The same isolating conditions applied to the now extinct dwarf elephants of Sicily, one variety of which was 2 m tall and weighed in at 1,000 kg.
Last year, scientists managed to extract and sequence DNA from a small, dense bone found in the base of the skull of this 1 ton variety.
These dwarf elephants were found to be descended from one of the largest land mammals ever to have lived: the straight-tusked elephant. It is thought that these 14 ton giants reached Sicily when sea levels were up to 100 metres lower than they are today, and then became trapped there after sea levels rose again.
The new research estimates that the giant elephants shrank in size by up to 200 kg per generation, shedding 8,000 kg to reach just 15% the size of their original size within only 40 generations.
This represents a very high evolutionary rate, and new data is being sought to understand this evolutionary scenario.
It all goes to show that evolution is not cut and dried and that scientists continue to seek a greater understanding of its processes.
The full story is here: https://www.nhm.ac.uk/discover/news...-from-extinct-miniature-elephants-sicily.html
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OK, no guarantees, but I like a Challenge. Useless Canon Coolpix Camera on Charge. Tripod located. 5AM is early for me. Obviously too early for all you too. But whatever.
A mere Astronomical Conjunction, the likes of which have been posted before....
Let's see how it goes. 🙂
Back to Physics. Greatly enjoying Lee Smolin's book ATM. "The Trouble with Physics".
A rarely funny Physics Book in which he discusses Supersymmetry:
"Unfortunately, no one has ever successfully postulated a supersymmetry holding between two known particles. Instead, in all the supersymmetric theories the number of particles are at least doubled. A new superpartner is simply postulated to go along with each known particle. Not only are there SQUARKS ans SLEPTONS and PHOTINOS, there are also SNEUTRINOS to partner the Neutrinos.
HIGGSINOS with the Higgs. and GRAVITINOS to go with the Gravitons. Two by Two a regular Noah's Ark of particles."
(Here's where it gets funny, IMO...)
Sooner or Later, tangled in the web of new snames or naminos, you begin to feel like Sbozo the clown. Or Bozo the clownino. Or swatever. 😀
A mere Astronomical Conjunction, the likes of which have been posted before....
Let's see how it goes. 🙂
Back to Physics. Greatly enjoying Lee Smolin's book ATM. "The Trouble with Physics".
A rarely funny Physics Book in which he discusses Supersymmetry:
"Unfortunately, no one has ever successfully postulated a supersymmetry holding between two known particles. Instead, in all the supersymmetric theories the number of particles are at least doubled. A new superpartner is simply postulated to go along with each known particle. Not only are there SQUARKS ans SLEPTONS and PHOTINOS, there are also SNEUTRINOS to partner the Neutrinos.
HIGGSINOS with the Higgs. and GRAVITINOS to go with the Gravitons. Two by Two a regular Noah's Ark of particles."
(Here's where it gets funny, IMO...)
Sooner or Later, tangled in the web of new snames or naminos, you begin to feel like Sbozo the clown. Or Bozo the clownino. Or swatever. 😀
Just surfaced from a long night of Astronomy. What went wrong? I think Commanding Officer Galu failed to mention that I was facing a "Falling Ecliptic"!
It was thus not my fault. Mission well executed, Orders wrong. Thus the Stars were low on the Horizon, and hard to see, one supposes. 😕
Even Physics (QED) Hero, Dick Feynman had his occasional defeats.
Another achingly funny contribution from Lee Smolin:
On Quantum Gravity ca. 1962, which interested Dick Feynman on a trip to a Physics Conference in Warsaw, as he related in a letter to his wife:
"I am getting nothing out of the meeting. I am learning nothing. Because there are no experiments, this field is not an active one, so few of the best men (or women... S7) are doing work on it. The result is there are hosts of dopes here.... and it is not good for my blood pressure. Remind me not to come to any more gravity conferences!"
There it is. Both barrels. 😀
It was thus not my fault. Mission well executed, Orders wrong. Thus the Stars were low on the Horizon, and hard to see, one supposes. 😕
Even Physics (QED) Hero, Dick Feynman had his occasional defeats.
Another achingly funny contribution from Lee Smolin:
On Quantum Gravity ca. 1962, which interested Dick Feynman on a trip to a Physics Conference in Warsaw, as he related in a letter to his wife:
"I am getting nothing out of the meeting. I am learning nothing. Because there are no experiments, this field is not an active one, so few of the best men (or women... S7) are doing work on it. The result is there are hosts of dopes here.... and it is not good for my blood pressure. Remind me not to come to any more gravity conferences!"
There it is. Both barrels. 😀
And there was I thinking that, from Portsmouth, you'd get a clear view of the SE horizon.
Are you sure you didn't miss the conjunction simply because you 'slepton'? 😀
Are you sure you didn't miss the conjunction simply because you 'slepton'? 😀
Oof. Just dropped here. Maybe someone worded that before.
The concept of space as a dimension is hard to grasp on. If this dimension is not developed, then there is literally nowhere to expand. Just incompatible. You cannot put anything behind, because there is no such thing as space in existence present.
How to explain it better...
There is no sound in vacuum, because it lacks the medium in which sound operates. The same way, the space can only operate in certain dimensional setup. Some kind of medium. If thas medium is not present, then the space dimension is not present either, and stuff happens dimensionless(in the meaning of length, width and such).
If someone objectively debunked this, pretty please, bring it to my attention, I am keen on that 🙂
The concept of space as a dimension is hard to grasp on. If this dimension is not developed, then there is literally nowhere to expand. Just incompatible. You cannot put anything behind, because there is no such thing as space in existence present.
How to explain it better...
There is no sound in vacuum, because it lacks the medium in which sound operates. The same way, the space can only operate in certain dimensional setup. Some kind of medium. If thas medium is not present, then the space dimension is not present either, and stuff happens dimensionless(in the meaning of length, width and such).
If someone objectively debunked this, pretty please, bring it to my attention, I am keen on that 🙂
Could the "medium" be the quantum vacuum?
Regarding dimensions, spacetime is 4 dimensional.
Spacetime is expanding, but it isn't expanding into anything.
It's simply that distances between remote points in our universe are getting bigger.
Regarding dimensions, spacetime is 4 dimensional.
Spacetime is expanding, but it isn't expanding into anything.
It's simply that distances between remote points in our universe are getting bigger.
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Of course I am not sure, but it does not seem to be quantum vacuum, as space cannot be for sure called a particle or wave. And also, absence of particle or wave does not allude absence of space.
It is very doubtful if we can for purpose of math divide spacetime into space and time. I think we can. It is just that the relations need to be kept in the equations.
The last paragraph of yours is closest to what I mean. The dimension can easily be growing and expanding on its edges, but it could as well develop itself globally in a way, into what you propose. This is pure speculation, but it is awesome that we can even abstract that.
It is very doubtful if we can for purpose of math divide spacetime into space and time. I think we can. It is just that the relations need to be kept in the equations.
The last paragraph of yours is closest to what I mean. The dimension can easily be growing and expanding on its edges, but it could as well develop itself globally in a way, into what you propose. This is pure speculation, but it is awesome that we can even abstract that.
The expansion of space is conceptually different from other kinds of expansions and explosions that are seen in nature.
Without the objects themselves moving, space is somehow 'growing' in between them.
It is the metric that is changing rather than objects moving in space. (The metric is a formula which converts coordinates of points in space into distances).
https://en.wikipedia.org/wiki/Metric_tensor_(general_relativity)
Unlike the metric of space, the metric of spacetime is non-Euclidean i.e. not just three dimensions and three coordinates, but four, to include time.
The non-Euclidean nature of spacetime manifests itself by the fact that the distance between points with constant coordinates grows with time, rather than remaining constant.
In other words, in expanding spacetime, distance is a dynamical quantity that changes with time.
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The individual components in Euclidian space and time may differ due to length contraction and time dilation. This is because Euclidian space treats time differently than it treats the three spatial dimensions.
This all changes in the spacetime of general relativity, where space and time are interwoven. Here all frames of reference will agree on the total distance in spacetime between events.
Spacetime is equipped with a metric which yields the spacetime interval between two events when given their coordinates. In an expanding spacetime, the metric changes with time in a way that causes distances to appear larger at later times. This explains why galaxies that are more distant from us appear to be receding faster than galaxies that are closer to us (Hubble's Law).
Is a non relative universe spanning view/model possible and if so, usable? I mean its not that it doesn't exist...
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This morning's disappointment in Astronomy is now explained, I think:
https://www.bbc.co.uk/news/science-environment-61259569
Too much light pollution from where I was watching. I'm not going to try again tomorrow. I'd probably need to go miles down the beach to get a clear view away from the lights and the time window is short due to Jupiter and Venus being low at this time of year.
Someone in the Southern Hemisphere would find it easier, I think.
Back to the expanding Universe, Lee Smolin seems to be leading to the idea that Space is derivative. It is Time that is real. And only in the sense that Time determines one event following another causally. He also mentions that the Graviton is very different from a Photon. Gravitons not only interact with each other, but permanently create ripples in, er, Space-Time. Dark Energy intuitively pulls Space together, but due to General Relativity, actually pushes it apart.
No, I don't understand all that either. But keeping reading his book "The Trouble with Physics." Very good indeed. He has read all the original Einstein General Relativity papers, so ought to know what he is talking about.
https://www.bbc.co.uk/news/science-environment-61259569
Too much light pollution from where I was watching. I'm not going to try again tomorrow. I'd probably need to go miles down the beach to get a clear view away from the lights and the time window is short due to Jupiter and Venus being low at this time of year.
Someone in the Southern Hemisphere would find it easier, I think.
Back to the expanding Universe, Lee Smolin seems to be leading to the idea that Space is derivative. It is Time that is real. And only in the sense that Time determines one event following another causally. He also mentions that the Graviton is very different from a Photon. Gravitons not only interact with each other, but permanently create ripples in, er, Space-Time. Dark Energy intuitively pulls Space together, but due to General Relativity, actually pushes it apart.
No, I don't understand all that either. But keeping reading his book "The Trouble with Physics." Very good indeed. He has read all the original Einstein General Relativity papers, so ought to know what he is talking about.
I didn't even contemplate it. Apart from having to get up so early, I would actually have had to walk 😱 to where my view of the eastward horizon would be unobstructed by the houses opposite me.
I'll have to take it that by "a non-relative universe" you mean "a universe having nothing to do with relativity".
Such a universe would be unimaginable since relativity is 'baked into' the laws of physics.
Galileo introduced relativity, realising that the fundamental laws of physics are the same in all frames of reference moving with constant velocity with respect to one another. Today, we can make the same observation when travelling in a plane.
Newton adopted Galileo’s relativity principle, but believed in an absolute frame of reference - a frame of absolute rest with respect to which all motion could be measured. He also declared that time was absolute i.e. there's no difference in time in different reference frames.
Three centuries after Newton, experiments to study the postulated Aether showed that there was no preferred reference frame for the speed of light. This introduced the need for a new relativity principle, and that's where Einstein stepped in.
Our description of the universe is based on Einstein's two postulates:
- ALL the laws of physics are the same in every inertial frame of reference.
- The speed of light is independent of the motion of its source. Or: The speed of light in free space has the same value c in all inertial frames of reference.
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What would Einstein potentially have come up with in the place of Newton? IOW, how much of what he presented actually came from him? How much further than Newton could he have brought us?
I love James Burke. 🙂
I love James Burke. 🙂
Physicists generally agree that time is a very real property of the Universe, they're just a bit divided on what causes it to exist.
Einstein said, "Time has no independent existence apart from the order of events by which we measure it".
Like I said, I don't understand the physics very well.
Lee Smolin is talking about the search for a theory of Quantum Gravity. Standard Model can't do it. String Theory seems a bit too weird with 9 or 25 dimensions of Space. All a problem.
It is known that Black Holes have an Entropy proportional to their surface area, and a temperature that drops as you add matter or energy and make them bigger.
He said he has understood what it was that Einstein did in his successful theories. He made General Relativity "Background Independent".
And I didn't understand the next bit, but he says quantum Theory is Background Dependent. A bit like the discredited "Aether" theory. Must finish the book, but my little brain is feeling a bit fried by all these new concepts right now. I followed a Stanford course on String Theory and also General Relativity, so some of it is at least a bit familiar.
Regge Trajectories and Ricci flatness. But I think I am currently well out of my depth. This stuff takes years to get a grip on. Yikes!😳
Lee Smolin is talking about the search for a theory of Quantum Gravity. Standard Model can't do it. String Theory seems a bit too weird with 9 or 25 dimensions of Space. All a problem.
It is known that Black Holes have an Entropy proportional to their surface area, and a temperature that drops as you add matter or energy and make them bigger.
He said he has understood what it was that Einstein did in his successful theories. He made General Relativity "Background Independent".
And I didn't understand the next bit, but he says quantum Theory is Background Dependent. A bit like the discredited "Aether" theory. Must finish the book, but my little brain is feeling a bit fried by all these new concepts right now. I followed a Stanford course on String Theory and also General Relativity, so some of it is at least a bit familiar.
Regge Trajectories and Ricci flatness. But I think I am currently well out of my depth. This stuff takes years to get a grip on. Yikes!😳
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