Archive for the ‘Astronomy’ Category

« Older Entries

Earth is spinning faster …. or maybe not

August 8, 2022

The simple truth is that we haven’t a clue as to why the earth spins, how it started spinning and why the speed of spin varies.

These are all recent headlines.

Earth spinning faster.

Faster

Earth spinning slower

Slower

Why does the earth rotate in 24 hours? It’s just magic

June 26, 2017

The rotational speed of a planetary body around its own axis is primarily set by the angular momentum the mass of matter making up the body had when it first coalesced into a planet. What determined that initial angular momentum is unknown. All known effects thereafter (mainly tidal and all fundamentally gravitational effects) slow this rotation. For the last 3,000 years the earth’s rotation has been slowing down to cause the day to lengthen by about 2 milliseconds per century.

Currently the solar (siderial) day has a mean value of about 2 milliseconds greater than 86,400 seconds while the stellar day (relative to the fixed stars) has a mean value of about 86, 164 seconds.

But we have no real understanding of why it is what it is. …… 

We can observe that the day length on the planets are:

…….. The laws of physics (as we know them) did not apply at the Big Bang singularity. All the energy (dark, imaginary and real) in the universe and all the momentum in all the materia (dark or otherwise) making up the universe was determined in the singularity when the laws of physics did not apply. How the Big Bang caused matter to gain spin in the first place is also unknown. So the simple answer to why earth’s day is 24 hours long (and why any planet’s rotational speed is what it is) is that we haven’t a clue.

It’s just magic.

It used to be that a second was defined as 1⁄86400 of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each (24 × 60 × 60 = 86400). But the day is now taken to be 86 400 seconds where a second is now defined as the time that elapses during 9,192,631,770 cycles of the radiation produced by the transition between two levels of the cesium-133 atom.

“Caesium is a relatively rare element, estimated to average 3 parts per million in the Earth’s crust. Caesium (55Cs) has 40 known isotopes, making it, along with barium and mercury, one of the elements with the most isotopes. The atomic masses of these isotopes range from 112 to 151. Only one isotope, 133Cs, is stable”.

The very concept of a day derives from the spin of the earth. Of course, if a day was still defined as the period of the earth’s rotation around its own axis and and not as a multiple of the second, there would be no need to have any headlines.

I wonder sometimes whether a second now is longer than a second was then.

And how would we know?

Tags:
Posted in Astronomy, Physics | Comments Off on Earth is spinning faster …. or maybe not

We don’t exist, and even if we do we are doomed

May 5, 2019

The nice thing about cosmological theories is the the time scales involved make the theories unfalsifiable.

One of the latest theories is that the universe is cyclic.

  1. A sort of a Big Bang,
  2. Expansion,
  3. A Big Suck,
  4. Compression.

followed by another kind of a Big Bang, and so on ad infinitum.

But why that should be so is outside the realm of the knowable.

Two articles caught my eye this morning.

Universe shouldn’t exist, CERN physicists conclude

NEW RESEARCH SUGGEST ANDROMEDA AND MILKY WAY GALAXIES ARE ALREADY TOUCHING, MIGHT COLLIDE SOONER THAN WE THINK

One of the great mysteries of modern physics is why antimatter did not destroy the universe at the beginning of time.

To explain it, physicists suppose there must be some difference between matter and antimatter – apart from electric charge. Whatever that difference is, it’s not in their magnetism, it seems.

Physicists at CERN in Switzerland have made the most precise measurement ever of the magnetic moment of an anti-proton – a number that measures how a particle reacts to magnetic force – and found it to be exactly the same as that of the proton but with opposite sign. The work is described in Nature.

“All of our observations find a complete symmetry between matter and antimatter, which is why the universe should not actually exist,” says Christian Smorra, a physicist at CERN’s Baryon–Antibaryon Symmetry Experiment (BASE) collaboration. “An asymmetry must exist here somewhere but we simply do not understand where the difference is.”

The Milky Way and Andromeda galaxy won’t collide for next 4 billion years. But but a recent discovery of a massive halo of hot gas close to Andromeda Galaxy may mean that our galaxies are already touching. Astrophysicist Nicholas Lehner from University of Notre Dame, led a group of scientists using the Hubble Space Telescope to detect an enormous halo of hot, ionized gas about 2 million light years in diameter around the galaxy.

The Andromeda Galaxy and Milky Way are the largest member of a ragtag group of some 54 galaxies, called the Local Group. Andromeda, with almost a trillion stars — twice as many as the Milky Way — shines 25% brighter and can simply be seen with the naked eye from outlying and rural skies. If the recently discovered halo spreads at least a million light years in our direction, our two galaxies are way MUCH closer to touching than previously thought.

 

Tags:
Posted in Astronomy | Comments Off on We don’t exist, and even if we do we are doomed

The earth may be spherical but the universe is (largely) flat

May 1, 2018

The earth’s orbital plane is not quite flat. The ecliptic is currently reducing by about 1.4 degrees over 100,000 years.

 

Tags:
Posted in Astronomy, Space, Trivia | Comments Off on The earth may be spherical but the universe is (largely) flat

Dwarf planets demand full planetary rights and an end to discrimination

March 26, 2018

The five dwarf planets (Ceres in the asteroid belt, and the trans-Neptunian planets led by Pluto)) have demanded that discrimination against them  cease immediately and that they be afforded full planetary rights along with the “Big 8”. Over 150 bodies are trans-Neptunian planets (TNPs) but only four are recognised as dwarf planets (Pluto, Eris, Haumea, and Makemake).

A spokesman for the TNP’s complained that the International Astronomical Union was being blatantly unfair against the “small and the distant” and was guilty of violating the fundamental, God-given rights of every planetary body. “The members of the IAU are all earthlings and small-minded and biased”, he said. “It is a travesty that even a planet as near the Sun as Ceres could be treated with such disdain”, he continued. He claimed that actually there were over 250 TNP’s but many had yet to be contacted. He accused the IAU of gross geocentrism. “It is morally unacceptable to deny these ancient planets their full rights and to stigmatise them by calling them dwarfs”. “Do we not all orbit the same Sun?”, he asked. ”

The International Astronomical Union denied any discrimination. A spokesman angrily refused to comment when accused of being geocentric. He denied that the IAU was steeped in dwarfism.

 

Tags:,
Posted in Astronomy, Trivia | Comments Off on Dwarf planets demand full planetary rights and an end to discrimination

Why does the earth rotate in 24 hours? It’s just magic

June 26, 2017

The rotational speed of a planetary body around its own axis is primarily set by the angular momentum the mass of matter making up the body had when it first coalesced into a planet. What determined that initial angular momentum is unknown. All known effects thereafter (mainly tidal and all fundamentally gravitational effects) slow this rotation. For the last 3,000 years the earth’s rotation has been slowing down to cause the day to lengthen by about 2 milliseconds per century.

Currently the solar (siderial) day has a mean value of about 2 milliseconds greater than 86,400 seconds while the stellar day (relative to the fixed stars) has a mean value of about 86, 164 seconds.

But we have no real understanding of why it is what it is. We can observe that the day length on the planets are:

We have no real explanation for why Mercury and Venus rotate as slowly as they do. But it is believed that at coalescence the angular momentum must have been similar but subsequent gravitational effects (solar gravitation effects on Mercury and “tidal” effects on Venus and it’s thick atmosphere) have drastically slowed the rotation. But this is mainly speculation. It is now thought that even distant Jupiter may be having an effect on Mercury’s orbit and spin.

Mercury spins three times on its axis for every two revolutions around the sun. It was natural to assume the sun was influencing Mercury’s spin. Now scientists have learned that distant Jupiter – largest planet and second-largest body in our solar system – also may also be influencing Mercury’s orbit and spin, which is more complex than scientists realized.

Among the outer planets there is a very rough correlation between the size of the planet and rotational speed. But there are no apparent correlations with mass, density, distance from the sun or any other parameter. All we can say about any planet’s spin is that it depends on the angular momentum of the material which coalesced to form the planet and thereafter it changed due to collisions as the planet formed, subsequent gravitational interactions with other bodies, and tidal interactions.

SciAm: In our solar system, the giant gas planets (Jupiter, Saturn, Uranus, and Neptune) spin more rapidly on their axes than the inner planets do and possess most of the system’s angular momentum. The sun itself rotates slowly, only once a month. The planets all revolve around the sun in the same direction and in virtually the same plane. In addition, they all rotate in the same general direction, with the exceptions of Venus and Uranus. These differences are believed to stem from collisions that occurred late in the planets’ formation. (A similar collision is believed to have led to the formation of our moon.)

Planetary spin (Pinterest)

The laws of physics (as we know them) did not apply at the Big Bang singularity. All the energy (dark, imaginary and real) in the universe and all the momentum in all the materia (dark or otherwise) making up the universe was determined in the singularity when the laws of physics did not apply. How the Big Bang caused matter to gain spin in the first place is also unknown. So the simple answer to why earth’s day is 24 hours long (and why any planet’s rotational speed is what it is) is that we haven’t a clue.

It’s just magic.

 

Tags:
Posted in Astronomy, Physics | 2 Comments »

The Big Bang theory is just another Creation myth

December 16, 2015

I was listening to some lectures on Relativity to celebrate the 100th anniversary of Einstein’s General Theory of Relativity. What struck me, again, was how claims to be entirely rational all contain an element of magical belief.

The concept of “time” is not, I think identical to “the elapse of time”. Suppose that “the elapse of time”, along with space-time and all matter and all energy, came into existence only with the singularity called the Big Bang. Then the Big Bang theory and the Genesis Creation myth are similar in that both ultimately rely on the invocation of Magic. Genesis labels the Magic as “God”. The Big Bang theory either assumes that the singularity just Magically came to be, or claims it was inevitable and due to the laws of quantum physics, which just Magically came to be. Both Genesis and the Big Bang theory begin with “In the beginning….”, which inherently contains the assumption of a concept not only of “time”, and the existence of a “before” and an “after” but also the concept of being “timeless”. The state of “before” applied to “the beginning of time”, can only be a timeless state (stasis) or a state where time exists but does not elapse.

Magic is to the Big Bang theory what God is to the Genesis Creation myth.

Physicists (cosmologists) claim that the Big Bang occurred 13.8 billion years ago (definitely less than 15 billion years ago according to Hawking), but I question that. Physicists are being illogical here. The existence of a singularity on the time axis itself requires that a “speed of time” exist. Since, at the singularity the “speed of time” was – must be – zero, it must have subsequently, in the first apparent moments after the singularity, accelerated to the current rate of elapse of time. So the 13.8 billion years ago is only an apparent, perceived point along the time axis where ℜeal time actually goes back to infinity (and must do so).

The Big Bang does not, apparently, mathematically permit of a time older than 13.8 billion years. Magical ℜeal time, of course, goes back to infinitely long ago. All can be resolved merely by accepting that ℜeal time elapsed at zero rate at the Big Bang and then gradually built up to the rate of elapse we are subject to now.

There are those (Stephen Hawking) who say that anything before the Big Bang is indeterminate and indeterminable because all the laws of physics, and even the conservation of matter, break down at a singularity. Therefore, Hawking claims, “time” starts with the Big Bang. He claims that whereas the Genesis Creation myth requires the external imposition of a God, the Big Bang theory is just an extrapolation backwards of the “dynamical laws that govern the universe” and is therefore “intrinsic to the universe, and is not imposed on it from outside”. Really? And pray by what Magic did the “dynamical laws of the Universe” come to exist or to apply? Hawking may be an atheist but he invokes Magic whenever he refers to the singularity of the Big Bang theory (even if he claims not to).

There are others (Alex Filippenko) who claim that quantum theory is the cause of the Big Bang and that the laws of physics are sufficient to bring about the singularity. But Filippenko is a little more honest than Hawking and admits that the “laws of physics” are in themselves Magical.

“The question, then, is, ‘Why are there laws of physics?'” he said. “And you could say, ‘Well, that required a divine creator, who created these laws of physics and the spark that led from the laws of physics to these universes, maybe more than one.'”

“The ‘divine spark’ was whatever produced the laws of physics,” Filippenko said. “And I don’t know what produced that divine spark. So let’s just leave it at the laws of physics.”

What we don’t know lies in the Space of Ignorance. One Magic (and there are surely as many Magics as humans have ignorances) is that which transcends perceived “time” and applies even across singularities such as the Big Bang. But this, let’s call it, “Creation Magic” – like all Magics – lies in the Space of Ignorance. And if some people wish to do so, they can give this Magic (which we are ignorant of)  the label of “God” or of “Nirvana”.

Related:

The fundamentals of physics are just magic

Dark energy and dark matter are just fudge factors for cosmic models that don’t work

Physics and cosmology are more magical than alchemy as dark energy goes phantom

Tags:, , , , ,
Posted in Astronomy, Physics | Comments Off on The Big Bang theory is just another Creation myth

It may be small but Pluto is still a planet

July 13, 2015

It orbits the Sun. It has five moons. It is the tenth most massive object orbiting the Sun. It is not that Pluto is not a planet, but that there are many more planets than the “big ten”. The asteroid belt and the Kuiper belt objects are all also planets. Inventing new definitions and calling them “dwarf planets” or “planetoids” doesn’t change the fundamentals.

The International Astronomical Union (IAU) defines a planet thus:

A planet is a celestial body which:

  1. is in orbit around a Star,
  2. has sufficient mass to assume hydrostatic equilibrium (a nearly round shape), and
  3. has “cleared the neighbourhood” around its orbit.

Calling Pluto a “dwarf planet” rather than a “planet” has nothing to do with its properties or the properties of the Sun. It is not even a matter of language or semantics. It is merely for the convenience of a bunch of lazy astronomers who were afraid of having too many planets to classify.

Ultimately it is just a matter of usage. For me any celestial body orbiting another is and remains a planetary body. And every body which orbits the Sun directly (and not by virtue of orbiting a planetary body first) is a planet. Every asteroid is a planet of the Sun. Jupiters moons remain planets of Jupiter. And that makes Pluto a planet. New planets may well have been found in the Kuiper belt – but Pluto remains a planet for me, in spite of the failings of the IAU.

Tags:,
Posted in Astronomy, Language | Comments Off on It may be small but Pluto is still a planet

“Let there be cesium” and there was a leap second

June 28, 2015

On 30th June 2015 at 23:59:60, a leap second will be added before 1st July 2015, 00:00:00 because the difference between Coordinated Universal Time (UTC) and Universal Time (UT1) would have reached 0.9 seconds. Universal Time also known as Astronomical Time is based on the Earth’s rotation around its own axis, which determines the length of a day. Since 1972, 25 leap seconds have been inserted to synchronise these two clocks and this leap second will be the 26th. The differences are so irregular that the need for a leap second cannot be predicted more than about 6 months in advance.

The leap second is for synchronising the two clocks and not – directly – for compensating for the slowing down of the earth and the lengthening of the day. That adds about 1 second every 58,800 years (1.7ms per century). Since modern humans arrived on the scene some 200,000+ years ago the length of the day has increased by about 4 seconds.

International Atomic Time (TAI) is the “standard” used to synchronise the other two clocks and is built up by combining the output of some 200 highly precise atomic clocks worldwide and where the second is defined by the resonant oscillation frequency of cesium 133.

Atomic clocks use the second as the base unit and hours, days and years are taken to be multiples.

“The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom.”

The wise men of our age believe (they cannot know) that this resonant frequency of the cesium 133 atom will remain “stable” for millions of years and is far more stable than the period of rotation of the irregular orbit of the earth around the sun or the even more irregular (and slowing) rotation period of the earth on its own axis.

All we measure, or try to measure, are periods of time – provided of course that time exists. Cesium would not have come into existence until about 3 minutes after the Big Bang, but time, presumably, began with the Big Bang. Initially there was only hydrogen and then came Big Bang Nucleosynthesis (BBN), which after about 10 seconds (cesium 133 seconds, though cesium still didn’t exist) started producing helium. The heavy elements came about 3 minutes after the BB and after about 20 minutes BBN ceased. Light would have been created as soon as the fusion of hydrogen started with the BB itself.

Rephrasing Genesis

The Big Bang was the Beginning and then came Fusion. The expanse was without form and void, and dark energy was over the face of the deep. And the Spirit of Gravity hovered over the face of the aether. And Gravity said, “Let there be Coalescence” and the stars of the heavens came to be. “Let there coalesce a Sun” said Gravity, and so there was light. “Let coalescence proceed” and under Gravity came the earth bathed in the light of the Sun. And the light was good. 

And the rest is history.

 

Tags:, , , ,
Posted in Astronomy, History, Time | Comments Off on “Let there be cesium” and there was a leap second

Sea surface temperature and the 18.6 year lunar nodal cycle

October 15, 2014

There is a growing body of scientific papers (some reported in my post here) which show long period connections between the 18.6 year lunar nodal cycles and sea level, tidal sedimentation, tidal mixing, sea surface temperature, Arctic climate and even drought. The mechanisms by which these influences are transmitted are hypothesised but are not known.

Compared to solar cycles the lunar cycles are not well known:

The lunar nodal cycle is not something that is very well known but it is another celestial cycle which is clearly not to be ignored. Naturally the IPCC takes no notice of solar cycles, planetary cycles or lunar cycles and all these are lumped into what could be considered “natural variability”.

(Sourced from Wikipedia)

The lunar orbit is inclined by about 5 degrees on the ecliptic. The moon  therefore can lie up to about 5 degrees north or south of the ecliptic. The ecliptic is the plane of the apparent path of the Sun on the celestial sphere, and is coplanar with both the orbit of the Earth around the Sun and the apparent orbit of the Sun around the Earth.

File:Lunar eclipse diagram-en.svg

Lunar eclipse orbital diagram: wikipedia

The lunar nodes precess around the ecliptic, completing a revolution (called a draconitic or nodical period, the period of nutation) in 6793.5 days or 18.5996 years.

The effects of the 18.6 year lunar nodal cycle on climate on tides and geological sediments and on weather and climate have long been of interest (though not apparently for the IPCC).

The lunar nodes and the nodal cycles were known even to ancient astronomy (Greek, Hindu, Tibetan…) and has found a place in both Eastern and Western astrology. Since astrology is not considered “scientific”, suggestions that the lunar nodal cycle has any impact on the earth’s geology and climate are very often treated with ridicule. Yet the undoubted lunar effects on tides and tidal sedimentation and (therefore) geologic events are not disputed. The nodal period also controls when eclipses can occur.

Eclipses occur only near the lunar nodes: Solar eclipses occur when the passage of the Moon through a node coincides with the new moon; lunar eclipses occur when passage coincides with the full moon. A lunar eclipse may occur if there is a full moon within 11° 38′ (Celestial Longitude), of a node, and a solar eclipse may occur if there is a new moon within 17° 25′ of a node.

It is not surprising that the ancient astrologers/astronomers attributed many effects to the lunar nodes and the nodal cycles:

In Hindu astronomy, the ascending node is called Rahu and the descending node is called Ketu. Rahu and Ketu are thus the north and the south lunar nodes. Rahu represents the severed head of an asura, that swallows the sun causing eclipses. Times of day considered to be under the influence of Rahu are considered inauspicious even today in many parts of India (for weddings, starting journeys …..)

A new paper considers the effects of the 18.6 year lunar nodal cycle on Sea Surface Temperature (SST) and the Pacific Decadal Oscillation (PDO).

S. Osafune, S. Masuda and N. Sugiura, Role of the oceanic bridge in linking the 18.6-year modulation of tidal mixing and long-term SST change in the North Pacific, Geophysical Research Letters, DOI: 10.1002/2014GL061737

HockeyShtick reports:

A paper published today in Geophysical Research Letters finds a “significant contribution” of the 18.6 year lunar-tidal cycle to “wintertime sea surface temperatures near the center of action of the Pacific Decadal Oscillation [PDO] in the eastern Pacific,” and that

“This result supports the hypothesis that the 18.6-year tidal cycle influences long-term variability in climate; thus, knowledge of this cycle could contribute towards improving decadal predictions of climate.” [which IPCC climate models do not incorporate]

The approximately 60-year long Pacific Decadal Oscillation [PDO] in-turn profoundly affects global climate and interacts with other ocean and atmospheric oscillations. A very simple climate model based solely upon the sum of the sunspot integral, Pacific Decadal Oscillation [PDO], and Atlantic Multidecadal Oscillation [AMO] explains 96% of climate change over the 20th century: …..

 

Paper Abstract:The impact of the 18.6-year modulation of tidal mixing on sea surface temperature (SST) in the North Pacific is investigated in a comparative study using an ocean data synthesis system. We show that remote impact through a slow ocean response can make a significant contribution to the observed bidecadal variation in wintertime SST near the center of action of the Pacific Decadal Oscillation in the eastern Pacific. A comparative data synthesis experiment showed that the modified SST variation is amplified by bidecadal variation in the westerly wind. This relationship between SST and wind variations is consistent with an observed air–sea coupled mode in the extratropics, which suggests that a midlatitude air–sea interaction plays an important role in enhancing the climate signal of the 18.6-year modulation. This result supports the hypothesis that the 18.6-year tidal cycle influences long-term variability in climate; thus, knowledge of this cycle could contribute towards improving decadal predictions of climate.

I am of the opinion that climate is predominated by solar effects which are mediated primarily by the oceans over multidecadal periods and only over shorter periods by the atmosphere. And if lunar nodal cycles influence the tidal flows and tidal mixing then they will also influence the climate – also on the decadal scale.

We dance to a celestial music and the moon provides the variations on the climate themes set by the sun.

 

Tags:, , ,
Posted in Astronomy, Climate, Science | 1 Comment »

Poltergeists on Mars

January 21, 2014

Mysterious forces and poltergeists are at work  on Mars (which in due course will be found not to be so mysterious after all). But stories about moving rocks, and possible aliens are not new. The latest however is just doing the rounds based on the pictures SOL 3528 and 3540.

Rock appears mysteriously in front of Mars Opportunity rover

Rock appears mysteriously in front of Mars Opportunity rover

(Phys.org) —The lead scientist for NASA’s Mars rover exploration team (Steve Squyres) has announced that recent images beamed back by the Opportunity rover show a rock sitting in a place nearby where there wasn’t one just twelve days prior. The image, he says, has caused quite a commotion with the rover team as possible explanations for the sudden appearance of the rock are bandied about. The announcement was part of a meeting at California Institute of Technology to celebrate a decade of service by the tiny rover. …… 

….. How it got there has NASA’s best scratching their heads. Thus far, they have two main likely explanations: either the rock was tossed to that spot after a meteorite impact nearby, or far more likely, it came to rest there as a result of clumsy maneuvering by Opportunity itself. The rover is having trouble getting around these days as one of its actuators has failed. This means one wheel winds up scrapping the ground during turns, producing what Squyres described as “chatter” which he said could have caused some debris to be flung to where the rock is now.

But these stories have been appearing since – at least – about 2009 (based for example on pictures SOL 1833 onwards). Moving rocks on Mars have a long history of fanciful – and some not so fanciful – notions. A whole bunch can be found here and here. But it would seem that most of the conspiracy theories and “Life on Mars” stories are connected to the selling of particular books.

As far as stories are concerned, the first ever fictional account of Mars was probably Across the Zodiac (1880) by Percy Greg. But for me, The War of the Worlds (published in 1898) by H. G. Wells  and Edgar Rice Burroughs and his Martian Trilogy – published between 1912 and 1943 and which I first read in 1959 – are not easily surpassed.

Tags:, , , , ,
Posted in Astronomy, Literature, Space | Comments Off on Poltergeists on Mars

« Older Entries
%d bloggers like this: