Scientists are reaching the limits of their ability to understand the universe with the existing physical theories. One such area where there is an inability to currently make any useful attempts at explanation is the extremely short period of time just after the big bang, when energy was so dense that gravitational effects were influential at the quantum scale. In the universe humans have been able to explore, the strong and weak nuclear force, and the electromagnetic force are so many orders of magnitude stronger than gravity that at the sub-atomic scale, these forces rule, and the effects of gravity are negligibly small. For this reason theories at this scale have ignored gravity and, for the most part, relativity. Likewise, on the large scale, because of the limited range over which the nuclear forces influence matter, and the fact that mass at large scale tends to be electrically neutral, gravity is the interaction that defines the make-up of the universe and how it structures itself. But the weakness of Relativity is that it ignores quantum truths, such as the fact that the universe is discrete, rather than continuous. It also may or may not be deterministic (quantum mechanics isn’t well enough understood to say definitively). It is actually fortunate that gravity has just the value it has, because it is just the right strength for the formation of stars (I’m grossly oversimplifying, of course). If gravity were much stronger, the stars that formed would be too small and burn out much too quickly. If gravity were even weaker than it is, far less matter would collect to form stars in the first place, and the stars that did form would be enormous and explode, I believe. I haven’t double checked that info so it could be wrong.
But anyway the point I was getting at is that physics is almost stuck until it successfully develops a workable and verifiable theory of quantum gravity. This is of course what String Theory is supposed to be, but I have doubts about string theory being correct, especially given it is a theory formulated in a Newtonian background, one in which space and time are absolute. I have more hope for Loop Quantum Gravity, because it fully embraces the relational universe which we know more accurately describes the universe. I also think that a theory of quantum gravity will be necessary to solve the conundrums of the black holes.
Oops, I meant to write this as a reply in “Size of the Universe,” but I accidentally made my own thread instead. That just shows how long it’s been since I’ve posted anything!
If I remember correctly another problem with the string theory is also that these “strings” that they base the argument on can never and will never be able to be measured with any device, so it will always be an unverifiable theory. It’s been a while since learning all that shit, reading this makes me realize I need to brush up on my physics theories.
[quote]AndrewG909 wrote:
If I remember correctly another problem with the string theory is also that these “strings” that they base the argument on can never and will never be able to be measured with any device, so it will always be an unverifiable theory. It’s been a while since learning all that shit, reading this makes me realize I need to brush up on my physics theories.[/quote]
I don’t know too much about string theory either, so I’ll take your word for it that the strings could never be directly measured/detected. However, many theories that are considered verified do so through indirect means, so direct measurement would not be necessary to verify string theory per se. If the formulation of the theory leads to unique predictions for an experiment, for example, this makes the theory falsifiable at least. And in science, they say that a theory is never completely proven, but it can be falsified. Tentative acceptance of a theory occurs when it is currently the best explanation for existing data compared to competing theories, and based on this the probability of the theory being true increases. For example, it can not be proven 100% without a doubt that a supernatural god doesn’t exist. But the probability that one does exist is small enough that I feel confident in saying definitively that there isn’t one. Dawkins gives good arguments for this in his book, even though I know many people don’t like him for some reason.
…a new theory proposed by dutch scientist Erik Verlinde. Ofcourse 99% goes over my head, but it seems that the scientific community is very excited about this…
I don’t think that your understanding of special relativity vs. Quantum is a little bit off. They are not entirely divided between larger than atomic particles and sub-atomic particles. There is a lot of overlap. Relativity has a lot to say about photons and electrons, and you can still apply quantum to larger objects.
I once had to calculate the frequency of major league fastball. Relativistic effects are also the cause of the electromagnetic forces. Fermi accelerators using atomic particles are what has been used to verify time dilation. It’s not as black and white as you seem to think.
It depends on what you are trying to calculate as to what system you use, but there isn’t and easy way to categorize the 2, and both can apply to the same particles.
[quote]AndrewG909 wrote:
If I remember correctly another problem with the string theory is also that these “strings” that they base the argument on can never and will never be able to be measured with any device, so it will always be an unverifiable theory. It’s been a while since learning all that shit, reading this makes me realize I need to brush up on my physics theories.[/quote]
I know nothing about string theory, but you can say this about quantum. One of the basic theories in quantum holds that a system can never be completely determinate. There is a built in error to the system that is larger than measurements much of the time.
“Not only does God play dice, but… he sometimes throws them where they cannot be seen.”
– Stephen Hawking
I don’t know anything about physics but I am interested in string theory. There was a good BBC series on it you can find on youtube, also a good PBS series on youtube.
I was going to pick up the book “The Elegant Universe” which I hear is a good low level explanation or string theory or M-Theory or whatever you want to call it.
[quote]DoubleDuce wrote:
I don’t think that your understanding of special relativity vs. Quantum is a little bit off. They are not entirely divided between larger than atomic particles and sub-atomic particles. There is a lot of overlap. Relativity has a lot to say about photons and electrons, and you can still apply quantum to larger objects.
I once had to calculate the frequency of major league fastball. Relativistic effects are also the cause of the electromagnetic forces. Fermi accelerators using atomic particles are what has been used to verify time dilation. It’s not as black and white as you seem to think.
It depends on what you are trying to calculate as to what system you use, but there isn’t and easy way to categorize the 2, and both can apply to the same particles.[/quote]
Well yes, I’m definitely no expert in theoretical physics, I only went to school for engineering. I only know physics through self-study, so I know I’m missing a lot of information about the subject. But as far as applying quantum physics to larger objects, the important point is that general relativity can not be derived from quantum mechanics being scaled up to cosmological levels, nor can general relativity reduce to quantum mechanics at small scales the same way it reduces to Newtonian mechanics. You’re right that in reality the theories can and do have levels of overlap, and I admit I didn’t write the best synopsis of the situation. I guess the reason is that I really wrote it to describe my great interest in the development of a theory of quantum gravity, so that’s what I was rushing to get to.
What I find so interesting is how the gravitational field was not able to be quantized using the same methods of field quantization that worked for the other three fields, which is the basis of the Standard Model of Particle Physics used today, consisting of the unified electroweak interaction (the unification of the electromagnetic force and the weak nuclear interaction) and Quantum Chromodynamics (a Yang-Mills theory describing the strong nuclear force). From what I remember, the gravitational field, unlike the other force fields, has an effect on itself, making a complete mathematical description as of yet unattainable.
…a new theory proposed by dutch scientist Erik Verlinde. Ofcourse 99% goes over my head, but it seems that the scientific community is very excited about this…[/quote]
Oh my god, my mind is being blown by this article! I wish I didn’t have to work all the time so I could devote myself to learning this stuff instead! If there is any validity to these new ideas deriving theories once seen as fundamental from statistical thermodynamics, then this is fucking exciting indeed! I have to go to sleep now and let these new ideas process and build connections in my brain. Oh god I looove phyisics…