The nature of Space Time Energy and Matter.

[Lasse]

Could the reason for the present Universe be, that space expands with c2 and energy and matter is created and evolving in proportion to it's development?

Such a 4D, outward pointing, linear-exponential, infinite drive would be a strong force behind the presence of energy and matter(mass) and could explain the determined nature of the universe.

Can anything disappear from spacetime without a trace?

Edited April 20, 2018 by Lasse

[Strange]

8 minutes ago, Lasse said:

Could the reason for the present Universe be, that space expands with c2

Do you mean c² (which isn't a speed) or 2c? And why do you think it expands with that speed?

And the expansion of space is not described by a speed but by a scaling factor. Which means that the speed of separation between two points is proportional to the distance between them. So there will be points that are far enough apart that they will be receding at 2c.

Quote

and matter is created in proportion to it's development?

There is no evidence that matter is created.

15 minutes ago, Lasse said:

Such a 4D, outward pointing, linear-exponential, infinite drive

Blah, blah, blah. Colourless green sheep dream furiously.

17 minutes ago, Lasse said:

Can anything disappear from spacetime without a trace?

The nearest is something falling into a black hole. But that is not entirely without trace. Its mass, electric charge and angular momentum are preserved. Quantum information may also be preserved, but that is an area of research.

So, no.

[Lasse]

Can a black hole explode?

[Strange]

3 minutes ago, Lasse said:

Can a black hole explode?

No.

[JacobsLadder]

9 minutes ago, Strange said:

No.

I'm pretty sure that Hawking radiation suggests that if a black hole is small enough it would evaporate extremely quickly and violently.

In my book that would be an explosion.

So, my answer is yes a black hole COULD explode.

Edited April 20, 2018 by JacobsLadder

[Strange]

You are right. Really, really tiny black holes will explode. (I was thinking of the ones we know exist.)

As far as I know, there is no mechanism for creating black holes that size and no evidence they exist.

[StringJunky]

31 minutes ago, Strange said:

You are right. Really, really tiny black holes will explode. (I was thinking of the ones we know exist.)

As far as I know, there is no mechanism for creating black holes that size and no evidence they exist.

I think the Chandrasekhar Limit sets the lower limit, doesn't it? About 1.5 solar masses.

Edited April 20, 2018 by StringJunky

[interested]

1 hour ago, Lasse said:

Can anything disappear from spacetime without a trace?

Virtual particles/quantum fluctuations can disappear without a trace. Spacetime is full of quantum fluctuations.

Black holes may be able to evaporate due to hawking radiation. Smaller black holes radiate more xrays than larger black holes increasing there rate of energy loss. What happens to them below the Chandrasekhar limit it is not obvious do they supernovae or something else. Laws of thermodynamics suggest they will be full of radiation. If they did explode the energy/mass absorbed by the black hole would be released/reappear.

[JacobsLadder]

22 minutes ago, StringJunky said:

I think the Chandrasekhar Limit sets the lower limit, doesn't it? About 1.5 solar masses.

That concerns  gravitational collapse

It is not the same thing as black hole evaporation.

16 minutes ago, interested said:

What happens to them below the Chandrasekhar limit it is not obvious do they supernovae or something else.

The Chandrasekhar limit concerns collapsing stars. It is not a factor for existing black holes.

[interested]

11 minutes ago, JacobsLadder said:

The Chandrasekhar limit concerns collapsing stars. It is not a factor for existing black holes.

Chandrasekhar limit

From Wikipedia, the free encyclopedia

 

 

The Chandrasekhar limit (/tʃʌndrəˈʃeɪkər/) is the maximum mass of a stable white dwarf star. The currently accepted value of the Chandrasekhar limit is about 1.4 M_☉(2.765×10³⁰ kg).^[1][2][3]

White dwarfs resist gravitational collapse primarily through electron degeneracy pressure (compare main sequence stars, which resist collapse through thermal pressure). The Chandrasekhar limit is the mass above which electron degeneracy pressure in the star's core is insufficient to balance the star's own gravitational self-attraction. Consequently, a white dwarf with a mass greater than the limit is subject to further gravitational collapse, evolving into a different type of stellar remnant, such as a neutron star or black hole. 

 

38 minutes ago, StringJunky said:

I think the Chandrasekhar Limit sets the lower limit, doesn't it? About 1.5 solar masses.

What do you make of these scientists claim from last year, https://mashable.com/2017/05/31/x-ray-laser-molecular-black-hole/#gGkllTNunSqA This BH is a bit smaller than than 1.4M_☉

[JacobsLadder]

Black holes get smaller because of Hawking radiation and eventually disappear.

There has to be countless black holes with under 1.5 solar masses.

[Strange]

2 minutes ago, JacobsLadder said:

Black holes get smaller because of Hawking radiation and eventually disappear.

There has to be countless black holes with under 1.5 solar masses.

A black hole of that size will absorb more mass than it loses due to Hawking radiation. Even if it were in remote space with no matter to absorb, it would absorb more energy from the CMB than it loses.

[interested]

1 hour ago, Lasse said:

Can a black hole explode?

Maybe

https://www.nature.com/news/quantum-bounce-could-make-black-holes-explode-1.15573

Edited April 20, 2018 by interested

[StringJunky]

17 minutes ago, interested said:

Chandrasekhar limit

From Wikipedia, the free encyclopedia

 

 

The Chandrasekhar limit (/tʃʌndrəˈʃeɪkər/) is the maximum mass of a stable white dwarf star. The currently accepted value of the Chandrasekhar limit is about 1.4 M_☉(2.765×10³⁰ kg).^[1][2][3]

White dwarfs resist gravitational collapse primarily through electron degeneracy pressure (compare main sequence stars, which resist collapse through thermal pressure). The Chandrasekhar limit is the mass above which electron degeneracy pressure in the star's core is insufficient to balance the star's own gravitational self-attraction. Consequently, a white dwarf with a mass greater than the limit is subject to further gravitational collapse, evolving into a different type of stellar remnant, such as a neutron star or black hole. 

 

What do you make of these scientists claim from last year, https://mashable.com/2017/05/31/x-ray-laser-molecular-black-hole/#gGkllTNunSqA This BH is a bit smaller than than 1.4M_☉

The operative words are "akin to a black hole", it doesn't mean it's composed of extremely curved spacetime... they actually call it a 'void', which presumably means empty..

[JacobsLadder]

13 minutes ago, Strange said:

A black hole of that size will absorb more mass than it loses due to Hawking radiation. Even if it were in remote space with no matter to absorb, it would absorb more energy from the CMB than it loses.

Correct for larger BHs.

But of course BHs over the CMB temperature threshold will get smaller.

Edited April 20, 2018 by JacobsLadder

[Strange]

2 minutes ago, JacobsLadder said:

But of course BHs over the CMB temperature threshold will get smaller.

This threshold is about 100th the Earth mass. And the lifetime at that size would be about 10⁴⁴ years.

For a black hole to evaporate in less than a second, its mass would have to be about 200 tons.

[JacobsLadder]

3 minutes ago, Strange said:

This threshold is about 100th the Earth mass. And the lifetime at that size would be about 10⁴⁴ years.

For a black hole to evaporate in less than a second, its mass would have to be about 200 tons.

Yes, Isn't that what we are discussing?

[Strange]

3 minutes ago, JacobsLadder said:

Yes, Isn't that what we are discussing?

Yes. That is why I said it.

Just thought it was useful to quantify things a bit.

[Lasse]

9 minutes ago, Strange said:

This threshold is about 100th the Earth mass. And the lifetime at that size would be about 10⁴⁴ years.

For a black hole to evaporate in less than a second, its mass would have to be about 200 tons.

Could a black hole decay without recognisable energy release i.e mass=>energy transformation

[Strange]

Just now, Lasse said:

Could a black hole decay without recognisable energy release i.e mass=>energy transformation

Well, the mass would have to go somewhere. And Hawking radiation is the only (currently) known method for that.

[Lasse]

4 minutes ago, Strange said:

Well, the mass would have to go somewhere. And Hawking radiation is the only (currently) known method for that.

Did we ever saw a black hole decay? What is left after the 2 neutron stars collision? Will there be some kind of mass there and matter or there is just empty space-time?

[Strange]

11 minutes ago, Lasse said:

Did we ever saw a black hole decay?

No. And unless we find a method of creating micro black holes in the lab, I doubt we ever will.

13 minutes ago, Lasse said:

What is left after the 2 neutron stars collision? Will there be some kind of mass there and matter or there is just empty space-time?

It will probably have formed a black hole, but there isn't enough data to confirm this. It could have formed a neutron star that is still above the limit of collapsing to a black hole. 

[JacobsLadder]

23 minutes ago, Lasse said:

Did we ever saw a black hole decay? What is left after the 2 neutron stars collision? Will there be some kind of mass there and matter or there is just empty space-time?

There is not enough data either way but I tend towards the energy being reabsorbed into the firmament.

[beecee]

8 hours ago, JacobsLadder said:

Black holes get smaller because of Hawking radiation and eventually disappear.

There has to be countless black holes with under 1.5 solar masses.

Of the BH's that we know exist, that is those of stellar and supermassive size, it would take the lifetime of the whole universe before they evaporated. In a timeframe of around 100 trillion years, long after all stars have been extinguished, the CMBR will be effectively zero, and BH's will have evaporated.

7 hours ago, Lasse said:

Did we ever saw a black hole decay? What is left after the 2 neutron stars collision? Will there be some kind of mass there and matter or there is just empty space-time?

While Hawking radiation is logically consistent, as yet we really have no evidence that it does take place.

When two Neutron stars collide, depending on trajectory, I would say a BH would be formed.

 

7 hours ago, JacobsLadder said:

There is not enough data either way but I tend towards the energy being reabsorbed into the firmament.

The "firmament" is actually a long out dated mythical terminology construct from the book of myths [the bible] and is a terminology only used today by creationists and other religious nuts. 

Edited April 20, 2018 by beecee

[swansont]

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Moderator Note

A reminder that responses to speculation should be based on mainstream science, not further speculation