Researchers at St. Andrews University, Scotland, claim to have found a way to simulate an event horizon of a black hole – not through a new cosmic observation technique, and not by a high powered supercomputer… but in the laboratory. Using lasers, a length of optical fiber and depending on some bizarre quantum mechanics, a “singularity” may be created to alter a laser’s wavelength, synthesizing the effects of an event horizon. If this experiment can produce an event horizon, the theoretical phenomenon of Hawking Radiation may be tested, perhaps giving Stephen Hawking the best chance yet of winning the Nobel Prize.

So how do you create a black hole? In the cosmos, black holes are created by the collapse of massive stars. The mass of the star collapses down to a single point (after running out of fuel and undergoing a supernova) due to the massive gravitational forces acting on the body. Should the star exceed a certain mass “limit” (i.e. the *Chandrasekhar limit* – a maximum at which the mass of a star cannot support its structure against gravity), it will collapse into a discrete point (a singularity). Space-time will be so warped that all local energy (matter *and* radiation) will fall into the singularity. The distance from the singularity at which even light cannot escape the gravitational pull is known as the *event horizon*. High energy particle collisions by cosmic rays impacting the upper atmosphere might produce micro-black holes (MBHs). The Large Hadron Collider (at CERN, near Geneva, Switzerland) may also be capable of producing collisions energetic enough to create MBHs. Interestingly, if the LHC can produce MBHs, Stephen Hawking’s theory of “Hawking Radiation” may be proven should the MBHs created evaporate almost instantly.

Hawking predicts that black holes emit radiation. This theory is paradoxical, as no radiation can escape the event horizon of a black hole. However, Hawking theorizes that due to a quirk in quantum dynamics, black holes *can* produce radiation.

Put very simply, the Universe allows particles to be created within a vacuum, “borrowing” energy from their surroundings. To conserve the energy balance, the particle and its anti-particle can only live for a short time, returning the borrowed energy very quickly by annihilating with each other. So long as they pop in and out of existence within a quantum time limit, they are considered to be “virtual particles”. Creation to annihilation has net zero energy.

However, the situation changes if this particle pair is generated at or near an event horizon of a black hole. If one of the virtual pair falls into the black hole, and its partner is ejected away from the event horizon, they cannot annihilate. Both virtual particles will become “real”, allowing the escaping particle to carry energy and mass away from the black hole (the trapped particle can be considered to have negative mass, thus reducing the mass of the black hole). This is how Hawking radiation predicts “evaporating” black holes, as mass is lost to this quantum quirk at the event horizon. Hawking predicts that black holes will gradually evaporate and disappear, plus this effect will be most prominent for small black holes and MBHs.

*So… back to our St. Andrews laboratory…*

Prof Ulf Leonhardt is hoping to create the conditions of a black hole event horizon by using laser pulses, possibly creating the first direct experiment to test Hawking radiation. Leonhardt is an expert in “quantum catastrophes”, the point at which wave physics breaks down, creating a singularity. In the recent “Cosmology Meets Condensed Matter” meeting in London, Leonhardt’s team announced their method to simulate one of the key components of the event horizon environment.

Light travels through materials at different velocities, depending on their wave properties. The St. Andrews group use two laser beams, one slow, one fast. First, a slow propagating pulse is fired down the optical fiber, followed by a faster pulse. The faster pulse should “catch up” with the slower pulse. However, as the slow pulse passes through the medium, it alters the optical properties of the fiber, causing the fast pulse to slow in its wake. This is what happens to light as it tries to escape from the event horizon – it is slowed down so much that it becomes “trapped”.

“

We show by theoretical calculations that such a system is capable of probing the quantum effects of horizons, in particular Hawking radiation.” – From a forthcoming paper by the St. Andrews group.

The effects that two laser pulses have on eachother to mimic the physics within an event horizon sounds strange, but this new study may help us understand if MBHs are being generated in the LHCs and may push Stephen Hawking a little closer toward a deserved Nobel Prize.

Source: Telegraph.co.uk

apologies… typo on my part – changed “peace prize” to “physics”

So, first we “simulate” and event horizon. Zounds! So I guess it means we “simulate” a singularity and then somehow we can see if Hawking Radiation exists — even if only simulated!

I think Hawking would more likely win the Nobel prize in Physics for this one.

I guess if we all got sucked into the black hole we’d have Peace?

Negative mass? Can you explain this? I’ve never understood how virtual particles parting ways at the horizon can remove mass from the black hole. It always seemed to me that the black hole would only get more massive as it stole these virtual particles. This is the first time I’ve seen negative mass mentioned.

just a note here, wouldn’t this help stephen hawking win the nobel prize in physics not the not the nobel peace prize, there are many catagories of the nobel prize given out, for example anything anti american or anti capitolism will lock you into to getting one without having any hint of intellect or wisdom. see al gore.

Uh… The title “Synthetic black hole event horizon CREATED in a UK laboratory” yet nowhere in the article was this claimed. I really am dissapointed in “Hype” headlines

How good is Mr Leonhardt at creating Catastrophies?? ;-))

Hhhhmmm . I think I’ve heard about this before.

http://www.ted.com/talks/view/id/167

Cool stuff. And of course, this eerily resembles the “cavitron” device that makes micro-black-holes in my novel EARTH.

In fact we all have to keep a nasty little voice on our shoulders, reminding ourselves that the Galaxy seems to have fewer intelligent, communicating life forms than we expected, a while ago. This “Great Silence” is puzzling…

…and one possible explanation is that every physics-wielding species eventually makes the same Big Mistake. Shudder.

Keep at it tho…

With cordial regards,

David Brin

http://www.davidbrin.com

Sorry I could not understand one part—You said-“Light travels through materials at different velocities, depending on their wave properties.” and then u say that they fired two lasers of different velocities through a same optical fiber?? If the optical fiber was same how was the velocity of laser faster or slower than the other?? My understanding is that the speed of light is dependent on the medium in which it travels. what other properties will change the speed of light??

The speed of light IN A VACUUM is a constant (about 300,000,000 m/s) but in a material e.g. glass, ice or even air it slows down (in glass it is typically around 200,000,000 m/s) however the speed depends on both the medium and wavelength of the light. The change of speed leads to refraction (the bending of light when it enters a new medium) and the difference in speeds for different wavelengths leads to dispersion (the way the colours split up in a prism).

By the way, the Chandrasekhar limit is the point at which a white dwarf can no longer support itself, about 1.44 solar masses. Above this the white dwarf will collapse into a neutron star. To create a black hole the figure is higher, about 2.5 solar masses.

One can get the essentially the same formulae for Hawking

radiation by considering the propagator for EM in a classical

Schwartzchild or Kerr background space–see work by S.T.Yau et alia.

I prefer this approach, as it uses only CLASSICAL general relativity, and first quantization propagators. No virtual particles are needed–aka no second Quantized QFT.

It is even interesting to consider the CLASSICAL Green

Function for EMT in a Schwartzchild background space.

There is a classic work called ” The Wave Equation in Curved

Spacetime”, but it’s too perturbative for my taste.

Another approach to simulation is to use rotating liquids

to simulate distorted spacetime. There was a Scientific Amercian Article on this within the last few years.

It would be nice for Hawking to get a Nobel Prize.

Penny Smith

p.s. I am a big fan of David Brin’s science fiction. It’s science fiction in the OLD hardscience tradition.

I also wonder if one can use the 1990’s method used to slow light to a crawl ( as in recent work on Bose-Einstein Condensates) to simulate event horizons?

Penny Smith

Perhaps, that is actually what the Saint Andrews people are doing? Hard to tell from the description here.

The quality of popular science journalism is very poor lately.

Essentially, no article is even close to correct. I wonder what causes that, as some of the editors and writers have science educations?

Good PR for St. Andrews University. It is apparently true that scientific imagination still has no limits. This is scientific imagination in it’s finest hour, It is conjecture being reported as if it is fact. just waiting to happen. I can think of a thousand experiments that can produce a mini blackhole. Just give me some grant money and i will produce the concepts.

“Interestingly, if the LHC can produce MBHs, Stephen Hawking’s theory of “Hawking Radiation” may be proven should the MBHs created evaporate almost instantly.”

Hawking had better be right about that evaporation. Otherwise, we might have problems!

What’s with the headline. Says “…event horizon created.” I must be stoopid–seems to me they “hope to create” one. Physics is the only science where this kind of unproven garbage gets published on a regular basis as a discovery or advancement of the state of the art. Ha! “Synthetic” event horizons, synthetic singularities, etc. Now wonder physics is the laughing joke of all modern sciences.

I’m with Jose Garcia and Akshat Tanksale. Those were poorly laid out in the article. I’ve been trying to get even the semblance of a handle on Hawking radiation and it has NEVER made any sense until you introduced that idea that the particle that goes in has “negative mass”. What the heck is Negative Mass?

Even positronic (or antimatter) mass is positive mass when it comes to Black holes!

Negative mass? And evaporating black hole? All this time we were told that a black hole steals mass from its suroundings etc. So finally it all amounts to a lot of hypothesis and a realisation that we still are groping in the dark.

Groping is fun, especially in the dark! Thing is, scientists need to get out of the labority more often if they are going to spend their most of their time doing just that!

This website and it’s sister website has gotten REAL bad reccently about reporting unproven theories as fact. In the case of http://www.livescience.com it has been statements that global warming theory is a proven fact, and now this website reporting that an experiment not even done yet has produced results.

Is there a pulishing catagory for “science tabloid”? Cause there sure are publishers that fit that description!

Remember though folks, the failure of this experiment to produce any black hole evaporation or exhibit any of the quantum effects of event horizons the scientists are looking for will not make anyone doubt for a moment that black holes, neutron stars, dark matter etc. actually exist.

The part of the article that talks about the quantum barrier, the point in the mathematical explanation for a black hole where the rules of quantum mechanics stop explaining everything, is telling. That point is why people should be concerned about whether black holes are real. The same barrier exists when describing black hole formation in terms of gravity as well. The reason you hit this barrier is it doesn’t make any sense to say that a whole bunch of stuff is there but doesn’t occupy any space. Whatever.

Hawkins is an dumb arse cripple with nothing to do but dream up crap. i have more intelligence in the tip of my little finger than this fool could ever even imagine. Get a job stephen – you useless fame seeking arsehole

I like the idea of a “science tabloid”, we laypeople need such a thing to keep up with this stuff, we don’t need to read technical physics abstracts. I very much appreciate UT and LIveScience just as they are.

Sam,

Who is Hawkins?

Prof Steven Hawking Phd FRS, on the other hand, has a job–he is Lucsian Professor of Mathematics at Cambridge University–that’s Newton’s chair. He is an eminent mathematician responsible for –among other things–the Hawking/Penrose singularity theorems.

Black Holes are not crap–the mathematics of the rotating

Kerr solution are the basis for the accuracy of the GPS navigation system–and gave us a trillion dollar industry.

Penny

Other practical achievements of Lucsian Profs:

Newton–all of practical mechanics, including the space program, modern machinery, and engines.

Dirac– the mathematics of relativistic spin–wbich gave us the spin technology that allows you computer’s hard drive to store

gigabytes of data in such a small space for rapid access.

Penny

p.s. Abstract math is very useful. Consider James Clerk Maxwell, the mathematician whose equations gave us…

all of radio and electronics.

Like Dirac, and Newton and Hawking, he was just dreaming up stuff.

KAS,

Matter is energy in General Relativity. The existence of negative energy was predicted in a QM context by Casimir.

This Casimir effect was experimentally verified by Philips electronics decades ago.

The negative energy of a quantized black hole is similar.

Penny

Sam,

Maybe the “tip of your little finger” can provide us with the correct theories then?

Send us a picture so that we might make fun of it as well. After all, we want to honor your maturity level.

I still have trouble buying the mathematical construct of an infinitely dense singularity arising from gravitational collapse. It’s mathematics, not demonstrable physics. No one has even demonstrated in a lab that the physics behind neutron star creation…the creation of a neutron by merger of proton and electron in a high grav field…can even happen (not one single such event ever recorded), which would have to be a precursor to a black hole. As to the comment above on abstract mathematics, Maxwell may have written the equations; it’s Tesla and Marco who gave you radio.

correction: Marconi

Probably the prophecies is right in 2012, we all mysteriously end. Not wars nor asteroids but a Black Hole we created suck us all in to the unknown world.

â€œAt present there are about 2000 known neutron stars in the Milky Way and the Magellanic Clouds.â€? http://en.wikipedia.org/wiki/Neutron_star#Population_and_distances

Thatâ€™s three reputable labs repeating the same experiment.

Hertzâ€™s â€œlaboratory experiments confirmed Maxwell’s theory of electromagnetic waves.â€? He â€œdied, when not quite 37â€¦. Marconi started his experiments in December that year and put the work of Faraday, Maxwell, Hertz, and Oliver Lodge to practical use in his experiments with wireless telegraphy.â€? http://www.rockradio.freeserve.co.uk/hertz.htm.

It is possible that in an alternative universe Marconi could get all the necessary steps on his own, without â€œstanding on the shoulders of giants,â€? but he also might – just as well â€“ be only motivated to draw doodles in the sand. In this universe, â€œobserving that no amount of commercial success could save Marconi’s patent, the Court held it invalid.â€? http://www.hbci.com/~wenonah/new/tesla.htm. There is no doubt that Teslaâ€™s ingenuity was based both on knowledge of the Maxwell’s theory and relentless experimentation to create knew knowledge.

As to the existence of black holes – if Sam is real (Descartes would disagree,) he just demonstrated one inside his had. JamesB seems real, but he failed to read IPCC reports. Here is an easier text: â€œA guide to facts and fictions about climate changeâ€?

http://royalsociety.org/downloaddoc.asp?id=1630.

We’re all going to die!

Bill,

Not Tesla, but H. Hertz who demonstrated spark gap transmission based on Maxwell. Before the math, nobody even suspected the existence of “radio waves” other than light. ( Include Faraday in Maxwell–they were collaborators.)

Marconi may have invented the grounded antenna, but that is in dispute. Basically, he was a businessman.

Tesla was basically a fraud–he didn’t invent even the “tesla”

coil, which was prepatented ( like polyphase motors and generators) before Tesla.

http://www.lindsaybks.com/gallery/teslamyth/ttesla2.html

//The “Tesla Coil” was actually invented by the talented electrical experimenter, Elihu Thomson, who received his letter patent on July 4th, 1893. You can download a free copy from the patent office using the number 500630. Issues of Electrical World released in February 1892 reveal that Thomson had created arcs as long as five feet.

//

Like his archrival edison Tesla was a great thief!!

AC current was made practical–not by Tesla–but by the MATHEMATICIAN Charles Proteus Steimetz–who was also the first to make artifical lightening. Steimetz also invented the efficent transformer, the efficent motor, and the balanced AC grid.

Tesla Supporters have become a cult–mostly based on

unproved and unpatented claims of Tesla for efficent broadcast energy and death rays.

Broadcast energy is already contained in Maxwell’s equations—ground waves for example.

But, the contribution of Steinmetz is well documented–check out his listing at Wikepedia.

You see –cultists love Tesla because he was a physicist, and Steinmetz was a mathematician. That is because the Descriptions of Tesla’s Patents are easy to understand–even by

children–and have no math. Steinmetz’s work requires you to know calculus.

But, it is the calculus that makes everything PRACTICAL.

That is why Electrical engineers study Calculus, Differential equations,

Maxwell theory, Linear Algebra, etc.

Tesla put a transmitter on a toy model boat and claimed to invent robotics. But, NORBERT WIENER–PHD mathematician–is the real inventor of modern robotics, as he invented the mathematics of control–aka “Cybernetics”.

Look up Wiener on Wikipedia. Of course, to understand Wiener, one needs calculus etc.

Bill,

Odd, how the abstract math of general relativity predicted the existence of Einstein Rings, Multiple Einstein Rings, black hole

jets, gravitational time dilation, frame dragging etc. And, all have not only been later observed, but have been measured to match the

numerical predictions of Abstract Math very closely!

In the same way, abstract math of Quantum mechanics

predicted the otherwise unsuspected existence of the Laser, and Maser–which was then built–based on that Math.

MATH–Abstract Math— is the KEY to understanding nature, and the key to efficient technology, and the key to unsuspected, counterintuitive invention in physical science

and engineering.

Which brings us back to the importance of the math based

experimental simulation at St. Andrews described above.

It is important to do such things!

Bill,

The first use of radio commercially was based on the

Spark Gap ( Hertz) and the Coherer ( Oliver Lodge–a physicist and –in fact—prof of MATH–in Britain.)

Radio didn’t become really practical until the work of

MATHEMATICAL PHYSICIST and prof of physics at Columbia

university Dr. Armstrong. Amstrong–based on the abstract math of differential equations–invented and patented

1)the rf tube oscillator

2) the Tuned Rf Amplifier

3) The superhetrodyne

4) The Superregenerative

5) FM

That is basically EVERY important circuit in electronics until the 1950’s. All based on ABSTRACT MATH–and all reduced to

PRACTICE.

A very instructive post with so many responses.

Calculus is defined as the “study of symbols”. The zero is a hypersphere and the one is a symbol for rotation. Without a set of axis ( cross or square ) inside a sphere

( circle ) to square the circle there is no such natural thing as a negative. Substituting the all seeing “i” for the square root of negative 1 is a distraction from the holographic , fractal reality that all is one. Newton was a secret society club president and Leibniz was the royal family geneologist so don’t believe everything they teach in engineering school. Egyptian math is centered at the 1 with the left hand side being fractions of the one, the all, illustrating the fractal, fractions of the all.

Ball lightning, a giant Macro Atom is a better possibility to what exists at the galactic center than a “black hole”. This has been suppressed for decades, but you can google Kiril Chukanov and research it some more.

The “apple” that fell on Newton’s head was the hypersphere – visit http://www.goldenmean.info for an accurate definition of “gravity”.

Dear Darren,

Most of your post makes no sense to me. But, I will reply to:

//Newton was a secret society club president and Leibniz was the royal family geneologist so don’t believe everything they teach in engineering school.//

The point of math is that a mathematical proof is a mathematical proof and is open and accessible for checking to anyone with the intelligence to read it.

It doesn’t matter what the creator of the theorem believed, what secret societies he belonged to, what his job was. All that matters is right on the page–in the proof.

Penny

p.s. Given that, yes Newton was involved in several secret societies—-such as the invisible uni, which was a multinational club of scientists that cut across class lines.

It is –irrelevant.

Dear Darren,

What we mathematicians call calculus or ” the calculus” is not the study of symbols, but the study of certain infinite limit processes.

What you are referring to is the OCCULT study of symbols–so called “sacred math”–which has ABSOLUTELY nothing to do with “the calculus”.

Fractals are in fact used by mathematicians–we call it geometric measure theory, and I have published extensively on it. Fractals are not “Fractions”.

Indeed the ancient Kem ( aka Egyptians) were very intested in what you describe, which is the mathematical

theory of approximation by continued fractions. It has its uses and is mathematics. The ancient greeks tried to base

a theory of physics on it–See the classic book “Dynamic Symmetry”, which can be obtained from Dover publications.

But, ” the calculus” is a better description of physics–that is

it predicts better and with less ad hoc assumptions.

The “all seeing eye” aka the Eye of Horus has nothing to do

–except poetically to occultists–with the square root of minus one.

As to your comment on the hypersphere:

It is true that one of the main interests of occultists in the 19th

and early 20th century was hyperdimensional geometry. That is why Flatland was written by an abbot, and why the occultist

Hinton (who was also a talented amateur mathematician) wrote a prize winning popular book on synthetic four dimensional geometry.

However, as a multidimensional geometer (that is: as a

researcher in differential geometry), I can assure you that modern mathematical investigations of hyperdimensional geometry ( such as hyperspheres) has NOTHING to do with the occult. It’s just pure math!

As to the ” giant atom” at the center of the galaxy idea–

it is a bit odd—but, of course a neutron star is just a giant atomic nucleus.

Sometimes occult people are laughed at, and we just have to understand that some of their ideas are not totally bizarre

( though many are). For example, I have neodruid friend who is very into “crystals” as a source of power over nature.

I informed her that modern technology is, in fact, largely based on crystals–such as quartz crystal oscillators, synthetic ruby crystal lasers etc.

For a better understanding of gravity ( in the context

of General relativity–which does use four dimensions), a non-mathematician should take a look a “Relativity for the Million” and other popular classics. I cut my teeth on them as a child–shortly after reading Flatland–and just before reading HInton’s ” The Fourth Dimension simply Explained”,

which is available from Dover.

As an example of my comment on “a proof is a proof”.

Their was a 19th century mathematician named Wronsky,

yes, the same Wronsky as in ” the Wronskian”.

Wronsky believed many strange things–he was a major figure in the occult ( in fact, the teacher of Elphias Levy!), but

–all that aside– the theorm of the Wronsky Determinate ( aka the Wronskian) is correct and useful mathematics taught in

a first course on differential equations to all engineers, for example.

A theorem is a theorem, a proof is a proof, and we mathematicians don’t care if the creator of the theorem and proof worshipped invisible unicorns from Mars.

The proof stands on its own.

What?

Darran,

You might be referring to a more recent “all seeing eye”–the masonic syncretic one on the dollar bill. But it doesn’t matter.

The use of the letter i for the square root of minus one is due to i being the first letter of the word imaginary. That is because

–before the modern definition of complex numbers as ordered pairs of real numbers with a special multiplication and addition– people thought that the square root of minus one was an “imaginary” number.

It has no other significance in math.

All of this is getting fairly far from a discussion of black hole horizons. So, I think I am done here.

Sorry for the tangency–but, I was addressing the comments of others in –I hope–a helpful way.

For Jose Garcia

The black hole will not get more massive. These virtual particles are formed from the gravitational energy of the black hole (the energy is transformed in matter). One particle falls into black hole, and one particle escapes, so the black hole will lose gravitational energy, therefore it will lose mass.

Far be it to belittle the importance of math. I will say that all mathematical results do not have physical correspondence. There is still debate, though many will not countenance it, regarding the existence of black holes. There are alternate explanations for the high energy phenomena such as “black hole jets”. Recenty brown dwarves were found to have similar jets, and by their definition there is no singularity (nor a thermonuclear core!), so perhaps the jets need no singularity anywhere.

Hawkins in nothing but a pure waste of oxygen. He is not alone though. Einstein, Newton, Plank et al and there idiotic ideas are not necessary for a full and happy life. There is a theory of everything and I know what is. For all you pathetic arsehole academics out there listen up ok.

The only all encompassing theory of everything is that there is’nt one. There will never be one ever! – since the theory itself will disprove that which is not the theory. All of you lazy, useless, pasty, unfit to live on this planet measuring maniac control freaks do something useful or f off and die!! YEAH – especial you Hawkins you fame seeking bullshit artist!

Dear Bill,

Actually, the “black hole jets” are NOT caused by the singularity but by the gravitiational tidal effects. There are many types of jet like phenomena in the universe.

Try this instead:

http://science.nasa.gov/headlines/y2001/ast12jan_1.htm

It’s a strong experimental observation that fits black holes and nothing else known.

M.B. Altaie, a scientist at Yarmouk University in Jordan, have shown that the created particle of Hawking can only exist in a region below 1.5 times the Schwarzschild radius (in fact within a region that is 4/3 times the Schwarzschild radius), then according to general relativity such particles will eventually fall again into the black hole and none can escape. This may explain the non-existence of Hawking radiation. But the black holes may then inflate. For reference see

Hadronic Journal 26, 779-794, (2003)

also see full text of the paper at

http://arxiv.org/gr-gc/0105024

Nada

Forget about black holes. Like all things black they can be sidelined or marginalized or reduced or starved out of existence by A-Holes that spend hundreds of billion on pathetic experiments to satisfy some craving for fame and to prove that their fantasies are right.

There are only two holes of any concern. The A-Hole and the Pink Hole. A-Holes do not get enough Pink Hole and get frustrated and contract, retaining toxic waste. This fogs the brain which becomes delusional and is unable to create an event horizon around the pink hole. The pink hole , now starved of charm retreats into a singularity and devours all that crosses it’s path. A-Holes, in an effort to reduce this ferocious suction, feed the Pink Hole mega tonnes of bullshit to expand the event horizon so they have a better chance of getting some. The more complicated the bullshit the tastier it is for the pink hole which oozes in appreciation and takes on the new spin and jumps to a brand new energy level. This in turn excited the A-Hole in new and unexplored territory where entire languages are invented to further excite the Pink Hole.

Now it hasn’t happened yet but one day the event horizon will expand to include the A-Hole in the Pink Hole territory and an explosion only measurable in Schwarzschild/Hawking cumletmefucku units will occur, obliterating all traces of the A-Hole and the Pink Hole, and sadly the poor old black holes.

Ahhh nature – so unforgiving!

Penny wrote:

“The use of the letter i for the square root of minus one is due to i being the first letter of the word imaginary. That is because

â€“before the modern definition of complex numbers as ordered pairs of real numbers with a special multiplication and additionâ€“ people thought that the square root of minus one was an “imaginary” number.”

I used to teach mathematics and I think the square root of -1 is not real ie imaginary!!! In fact, try ordering a set of complex numbers and all you get are contradictions! Real numbers can be ordered and no logical contradictions are created.

If I am not correct, please correct me.

Thanks.

Yes, cosmology is in a parlous but interesting state.

90% of mass is missing in galaxies but the ‘universe’ is expanding too rapidly – hence

‘dark energy’.

On negative mass, it seems that if a negative mass and a positive mass were in orbit around each other, they would rotate around a centre with nothing in it!. Hmmmm.

Newton shortly before his death remarked –

‘I do not know what I may appear to the world, but to myself I seem to have only been like a boy playing on the seashore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocaen of truth lay all undiscovered before me’.

– oh and by the way hospitals use positrons, ie. anti-electrons, in their PET scanners….

I can create all of this in a program of viruses based on math and fundamentals. A Universe, a million galaxies at the dial of a mouse. As users of this program we can travel at the speed of whatever we feel. Gravity, magnetism, radiation, atoms, molecules. I can manufacture life that sees itself as real through the program. The animal kingdom and its instinct or the program within a program like I would like to call it could potentially grow like a mirror looking into a mirror for ever. How long could we keep the program running?

You idiots! This could ruin the whole world! great job at killing all of us!

How big does a black hole have to be before it doesn’t disappear?

“How big does a black hole have to be before it doesn’t disappear?”

Black holes will evaporate no matter what their size. Large black holes (millions of solar masses) can’t evaporate right now because the cosmic microwave background gets absorbed by them and is enough to sustain their mass. In the far distant future the cosmic microwave background will be much weaker and won’t be able to sustain the larger black holes.

Hope he gets a Nobel prize before he dies. He truly deserves it for his great contributions to science.

If dark matter has a mass then does a black whole suck in this dark matter and if so then will a large black whole ever evaporate?

The style of writing is quite familiar . Did you write guest posts for other blogs?