Ask a physicist anything. (7)

[Chalnoth]

So, if you combine quantum physics with religion, would you come up with
"God exists if you believe that He does and if you don't believe He exists, then He does not."?
Or would it be that "you can never really touch God, because once you locate Him, He moves"?

Not at all. Quantum mechanics absolutely, positively does not say that anything about the nature of reality depends upon belief. In fact, what we believe has no impact whatsoever on the nature of reality (except to the extent that our beliefs affect our own actions and our actions affect reality).

 

[LOCO]

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Are neutrinos really breaking the speed of light? Wouldn't the bodies effective mass increase when it approaches the speed of light resulting in a decrease the speed. Or are they testing a massless particle?

Blessings

 

[Chalnoth]

Are neutrinos really breaking the speed of light? Wouldn't the bodies effective mass increase when it approaches the speed of light resulting in a decrease the speed. Or are they testing a massless particle?

Blessings

A few points:
1. Probably not. The smart money is on this being a measurement error somewhere.
2. Physicists no longer use the language "effective mass". It led to too many mistakes. But yes, the energy and momentum do go to infinity as a massive object approaches the speed of light.
3. Neutrinos do have mass (albeit a small one). And even if they didn't, they would only travel at the speed of light, not past it.

 

[pgp_protector]

Q: Do seeds really die when planted, or is that old saying not truly correct?

 

[Chalnoth]

Q: Do seeds really die when planted, or is that old saying not truly correct?

That doesn't make any sense to me. For the plant to grow, it has to grow from a living cell. There must be a continuity of life from the parent plants to the children.

 

[Tuddrussell]

They die in that they transition from one state of being into another, in much the same way that in becoming an adult the child version of you dies.

 

[ToBeInChrist]

When people talk about singularities, are they just engaging in wild speculation or is there solid physics behind singularities?

What, if anything, is 'solid' about theories involving singularities?

 

[Chalnoth]

When people talk about singularities, are they just engaging in wild speculation or is there solid physics behind singularities?

What, if anything, is 'solid' about theories involving singularities?

Singularities are artifacts in the math. Basically, it's kind of like dividing by zero (in a sense, that's exactly what it is). Which, if you know anything about math, is a big no-no.

So the fact that our current best theory of gravity (General Relativity) predicts singularities is a strong indication that it isn't entirely correct, that some other, more accurate theory of gravity must take over for extremely dense matter.

I don't think anybody in physics expects singularities to be actually real.

 

[mzungu]

Very interesting find: A Treasure Trove of Dinosaur Protofeathers, Trapped in Amber | Popular Science

 

[Wiccan_Child]

Tsk, I leave for a week, and I miss pages of discussion on FTL neutrinos! Rage.

 

[Wiccan_Child]

Singularities are artifacts in the math. Basically, it's kind of like dividing by zero (in a sense, that's exactly what it is). Which, if you know anything about math, is a big no-no.

Unless you include nullity and the transreal numberline. Annoyingly, saying "you can't take the root of a minus one. But if you could, it'd be i" is perfectly valid, and "you can't divide by zero. But if you could, it's be Ф" doesn't seem to be any different...

 

[Naraoia]

Even if they are off in the measurement by a similar amount, the second team is almost certainly going to be off in a different direction.

Wouldn't that be a 50-50 chance rather than near-certainty? Or are we talking "direction" as in "14 degrees from north"?

 

[Naraoia]

Unless you include nullity and the transreal numberline. Annoyingly, saying "you can't take the root of a minus one. But if you could, it'd be i" is perfectly valid, and "you can't divide by zero. But if you could, it's be Ф" doesn't seem to be any different...

Does that math actually work? Consistent with the maths we learn at school?

 

[Wiccan_Child]

Does that math actually work? Consistent with the maths we learn at school?

Nope. The idea is, like i, it adds a whole new numberline to play with. It's not taken very seriously by mathematicians, though, so I suspect there's something fundamentally unnatural about it that means we can't use it, unlike i.

 

[ToBeInChrist]

the fact that our current best theory of gravity (General Relativity) predicts singularities is a strong indication that it isn't entirely correct, that some other, more accurate theory of gravity must take over for extremely dense matter.

I don't think anybody in physics expects singularities to be actually real.

Wow, thanks. It's awesome to be able to say something intelligent about singularities at social events!

 

[chris4243]

Unless you include nullity and the transreal numberline. Annoyingly, saying "you can't take the root of a minus one. But if you could, it'd be i" is perfectly valid, and "you can't divide by zero. But if you could, it's be Ф" doesn't seem to be any different...

But it's rather different -- i is defined as the square root of -1, and more importantly, i = i. With 1/0 you'll get infinity -- but you might get a positive or a negative infinity. 0/0 is much more useful, as we use something similar to it for calculus -- but it generally won't be equal to another 0/0, and technically what we're doing is taking limits as a number gets really small. So for example we have 3x/x = 3 no matter how small we make x, and it is very tempting* to say it will still be 3 when x = 0. Whereas trying to define 0/0 = Ф even if you pretend that Ф = Ф would mean that 3x/x = 2x/x when x = 0, which doesn't make sense.

* It becomes much less tempting to say that 3x/y = 3 when both x = 0 and y = 0, especially since it could turn out that y = 2x is also true.

Perhaps it might make sense to define a symbol <small> to use as a sign along with + and -. Putting <small> in front of a number would make it zero for all intents, except that it could be canceled by dividing by another <small> number. Similarly, we could have another number, <big>, which would be the multiplicative inverse of <small>. Basically like keeping track of all numbers but also whether it is zero or infinite or finite. It wouldn't allow anything new over using variables and limits, but it might be convenient nonetheless.

 

[chris4243]

How many grams of carbon dioxide in a 2 L bottle of coke?

 

[chris4243]

Wouldn't that be a 50-50 chance rather than near-certainty? Or are we talking "direction" as in "14 degrees from north"?

If someone repeats the experiment and finds that the neutrons are faster than light by 80 ns +/- 10 ns instead of 60 ns +/- 10 ns at the same distance, it would be a contradictory result, not confirmation. It would show that one or both the experiments were wrong, if only in that their claimed accuracy was wrong.

 

[Naraoia]

If someone repeats the experiment and finds that the neutrons are faster than light by 80 ns +/- 10 ns instead of 60 ns +/- 10 ns at the same distance, it would be a contradictory result, not confirmation. It would show that one or both the experiments were wrong, if only in that their claimed accuracy was wrong.

That's true, but Chalnoth's sentence was a hypothetical assuming that they were off by the same amount. I interpet that as there being a true speed of neutrinos, and the two independent measurements being <speed> +/- <bias> +/- <error>, where <bias> is the same for both, except it could be either negative or positive.

 

[Chalnoth]

That's true, but Chalnoth's sentence was a hypothetical assuming that they were off by the same amount. I interpet that as there being a true speed of neutrinos, and the two independent measurements being <speed> +/- <bias> +/- <error>, where <bias> is the same for both, except it could be either negative or positive.

You would only expect the bias component to be the same for both if the two teams used the same experimental setup.

For example, imagine, if you will, that the bias arose from getting the GPS position of the neutrino-emitting instrument wrong. The other detector would be in a different location on the Earth, and so even if they used the same detector position, and it was wrong by the same amount, it would mean something very different for the inferred neutrino speed.