A question for you- have you ever played the game "telephone?"
You know, the game where someone whispers something to someone and then that person
whispers it to someone else and then that person whispers it to someone else…and by
the time you get through everyone playing, the original message is all messed up?
I used to kind of dread that game---most people seemed to like it---but somehow whenever it
reached me, the message was always really messed up so I felt like I was spreading nonsense.
Well, either that, or it was me all along that misheard it.
Anyway, the game is all about communication and how things spread.
Communication is incredibly important not just for us but for the things that we are
made up of.
Like our cells!
Cells make up all living things.
And while they don't talk in the way that you and I do, it's important for their messages---their
signaling---to be transmitted and received appropriately.
Multicellular organisms need their many cells to be able to work together to carry out functions.
Just consider all of the cells working together in one of your organs—like you heart—for
example!
First some vocabulary---we're going to be talking a lot about receptors.
A receptor is a molecule---such as a protein---where a signal molecule can bind.
One place you can find receptors is on the surface of a cell membrane.
When a signal molecule binds the receptor, amazing things can happen.
The receptor might start activating another molecule for an action to happen---the receptor
often changes its shape slightly in the process---more about that later.
So receptor.
Signal molecule.
The signal molecule can be considered a ligand, a fancy term which basically means it's
the smaller molecule that binds to a typically larger molecule.
Signal molecules can be a variety of things such as gas molecules or hydrophobic biomolecules
like lipids or hydrophilic biomolecules like some kinds of proteins.
But ligands are generally smaller than the receptors they bind.
Ligands and receptors can have a very specific fit as well.
Let's talk about the general sequence of cell signaling.
First, Reception.
Typically, a signal molecule binds a receptor.
Second, Transduction.
The receptor gets activated by this binding.
This often means the receptor will change its shape.
It could even involve a whole series of molecules changing their conformation in something called
a signal transduction pathway.
This can amplify the original signal.
Third, Response.
There is some kind of response that is going to happen.
A portion of DNA that is found in the nucleus getting transcribed for example, that's
a type of response.
Now cell signaling can involve intracellular signaling---which occurs within the cell itself---
and intercellular signaling where a cell communicates with another cell.
In many cases, signaling involves both: signaling between cells and then also the signaling
within cells.
Now, when we're talking about signals traveling from one cell to another--- distance matters.
Some cells are close and have direct contact.
In the case of these two animal cells, they are gap junction close.
Gap junctions in these animal cells---or plasmodesmata in plant cells---are connections between two
close together cells that can allow ions or other small molecules to pass and by doing
so, they don't have to pass across the plasma membrane.
Paracrine signaling allows a cell to target another cell by a signal molecule that may
diffuse between them---these cells are still close---but need not be connected.
The ligands in paracrine signaling tend to be rapidly reabsorbed and rapidly degraded;
the ligands are typically not traveling far as this is local signaling.
Synaptic signaling which specifically involves neurotransmitters in a synapse is another
example of this local signaling.
And what about long distance?
Endocrine signaling can allow a cell to communicate with a target cell from far away.
Signals may be carried in the bloodstream.
Hormones released by certain types of endocrine cells are a great example.
We also want to point out that a cell could just signal itself.
For example, in autocrine signaling, a cell could secrete a certain type of molecule which
then binds to its own receptor and causes a response.
A cell releasing its own growth factor could be an example of this.
Let's just give a few signaling examples so we can get a basic understanding of the
vocab and what this can look like.
Let's say we have a steroid hormone that travels through the cell's semi-permeable
membrane.
Remember that would mean the steroid hormone is our signal molecule, our ligand.
Once inside the cell, it binds a protein receptor within the cell.
Now the protein receptor is active.
The protein receptor travels into the nucleus where the cell's DNA is found.
This protein receptor binds to DNA and is involved in getting transcription of a certain
gene going, which eventually can be used to produce a specific protein.
This is an example of signaling inside the cell, simplified a bit.
Now in that example, the receptor was inside the cell, a cytoplasmic receptor.
But it doesn't have to be.
Receptors are frequently part of the cell's membrane surface.
If a receptor is sitting outside on the cell membrane surface, then the ligand doesn't
have to come in.
In fact, there could be properties of the ligand that may not allow it to pass the membrane:
the ligand could be hydrophilic which would make it hard to pass through.
Let's mention an example of a cell surface receptor type: a ligand-gated ion channel.
Ions normally don't go unassisted through the cell membrane --- they are charged after
all --- see our cell transport video.
But a ligand-gated ion channel gives them a way through---through a channel!
But it is controlled.
In this example, the channel is closed.
But here comes a signal molecule, a ligand, it binds the receptor---which is the channel
protein in this case.
Now the channel protein responds by opening.
The ions - not the ligand- go through.
Once ions get through, the concentration of ions increases inside the cell.
And you may wonder, "Ok, so now there are ions in the cell, why does that matter?"
Well the increasing ion concentration can trigger a cellular response.
After reaching a certain concentration and stimulating a cell response, the ligand can
leave its binding site from the receptor and the channel can close.
Ligand gated ion channels can be used by neurons--- a neurotransmitter may be the ligand for the
channel to open.
This could happen at a synapse.
But just be aware that not all ion channels are ligand-gated ion channels.
Ion channels can be gated by other things.
A voltage gated ion channel, for example, depends on electrical membrane potential---not
a ligand.
Voltage gated ion channels are used by neurons too.
Check out action potential in neurons to learn more.
There are other types of cell membrane surface receptors we don't have time to go into
in this video.
G-protein linked receptors and enzyme linked receptors are two other types that we encourage
you to explore!
So, in summary, why do we care about this cell signaling thing?
Well, realize that your body processes that keep you alive rely on your cells' ability
of cell signaling.
From the regulation of your heartbeat to the hormone signals traveling long distances in
your body to the ways the neurons in your brain communicate---your multicellular self
needs cell signaling.
But there are many disorders where cell signaling does not work as it should and so understanding
all of the complexities of cell signaling is critical in order to find ways to treat
them.
Cancer is an example of a disease that can involve body cells with problems in cell signaling.
When we mentioned autocrine signaling – a cancer cell could have a problem where it
produces too much of its own growth factor causing excessive division.
Cancer cells can also have many other cell signaling difficulties where they do not function
like normal, healthy cells.
Or another example, there are also pathogens – such as viruses or bacteria – that can
take advantage of cell signaling.
Consider the virus HIV which targets Helper T cells.
Helper T cells are important immune cells in your body, and they have something called
a CD4 receptor on their surface.
That receptor is important so that Helper T cells can communicate with other immune
cells.
But as mentioned in our viruses video, HIV targets that CD4 receptor.
It is because of the virus binding to that receptor on Helper T cells that the virus
can attach and infect the cell in the first place.
A fact that continues to be researched for treatment options.
The understanding of the details of cell signaling continues to expand.
Well that's it for the Amoeba Sisters, and we remind you to stay curious.
For more infomation >> Intro to Cell Signaling - Duration: 8:59.-------------------------------------------
4- His humility | responding to Wilders' #MuhammadCartoonContest | Fadel Soliman - Duration: 0:31.
For more infomation >> 4- His humility | responding to Wilders' #MuhammadCartoonContest | Fadel Soliman - Duration: 0:31. -------------------------------------------
Avengers 4 GALACTUS Is The Power Stone REVEALED!? You Won't See This Coming! - Duration: 7:44.
voted into existence and the remnants of
these systems were forged into
concentrated ingots infinity stone he
stones it seems can only be brandished
by things of extraordinary strength
observe these carriers can use the stone
to mow down entire civilizations like
wheat in a field once what a moment that
group was able to share the energy
amongst themselves but even they were
quickly destroyed by it
what is good youtube Warstu here with a
video on Avengers 4 so it's coming up to
September that's when the infinity war
blu-ray officially comes out over here
so I'm starting my giveaway on this
video I'm gonna be giving away up to
three at least one so all you got to do
is subscribe to the channel make sure to
like share and comment down below who is
your favorite MTU villain and why so
today's video is insane and it's come
from a fellow youtuber who I speak to
called the cosmic Wonder don't worry I
spoke to him back going over this theory
and he okayed it so he's a fellow
youtuber in the Marvel creator community
that we have here pretty awesome dude
so yesterday post an insane theory which
makes a lot of sense about Galactus
being the Power Stone or trapped in the
past own so make sure to subscribe to
him guys the link will be down below and
he's also been on my recommended channel
list for a while so guys make sure to
subscribe
so yesterday I posted a video about the
Infinity Gauntlet snack waking up or
creating Galactus inside with a quantum
well but what if this isn't true and he
is in fact the power stone like this
video just say so ages ago there was a
theory are going around about the
finalists Easter Egg from guardians of
the galaxy B and Galactus inside the
celestial staff because of the helmet
but it was debunked by James Gunn
now James Gunn has nothing to do a
Marvel because they fired him due to
what was going on we don't know what the
final Easter Egg is ever going to be
although some people say it was
confirmed it wasn't really confirmed he
debunked it so the theory is Galactus is
the power stone or is trapped in the
Power Stone but to answer this question
you have to know what the infinitive
Infinity stones are throughout the whole
m2u we've learned a band from various
people in this video from the theory
I've said and where it's come from Odin
and the collector mainly are the sources
of information
our relics that predate the universe
itself what lies within
so in dark world
Odin said there were relics that predate
the universe itself then in gardens that
galaxy the collector went into more
detail about the creation itself there
were six singularities then the universe
exploded into existence and the remnants
of the system will forge into
concentrated in Gong's aka leo infinity
stone so in the flash there are remnants
there's time remnants when you
manipulate the timeline manipulate a
universe and kind of do stuff you're not
supposed to do it so that's not really
relevant to this I just thought it's
kind of funny that as remnants in the
MCU and there's remnants inside the
flashy universe so what this theory is
saying is both Odin and that the
collector said that these relics existed
before our own universe existed and when
it exploded these relics left from these
universe and the remnants pieces all
fought into Infinity stones hence why
they are so strong this is how and why
the Infinity stones were actually
created so how this theory worked is
really due to the origin of collectors
himself the lion who gained cosmic
abilities by passing a near star and
then the character was further developed
revealing that Galan lived during the
previous universe that existed prior to
the Big Bang which begun the current
universe as client universe became to an
end he merged with a Centon of the
universe to become Galactus an entity
that wielded such cosmic power as to
require devouring entire planets to
obtain his existence he's essentially a
source of power he is the power who is
Galactus the world eater
so the Galactus came before the current
universe before the Big Bang his
universe was wiped out and he could be a
remnant from the universe which could
easily be one of the six six seven six
six
singularities that we spoke about the
MCU and Marvel Comics aren't exactly the
same but Marvel directors like the Russo
brothers who made infinity war civil war
an event
for like to pull from the comic but the
Russo brothers pacifically won't carbon
copy anything from the comics but they
will take Emperor inspiration and they
will modify a story or talent in
different way so the power stone angle
actors are the same color we see this in
the gardens the galaxy Easter egg with a
celestial and that's why most people
think that is the last Easter egg which
is interesting during the flashback we
see a celestial with what looks like the
Power Stone and the helmet looks like
practice helmet wiping out a whole
planet which shows the true power of
Galactus the world here and obviously
their similarities so if you follow this
video the idea that Galactus could
either being a Power Stone or be stuck
in that the Power Stone makes a lot of
sense but who could have actually
brought them in there I'm not sure in
the comics it was the watcher so maybe
they could do it and here so I don't
know guys it would be a really
interesting concept I know what some
people would say but would you the fox
deal hasn't gone through well yeah he is
part of the Fantastic Four and that kind
of stuff but you never know they might
have a secret deal like I said in
yesterday's video that could allow
Galactus to be SERP for the Avengers 5
overall villain he could appear it could
be a little cheeky Easter Egg telling
you oh my god Galactus is stuck in the
Power Stone you got remember cuz we
never seen the Power Stone get taken did
we it got took from Xander but that
scene got deleted did it get deleted
because of the hole he is Galactus stuck
in the Power Stone I think it's very
interesting so guys I like I said that
the style video make sure to check out
the original video from the cosmic
Wonder is links in the bio it's also in
the community and I sorry it's also in
the feature channels at the left at the
right off the top of the channel so guys
would love to know what you think about
his theory I think it would be insane I
know - like this videos back to back I
am working on an Adam warlock video I
think there is a way the Adam warlock
was secretly inside infinity war and
Avengers 4 so I'm posting that later on
if I've got time should be posting it a
couple of hours after this two or three
hours out of this
if I get time so I call his guys check
out the competition let me know who's
the best MCU villain ever and don't you
say that offs please please because we
want a nice low-key jokes anyway guys
please like subscribe and comment and I
will catch you in another video very
soon catch you
-------------------------------------------
True Mitsubishi Eclipse CROSS 2019 - Duration: 7:47.
Autobloggers start to make their projects
I thought why me, who make
some projects half of my life
do not start doing reviews
I made a review for eclipse cross
Well, does it open here?
and it is without an electric motor
this is the eighteenth year now
wacky machine
incomprehensible to anyone especially by name
I understand if it was called an outlander
all would perfectly understand the outlander cross
everybody approve it looks like an outlander
called as outlander but eclipse
Use the Eclipse name for crossover - this is nonsense
I made review for it
but after a while i can't
live with thought that I did not criticize it
It is necessary to tell the truth what kind of car it is
and how it should looks like
in real, that's why I made my ECLIPSE CROSS
this one
[music]
in my opinion this is eclipse and this is
eclipse CROSS
I do not know budgets of mitsubishi
for the construction of new machines
but even I can do an automatic transmission
all-wheel drive, front-wheel drive
rear-wheel drive
mechanical transmission with the same options
this is a mechanical 6-speed Transmission
from mitsubishi evolution
it already was installed on this eclipse
since I made it all-wheel drive
in general, it was the first AWD conversion
of eclipse of 4th generation
in the world
unfortunately it is not released
from the factory with all-wheel drive option
[music]
Also it's possible to build it with
the automatic transmissionon, with the five-step modern automatic transmission
I do not understand why mitsubishi
do not produce now automatic transmissions
for them everything is expensive
but since I'm talking about full drive
the most important part of the all-wheel drive car
this is the rear transmission
in mitsubishi eclipse CROSS same transmission as in outlander
but I think the owners of the outlander
perfectly understand me - this is not the best
mitsubishi decision in last years
it is easy become overheated it does not hold anything
it's always turns off. Well, in general this
not my option! my version is - cast iron!
a real "true" rear DIFF which
hold any loads
there is a block 1.5way
disk block with the possibility I do not know what
Well, there it should be
in connection with this reducer, you can
use several different
transfer transmissions mitsubishi
this is an option with interaxle diff lock
and the front axle diff lock
You can also know this system as
electronic lock system
of the differential - ACD
but all of these systems, all diff locks
all full drives and transmissions are not important
without a powerful heart
this is not 1.5L turbo is a real 3.8L mivec
in the atmospheric version of this engine
we have 300 HP.
but we are YouTubers. we are building eclipse cross
so, this two turbines
allow us get
hmm.. 500 HP, not less
we are making offroad car. we are making cross
eclipse CROSS and the most important
parameter is a clearance
[music]
[music]
[music]
all reviewers check clearance
by cigarette box
let's try
i think it's not our version
40 cm till spar!!! enough???
as the result we have "true"
mitsubishi eclipse cross 3.8 L
all wheel drive transmission
as manual
and also automatic, diff locks of all axles
big read clearance
offroad options
yes, it's not crossover but this is eclipse and this eclipse is a "true"
cross in my opinion, but not in the minds of mitsubishi
mitsubishi learn
how to make cars
till we made this review i thought
we can really make this project
build this MONSTER
it's depend on you my followers
as each youtuber i'm mercantile
if followers want cross - let's CROSS
followers want Concept RA
by the way link in the description of this body kit
let's build concept RA
so please write your comments
depends on your opinion
destiny of this project. To build or not to build
Subscribe, put likes
call the bess, Ciao!
[music]
no, you must give it to me
this is left hand if you see
can you raise it up?
[music]
[laughing]
[music]
-------------------------------------------
KAMOU SAVAGE " A La Francaise" ( Clip Officiel ) - Duration: 2:07.
For more infomation >> KAMOU SAVAGE " A La Francaise" ( Clip Officiel ) - Duration: 2:07. -------------------------------------------
Сергій Юрченко Батьківський поріг (аudio) - Duration: 3:05.
For more infomation >> Сергій Юрченко Батьківський поріг (аudio) - Duration: 3:05. -------------------------------------------
31- His integration as an immigrant | responding to Wilders' #MuhammadCartoonContest | Soliman - Duration: 0:53.
For more infomation >> 31- His integration as an immigrant | responding to Wilders' #MuhammadCartoonContest | Soliman - Duration: 0:53. -------------------------------------------
22- His modesty | responding to Wilders' #MuhammadCartoonContest | Fadel Soliman - Duration: 0:55.
For more infomation >> 22- His modesty | responding to Wilders' #MuhammadCartoonContest | Fadel Soliman - Duration: 0:55. -------------------------------------------
1 How to respond to Islamophobes?| responding to Wilders' #MuhammadCartoonContest | Fadel Soliman - Duration: 0:41.
For more infomation >> 1 How to respond to Islamophobes?| responding to Wilders' #MuhammadCartoonContest | Fadel Soliman - Duration: 0:41. -------------------------------------------
How Are We Searching For Dark Matter? And How Do We Even Know It's Real? - Duration: 16:02.
Whenever I mention dark matter in anyway in the Guide to Space, or in a questions show,
I get a bunch of responses that have essentially the same point.
Astronomers are just speculating, why do they even think dark matter is a thing?
They're sure going to be embarrassed in the future when they realize they were wasting
all this time.
Oh, astronomers.
Foolish, gullible astronomers.
The reality, of course, is that many astronomers have dedicated their lives to the mystery
of dark matter.
More than a decade of school, working with incredibly complicated math, and then many
more years of observations, using some of the most powerful and sensitive instruments
ever designed by human beings.
And obviously I know that people can spend their lives dedicated to nonsense.
So in this video I want to do two things.
First, I'm going to spend some time explaining how astronomers realized that dark matter
is something real.
In fact, the evidence is overwhelming, and I'm going to get into it.
And then I'm going to talk about the fascinating work going on around the world to search for
dark matter.
What are the individual experiments, observatories and projects which are trying to chip away
at this mystery.
Before I go further into this dark matter.
I want to give you an analogy that comes from my Astronomy Cast co-host, Dr. Pamela Gay.
Because I don't think that most people really understand the state of the search for dark
matter.
Let's imagine you're driving your car and it starts to make a knocking sound.
You take it into the mechanic and they can't figure out what's causing it.
They ask you to drive some more in different conditions and maybe you can help located
the problem.
You realize that it only makes the sound when you're going up a hill and turning left.
You bring back this new information to the mechanic and this gives them a better place
to search for the source of the problem.
If some friend ridiculed you because of your "dark knocking sound", all they'd have
to do is spend a little time in your car and they'd hear the sound too.
The problem is definitely there, it's just that you and the mechanic haven't figured
out what's causing it yet.
But you will, oh… you will.
You have a mystery, and you haven't solved it yet.
That's dark matter.
And dark energy is an stranger mystery, but that's a topic for another video.
I think the name "dark matter" is probably the source of the confusion.
It should have been called something like invisible matter, or mystery matter, or crazy
gravity, or… something.
Okay, back to dark matter, and let's start with a brief history.
I'd like to thank Dr. Brian Koberlein for his comprehensive history of dark matter on
his blog.
I'll put a link in the shownotes so you can learn more about it.
The effect of dark matter was first discovered by the astronomers Fritz Zwicky, who was studying
the motion of galaxies in the Coma Cluster.
Located about 321 million light-years from Earth, this cluster contains more than 1,000
separate galaxies.
During his study of the cluster in 1933, Zwicky calculated that the motion of all the galaxies
was too fast for the gravitational interactions of the galaxies themselves.
There had to be some kind of missing mass that was contributing to their movement.
Of course, it's possible that the individual galaxies happened to be flying past each other,
but the same result was found in all the galaxy clusters that astronomers could locate.
The next key piece of evidence came with the way that galaxies themselves rotate.
Think about the way that planets orbit the Sun.
Each planet goes at a different speed depending on its distance from the Sun.
Mercury completes an orbit every 88 days, while Earth takes 365 days and Pluto takes
248 years.
You would expect the stars within a galaxy to do the same thing.
Stars close to the center of the galaxy whip around quickly, while the ones in the outskirts
take their time.
Through her pioneering work of measuring the rotation rates of individual stars in distant
galaxies, Vera Rubin figured out that spiral galaxies rotated like disks.
All the stars moved the same speed around the galactic center.
One idea, of course, was that there was some kind of hidden matter, like the dark nebula
we can see here in the Milky Way.
These block the light from a more distant object, hiding it from our point of view.
But astronomers developed techniques to measure the radio signals coming from these dark clouds
of matter, and the amounts in galaxies didn't account for the amount of mass it would take
to make galaxies and galaxy clusters behave the way they do.
Astronomers were left with two possibilities.
Either their understanding of gravity at the largest scales was wrong.
This idea was known as Modified Newtonian Dynamics, or MOND.
As long as you were willing to put in new equations for gravity, you could predict the
kind of motions observed in nature.
The other idea was that there was some kind of invisible particle.
A particle that accounts for the vast majority of the mass in the Universe, but it doesn't
interact with regular matter in any way we can detect, apart from gravity.
These were known as Weakly Interacting Massive Particles.
In order to better map out the dark matter in the Universe, astronomers used a technique
called gravitational lensing.
This is where the gravity from a foreground object, like a galaxy cluster, distorts the
light from a more distant object, like another galaxy cluster.
Astronomers have done incredibly comprehensive surveys of the sky, and mapped out where the
blobs of dark matter are, and how they surround galaxy clusters.
One famous example of this is the Bullet Cluster, where astronomers could observe clusters of
galaxies colliding with each other.
They could see the stars in the galaxies, they could measure the locations of giant
clouds of hot gas colliding because of the X-rays they emit, and they could measure the
dark matter through its gravitational lensing.
And what they found was amazing.
The stars are so far apart, they just pass by one another without colliding.
The gas does collide, and bunched up into regions that glowed bright in X-rays.
But surprisingly, the dark matter didn't collide with anything, not with the gas, stars
or even itself.
If dark matter is a particle, it must be tiny - astronomers say it has a small cross section.
And yet, it has to be massive, since it dominates the area with its gravity.
Better observations across the large scale structure of the Universe show how dark matter
must have been necessary to get these galaxy clusters collapsing in the ways they do, and
the gravitational lensing observations are now so precise, they can see the exact distributions
that match these predictions.
Another survey of dark matter was to search for it in the Cosmic Microwave Background
Radiation, of course.
This is the afterglow from the Big Bang.
A time when the Universe was about 380,000 years old, and light was finally able to escape
into space.
The European Space Agency's Planck satellite performed an all sky survey of this cosmic
microwave background, mapping out the distribution of dark matter compared to regular matter
in the sky.
When you look at the CMB, the temperature fluctuations tell you how much regular matter
and energy there is compared to dark matter.
When that early Universe was so hot and dense, the radiation pushed against regular matter,
while it didn't push against the dark matter.
Astronomers have built models with different ratios of dark matter to regular matter, to
match up the one they see in the CMB.
Based on this survey, astronomers were able to calculate that the Universe is made of
4.9% regular matter and 26.8% dark matter.
Oh, and another 68.3% dark energy, but again, that'll have to be another episode.
Astronomers are certain that dark matter is there, but they still don't know what it
is.
As my friend Dr. Ethan Siegel says, "When someone puts forth the hypothesis that dark
matter doesn't exist, the onus is on them to answer the implicit question, okay then,
what replaces General Relativity as your theory of gravity to explain the entire Universe?"
What's your general theory of sound that replaces my idea that my car is making a strange
knocking noise?
Now, I hope, I've convinced you that astronomers aren't arrogant, they've got a genuine
mystery they're trying to chase down through observation and experiment.
And I'll get to them in a second, but first I'd like to thank:
Hadi Zolfaghaari Dany Noacco
Gaute Moon Incrediwebbs
Joseph Matheny Bruce Jividen
And the rest of our 837 patrons for their generous support.
If you love what we're doing and want to get in on the action, head over to patreon.com/universetoday.
In the last few decades, astronomers have continued to search for dark matter.
Narrowing down what it might be: invisible particles or gravity behaving strangely at
large distances.
When it comes to particles, there are three possibilities: hot, warm and cold.
In this case, hot dark matter would be a particle that's moving close to the speed of light,
while cold would indicate that it's moving very slowly.
An example of hot particles are neutrinos.
These are the nearly massless particles streaming from the Sun and other stars.
At any point you've got about 100 trillion of these tiny particles passing through your
body, moving at nearly the speed of light.
They rarely interact with anything out there in the Universe.
In fact, a neutrino will, on average, be able to fly through a light-year's worth of lead
without getting stopped.
Physicists detect neutrinos in enormous underground reservoirs of water surrounded by incredibly
sensitive detectors.
When the occasional neutrino does interact with a molecule of water, it releases a cascade
of particles which can be detected.
That sounds like a good candidate for hot dark matter, right?
Well, the problem is that neutrinos are moving close to the speed of light.
This means that won't ever clump up in the way that astronomers observe dark matter doing,
through gravitational lensing and the cosmic microwave background radiation.
Since dark matter doesn't seem to clump at all, hot, fast moving particles are ruled
out.
Sorry neutrinos.
Instead, slower moving, cold dark matter particles seem like the most likely culprit.
There are literally dozens of experiments searching for cold dark matter particles right
now.
They're all based on the idea that even if dark matter barely interacts with matter,
it can happen from time to time and you can observe it.
Experiments are running to detect every possible particle theorized.
Let me give you just one example: the Super Cryogenic Dark Matter Search, or SuperCDMS.
The experiment is located 700 meters underground in an old mine in Minnesota.
Assuming that dark matter is this cold, slow moving particle that comprises the vast majority
of matter in the Universe, and assuming that it doesn't really interact with regular
matter, you'd expect many of these particles to be passing through any spot on the Earth
at all times.
Every now and then, one of these dark matter particles would interact with regular matter
and release a cascade of particles that could be detected.
This old mine is deep underground, shielded away from cosmic rays and human pollution,
so only particles that can pass through hundreds of meters of rock will be detected.
It gives scientists a clean signal.
The detector is equipped with silicon and germanium crystals cooled down just above
absolute zero.
This is going to sound totally new age, so bear with me.
If dark matter particles pass through the detectors, they'll set off vibrations in
the crystals that will be detectable.
An even more sensitive version is under construction at a deeper facility in Sudbury, Canada.
Once it's fully operational in the 2020s, SuperCDMS SNOLAB will be able to detect cold
dark matter particles with a mass between 1 and 10 protons.
Another way scientists are searching for dark matter is using particle accelerators, like
the Large Hadron Collider.
Instead of waiting for dark matter particles to drift into their detectors, they've tried
to create them.
Particle accelerators work by pushing particles to immense speeds, creating an enormous amount
of kinetic energy.
When the particles are slammed into each other, that kinetic energy freezes out into matter,
which can then be studied.
Different models for dark matter have been proposed, and the right combination of energy
and particle collisions could generate a particle that matches the properties of dark matter.
Another experiment at CERN is called OSQAR, or the Optical Search for QED Vacuum Bifringence,
Axions and Photon Regeneration.
It's searching for particles known as axions, which could be a candidate for dark matter.
It involves firing a laser down a vacuum chamber which is exposed to an incredibly powerful
magnetic field.
As the photons travel down this chamber, some of them could turn into axions.
At the end of the chamber there's a barrier.
The visible light is blocked by the barrier, but the axions should be able to pass through
this wall and then turn into photons on the other side again.
At this point, there's no concrete evidence for axions, but there are several experiments
searching for them.
A much longer vacuum chamber is in the works, and there's a counterpart to OSQAR called
the CERN Axion Solar Telescope, which is looking for axions coming from the Sun.
There's a detector on board the International Space Station called the Alpha Magnetic Spectrometer
which could be the one to discover dark matter.
In its first 5 years of operation, the instrument detected over 90 billion cosmic ray events:
protons and other particles moving at close to the speed of light.
These particles contain vastly higher energy than anything that could be produced in the
Large Hadron Collider, so they're like a natural particle accelerator.
One indication for dark matter could be the hundreds of thousands of particles of antimatter
which have already been detected by the AMS.
The source of this antimatter is still a mystery, but one idea is that it's a side effect
from particles of dark matter occasionally colliding with itself.
Perhaps the most epic particle detector is the IceCube neutrino lab, located in Antarctica.
This giant telescope is a series of detectors embedded into a glacier - it's one cubic
kilometer of ice.
When neutrinos and other particles pass through a vast volume of water, they can occasionally
interact and release a cascade of particles.
IceCube has been one of the most important instruments for physicists, setting limits
on the mass of particles that dark matter could be.
At this point, scientists still don't know what dark matter is.
But with dozens of experiments, they're continuing to search, and better narrowing
down what it can't be.
At some point in the future, we can look back at this search with a definitive answer.
I really enjoy a mystery, and being a journalist gives me a chance to watch the search for
dark matter unfold, day after day, as ideas are tested, falsified, rejected, and replaced.
This is science.
This is how it works, and the journey is as important as the destination.
What do you think?
Let me know your thoughts in the comments.
Once a week I gather up all my space news into a single email newsletter and send it
out.
It's got pictures, brief highlights about the story, and links so you can find out more.
Go to universetoday.com/newsletter to sign up.
All of my videos are also available in handy audio and video podcast formats so you can
have our latest episodes show up right on your audio device.
Go to universetoday.com/audio or universetoday.com/video to get the one you want.
And I'll put the links in the shownotes.
And finally, here's a playlist.
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6- His walk | responding to Wilders' #MuhammadCartoonContest | Fadel Soliman - Duration: 0:39.
For more infomation >> 6- His walk | responding to Wilders' #MuhammadCartoonContest | Fadel Soliman - Duration: 0:39. -------------------------------------------
17- His sentimentality | responding to Wilders' #MuhammadCartoonContest | Fadel Soliman - Duration: 0:39.
For more infomation >> 17- His sentimentality | responding to Wilders' #MuhammadCartoonContest | Fadel Soliman - Duration: 0:39. -------------------------------------------
FORTNITE Tomato Challenge IRL - The NEW Ice bucket challenge - Duration: 5:30.
hey you what's going on guys it's Finn's
here wpg and we played games Network and
we're back with an amazing amazing
amazing video I hope you guys like it
it's the challenge Oh
challenges stick around you're gonna
find out more about it you gotta love it
you're gonna love it
hey guys welcome back all right now
you're probably wondering where robox
channel what do we got for tonight
up on the screen well you know I play
for tonight you know I love for tonight
you know I love watching for tonight
and this is a fortnight face challenge
and please guys stick around to the end
find out all information it's gonna be
amazing it's an amazing amazing
challenge within an amazing goal in mind
so let's go ahead and talk about it real
quick so this is for tonight as you can
see we got the praise the tomato and
moat up on the screen now what is it man
if you don't know what it is man you've
been living under a rocket this is the
praise the tomato ammo wait for it oh
poor dude poor dear poor dude
but guys so this challenge was brought
to us by mustard plays if you don't know
muster place and mustard man I don't
want to put too much information out
there but this dude is an amazing
family-friendly fortnight streamer kind
ID you know I don't want to throw too
much info out there but his brother is
actually the I believe the director of
creative operations for Epic Games which
is very cool very cool
and mustard love to play for tonight
family-friendly streaming and he brought
this challenge out today and I'm reading
this information off of Twitter here I
mean you probably read it already but
today I'm starting a new challenge for a
charity I'm calling it a boat night
tomato challenge and hoping we can help
raise money to fight cancer and have
some fun reenacting the praise the
tomato mote from 49 more details can be
found here I recommend you guys check
them out on Twitter
go to the link subscribe to his channel
this will take you directly to a video
on his channel and here's a little
preview of what we got to look forward
to
oh man I'm the face right in the face is
amazing bro who's amazing so there are a
little there's there's a little more to
the challenge so first off here's out
worst like he says you don't want to
pick a cancer charity to donate whatever
amount you can he did only $25 to the
American Cancer Society but he says
whatever amount you can and whatever
cancer charity is gonna work guys
secondly make a video of you doing the
praise of tomato mote from fortnight and
post the video to one or all of your
social medias and you know it's got to
get the word out right three challenge
at least five friends to do the
challenge to be sure to tag them in the
post oh I definitely will actually I'll
go ahead and call some people out right
now I wouldn't say that we are friends
but hey I know some guys out there
pretty big roblox youtubers that play
for tonight actually have some pretty
big 49 channels let's call them out
right now
Nick store very I know you're for
tonight channels been blowing up
recently bro love to see you do the
challenge rink your boss bro you want to
be a boss you got a fortnight channel
let's see what you got man there's a
couple other guys I know that would be
interested I'll let all these roblox
youtubers if you guys are interested
doing this man we'd love to see some
challenge videos I know a lot of you
play fortnight those are just two I'll
tag some more in my post now he has
challenged his brother Donald muster and
like I said that is the let's see what
he says
worldwide great of director of epic game
amazing he's also challenging some very
cool fortnight youtubers if you guys are
know I'm a seven sterling Upshaw stellar
will a bunch of other guys and Daryl
Eastern anyway guys without further ado
I know that I'm taking a lot of time
we're gonna go ahead and go right into
it
here's my fortnight tomato challenge
hope you guys enjoy
alright guys I hope you enjoyed the
video it was a good time for an amazing
cause
mustard plays bro you got great ideas if
you guys like I said if he doesn't know
mustard definitely go check him out I'm
gonna leave a link to his Twitter and
his YouTube channel down below as well
as I'm gonna leave a link to cancer or
Gore I mean there it is the American
Cancer Society webpage if you're
interested in donating
once again you can donate any amount I'd
love to see some video submissions broke
calling you Wow
you know who I'm talking about man I'm
calling you guys out get on in there and
get some video submissions if you guys
happen to be new to the channel man
what's up my name is Vince WB GN blue
the games Network
don't hesitate to subscribe smash that
like one if you liked the video and if
you guys would make sure and check out
these videos right over here thank you
guys have a wonderful day
peace
you
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