does all of the laws apply on other planets

[japan rocks/andromeda]

do you think the laws apply everywhere

[Equilibrium]

not really i think depending on the size of the planet the amount of gravity will change, which will force us to change the equations

[D H]

That gravitational acceleration on the surface of the Earth is [math]g=0.980665\,\text{m}/{\text{s}^2[/math], is not a universal law of physics. Heck, it isn't even universally true on the Earth. Acceleration due to gravity is 9.779 m/s² in Mexico City but 9.819 m/s² in Oslo.

Edited October 5, 2010 by D H

[MRlogic]

That gravitational acceleration on the surface of the Earth is [math]g=0.980665\,\text{m}/{\text{s}^2[/math], is not a universal law of physics. Heck, it isn't even universally true on the Earth. Acceleration due to gravity is 9.779 m/s² in Mexico City but 9.819 m/s² in Oslo.

 

 

the 4 universal elements keeps our universe together

[ajb]

As far as we know, it is believed that the laws of physics apply everywhere, they are universal. In essence, this is a version of the cosmological principle.

[Klaynos]

the 4 universal elements keeps our universe together

 

!

Moderator Note

Please keep replies in the science sections to ONLY mainstream science ideas. Unless of course you mean the four fundemental forces (strong, weak, EM and gravity), in which case, carry on...

[DanielC]

As far as we know, it is believed that the laws of physics apply everywhere, they are universal. In essence, this is a version of the cosmological principle.

 

Not only that, but we have tested our physical theories at great scales, from locally down here on earth all the way up to stars and galaxies. You don't have to invoke the cosmological principle as an a-priori assumption. The universal applicability of the laws of physics is something you can test empirically. Things like the CMBR, pulsars and binary pulsars all provide important testing grounds for both GR and quantum theory. For example, the masses of white dwarfs and neutron stars requires the application of both GR and quantum theory, and the observed masses match the predictions. Also, to make stars work you need quantum theory - not only for the fusion part, but because stars would not work without quantum tunneling. The energy output of stars thus provides a real test for the laws of quantum mechanics.

 

It is wrong to think that scientists just dream up theories, try them out here on earth and assume that they work everywhere. This is not how science works. Astronomers regularly look for ways to test physical theories on the large scale. For example, one post-doc at my university is exploring ways that you could use observations of binary stars in the galactic center to test supersymmetric theories of dark matter.

[ajb]

Not only that, but we have tested our physical theories at great scales, from locally down here on earth all the way up to stars and galaxies. You don't have to invoke the cosmological principle as an a-priori assumption. The universal applicability of the laws of physics is something you can test empirically.

 

It is certainly not obvious that physical laws as we know them are applicable everywhere in the observable universe. You are absolutely right that observational cosmology and astrophysics generally help establish the universality.

 

 

It is wrong to think that scientists just dream up theories, try them out here on earth and assume that they work everywhere. This is not how science works.

 

It will depend on what one is working on as to how hard one would worry about this. But the point is noted.

 

Astronomers regularly look for ways to test physical theories on the large scale. For example, one post-doc at my university is exploring ways that you could use observations of binary stars in the galactic center to test supersymmetric theories of dark matter.

 

To my mind the best place to explore more speculative theories of gravity and particle physics (say SUSY and strings for example) is via observational cosmology, astrophysics and astronomy. Energy scales far beyond what we can create in colliders can be observed. With the recent advances in computer technology, telescopes, satellites etc. observational cosmology has become a real science. I fully expect in the future ingenious ways to test fundamental theories will be put forward.

 

For example, I think our best probe of quantum gravity would be cosmology and black holes. Maybe even the only probes for a long time.