[Petrochemicals (OP)]

As the singularity in a black hole apparently is defined by a mathematical infinity, does this mean our physics has failed, is there something other than dense matter at the heart of it?

[alancalverd]

Physics is the mathematical description of what actually happens. As you condense the universe towards a single point, so the gravitational field increases and time slows down. Thus it takes for ever to squeeze it into an infinitesimal point.

You can calculate the convergence of two infinities if you wish, but it's worth considering the hyperboloid paradox. If you rotate one branch of a hyperbola around its asymptote you will generate a surface with infinite area and finite volume, so you can quote a fixed sum for the amount of paint required to fill it, but it will take for ever to cover the surface.

Which is why "a worldbeating track and trace system" is hyperbollocks.

[Bored chemist]

Which is why "a worldbeating track and trace system" is hyperbollocks.

That's balls because it's a Tory promise.

[alancalverd]

Maybe it's the inverse of hyperbollocks. You can pour infinite cash into it and achieve no coverage.

Incidentally do we have any updates on HS2? Last time I looked at the numbers, it was costing £625,000 per meter just to lay the tracks, which doesn't compare favourably with NASA's budget of  $120 per meter to fly to the moon.

[yor_on]

Yes, it's called a singularity for a reason. Our physics breaks down, which doesn't stop theorists from creating scenarios though.

https://physics.stackexchange.com/questions/590774/what-does-it-mean-when-people-say-physics-break-down

Ps: the nicest answer should be Cort Ammon. Makes perfect sense to me at least.

[Bored chemist]

which doesn't compare favourably with NASA's budget of  $120 per meter to fly to the moon.

How does that compare with the Mars lander budget?

[Eternal Student]

Hi.

Looks like you've had some good answers (and some ploitics) already presented.

I suppose we should check - what singularity are you (petrochemicals) refrerring to?  We're all assuming you meant the one that arises in black hole solutions.  Technically there's more than one of those but you probably meant the really nasty one that is non-removable and is often loosely described as being at the centre of the black hole?

There's recently been several discussions about Black Holes and singularities, which is probably why people have drifted off topic a bit.

[alancalverd]

Still unhappy about physics "breaking down". Physics is descriptive, not prescriptive. When it happens, we'll model it.

[Petrochemicals (OP)]

Still unhappy about physics "breaking down". Physics is descriptive, not prescriptive. When it happens, we'll model it.

Sort of like physics breaking down for newton's laws, thus Einstein came about.

[Petrochemicals (OP)]

Hi.

Looks like you've had some good answers (and some ploitics) already presented.

Lol

I suppose we should check - what singularity are you (petrochemicals) refrerring to?  We're all assuming you meant the one that arises in black hole solutions.  Technically there's more than one of those but you probably meant the really nasty one that is non-removable and is often loosely described as being at the centre of the black hole?

yes the one in the black hole. I will amend the title.

There's recently been several discussions about Black Holes and singularities, which is probably why people have drifted off topic a bit.

Yes, I started a thread on a singularity in a black hole, which lead to this question.

[Eternal Student]

Hi again.
   OK. So we've got the new question.
If a BH singularity defies our mathematics does it also defy our physics?

Here's three answers:

(short)    Yes.

(Medium)   Current best models in Physics utilise Mathematics, so yes.

(Long)   Yes but not just because the Mathematics breaks down.   The central singularity is hidden behind an event horizon, you can send people across the event horizon but they can't get out to tell you about it (or send out a radio signal etc.).   There could be forests, fairy folk and long lost celebrities like Elvis on the other side of the event horizon.

  - - - - - - - - -
More general discussion:   Using General Relativity as our best model,  the singularity cannot be included in the manifold (the spacetime) that we model.  There is no way to extend the manifold (while still working in the framework of General relativity) to include that point.  This leads to two reasonable ideas:
    (1) It is a place in our universe but our model breaks down there,
or more interestingly   (2)   it could also be that it just isn't a place in our spacetime and that's why it was impossible to extend our manifold to include it.

Option (1) leads to possibilities like maybe we need a better model.  A Quantum Theory of gravity for example.
Option (2) has a bit more Sci-Fi   Razzmatazz (or whatever the new hip and trendy word is).  After all if it isn't a place in our universe then is it a place in some other kind of universe,  or is it that anything that gets to that singularity simply ceases to exist in our spacetime - a bit like total disintegration.

Text books on General relativity are very carefull NOT to state or demand that a Black hole has matter with some mass inside it, only that there is a parameter associated with a black hole that is like Mass.   Once inside the event horizon, all light cones are leading to the singularity:  So all the particles that were inside the event horizon are going to one point soon enough and there is no acceleration they could have (or if you prefer, no force that can be applied to them) that would be sufficient to keep them away from that singularity.  It's often suggested there could be an infinitely dense point of matter where all these particles end up - but there doesn't have to be.  As previously discussed the singularity is not in the spacetime that we can model,  so if all the matter goes there then it is NOT in the spacetime we can model.  We don't have a clue where the Mass has gone anymore - it could be sat around waiting in some parallel universe all of it's own for all we know.  All we know is that the black hole retains a parameter, M, that is the sum of all the matter (and energy) that has ever gone into it.

Meanwhile, if you're more of an option (1) kind of person then you would tend to think that a good theory of Quantum Gravity might prevent all the matter collapsing to one point.  In which case you would be expecting to find something like dense matter inside a black hole.  Some physicists like to think as black holes as being  "black mountains" rather than holes... they think the mass is still there just really densely packed inside the event horizon.

Hope that's of some help or interest.  Best wishes to you.

[alancalverd]

Sort of like physics breaking down for newton's laws, thus Einstein came about.

Strangely, there was no obvious breakdown. Einstein began with a series of thought experiments that led to predictions of phenomena that had not previously been observed (gravitational lensing, time dilatation) or considered more than curiosities (kinetic energy of nuclear decay particles). Newtonian physics still dominates everyday engineering and remains an entirely valid approximation where v<<c. 

[charles1948]

When you mention "gravitational lensing", does this have to be a proof of Einstein's Relativity Theory?

Couldn't it be explained by optical effects, resulting from the passage of light through the interstellar gas which surrounds a massive object, such as a distant star or galaxy.

The interstellar gas may be very thin.  But it exists, and so may be supposed to influence the light passing through it.

So inducing refractive effects, just like a glass lens does, in the form of a terrestrial "magnifying glass".

Obviously no-one claims that the magnifying effects of glass lenses prove Relativity, so why claim it for Interstellar gas?

[Kryptid]

When you mention "gravitational lensing", does this have to be a proof of Einstein's Relativity Theory?

Couldn't it be explained by optical effects, resulting from the passage of light through the interstellar gas which surrounds a massive object, such as a distant star or galaxy.

The interstellar gas may be very thin.  But it exists, and so may be supposed to influence the light passing through it.

So inducing refractive effects, just like a glass lens does, in the form of a terrestrial "magnifying glass".

Obviously no-one claims that the magnifying effects of glass lenses prove Relativity, so why claim it for Interstellar gas?

Did you not read the most recent personal message you received from Colin2B?

[charles1948]

Yes I did.  It said that if I refused to believe in the Higgs Boson, I'd get thrown out.
Is that what Science has come to?

[Kryptid]

Yes I did.  It said that if I refused to believe in the Higgs Boson, I'd get thrown out.
Is that what Science has come to?

That is not what that PM said. Go back and read it again.

In the meantime, follow the guidelines of that message and post only in this thread: https://www.thenakedscientists.com/forum/index.php?topic=82437.0

If you want to complain about it, do it over PMs. I won't be warning you again.

[Bored chemist]

When you mention "gravitational lensing", does this have to be a proof of Einstein's Relativity Theory?

Couldn't it be explained by optical effects, resulting from the passage of light through the interstellar gas which surrounds a massive object, such as a distant star or galaxy.

The interstellar gas may be very thin.  But it exists, and so may be supposed to influence the light passing through it.

So inducing refractive effects, just like a glass lens does, in the form of a terrestrial "magnifying glass".

Obviously no-one claims that the magnifying effects of glass lenses prove Relativity, so why claim it for Interstellar gas?

Notwithstanding the fact that this message shouldn't have been posted, it's easy enough to answer.

Yes there's a little gas in the way of the light from distant stars.
Yes, it will (very slightly) alter the path of that light.
But here's the interesting bit; it will alter the path of blue light more than it will alter the path  of red light.
So, if the effect were significant the stars would all be spread out into spectra- like tiny rainbows.
And they aren't so we know the effect is too small to observe in most cases..
Also, gravitational lensing doesn't have this effect- all colours are bent equally.

And that's what we see when we look at lensed objects- they aren't spread out into spectra like they would be if it was simply refraction.

[Petrochemicals (OP)]

Sort of like physics breaking down for newton's laws, thus Einstein came about.

Strangely, there was no obvious breakdown. Einstein began with a series of thought experiments that led to predictions of phenomena that had not previously been observed (gravitational lensing, time dilatation) or considered more than curiosities (kinetic energy of nuclear decay particles). Newtonian physics still dominates everyday engineering and remains an entirely valid approximation where v<<c. 

Yes there was. The presession of mercury

http://farside.ph.utexas.edu/teaching/336k/Newtonhtml/node116.html

Thus led to the aether and the michelsonmorley, t'was ever such.

[Petrochemicals (OP)]

Yes I did.  It said that if I refused to believe in the Higgs Boson, I'd get thrown out.
Is that what Science has come to?

That is not what that PM said. Go back and read it again.

In the meantime, follow the guidelines of that message and post only in this thread: https://www.thenakedscientists.com/forum/index.php?topic=82437.0

If you want to complain about it, do it over PMs. I won't be warning you again.

Could Colin post it please?

[Petrochemicals (OP)]

Text books on General relativity are very carefull NOT to state or demand that a Black hole has matter with some mass inside it, only that there is a parameter associated with a black hole that is like Mass.   

And what of the state of neutron stars? They are seen, yet the matter is very abnormal, what laws explain these adequately? And jets seem to defy light speed limitations not only because of their speed but also they accelerate out of a light trap