do you mean by "man made theory"? what do you mean by "real theory"? why should real theories be "non-man made" or why should a "man made theory" imply a theory that isnt true?

10. Sep 9, 2009

### 27Thousand

Einstein said we can't know for sure if something's for sure in Science. Many would say we have approximations, some say they're close to external reality while other scientists say all we know is they're good instruments for making predictions. What I'm saying is I don't know anyone who says we can have absolute truth rather than relative truth.

Scientists go with the scientific explanation which is the "best explanation for the evidence". Many believe Quantum Theory may be refined or replaced by a theory which explains the evidence better. Spacetime curvatures replaced Newton's force theory. Newton's ideas were approximations. Einstein's were explanations which made more predictions. The key to all this is "better explanation". I don't understand how anyone could say Science is bad since it's the best explanation to the evidence.

As far as the Scientific Method itself, well I guess no one in this forum can place monetary bets for this lifetime. However considering that there are supposed to be billions of more years left for the earth to live, and who knows how long humans will live, and that history often repeats itself in finding better and better methods, who knows. The key would be "no backsliding allowed".

11. Sep 10, 2009

### Staff: Mentor

We can find the absolute Truth (or rather, we have no reason to believe we can't). The problem is that we can never be certain that we have found it. As problems go, though, that isn't much of one.

12. Sep 10, 2009

### WhoWee

Why not apply the Scientific Method to your question and report results?

13. Sep 10, 2009

okay, but why should a "man made" theory imply that it is not true or "real"? what is the definition of a "real" theory?

Well, unlike the physical theories the scientific method produced, deciding if the scientific method is the best truth finding method does not depend on physical evidence, but just reason itself. So we dont need to wait for some observation to occur to decide that it needs replacement, all we need, if we are going to show it needs replacement, is for someone to come up with a scenario where the scientific method would conclude theory A is the best one given evidence when its obvious that theory B is really the best one given the evidence, thus proving the scientific method concluded the wrong theory given the evidence. But that's not possible, since the scientific method uses the correct criteria for deciding what the "best" theory is given the evidence, thus no counterexample scenario can ever be thought up, and therefore it cant be replaced. only the theories it produces can be replaced...

14. Sep 10, 2009

### 27Thousand

Although I'm going to agree that we may have absolute truth and not be aware of it, I'm going to have to appeal to history. Almost every scientific observable principle law gets refined, even if just a very tiny bit, over time. That doesn't mean they're not untrustworthy or not a close approximation of truth, but just that I feel skeptical that we have absolute truth. Newton's physical laws were tested and then later modified a little with Einstein. Newton's physical laws work in most situations, but not all. So thus I'd think that's really good relative truth, but not quite absolute truth. Again, I'm not bashing Science, but rather saying anything can be improved on. I would think many scientists think it's exciting to make new discoveries.

15. Sep 10, 2009

### 27Thousand

I've been thinking lately that it would be cool to apply to the Scientific Method to various arguments in the scientific realism vs. anti-realism debate. It would be fun to test their arguments to see if some of their concerns hold up, or are mostly rubber.

16. Sep 10, 2009

### 27Thousand

What sounds reasonable to me is it's the best explanation for the evidence, and thus not reasonable to act like it's not true. I tell people to remember back when they had science fair experiments and you would say, "If this is true this will happen." If it can make predictions over and over again from many different angles, then even if it's not true the world behaves closely to how it would if it were true, so thus it's useful. If it's good at predictions, it's going to be very useful for technology. Combine falsifying what you can brainstorm for alternatives and going with the best explanation, it's also the most reasonable explanation.

With the billions of years remaining and who knows how much more time for humans, what if they were to come up with an even better method than the already great Scientific Method? Haven't they already had quite a few revolutions throughout human history? Just another million years and with Science & Technology speeding up even more quickly, who knows what will happen.

17. Sep 17, 2009

### 27Thousand

As many may possibly remember from earlier, some members on physicsforums said that one has to be creative and imaginative, including every last single vocabulary word, to the point you can't have any human thoughts/feelings. So in return to them, if we're strong in our message here, if we're as consistent as the sun rising, then we should be as creative in saying that Science will change. What's good for the goose is good for the physicsforums.

Something many may want to consider, just like a record player repeats itself, so does history itself. History shows us that a major constant in human knowledge is change itself. The facts: The National Academy of Sciences is the highest science organization in the U.S. Many of its members say they don't have "faith" in scientific laws and theories, but rather "accept" them, because there's always the possibility that Science can change with new incoming evidence.

If we want to be as creative as the amount of rain drops falling in a rainstorm, and as imaginative as the rainbow after wards, the scientists who claim Science can change with new evidence will probably be the ones making the innovations. I know some members of physicsforums earlier were saying that anything scientific/technical sounding is automatically not creative, no matter how unique, but that's their cup of tea.

Last edited: Sep 17, 2009
18. Sep 17, 2009

### D H

Staff Emeritus
General Relativity completely replaced Newton's law of gravity? Not a chance. Engineers do not use General Relativity when they compute the stresses and strains on the new building design. They don't even use Newton's law of gravity. Most likely, they'll assume Earth standard gravity and be done with it. If they want to be a bit more accurate, they'll use the following formula, which doesn't look much like Newton's law at all:

$$a_g = 9.780327(1+0.0053024\sin^2\phi-0.000058\sin^22\phi)\,\text{m/s}^2$$

This equation is an empirical rule. It considerably more accurate than this:

$$a_g = \frac{G M_e}{r^2}$$

where r is the distance from the center of the Earth to the point on the surface of the Earth where the building is to be constructed. It is more accurate for two reasons. First, the above is a misapplication of Newton's law. It assumes the Earth is spherical. Second, Newton's law of gravity doesn't have a centrifugal force term. "But wait, centrifugal force isn't a real force!" So what? The effects of it on a building are real.

When NASA or any other space agency launches a spacecraft into space, they do not use general relativity. The use good old Newton's law of gravity (applied correctly of course, taking into account that the Earth isn't spherical). Even in space there are very few applications where general relativity is needed. A simplified form of general relativity in which general relativity is a perturbing force in addition to Newtonian gravity is used for predicting the orbits of the planets for hundreds of years. General relativity is absolutely essential for GPS. Other than that, rocket scientists tend to use Newtonian gravity. Newton's law of gravity did not suddenly stop working when Einstein came up with general relativity.

Here is a paper by a physicist who finally got fed up with the way some of his fellow academicians thought.
http://physics.nyu.edu/sokal/transgress_v2/transgress_v2_singlefile.html

19. Sep 17, 2009

### 27Thousand

You're correct about the actual implications in virtually most situations, but I'm not so sure about the actual reality of Newton's Gravitation. Keep in mind, that's why I said in the rare case where something in Science is replaced rather than just slightly modified, the actual implications usually stay very similar. The implications were similar from Newton to Einstein. However, many say gravitation being the bending of space and time in reality is very different than being an actual external force, even if the implications are pretty much the same. Before Newton and during ancient Greek times, Aristotle said there was a natural law that things move to their natural positions, because of heaviness. Although Newton's implications changed gravitation when going to space, people are going to say many previous implications on Earth were similar (apples still fell to the ground like Aristotle's time, even if falling in a vacuum was modified). Now a days, many say the actual implications for situations like a black hole are different than what Newton would have claimed. The explanations through time changed, although the implications built on top of each other.

Here's some food for thought, right now many elementary school kids will say Newton saying there's an external force is proven because they can see apples falling from a tree, photos show planets revolving around the Sun, and how else do we explain that (they don't know about General Relativity). Just because the implications work for most situations, does that mean Newton's reality is reality? Before Galileo/Newton, people would say Aristotle's idea that things move to their natural position was proven because from personal experience they could see apples falling from a tree and see stars/planets move across the sky (affirming the consequent). They would argue that the evidence of falling objects proves you can't argue with Aristotle. How do we not know the explanation of what gravitation actually is might dramatically change with a better explanation in the future, to the magnitude of going from Aristotle to Einstein, while the implications staying very similar but new ones building on top of each other?

Last edited: Sep 17, 2009
20. Sep 17, 2009

### D H

Staff Emeritus
Newton's formulation did not change how things behaved one iota. Nor did Einstein's formulation. Things do whatever it is they do. The planets did not suddenly change the way they orbit when Newton and Einstein came up with their theories of how gravity works / what it is. It is axiomatic to science that there is some external truth out there somewhere, and a scientists job is to find it, explain it, and do so in as simple a form as possible. So far, there is no evidence that that axiom is anything but true.

You are quibbling with semantics regarding the reality or non-reality of gravity as a force. It really is just quibbling and just ontology. From the perspective of Newtonian mechanics it is a "real" force. In Newton's world, a force is anything that causes acceleration in a Newtonian inertial frame. Newton didn't know about photons, gluons, W bosons, Z bosons. In general relativity a force is anything that causes an ideal accelerometer to register something other than zero. GR, like Newtonian mechanics, is a classical (non-quantum) theory. We do not yet know how to meld general relativity with quantum mechanics. Suppose we do, we find some bosons that mediate gravitation. Does this mean gravity magically becomes a force once again?

How we look at things and what we look at things are not the same. Thinking that science is an invention of the human mind implies that the right kind wishful thinking will make it so that falling off the top of a 20 story building is no longer fatal. Sorry, you are going to fall to your death. All the wishful thinking in the world is not going to change that.