“You are not here merely to make a living. You are here in order to enable the world to live more amply, with greater vision, with a finer spirit of hope and achievement. You are here to enrich the world, and you impoverish yourself if you forget the errand.” -Woodrow Wilson
It’s been another fantastic week here at Starts With A Bang, and I’ve got to laud all of you for doing your best to make it a good one! Let’s get right into what this past week held:
- Is there any such thing as pure energy? (for Ask Ethan),
- More than stars: the Milky Way’s dust mapped in 3D for the first time ever (for Mostly Mute Monday),
- Hey Shaq? Here’s how you can figure out the Earth is round for yourself,
- Why doesn’t antimatter anti-gravitate? (from Sabine Hossenfelder),
- 5 vital lessons scientists learn that can better everyone’s life, and
- Finding Earth’s twin in space may be impossible.
I’m sure you’ve caught our new Starts With A Bang podcast, on why Pluto isn’t a planet anymore, like 1,000 other people. What you may not know is, thanks to our generous Patreon supporters, we’re going to be constructing a history-of-the-Universe poster unlike anything you’ve ever seen before! Can’t wait!
I also wanted to thank everyone for keeping it more civil and adult in the comments than we’ve had it here in a long time. Keep it up, and nobody will need the banhammer any time soon. With that out of the way, let’s get right on into our comments of the week!
Global sea level rise since 1992 hits past the 8 centimeter mark in the AVISO altimetric graph. Image source: AVISO.
From Denier on, you guessed it, denying that global warming and its consequences are a concern: “First of all, the ocean has been rising for the past 22,000 years. You’re not going to stop it no matter what you do. It is currently rising at around 1.8 mm per year. Some places go a little faster and some go slower but 1.8 mm / year is the average. That comes to around 3.5 inches of rise in 50 years. Sooo Scary! Let’s destroy the economy immediately.”
Yes, melting ice and warming temperatures will cause the ocean level to rise. The current rate of rising is about double what you state, as you are giving a centuries-long average for the rise; it is rising faster now. Why? Due to the increased temperatures caused by humans. Yes, we have “only” increased by about 1 degree Celsius in the past 130 years or so, but about 0.8 degrees of that have come in the past 50 years.
Hotter temperatures melt ice faster; warmer oceans experience thermal expansion; melting ice adds to the mean ocean volume. But the biggest effect will happen in jumps, when ice sheets calve, fall into the ocean or otherwise cause a discontinuous jump in sea level. You talk about 8 meters in over ten thousand years, and I’m more worried about that first meter — or even a half meter — happening within centuries. Your lack of concern comes from a point of ignorance, either willful or not; I can’t say, that’s up to you. But your data is out-of-date. At least revise and resubmit.
Image retrieved from conspiracyuk.co.uk, you irony-savorers.
From Ragtag Media on Judith Curry: “@ Dingaling dean. Sooo when Judith Curry was a globull Nut Job climate change is real you loved her. Now that she has come to her senses for the climate scam going on you despise her.”
So I know it’s unlikely you’ve been following Curry in the level of detail I have, so let me give you a recap: in the mid-2000s, Curry, a hitherto respectable climate scientist, invested heavily in her “stadium wave” theory of climate models. She claimed there was an undiscovered natural variation in the climate, and that a periodic “waving” up-and-down was going to be discovered, as a flat and then cooling period would happen. Of course, the Earth continues to warm unabated, and her model has been thoroughly discredited.
She has since engaged in blatantly inappropriate data analysis — known as lying or fraud in a scientific field — and continues to argue her discredited case over and over, changing nothing even as the data continues to not support her claims. So there is fraud going on, but “the scam” has not been correctly identified by you.
Heat-trapping emissions (greenhouse gases) far outweigh the effects of other drivers acting on Earth’s climate. Source: Hansen et al. 2005, Figure adapted by Union of Concerned Scientists.
From eric on a number in much more agreement with actual sea level rise: “Here is the current Goddard satellite data, which shows that that old estimate was about half of what we are experiencing – instead of 1.7mm/yr, the observed rate is more like 3.4mm/year.”
Thank you. And there’s an important add-on to this, because temperatures continue to rise, driven by increased CO2 concentration, which also continues to rise. It’s 3.4 mm/year. And accelerating.
Even the United Federation of Planets facepalms for this!!
From Ragtag… “So I guess you are correct in me not finding any wisdom or common sense in that grey matter of yours no matter how hard I look because it simply does not exist.”
and Wow… “Just your average blithering idiot.
That WAS what you were waiting for, right, ragbag?”
This has not gone unnoticed. Knock it off. You were doing so well, and I like to think this is part of the backsliding behavior that you can’t help yourself about. But help yourself. This is the ban-worthy stuff I’m trying to eliminate.
And now, enough commenting about comments. Let’s get into the science!
Empty space with no matter, energy, curvature, gravitational energy, etc. Image credit: Amber Stuver of http://ift.tt/1Wcny3S.
From John on dark energy and the other forms: “This distinction between Dark Energy and the other forms energy assumes is intriguing.”
I absolutely agree with this. When it comes to all the other known forms of energy, they are particle-dependent. Gravitational, electrical, nuclear, etc., all rely on fundamental interactions. Chemical energy relies on more derived combinations of electromagnetic interactions and discrete quantum states. But dark energy appears to be tied to a fundamental field itself, with no particle equivalent. Is dark energy tied to a particle at some level? Is it related to the inflaton field? Is it changeable over time, depending on the Universe’s conditions?
I still hope that the 21st century will reveal some answers here.
Visualization of a quantum field theory calculation showing virtual particles in the quantum vacuum. Image credit: Derek Leinweber.
From Patrice Ayme on dark energy and energy creation/destruction: “If energy can be created ex-nihilo, independently of wave-particle transfers, as apparently observed, why couldn’t energy be DESTROYED during, because of, and AS the usual wave-particle transfer?”
It is important to recognize that only in the strictest sense — where energy is not defined in General Relativity — is the conservation of energy violated. If one imposes the work/energy theorem on the expanding Universe, then energy is conserved even in the case of dark energy; it’s just that we have no right to impose it in General Relativity.
Image credit: Sean Carroll via Steve Hsu of http://ift.tt/LGfxm5.
From CFT on how dark energy affects particles… without interacting with them: “It is silly to speculate that actual particles of our universe can not access/interact with imagined dark energy, while at the same time proposing that the dark energy is having an affect on those same said particles by accelerating them.”
I don’t understand where the silliness comes in here. If you’re on a trampoline and I don’t touch you, but I do touch the trampoline, can you see where I affect you, even though you and I never interact? Dark energy affects the fabric of the Universe where the particles reside; the particles are affected by the Universe’s fabric, but not by dark energy directly. It’s pretty straightforward.
Image credit: NASA/JPL-Caltech/N. Evans (Univ. of Texas at Austin)/DSS; Spitzer Space Telescope.
From PJ on cosmic dust’s redshift, quantified: “How much of the red shift in distant galaxies, etc., will this account for after calibration?”
It depends on where you look, but the amount of “redness” versus what’s expected otherwise can be very severe if you look in the galactic plane itself. One of the potential problems with looking at an object is that you only see the photons that reach you, and so if you see a red color in an object, you won’t know why it’s red: is there dust or is it redshifted?
But Wow‘s comment, “PJ Dust doesn’t cause redshift, it blocks blue. The light curve is totally different.” is germane and relevant. It causes an effective reddening, but not a red shift. If you use spectroscopy, you will see no additional shift; the ambiguity comes when you take photometric measurements only. If you know what the intrinsic light from your star/galaxy looks like, you can measure and quantify the dust present, which is what Pan-STARRS did.
Image credit: Ned Wright’s cosmology tutorial.
From Michael Kesley on tired light: “You may be interested in reading the Wikipedia article on “tired light”, which was one of the desperate attempts to explain away the observed cosmological expansion. The last second, “specific falsified models,” has useful details on dust reddening vs. proper redshift.”
Two of my favorite facts about tired light are that it would cause a non-blackbody CMB (above), grotesquely ruled out by the observations, and that it was proposed in 1929 by Fritz Zwicky, who then spent the rest of the paper trying to discredit the idea. It was an awesome way to propose a cosmological alternative: to throw it out there, make the case for it, and then talk about how to rule it out.
When you’re at the optimal distance to measure the Earth’s curvature, a buoy’s bottom will be visible right on the horizon line. For a human at sea level, that will never be as much as six kilometers from the buoy. Image credit: mark_az of Pixabay.
From Wow on why Americans call it ‘boo-ee’ instead of ‘boy’: “Is this why americans pronounce it “booey”?”
Apparently, there once were two ways of pronouncing the word in England, one of which took hold in the colonies and one of which took over in England. In the book A Practical Grammar of English Pronunciation by Benjamin Humphrey Smart (London, 1810), he writes:
Bw, in the words
(9) Buoy, buoyance
is represented by bu. They should never be pronounced boy, boyance.
Unfortunately, it seems that Shaq has not taken my challenge.
The two ways Earth could cast a circular shadow on the Moon: by being a spherical object (bottom) or a disk-like object (top). Image credit: Windows to the Universe Original (Randy Russell), under a c.c.a.-s.a.-3.0 unported license.
From Michael Mooney on special relativity and a pancake Earth: “The science of relativistic observational differences and “equal validity for all frames of reference” (SR) insists that a pancaked Earth is an “equally valid” description. Maybe it’s time to address length contraction as applied to Earth, Ethan.”
I am afraid that there is no amount of rational thought that will get you to change your mind on this. If you move fast enough to contract Earth, then you effectively contract all the other spherical objects and the distances between them as well, and all the physics will work out equally well in that reference frame as it does in this one.
You have been all over the internet for a long time, if I’ve pegged you correctly, telling the tales of your misinterpretation of special relativity and “paradoxes” that are easily resolved.
After all, this is you, isn’t it?
The identical behavior of a ball falling to the floor in an accelerated rocket (left) and on Earth (right) is a demonstration of Einstein’s equivalence principle. Image credit: Wikimedia Commons user Markus Poessel, retouched by Pbroks13.
From Frank on negative gravitational masses: “As far as I know creating particles with negative mass requires negative energy. Also negative energy known to exist but it is unknown if it can be created artificially.”
If you want to create a particle with negative mass, according to the presently accepted physics we have, you need negative energy. Antimatter is known to require a positive energy to create it, and to release positive energy when destroyed. However, that is a measure of its inertial mass, and it is only an assumption of the equivalence principle that inertial mass and gravitational mass must always be the same. This is true — as demonstrated experimentally — for matter, but not necessarily for antimatter. We still have work to do to know for certain.
Image credit: Wikimedia Commons user Stefania.deluca.
From Denier on a possible explanation for dark matter: “CERN Physicist Dragan Hajdukovic theorized that anti-gravity explained the MOND effect on galactic rotation curves. In one aspect at least it absolutely does explain an effect attributed to dark matter.”
I can’t blame you for misinterpreting this study too much, because it’s pretty deep into the weeds. What he’s claiming is that if you run standard quantum field theory but attribute a negative gravitational mass to antimatter, then creating particle/antiparticle pairs will create a “gravitational dielectric,” where the vacuum can be gravitationally polarized. This is similar to electromagnetic polarization, where a “medium” in between two parallel plates in a capacitor will increase the capacitance of the space in there, by effectively changing the permittivity and permeability of free space.
One of the thing that’s long been noted about MOND is that if you changed Newton’s laws by adding a non-zero dielectric medium throughout space, a minimum acceleration in galactic rotation is an emergent phenomenon. Hajdukovic’s paper basically puts these two effects together. A measurement of the gravitational mass of antimatter would kill this.
The gravitational behavior of the Earth around the Sun is not due to an invisible gravitational pull, but is better described by the Earth falling freely through curved space dominated by the Sun. Image credit: LIGO / T. Pyle.
From Michael Mooney on curved space and orbits: “Why is there no discussion in physics about the mechanics of “curved space” as a medium which guides planets in their orbits, applying force to keep them from flying off out of the solar system?”
Because when physicists do discuss these things, we discuss the mathematics governing them and the observational consequences. Those are physically interesting things to discuss. “Ontological interpretations of relativity” aren’t typically interesting to physicists, since they don’t teach us anything about our Universe, but rather our intuitive preconceptions. We must work to overcome those, not give into them.
You claim to challenge the assumptions of the math associated with relativity… but if you don’t understand the math itself, what makes you think you understand the underlying assumptions and their implications? Philosophy is useful for a tremendous number of things, but can you point me to even one scientific advance that happened because of a philosophical contribution?
Kepler’s Platonic solid model of the Solar system from Mysterium Cosmographicum (1596). Image credit: Johannes Kepler.
From Denier on five flamebait comments designed to troll scientists: “Scientists highly value being right. Their self-worth is often tied up in their knowledge and being seen as wrong translates in their mind to devaluing them personally. It is human nature to fill in the unknown parts of other people with your own traits, but that isn’t reality. Although every likes to be correct, it isn’t nearly the driving motivation in society that it is to academics.”
I would argue that this is highly contrary to… let’s say, 97% of the evidence. The overwhelming majority of scientists will change their mind on any issue when presented with persuasive, robust evidence. This happened in astrophysics with dark matter and dark energy; this happened in climate science with global warming; this happened in gravitational wave astronomy with the first LIGO detection; this happened in particle physics with the discovery of the Higgs boson at 126 GeV. Your psychological evaluation of scientists is suspect, and your comparison with scientists to the rest of a society that has been proven to Dunning-Kruger themselves at every turn is… well, let’s say lacking in evidence.
On the plus side, the UK just did the very thing you told me would be legally indefensible and highly unconstitutional in the USA.
Image credit: ESO Photo Ambassador Gianluca Lombardi.
From Wow, earlier today, crossing the line: “OK, so since you seem to think that compassion against you is insulting, I won’t bother, mooney. Or you”re just a whiney little asshole.
No, that is an apt description. Not an insult.
So, absent that whining, you still have nothing about proving your claim that science has nothing but contempt for psychology?
Because that’s an insult too.
Oh, I get it, you only care about people not being super special nice to you, amirite?
Aw, snowflake, nobody gives a rats ass. Either put up or shut up.”
This comment literally happened after I began writing this article today.
Sad!
Enjoy your week off, Wow. See you next Sunday.
A Minkowski diagram of the contracted ladder from the relativistic “ladder paradox” problem. Image credit: Wikimedia Commons user Life of Riley.
From the not-very-blameless Michael Mooney: “Same goes for length contraction if Ethan continues to refuse to address his distinction between contracted physical objects (not physical shrinking) and contracted distances between stars (“real.”)”
Did you seriously the Comments of the Week from two weeks ago where I addressed this at length and gave you a link to the Wikipedia page that discusses that exact paradox in depth, complete with resolution?
Image credit: Ant Schinckel, CSIRO.
And finally, from Frank on searching for non-carbon-based forms of life: “Few years ago I had read that hundreds of famous scientists sent a signed letter to NASA to not just search for carbon-based life, search for other kinds of life too.
But I don’t if they suggested any practical way how exactly such a search can be done.”
The life we’re searching for is the life we know how — or have conceived of how — to search for. This includes not only direct biological/biochemical signatures, but signals from all over the electromagnetic (and now gravitational wave) spectrum. If we find something promising, you’ll hear about it. If not from the entire world, then surely from me.
Have a great week, everyone, and I’ll see you back here tomorrow!
from ScienceBlogs http://ift.tt/2o0Xop9
“You are not here merely to make a living. You are here in order to enable the world to live more amply, with greater vision, with a finer spirit of hope and achievement. You are here to enrich the world, and you impoverish yourself if you forget the errand.” -Woodrow Wilson
It’s been another fantastic week here at Starts With A Bang, and I’ve got to laud all of you for doing your best to make it a good one! Let’s get right into what this past week held:
- Is there any such thing as pure energy? (for Ask Ethan),
- More than stars: the Milky Way’s dust mapped in 3D for the first time ever (for Mostly Mute Monday),
- Hey Shaq? Here’s how you can figure out the Earth is round for yourself,
- Why doesn’t antimatter anti-gravitate? (from Sabine Hossenfelder),
- 5 vital lessons scientists learn that can better everyone’s life, and
- Finding Earth’s twin in space may be impossible.
I’m sure you’ve caught our new Starts With A Bang podcast, on why Pluto isn’t a planet anymore, like 1,000 other people. What you may not know is, thanks to our generous Patreon supporters, we’re going to be constructing a history-of-the-Universe poster unlike anything you’ve ever seen before! Can’t wait!
I also wanted to thank everyone for keeping it more civil and adult in the comments than we’ve had it here in a long time. Keep it up, and nobody will need the banhammer any time soon. With that out of the way, let’s get right on into our comments of the week!
Global sea level rise since 1992 hits past the 8 centimeter mark in the AVISO altimetric graph. Image source: AVISO.
From Denier on, you guessed it, denying that global warming and its consequences are a concern: “First of all, the ocean has been rising for the past 22,000 years. You’re not going to stop it no matter what you do. It is currently rising at around 1.8 mm per year. Some places go a little faster and some go slower but 1.8 mm / year is the average. That comes to around 3.5 inches of rise in 50 years. Sooo Scary! Let’s destroy the economy immediately.”
Yes, melting ice and warming temperatures will cause the ocean level to rise. The current rate of rising is about double what you state, as you are giving a centuries-long average for the rise; it is rising faster now. Why? Due to the increased temperatures caused by humans. Yes, we have “only” increased by about 1 degree Celsius in the past 130 years or so, but about 0.8 degrees of that have come in the past 50 years.
Hotter temperatures melt ice faster; warmer oceans experience thermal expansion; melting ice adds to the mean ocean volume. But the biggest effect will happen in jumps, when ice sheets calve, fall into the ocean or otherwise cause a discontinuous jump in sea level. You talk about 8 meters in over ten thousand years, and I’m more worried about that first meter — or even a half meter — happening within centuries. Your lack of concern comes from a point of ignorance, either willful or not; I can’t say, that’s up to you. But your data is out-of-date. At least revise and resubmit.
Image retrieved from conspiracyuk.co.uk, you irony-savorers.
From Ragtag Media on Judith Curry: “@ Dingaling dean. Sooo when Judith Curry was a globull Nut Job climate change is real you loved her. Now that she has come to her senses for the climate scam going on you despise her.”
So I know it’s unlikely you’ve been following Curry in the level of detail I have, so let me give you a recap: in the mid-2000s, Curry, a hitherto respectable climate scientist, invested heavily in her “stadium wave” theory of climate models. She claimed there was an undiscovered natural variation in the climate, and that a periodic “waving” up-and-down was going to be discovered, as a flat and then cooling period would happen. Of course, the Earth continues to warm unabated, and her model has been thoroughly discredited.
She has since engaged in blatantly inappropriate data analysis — known as lying or fraud in a scientific field — and continues to argue her discredited case over and over, changing nothing even as the data continues to not support her claims. So there is fraud going on, but “the scam” has not been correctly identified by you.
Heat-trapping emissions (greenhouse gases) far outweigh the effects of other drivers acting on Earth’s climate. Source: Hansen et al. 2005, Figure adapted by Union of Concerned Scientists.
From eric on a number in much more agreement with actual sea level rise: “Here is the current Goddard satellite data, which shows that that old estimate was about half of what we are experiencing – instead of 1.7mm/yr, the observed rate is more like 3.4mm/year.”
Thank you. And there’s an important add-on to this, because temperatures continue to rise, driven by increased CO2 concentration, which also continues to rise. It’s 3.4 mm/year. And accelerating.
Even the United Federation of Planets facepalms for this!!
From Ragtag… “So I guess you are correct in me not finding any wisdom or common sense in that grey matter of yours no matter how hard I look because it simply does not exist.”
and Wow… “Just your average blithering idiot.
That WAS what you were waiting for, right, ragbag?”
This has not gone unnoticed. Knock it off. You were doing so well, and I like to think this is part of the backsliding behavior that you can’t help yourself about. But help yourself. This is the ban-worthy stuff I’m trying to eliminate.
And now, enough commenting about comments. Let’s get into the science!
Empty space with no matter, energy, curvature, gravitational energy, etc. Image credit: Amber Stuver of http://ift.tt/1Wcny3S.
From John on dark energy and the other forms: “This distinction between Dark Energy and the other forms energy assumes is intriguing.”
I absolutely agree with this. When it comes to all the other known forms of energy, they are particle-dependent. Gravitational, electrical, nuclear, etc., all rely on fundamental interactions. Chemical energy relies on more derived combinations of electromagnetic interactions and discrete quantum states. But dark energy appears to be tied to a fundamental field itself, with no particle equivalent. Is dark energy tied to a particle at some level? Is it related to the inflaton field? Is it changeable over time, depending on the Universe’s conditions?
I still hope that the 21st century will reveal some answers here.
Visualization of a quantum field theory calculation showing virtual particles in the quantum vacuum. Image credit: Derek Leinweber.
From Patrice Ayme on dark energy and energy creation/destruction: “If energy can be created ex-nihilo, independently of wave-particle transfers, as apparently observed, why couldn’t energy be DESTROYED during, because of, and AS the usual wave-particle transfer?”
It is important to recognize that only in the strictest sense — where energy is not defined in General Relativity — is the conservation of energy violated. If one imposes the work/energy theorem on the expanding Universe, then energy is conserved even in the case of dark energy; it’s just that we have no right to impose it in General Relativity.
Image credit: Sean Carroll via Steve Hsu of http://ift.tt/LGfxm5.
From CFT on how dark energy affects particles… without interacting with them: “It is silly to speculate that actual particles of our universe can not access/interact with imagined dark energy, while at the same time proposing that the dark energy is having an affect on those same said particles by accelerating them.”
I don’t understand where the silliness comes in here. If you’re on a trampoline and I don’t touch you, but I do touch the trampoline, can you see where I affect you, even though you and I never interact? Dark energy affects the fabric of the Universe where the particles reside; the particles are affected by the Universe’s fabric, but not by dark energy directly. It’s pretty straightforward.
Image credit: NASA/JPL-Caltech/N. Evans (Univ. of Texas at Austin)/DSS; Spitzer Space Telescope.
From PJ on cosmic dust’s redshift, quantified: “How much of the red shift in distant galaxies, etc., will this account for after calibration?”
It depends on where you look, but the amount of “redness” versus what’s expected otherwise can be very severe if you look in the galactic plane itself. One of the potential problems with looking at an object is that you only see the photons that reach you, and so if you see a red color in an object, you won’t know why it’s red: is there dust or is it redshifted?
But Wow‘s comment, “PJ Dust doesn’t cause redshift, it blocks blue. The light curve is totally different.” is germane and relevant. It causes an effective reddening, but not a red shift. If you use spectroscopy, you will see no additional shift; the ambiguity comes when you take photometric measurements only. If you know what the intrinsic light from your star/galaxy looks like, you can measure and quantify the dust present, which is what Pan-STARRS did.
Image credit: Ned Wright’s cosmology tutorial.
From Michael Kesley on tired light: “You may be interested in reading the Wikipedia article on “tired light”, which was one of the desperate attempts to explain away the observed cosmological expansion. The last second, “specific falsified models,” has useful details on dust reddening vs. proper redshift.”
Two of my favorite facts about tired light are that it would cause a non-blackbody CMB (above), grotesquely ruled out by the observations, and that it was proposed in 1929 by Fritz Zwicky, who then spent the rest of the paper trying to discredit the idea. It was an awesome way to propose a cosmological alternative: to throw it out there, make the case for it, and then talk about how to rule it out.
When you’re at the optimal distance to measure the Earth’s curvature, a buoy’s bottom will be visible right on the horizon line. For a human at sea level, that will never be as much as six kilometers from the buoy. Image credit: mark_az of Pixabay.
From Wow on why Americans call it ‘boo-ee’ instead of ‘boy’: “Is this why americans pronounce it “booey”?”
Apparently, there once were two ways of pronouncing the word in England, one of which took hold in the colonies and one of which took over in England. In the book A Practical Grammar of English Pronunciation by Benjamin Humphrey Smart (London, 1810), he writes:
Bw, in the words
(9) Buoy, buoyance
is represented by bu. They should never be pronounced boy, boyance.
Unfortunately, it seems that Shaq has not taken my challenge.
The two ways Earth could cast a circular shadow on the Moon: by being a spherical object (bottom) or a disk-like object (top). Image credit: Windows to the Universe Original (Randy Russell), under a c.c.a.-s.a.-3.0 unported license.
From Michael Mooney on special relativity and a pancake Earth: “The science of relativistic observational differences and “equal validity for all frames of reference” (SR) insists that a pancaked Earth is an “equally valid” description. Maybe it’s time to address length contraction as applied to Earth, Ethan.”
I am afraid that there is no amount of rational thought that will get you to change your mind on this. If you move fast enough to contract Earth, then you effectively contract all the other spherical objects and the distances between them as well, and all the physics will work out equally well in that reference frame as it does in this one.
You have been all over the internet for a long time, if I’ve pegged you correctly, telling the tales of your misinterpretation of special relativity and “paradoxes” that are easily resolved.
After all, this is you, isn’t it?
The identical behavior of a ball falling to the floor in an accelerated rocket (left) and on Earth (right) is a demonstration of Einstein’s equivalence principle. Image credit: Wikimedia Commons user Markus Poessel, retouched by Pbroks13.
From Frank on negative gravitational masses: “As far as I know creating particles with negative mass requires negative energy. Also negative energy known to exist but it is unknown if it can be created artificially.”
If you want to create a particle with negative mass, according to the presently accepted physics we have, you need negative energy. Antimatter is known to require a positive energy to create it, and to release positive energy when destroyed. However, that is a measure of its inertial mass, and it is only an assumption of the equivalence principle that inertial mass and gravitational mass must always be the same. This is true — as demonstrated experimentally — for matter, but not necessarily for antimatter. We still have work to do to know for certain.
Image credit: Wikimedia Commons user Stefania.deluca.
From Denier on a possible explanation for dark matter: “CERN Physicist Dragan Hajdukovic theorized that anti-gravity explained the MOND effect on galactic rotation curves. In one aspect at least it absolutely does explain an effect attributed to dark matter.”
I can’t blame you for misinterpreting this study too much, because it’s pretty deep into the weeds. What he’s claiming is that if you run standard quantum field theory but attribute a negative gravitational mass to antimatter, then creating particle/antiparticle pairs will create a “gravitational dielectric,” where the vacuum can be gravitationally polarized. This is similar to electromagnetic polarization, where a “medium” in between two parallel plates in a capacitor will increase the capacitance of the space in there, by effectively changing the permittivity and permeability of free space.
One of the thing that’s long been noted about MOND is that if you changed Newton’s laws by adding a non-zero dielectric medium throughout space, a minimum acceleration in galactic rotation is an emergent phenomenon. Hajdukovic’s paper basically puts these two effects together. A measurement of the gravitational mass of antimatter would kill this.
The gravitational behavior of the Earth around the Sun is not due to an invisible gravitational pull, but is better described by the Earth falling freely through curved space dominated by the Sun. Image credit: LIGO / T. Pyle.
From Michael Mooney on curved space and orbits: “Why is there no discussion in physics about the mechanics of “curved space” as a medium which guides planets in their orbits, applying force to keep them from flying off out of the solar system?”
Because when physicists do discuss these things, we discuss the mathematics governing them and the observational consequences. Those are physically interesting things to discuss. “Ontological interpretations of relativity” aren’t typically interesting to physicists, since they don’t teach us anything about our Universe, but rather our intuitive preconceptions. We must work to overcome those, not give into them.
You claim to challenge the assumptions of the math associated with relativity… but if you don’t understand the math itself, what makes you think you understand the underlying assumptions and their implications? Philosophy is useful for a tremendous number of things, but can you point me to even one scientific advance that happened because of a philosophical contribution?
Kepler’s Platonic solid model of the Solar system from Mysterium Cosmographicum (1596). Image credit: Johannes Kepler.
From Denier on five flamebait comments designed to troll scientists: “Scientists highly value being right. Their self-worth is often tied up in their knowledge and being seen as wrong translates in their mind to devaluing them personally. It is human nature to fill in the unknown parts of other people with your own traits, but that isn’t reality. Although every likes to be correct, it isn’t nearly the driving motivation in society that it is to academics.”
I would argue that this is highly contrary to… let’s say, 97% of the evidence. The overwhelming majority of scientists will change their mind on any issue when presented with persuasive, robust evidence. This happened in astrophysics with dark matter and dark energy; this happened in climate science with global warming; this happened in gravitational wave astronomy with the first LIGO detection; this happened in particle physics with the discovery of the Higgs boson at 126 GeV. Your psychological evaluation of scientists is suspect, and your comparison with scientists to the rest of a society that has been proven to Dunning-Kruger themselves at every turn is… well, let’s say lacking in evidence.
On the plus side, the UK just did the very thing you told me would be legally indefensible and highly unconstitutional in the USA.
Image credit: ESO Photo Ambassador Gianluca Lombardi.
From Wow, earlier today, crossing the line: “OK, so since you seem to think that compassion against you is insulting, I won’t bother, mooney. Or you”re just a whiney little asshole.
No, that is an apt description. Not an insult.
So, absent that whining, you still have nothing about proving your claim that science has nothing but contempt for psychology?
Because that’s an insult too.
Oh, I get it, you only care about people not being super special nice to you, amirite?
Aw, snowflake, nobody gives a rats ass. Either put up or shut up.”
This comment literally happened after I began writing this article today.
Sad!
Enjoy your week off, Wow. See you next Sunday.
A Minkowski diagram of the contracted ladder from the relativistic “ladder paradox” problem. Image credit: Wikimedia Commons user Life of Riley.
From the not-very-blameless Michael Mooney: “Same goes for length contraction if Ethan continues to refuse to address his distinction between contracted physical objects (not physical shrinking) and contracted distances between stars (“real.”)”
Did you seriously the Comments of the Week from two weeks ago where I addressed this at length and gave you a link to the Wikipedia page that discusses that exact paradox in depth, complete with resolution?
Image credit: Ant Schinckel, CSIRO.
And finally, from Frank on searching for non-carbon-based forms of life: “Few years ago I had read that hundreds of famous scientists sent a signed letter to NASA to not just search for carbon-based life, search for other kinds of life too.
But I don’t if they suggested any practical way how exactly such a search can be done.”
The life we’re searching for is the life we know how — or have conceived of how — to search for. This includes not only direct biological/biochemical signatures, but signals from all over the electromagnetic (and now gravitational wave) spectrum. If we find something promising, you’ll hear about it. If not from the entire world, then surely from me.
Have a great week, everyone, and I’ll see you back here tomorrow!
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