The early solar system must have been a maelstrom of hot materials! Hopefully with the mega observatories coming soon, we'll be around to witness amazing new discoveries in so many aspects of astrophysics!
Thank you for fixing the link!
Verlinde is trying to solve the riddle of Gravity through string theory but appears not to have made much progress over the last few years.
I guess this is a tantalizing problem because at a intuitive level, you can grasp why time and entropy could be the key (the larger the mass, the greater the entropy, the greater the distortion of time around the mass) but of course you have to be able to derive it and write an equation that will predict it - a bit like the Hooke/Newton example I mentioned previously.
Perhaps we are on the cusp of a breakthrough. I hope I live to see it!
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I have read the Discopete article about Space.
Space Isn’t What You Think It Is
Very confusing, IMO. A relevant point that since photons have no mass, why does gravity bend them? But I am OK with Gaussian curvature:
Currently on Prof. Verlinde's lecture:
(LIVE) Erik Verlinde Public Lecture: A New View on Gravity and the Dark Side of the Cosmos - YouTube
I am quite the fan of Information Theory. Some people believe information has mass. All done with Log to the base 2.
Of course, Quantum Qubit Information is not about 1 and 0. More about entangled plus 1/2 and minus 1/2. 😕
Other demands on my time. The Robot thing is on in 5 minutes, Episode 4. TBH, it's starting to creep me out. Bad things are looming IMO. 😱
Space Isn’t What You Think It Is
Very confusing, IMO. A relevant point that since photons have no mass, why does gravity bend them? But I am OK with Gaussian curvature:
Currently on Prof. Verlinde's lecture:
(LIVE) Erik Verlinde Public Lecture: A New View on Gravity and the Dark Side of the Cosmos - YouTube
I am quite the fan of Information Theory. Some people believe information has mass. All done with Log to the base 2.
Of course, Quantum Qubit Information is not about 1 and 0. More about entangled plus 1/2 and minus 1/2. 😕
Other demands on my time. The Robot thing is on in 5 minutes, Episode 4. TBH, it's starting to creep me out. Bad things are looming IMO. 😱
But, but!
Photons do have mass?! Even if it's relativistic, light has no "rest mass", but if light does not have "relativistic mass" everything just falls apart.
Just a few pages ago I posted this:
What is the mass of a photon?
I think it's a very good interpretation/summary. If the formula is too complex, a good approximation gets you 99% of the way.
Photons do have mass?! Even if it's relativistic, light has no "rest mass", but if light does not have "relativistic mass" everything just falls apart.
Just a few pages ago I posted this:
What is the mass of a photon?
I think it's a very good interpretation/summary. If the formula is too complex, a good approximation gets you 99% of the way.
C'mon Steve! You know that gravity is not really an attractive force between any two masses as described by Newton! 😉
In general relativity, objects must follow the shortest path between any two points in four-dimensional space-time. These paths are called geodesics.
In the absence of matter, the geodesics in four-dimensional space-time correspond to straight lines in three-dimensional space
In the presence of matter, four-dimensional space-time is distorted, causing the paths of objects in three-dimensional space to curve in the manner that Newtonian theory would explain was due to the force of gravity.
Light rays must also follow geodesics in space-time. Again, the fact that space-time is curved means light no longer appears to travel in straight lines in space, so general relativity predicted that gravitational fields should bend light.
I've extracted the above information from my copy of 'A Briefer History of Time' by Stephen Hawking with Leonard Mlodinow.
Yes, that’s how understand it Galu (also covered in the ‘Motion Mountain’ physics books!)
Matter (mass) warps space time, but it’s the underlying mechanism that we have to explain. Hence QLG, String Theory etc etc.
Matter (mass) warps space time, but it’s the underlying mechanism that we have to explain. Hence QLG, String Theory etc etc.
Photons do not have mass, but they do have energy and momentum.
The relativistic total energy of a particle is E^2 = (pc)^2 + (mc)^2, where E = energy and p = momentum.
We know that m = 0 for a photon. However, because of the Compton effect, we know p is not zero, so the relativistic energy of a photon simplifies to E = pc
Since Planck's equation states that the energy of a photon is given by E = hc/λ, we can quantify the momentum of a photon to be p = h/λ
So, you see, there's no need to talk about the mass of a photon. We know its energy and momentum and that is sufficient. 😎
Whoah whow! Incredible Physics mistake here! Even I can spot this one. 😀
The correct Einstein equation is NOT E^2 = (pc)^2 + m^2 c^2
It is E^2 = (pc)^2 + m^2 c^4
Just sayin, 🙂
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Incredible typing mistake, you mean!
Yes, it's (mc^2)^2 and not (mc)^2, but it makes no difference to the premise of my argument.
Yes, it's (mc^2)^2 and not (mc)^2, but it makes no difference to the premise of my argument.
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Wroooom.......
Breaking the warp barrier: hyper-fast solitons in Einstein–Maxwell-plasma theory
Eat your harts out ;-D
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Breaking the warp barrier: hyper-fast solitons in Einstein–Maxwell-plasma theory
Eat your harts out ;-D
//
Superluminal mechanisms are rooted in standard physics, like when photons travel over intercontinental distances in optical fibres.
The refractive index of the fibre decreases with photon wavelength at the infrared wavelengths used in fibre communications.
Short wavelength photons travel faster and move to the leading edge of the pulse, while longer wavelength photons travel slightly slower and stay at the trailing edge.
This produces special bell-shaped pulses known as solitons.
In water, a soliton is shaped like a hump, where the level of water suddenly rises, and it can travel for a long distance.
The soliton was first discovered in August 1834, by John Scott Russell as he was riding beside the Union Canal near Edinburgh.
First unchanging 'soliton' wave found in space | New Scientist
OK, let's look at faster-than-light travel via solitons then. 
The potential of the new research is that space-time curvature could be arranged into a soliton, or 'warp bubble', which would retain its shape while travelling long distances - analagous to the water soliton I described in my previous post.
If sufficient energy could be generated, the equations used in this research would allow space travel to Proxima Centauri and back to Earth in years instead of decades or millennia.
So enclose a space craft within a soliton and the sky's the limit? Well, not exactly! 🙁
The problem is that by "sufficient energy", the researchers actually mean astronomical amounts of energy! To enclose a spacecraft within a soliton would require a quantity of energy 30 orders of magnitude greater than that deliverable by a modern nuclear fission reactor! 😱
Breaking the warp barrier for faster-than-light travel: New theoretical hyper-fast soliton solutions -- ScienceDaily
The potential of the new research is that space-time curvature could be arranged into a soliton, or 'warp bubble', which would retain its shape while travelling long distances - analagous to the water soliton I described in my previous post.
If sufficient energy could be generated, the equations used in this research would allow space travel to Proxima Centauri and back to Earth in years instead of decades or millennia.
So enclose a space craft within a soliton and the sky's the limit? Well, not exactly! 🙁
The problem is that by "sufficient energy", the researchers actually mean astronomical amounts of energy! To enclose a spacecraft within a soliton would require a quantity of energy 30 orders of magnitude greater than that deliverable by a modern nuclear fission reactor! 😱
Breaking the warp barrier for faster-than-light travel: New theoretical hyper-fast soliton solutions -- ScienceDaily
If we want to keep up with the news from home, FTL communication will be useful when FTL travel takes us light years from Earth! 😉
The computer says NO! 😀
No, We Still Can't Use Quantum Entanglement To Communicate Faster Than Light
Question (serious one).
If a photon emitted from an object very distant is intercepted (ie interacts with another particle), it ceases to exist everywhere despite the fact that the photon ‘wavefront’ may be many light years across.
Could we use this property to communicate FTL?
If a photon emitted from an object very distant is intercepted (ie interacts with another particle), it ceases to exist everywhere despite the fact that the photon ‘wavefront’ may be many light years across.
Could we use this property to communicate FTL?
My friends, the future is as uncertain as the past.
Nothing goes faster than light. 🙄
Great personal interest in the upcoming 2021 Cheltenham Gold Cup for me:
Full Result | 15:30 Magners Cheltenham Gold Cup Chase (Grade 1) | Cheltenham | Sky Sports Horse Racing
Last years result. I have my eye, this year, on Lostintranslation at an excellent 33-1. I might split the bet with Delta Work (previously trained by the disgraced Gordon Elliot) which had a bad second jump in 2020 but recovered well.
Well you heard it here first. 😀
Nothing goes faster than light. 🙄
Great personal interest in the upcoming 2021 Cheltenham Gold Cup for me:
Full Result | 15:30 Magners Cheltenham Gold Cup Chase (Grade 1) | Cheltenham | Sky Sports Horse Racing
Last years result. I have my eye, this year, on Lostintranslation at an excellent 33-1. I might split the bet with Delta Work (previously trained by the disgraced Gordon Elliot) which had a bad second jump in 2020 but recovered well.
Well you heard it here first. 😀
This idea has come up before, and I was happy to go along with it.
However, on further reflection, I don't get it. Not that I will ever fully understand things that happen in the quantum domain! 🙁
Surely the 'waviness' of a photon lies simply in the probability of detecting it?
Isn't a photon a 'wave function' rather than a 'wave'?
Sometimes, physicists confuse us by describing the wave function as if it were a real wave rather than being only an equation.
In the double slit experiment, the 'waviness' only appears with the accumulation of the probabilies of finding a photon at any particular position on the screen.
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