Do electrons move at Absolute Zero?
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- Опубліковано 3 лис 2010
- Electrons, the Big Bang and sporting pursuits are among the topics raised by our viewers.
More physics at www.sixtysymbols.com/
With Laurence Eaves, Ed Copeland and Philip Moriarty and Roger Bowley - Наука та технологія
0:02 Uncertainty principle in action!
: ))))))) Best comment on this thread
Definitely more intellectual than quoting the question!
Now THAT is funny
Comment of the year
Schrödinger's cat is alive and well... always absconding with the prof's atoms! Damn it, I think I just revealed the location of the Fountain Of Youth. Nobody would've guessed that hopping into Schrödinger's box for a spell would grant immortality whilst faffing about.
"Its a mistake to think of the big bang as happening at a specific place, the big bang happened everywhere, its just at the time everywhere was very close together" is a great explanation, I love the way it was phrased.
Mr.Aptronym Yeah, but where was everywhere? It seems reasonable that we could locate a point where everywhere was by taking the reverse vectors of all the galaxies.
Ted Soto I think you are missing the point. The galaxies aren't just moving apart, the space between them is actually getting larger. You could find some kind of center that things expand from.
However, that's not really a place, all of the places that currently exist were just together, and the meaning of position as we know it probably does not apply. Everything it could be measured in reference to was right there. There was no larger space for it to have position in... probably.
Wladyslaw Szpilman
But the balloon occupied a space albeit smaller. Unlike a balloon which could move to an entirely different position, when the universe began it occupied a space within the space it grew into. It still seems logical to me that scientists could take all the vectors of the galaxies...reverse them and that would point to the beginning point.
Ted Soto No, the issue here is that all of space, at all points is expanding. Its not an expansion from somewhere, its everything. Furthermore we do not know what, if anything, exists beyond the universe, so there is no coordinate system to use to point out a position.
Ted Soto Szpilman is correct. The balloon can move in the space of higher dimensionality in which it might be embedded. That I grant you.
But if you live on the balloon, your question makes no sense. Mathematically there is not even a need for the balloon to be embedded in a space of higher dimensionality.....
In summary, if the law of physics requires a higher dimensionality, then your question would make sense in that superspace. In our own space, it does not. For us, the balloon always extended in all directions without a centre....every point on the balloon is equivalent to any other one.
I laughed too hard at "where have my atoms gone?"
dude, where's my atom?
Best t-shirt ever?
I just started the video and omg look at his expression!
and the mood is so serious! "where..err.. have my atoms gone? ..where.."
And I dropped down here looking exactly for your comment!
I wondered the same when I dived on my ship into the black hole. Wasted 3 years to gather them back!
Actually scientists are a pretty jokey lot.
"Where did my atoms go?" A bit worrisome if you suddenly lose your atoms.
hahaha, laughed so hard I almost lost my atoms.
+DarkBabyIon the fun part is that in quantum mechanics you never can be sure where they are, because of the heisenberg uncertainty principle.
Rafael Bezerra Dalla Costa well you assume they have SOME energy not approaching infinity, so you can be sure they are close enough together to not suddenly fly apart
+DarkBabyIon 1:42 Got them :)
+Rafael Bezerra Dalla Costa That only refers to electrons...
I love how after Moriarty says sports are bad for you, everyone else says they broke their ligaments.
Guilherme Pata +
Asin
Sports are clearly bad for you. I guess it is OK to do them if you enjoy them, but they will eventually cripple you.
There is a whole branch of medicine called "sports medicine" just to help people recover from the effects of sports.
David Messer I completely agree. I learned a while ago not to sacrifice my body while playing any type of sports for joy. Unfortunately I learned that a bit too late since I ended up with torn ligaments in both knees and moderate arthritis now at age 30.
He's right, you know.
Sports are bad, don't do them.
0:20. ok that about sums it up lol
No
And then Moriarty starts going on about how it may or may not be
The video should have end there, that would be hilarious
, especially with the other guy looking for his atoms first
@@arturgrygierczyk5636 As an april fools prank, with the full video being uploaded the next day. Just to screw with his audience.
"You can't reach absolute zero."
"You can't reach absolute zero."
"You can't reach absolute zero."
"You can't reach absolute zero."
OKAY. COULD YOU CRUSH MY DREAMS ANY HARDER?!
Outside the universe has to be absolute zero because the entropy of a point outside the universe has to be zero else it would be inside some type of a different universe.
Well, okay, _if_ you could reach A0, what would the speed of the electrons be?
Don’t worry damn atoms make up everything.
@@user-ec6kt2fg7m not really atoms are made up of fermions but there are many bosons out there like light, trillions and trillions of photons reach your retina and millions of neutrinos from the sun pass through you every second, i know it's a just but im just saying atoms actually don't make up everything
@@rufusapplebee1428 first of all if there is no multiverse then a point outside the universe is not possible. Because a point exists inside a space and a space means another universe.
Where have my atoms gone ..
I love the expression on their faces when they're talking. It's as if they're truly happy with the profession they've chosen in their lives. And they are so amused to share their fascinating knowledge.
They probably won't. Because there are theories in physics with which most of the physicists disagree but have to teach them to students because there is no alternative theories. Which is really annoying.
Are we viewing physicists as if they are zoo specimens?
@@dinil5566 That's just nonsense.
You don't teach what pleases you.
The vast majority of topics in a physics curriculum are not controversial at all.
Just nonsense.
I love the amazing consistency with which these physicists answered the questions.
Impressive. Most impressive.
Indeed amazing, considering they brought in the uncertainty principle.
Almost like they have the same job?
So in Britain it's "maths" and in America it's "math"... but in Britain it's "sport" and in America it's "sports". What are we doing?
Both are used in Britain. It may depend where in Britain, but most people I know use sports.
Most British people I know say sports like Americans do.
Equalising!!
ShadowFox178 I don't think anyone is desperate to do anything of the sort.
Joe Alias They call trousers, pants (underwear) and a liquid a gas (petrol). It seems pretty strange from my perspective.
"Where have my atoms gone?"
Now THERE'S a physicist who has spent too much time in the chemistry department, experimenting with LSD
Professor Moriarty - do you do sport
No all physical exercise is bad for your health xD love it
I love how excited they get when they're asked good questions xD They get all restless in their seat and quite expressive.
these guys are SO great! :) i wish the videos never ended.
Not many videos about astronomy, cosmology, or quantum mechanics impress me but the simplicity of these answers is brilliant. Great questions and wonderfully explained.
Brady, you do have a genious aspect in your own right; in your editing. You dont go from person to person, in whole; you do it in parts. This lets us see where each dr. goes in their own mindstate, i really love this. thank you so much for your efforts Brady, it's motivating me to do great things. I hope to see you and your colleagues on the field one day.
This one video explains more about the "cosmic microwave background" and "the big bang" fundamentals than most of all the other videos done interviewing a single person... awesome content here!
I love how enthusiastic these guys are. Every time I need a little faith in humanity restored I watch a few videos from this channel!
4:07 I remember my TV used to do that when I was a kid and I had the antenna. Brings me back. I haven't seen a TV with an antenna in a very long time.
"Where have my atoms gone" is a thought provoking insight into the existential dilemma we face every day.
I love these videos
"where have my atoms gone?
so perfect:)
It's 2021 and this footage is from 2010. The questions in this vid are timeless, 11 years is a faint amount of time but in UA-cam time... it's massive. Great upload! Ageing respectably.
i Brady,
Many thanks for yet another great video, really interesting.
Well this took a turn
Question: If, during the start of the Big Bang there was extremely heavy concentration of matter and energy in a small space, why did it not turn into a black hole?
Dark energy pushing it out everywhere
We don't understand everything! I mean, we dont understand Dark energy
The big stretch!
lol, I can think of a few that would fit that description, not just the BB.
Personally, I think what you have stumbled on here is pure genius.
6:28 lmao the cuts are hilarious, great editing 😂
4:20 when i learned this in early 60's, you were told to adjust the contrast control tell the field settles down but not empty and then you still see many dots that come and go, that being the background radiation. I was eight or nine at the time...
electron uncertainty be like: "Say my name"
Say it loud and clear
3:10 I love the way you explained that! This is absolutely hilarious.
Thank u!! this has been a burning question for a long time
"Where did my atoms go?" - Dr. Manhattan
9 years later I'm still laughing at "where've my atoms gone?!"
Great to see consistency between answers haha
ok, i have a question about the cmb, if it was at a high frequency when it was emmited, and due to redshift has moved into the microwave part of the spectrum, so where did the energy go? because these microwave photons have less energy than the high frequency ones that were emmited.
he had a miles davis poster. what a cool dude
If one were to imagine that the electrons were entirely still, what implications would it have on overall molecular structure and position of charges?
It would imply you didn't exist
John Peake Many things would imply that
Entraya Korsbakke Well, what he was saying is that it can't stand still for two reasons.
A) One way a particle moves is by what we call heat, which is a particle moving due to thermal energy, which you can never fully take away (that's a classical physics issue),
and
B) (a quantum mechanical issue) particles have an uncertainty, so if you knew it's position very accurately, it would have a large uncertainty in momentum and therefore it would have a lot of energy (and vice versa, if you knew it had low momentum and movement, you wouldn't know where it was, and it could be practically anywhere in the unvierse and therefore wouldn't actually be still).
+Entraya Korsbakke Then you wouldn't be able to find it. It could be anywhere in the universe.
It's explained in the video when they mention the Heisenberg Uncertainty Principle. You just can't know where it is when its velocity is zero. And when you know exactly where it is, its velocity could be anything. Either way when you know one thing you don't know the other.
Cinqmil yeah i know about the wobblyness of the universe, i was just curious about molecular structures, but i suppose the example was rather pointless as well as needlessly unrealistic to even provide any kind of insight or whatever
beautifully quoted " not only looking out at distances but also back in time"
OoOoh! you guys are from Nottingham Uni! Yaay! You’ve got a new subbie! 🙌
I have a question: What do you guys think about the concept of an oscillating universe? I know there’s a few different theories, so I’m interested to know what you guys think about those theories (and in particular, the oscillating universe theory)
Fankoo!
"In the history of physics everything, every discovery, was thought to be impossible until somebody did it."
Does that help?
perpetual motion has been invented its called the Atom.
***** You can't invent something that's already existed.
meagain2222 as in electrons spinning around?, well the electron is better modeled by probability functions than circular orbits, and even if so there has been discussion about the proton having a halflife
An invention is something that is artificially created by a life form - Not something that naturally exists.
tavi921 there is no such thing as inventing. Only discovering. 😃
+Daniel Cannata ; Invent :create or design (something that has not existed before); be the originator of.
Thank you for this video.
I wasn't expecting that sports question :)
I am not a scientist but an avid layman. Are these ideas, movement at absolute zero and Heisenberg uncertainty, the basis of the Bose-Einstein condensate? Since nothing can ever stop an electron other than its annihilation, some other property of electrons is exhibited very near absolute zero? They appear to be cloud-like because there is only a probability and nothing more that a given electron is in a given place at a given time? Do I have at least a not totally embarrassing layman's grasp of it?
moriarty is my spirit animal
Smiterbiter Dude you seen my atoms??
Is there a constant speed that electrons move around the nucleus of an atom? or is the speed relative to the type of atom. (ie: iron, cobalt, zinc, etc..)
actually kind of interesting this very different question about sports in the end :)
Black and blue or white and gold? 4:00
ninjapancake go back to 2014.
Isn't it more accurate to say that electrons don't actually "orbit" a nucleus but rather exist in a standing wave of probability as to their position?
The misconception of electrons flying around orbits like little planets is still being foisted on the public by the use of the Bohr model, which is horribly out of date! I see this even in so-called "science" museums, where accuracy is also ignored when the nucleus is shown as a large lump almost as big as the electron cloud instead of as a tiny blip 100,000 times smaller than this cloud. Why is this so hard to correct, I wonder?
Jack Wright with ya on this.
Because the Bohr model is still incredibly useful in most circumstances excluding small atoms. The QM model gets exponentially harder to solve with more electrons where the Bohr model is analytically almost totally correct for heavy atoms; we don't scrap Newtonian mechanics just because relativistic mechanics are a better model
Casey C off topic but I find it weird that I’m watching this video and find a fresh comment from 14 hours ago in this sea of old comments lol
As I understand it a comparitive model is a grapefruit as the nucleus in the centre of a major league/national sports stadium with pea sized electrons existing in (probabilistic) shells, starting somewhere typicaly around the outer walls -
Difficult to scale in a museum of science, though a footnote could be added to the models on display!
@Jack Wright: Not everyone is a capable quantum mechanics expert. Bohr's model may be out of date (is it really?), but Bohr and Planck combined are still sufficiently accurate to give some explanation on what everyday people experience in real life.
Can you make nice detailed video on PN junction?
Бојан Драшко en.wikipedia.org/wiki/Charge_carrier
en.wikipedia.org/wiki/Valence_and_conduction_bands
en.wikipedia.org/wiki/Intrinsic_semiconductor
en.wikipedia.org/wiki/Extrinsic_semiconductor
en.wikipedia.org/wiki/P%E2%80%93n_junction
Read those in order and you have yourself a crash course in how P-N junctions function. Pretty neat stuff...
is it measurable using frequency measurements and does frequency decrease as temperature lowers
07:02
Must... resist... urge... to make... arrow... to the... knee... joke...
So that's where the "s" at the end of "maths" came from - you took it off of "sports".
Could the I flatiron field and the later decayed inflatannts have been the result of a pressure wave of the immense force let go at T=1.10e-42? I know it breaks language to say it's expanding into "something" or "somewhere" because of how we define those terms but with a force like that I find it hard to believe there wasn't an echo or whiplash of some kind
Is it only in the immense pressure in the super dense core of black holes that electrons collapse down with the protons and neutrons and stop moving? Is there any gluon orbit or other movement in black holes?
If you misplaced you atoms, is that like loosing your marbles? :-P
5:42 - "degrees kelvin"
What's wrong with that?
Charlie Beadle seriously....
Thats like saying my desk is 40 inches meters
Poke Playah no it's not actually
Believe It Kelvin and Degrees are both units of measurement....
Heisenberg uncertainty principle is like the problem of determining position and velocity.
If you want to determine velocity, it has to be over a range of positions. If you want to accurately determine position, you can only use a velocity of 0.
From string theory if you where to a line all of the ''strings'' in one direction in a shape of a circle and have no matter in the middle would a worm hole(or white/dark hole ect) form and what type and how could this be done( magnetic field, electrical pulses ect)?
Yes they do keep moving. Temperature is a quality of the whole atom. It's the amount of energy/vibration it has. So atoms vibrate/move around more, the more energy they have. If the energy is taken away, the atom slows down and eventualy stops at absolute zero, but the subatomic particles move the same as they did before. Temperature is different from the quantum mechanics strong force and the shape of the wave-function determining kinetic energy, that governs the motion of electrons. At least that's how I understand it.
Who are these people? They answer so brilliantly!
ishaan malhotra they are physicists who work at the University of Nottingham, England
david mccormick Thanks for the info mate!
Does the uncertainty come from angular momentum in relation to a point in space that is not hurtling through space on the surface of a planet that's rotating and orbiting etc?
If the doubling rate of the universe is the same as the doubling rate of 1mm, there's really nothing "expanding" anywhere near the speed of light. The distant galaxies aren't moving through space away from us , there's just more space between us than there used to be.
Apart from the tedious repetition that "you can't actually get to absolute zero" you seem assume that electrons are distinct particles in orbits rather than say, a wave of an integral number of wave lengths around a nucleus.
At the moment we don't seem to have a relationship between temperature and wavelength (they are independent in a vacuum). Unless, the wave (electron) moves to a lower energy state (emitting energy) the electron (wave) would maintain its quantum state. Certainly the Brownian motion would cease at 0 K , and the mechanical motion of the atom would cease, but there is no reason to believe the wave would collapse. I do not recall any results that suggest that, as temperature is lowered, atomic structure changes valence or something of that sort. (Crystalline structures expand/contract somewhat but that is getting mixed up in the piezoelectric effect. Diamond has a coefficient of thermal expansion of 1E-6 / K but is that vibrations in the lattice or size of the atoms? I have not heard any claim that the carbon atoms shrink as the temperature is lowered).
Additionally, there is no apparent dependence of Maxwell-Faraday equations on temperature (what is temperature in an absolute void?). Similarly, the photo-electron effect depends on the frequency of radiation and temperature.
And of course, temperature is really just a measurement of the kinetic energy of the atom (molecule). Considering just a single atom, the kinetic energy is related to the inertial measurement frame. If we change the reference frame to match the atom, the absolute temperature is exactly zero. No energy is lost, the electron (wave) still continues about the nucleus as usual.
This "trick" won't work with a collection of atoms since they are going all different directions. But, individually, each atom maintains its own atomic structure when the collection is cooled to 0K since it doesn't "know" what the other atoms are doing. (Unless you can show some kind of thermal entanglement phenomena!)
To the editors at sixty symbols: you really needn't be so condescending. The You-tube viewers might not be as unlearned as you think.
Finally some physicists who are able to think in terms of "IF YOU COULD", and don't just grab on to physical reality for dear life.
“If the Universe is expanding slower than the speed of light why has not the light from the Big Bang already passed us?”
This is the question I have been asking myself for years. Really good explanation!
3:10
Finally someone explained that in a way I actually understood.
What about reaching Ab0 without knowing it?
what stops light from moving faster than 300,000 km/s ?
obviously it ain't friction.
***** It's a principle of our universe. That objects with no mass have no choice but to move at the speed of light.
how is it that it can have no mass.
by no mass, do they mean very, very small mass? I can't imagine something having no mass. Everything has to have some mass.
i can see from the E=mc2 equation that mass can approach zero (i.e. become very small) and energy (like that of a photon) can still exist.
But if m is 0, then the right hand side of the equation (mc2) is zero. Which means there is 0 energy E.
Therefore just from my layman's perspective looking at the equation, I am concluding there is no such thing as no mass. When the words no mass is used, I presume what is meant is very, very small mass.
You are misinterpreting reality. Photons have no mass. That's why it's described by small "c" in the equation. It's the constant of light in a vacuum. If you want to disprove this I suggest you write about it in and submit it to peer review.
If you want to learn about it, you will need to read about it yourself. But you are arguing against reality itself. Learning about relativity will teach you what you want to know.
***** mass is now defined as the interaction with the Higgs Field
photons and gluons have no mass, they do have energy however, and therefore have relativistic mass.
The intrinsic frequency of any matter wave if I remember correctly is Hbar*omega
70 (km/s)/Mpc, it was first calculated by the Hubble telescope by measuring something called the redshift. The value is ~2.27e-18 hertz which has been calculating by how much the light spectrum of distant stars is being shifted towards the infra-red end of the spectrum.
I thought the title asked if erections move at absolute zero.
Rename this vid to: SPORTS ARE BAD!
fair point! So is there/Can we know something beyond the observable universe?
What started the first electrons moving ? Was there a time of absolute zero motion in the universe and if
so, what started everything in motion ?
WHERE ARE MY ATOMS?!?!?!
He couldnt find his atoms, yet they were right in front of him! Hah!
Ill show myself out..
As atoms cool do the vibrations change in amplitude or frequecy or both?
The sports bit was amazing
What?! The Electros still whizz about at absolute zero? I feel raped now!
Wait a minute. If electrons can never be stopped, not even at absolute zero, then that's means that they are always moving. Always. So electrons have been buzzing around their host nuclei for over 13 BILLION years. How is that possible? Wouldn't they run out of energy? Unless I'm missing something here, it seems as if electrons have infinite energy.
itsMinuteMaid energy is defined as the capacity to do work, so no, they do not require to spend energy to stay around a nucleus
itsMinuteMaid Quantum physics is insanely hard to explain in words, but basically, an electron's position in space cannot be precisely known, so it exists as a cloud of possibility over a nucleus. Changing its energy changes how far above the nucleus the electron is, but it doesn't change whether or not it is actually in motion.
It doesn't make any sense, but that's how quantum physics do.
itsMinuteMaid a particle moving at constant velocity retains its energy. A simple classical equation is KE=1/2mv^2.
Kinetic energy = a half of the mass multiplied by the velocity squared.
For it to lose energy it would have to hit something and transfer some of its energy to another particle.
Your actually confused about the same thing as ancient Greek philosophers. Our world is dominated by friction so everything always slows down. Of course friction is the particle colliding with the air molecules or something else.
Weird things happen in a quantum level.
itsMinuteMaid " If electrons can never be stopped, not even at absolute zero, then that's means that they are always moving. Always."
Yes!
"Wouldn't they run out of energy?"
No - the question you are asking was asked by physicists at the start of the 20th century - and in the struggle to understand how electrons can orbit the nucleus *forever* and never lose *any* energy Quantum Mechanics was born.
You should read about it - its fascinating.
"it seems as if electrons have infinite energy"
No, they have a definite fixed amount of energy ( a Quantum - a definite amount.) and they lose zero energy if they stay in a stable orbit.
Zero energy lost per second is zero energy lost per day, zero energy lost per year and zero energy per Billion years.
They loose no energy *at all* orbiting the nucleus in a stable orbit. That is why they can do it forever.
"If an electron loses 0 energy per year, how much will it lose in 100,000,000 Billion years ? Answer : 0 "
It is counter - intuitive but so is much of fundamental reality.
8-)
I love that they all played sport, it shows you can live a rounded life and be a physicist, rather than a sequestered person that never exercises.
I have a question. Is module british for course?
if atoms are always vibrating, could it be possible to create a device that harnesses these vibrations and converts that into energy? free energy??
This kinetic energy of the atoms (though not sure if this is the right term in this context) is manifested in the macro scale as heat. So we have been harnessing this energy for tens of thousands of years, ever since we got control of fire.
Unfortunately it's not free energy (excepting solar collectors) because energy has to be provided to increase/maintain the energy levels of the atoms.
Re. free energy. Remember the 1st Law of Thermodynamics which simply put states that any energy put into something must be taken out of something else.
Kimdino1 So where does the energy which powers the electrons obrit around the nucleus come from?
Moses Bullrush Electrons don't actually orbit around the nucleus of an atom, it's much more difficult to explain how they are actually existing in relation to the atomic nucleus - but to answer your specific question of where the energy comes from, the motions of electrons are intrinsic quantum mechanical properties, nothing is "pushing" them around so to speak, instead the electron is designed by nature to jiggle around and pop in and out of different positions around the nucleus, it just does what it does, it's not a matter of needing a source of energy it's just a quantum phenomenon.
Moses Bullrush
Quantum mechanics of the universe create energy and particles out of nothing is the take home message.
Morris The Cat That's not exactly true.
Yes, there are particles being created out of nothing all the time but always two at once which behave exactly opposite from one another. Because they are opposites they effectively cancel out. Like matter and anti-matter.
Sometimes particles pop into existence at the very edge of a black hole which results in one particle falling into the black hole and the other shooting away into the universe. This phenomenon is called the Hawkings Radiation but it's not proven yet.
Still, there is only so much energy in the universe and it can never increase nor decrease. However, entropy is always increasing and at some point in the future, which is estimated at about a googol (10^100) years, all the energy will be spread out evenly. This scenario is called the Heat Death of the universe.
Why do they need to keep asserting "you can't reach absolute zero". It's not as if physics students are not familiar with 'ideal' situations while solving problems in school. We have frictionless surfaces, air that provides no resistance, gases that behave ideally, fluids that have no viscosity, harmonic motions with no energy loss, *perfect* resistors, capacitors and inductors, wires with zero resistance. All these situations are impossible in real life but our teacher didn't keep saying they can't exist over and over. I'm pretty sure almost everyone knows that the question is purely hypothetical. I'm NOT annoyed. I'm just wondering whether there is actually some reason why they need to repeat it.
Because this is youtube and not everyone on here knows that
Most of the listeners are not physics students.
The answer is simple: each scientist only said it once, but the filmmaker interviewed several scientists.
Captain Quirk :-D
Even theoretically absolute zero is prohibited by the laws of physics, the same way that faster than light travel is impossible. The other situations you listed are not theoretically prohibited (the opposite in fact), they're just complicated by other real world factors.
Also, how does the uncertainty principle reconcile with black holes? If matter collapses in on itself at the center then wouldn't that make it a quantum-scale entity (not sure if it counts as a particle)? If that's the case then shouldn't the principle apply? If it does, and you can measure it's position and momentum (by observations of the gravity well) would that violate the principle? Also, wouldn't that constrict movement and therefore bring the temperature down?
What you are looking for is kinectic energy:
K=mc^2(gamma-1)
gamma=1/(sqrt(1 - (v^2/c^2))
Although this formula only applies to velocities greater than 0,1c because if aplied to cosmic matter(objects moving in space) because of gamma - the relativistic constant and gamma is used the see the correlation between time observed by us because objects faster than 0,1c suffer time contraction and its also used calculate time,energy in a moving referencial from a static referencial(e.g. The earth)
I have a question. I'd be greatful if someone could answer this. If we cant reach absolute zero then howcome this temperature is included in the definition of a second when measured by an atomic clock? Doesnt the fact that we cant get t zero make the definition useless?
Thank you
So competitive. No one said anything like "yeah, I have lots of fun practicing my sport"...
How can you meassure temperature of vacuum? Vacuum being the absence of particles of gases or anything else and temperature being the average speed of particles. Or do I get it wrong?
Hi.
Can you make a video about why does screen static work as a cosmic radiation detector?
There should be a Brady Haran convention, which would get people featured in Sixty Symbols, Numberphile, Nottingham Science etc together to deliver lectures to visitors and meet and greet them and such. That'd be great. :)
That would be awesome.
3:00 This is a question I've always had and never asked.
I appreciate the answer! Also I understand that for other reasons a question would it feel cold in vacuum, say in space, is irrelevant since it would do all sorts of other than thermal demage to unprotected skin. Correct?
Momentum is related to energy. Photons have momentum given by planck's constant divided by the photon's wavelength, or the photon's energy divided by its speed
I would also add that the electrons are forced to keep moving by the Pauli exclusion principle. Even at absolute zero, they must obey Pauli-Dirac statistics, so that two electrons could fall down to the lowest momentum state, but the rest would have to occupy the higher states. The fastest electrons are on the surface of something called the Fermi sphere, which is a sphere in momentum space, and these electrons, even at absolute zero, would be moving at the Fermi velocity, which depends upon the physical properties of the material in question, but it's around 1% the speed of light.
I love you guys and wish you'd been my physics teachers. I did get a four-year degree in Astronomy (which of course included physics and math) so these days I call it Astrophysics because it sounds so much more impressive. I moved on to software design as a career but never lost my interest in the subject, and your videos bring back some fond memories as well as covering topics that hardly existed back in the sixties!
So.. can the difference in temperature of the background radiation depending on what way you look tell you something about what's in that direction and might have affected it to have a different temperature from something coming from a more empty area?
would the quantum effect (i.e. light thru multiple slits) still work at abs O???mmmmm.