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Τετάρτη 30 Δεκεμβρίου 2015

What Is the Gemini Planet Imager (GPI)

                





What Is the Gemini Planet Imager (GPI)

Δημοσιεύτηκε στις 12 Νοε 2015
What
is GPI? A video describing the GPI project and recent results obtained
with the instrument (credit: F. Marchis, D. Futselaar, H. Marchis)
ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 30/12/2015





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How to survive a trip to Mars - SETIcon 2 Panel

                      

How to survive a trip to Mars - SETIcon 2 Panel



Δημοσιεύτηκε στις 2 Οκτ 2015
Featuring SETI Institute scientists Nathalie Cabrol, Pascal Lee and Margaret Race
ANAΡΤΗΣΗ ΑΠΟ ΤO YOUTUBE 30/12/2015












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Δευτέρα 28 Δεκεμβρίου 2015

Brian Greene: Time Travel is Possible | BEST OF 2015

                       



Brian Greene: Time Travel is Possible | BEST OF 2015

Δημοσιεύτηκε στις 25 Δεκ 2015
Is
the time we experience in our day-to-day lives real? Theoretical
physicist Brian Green explores the potential particles of time and why
we could, in theory, travel forward in time but not back.

Read more at BigThink.com: http://bigthink.com/videos/time-travel

Follow Big Think here:
YouTube: http://goo.gl/CPTsV5
Facebook: https://www.facebook.com/BigThinkdotcom
Twitter: https://twitter.com/bigthink

Transcript
- We know a lot about time. We know that time in some sense is at rock
bottom that which allows change to take place, right. When we say that
time has elapsed we notice that because things now are different from
how they were a little while ago. That’s what we mean by time elapsing.
But is time some fundamental quality of reality or is it something that
our brains impose on our perceptions to organize our experience into
some coherent framework that allows us to survive. I mean I can well
imagine that we have been under evolutionary pressure over the millennia
to organize perception so that we can survive, get the next meal, plan
for the future. All of that would seemingly require that we have a
conception of time that we apply to what we experience out there. But
that doesn’t mean time as we experience it is real. It doesn’t mean that
time as we experience it is how the world is actually structured. I
mean there are many ideas that people put forward. The possibility for
instance that, you know, we all know that matter is made of molecules
and atoms. Could it be that time is also made of some kind of
ingredient? A molecule of time? An atom of time? Is that really what
time is at a fundamental level?

Time travel is absolutely
possible. And this is not some sort of weird sci-fi thing that I’m
talking about here. Albert Einstein taught us more than 100 years ago
that time travel is possible if you’re focusing upon time travel to the
future. And I’m not referring to the silly thing that we all age, right.
We’re all going into the future. Sure, I’m talking about if you wanted
to leapfrog into the future, if you wanted to see what the Earth will be
like a million years from now, Albert Einstein told us how to do that.
In fact he told us two ways of how to do it. You can build a spaceship,
go out into space near the speed of light, turn around and come back.
Imagine you go out for six months and you turn around and you come back
for six months. You will be one year older. But he taught us that your
time is elapsing much slower than time back on Earth. So when you step
out of your ship you’re one year older but Earth has gone through many,
many years. It can have gone through 10,000, 100,000 or a million years
depending on how close to the speed of light you traveled.

And he
also taught us if you go and hang out near the edge of a black hole
time again will elapse more slowly for you at the edge of the black hole
than back on Earth. So you hang out there for a while, you come back
and again you get out of your ship and it will be any number of years
into the future, whatever you want all depending on how close you got to
the edge of the black hole and how long you hung out there. That is
time travel to the future. Now of course what people really want to know
about is getting back. Can you travel back to the past? I don’t think
so. We don’t know for sure. No one has given a definitive proof that you
can’t travel to the past. In fact, some very reputable scientists have
suggested ways that you might travel to the past. But every time we look
at the proposals and detail it seems kind of clear that they’re right
at the edge of the known laws of physics. And most of us feel that when
physics progresses to a point that we understand things even better,
these proposals just will be ruled out, they won’t work. But I guess I
would say there’s a long shot possibility based on what we know today
that time travel to the past might be possible. But most of us wouldn’t
bet our life on it.

Directed / Produced by Jonathan Fowler, Elizabeth Rodd, and Aaron Lehmann
ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 29/12/2015






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4th Generation Nuclear Weapons

                            



4th Generation Nuclear Weapons

Δημοσιεύτηκε στις 16 Δεκ 2013

Like me on Facebook,
https://www.facebook.com/Enigmahood

Follow me on Twitter,
https://twitter.com/EnigmaHood

This
is an overview of the 4th generation of nuclear weapons outlined in the
report, Fourth Generation Nuclear Weapons: Military effectiveness and
collateral effects, condensed into an easy to digest video.

Full report click here,
http://arxiv.org/abs/physics/0510071v5

FAQ:
Q: In a nutshell what is a Fourth Generation Nuclear Weapon (FGNW)?
A:
It is a nuclear fusion weapon that doesn't use a fission trigger. The
most feasible method to trigger fusion in a FGNW is to use microscopic
amounts of anti-matter.

Q: What advantages do FGNWs have over conventional nukes?
A:
They are "clean" (radioactive fallout negligible, about on par with
conventional depleted uranium weapons that are already in use), they are
very small (potentially can fit in your pocket), and fill in the "yield
gap" between the most powerful conventional weapons and the lowest
yield conventional nukes.

Q: Will FGNWs really be more politically acceptable to use in actual combat?
A: Who knows? Only time can tell for certain, but their "radioactive cleanness" is a compelling argument in favor for it.

Q: What would be the TNT equivalent of a FGNW be?
A: A 3 gram pellet of fusion fuel would release around 302 gigajoules of energy (about 72 tons of TNT), so around that.

Q: How much antimatter is needed to catalyze a single FGNW?
A: A 3 gram pellet of fusion fuel would need 1x10^11 antiprotons to catalyze nuclear fusion

Q: Isn't carrying antimatter dangerous? What would happen if containment failed?
A:
The quantity of antimatter is extremely small. 1x10^11 antiprotons
would release the equivalent of about 6 milligrams of TNT, that's less
than a firecracker. However the energy would be released in the form of
ionizing radiation so it would be a radiological hazard if containment
failed.

Q: Wouldn't failure of antimatter containment result in the FGNW detonating?
A:
No, nuclear fusion requires very precise injection of antimatter to
catalyze fusion. Failure of containment would not result in the precise
injection of antimatter to the fusion fuel. Added safety measures can be
taken by separating the fusion fuel from the antimatter containment
until the weapon is ready to be armed.

Q: If you accidentally drop it, wouldn't containment fail?
A:
These weapons are intended to be incredibly rugged with one of their
applications being bunker busters. They contain little to no moving
parts and are "full like eggs". The FGNW report indicates that the
overall ruggedness would be far superior over conventional nuclear
bunker busters so no, simply dropping it wouldn't cause containment to
fail.

Q: Wouldn't FGNWs be attractive for nuclear terrorism?
A:
No, it's easier to build conventional nuclear weapons. FGNWs require
extremely large particle accelerators to manufacture the antimatter
necessary for the FGNW. A terrorist who wants a suitcase nuke is better
off with something like the M-388 Davy Crockett.

Q: Are FGNW a proliferation concern?
A: No, see above.

Q: Why not make pure anti-matter weapons instead?
A:
A couple of reasons. It's prohibitively expensive. It's single handedly
the most expensive substance in the world and incredibly difficult to
make. Right now, if we took all the antimatter we produced and
annihilate it, it would only be enough to power a lightbulb for a few
hours. On the other hand, fusion fuel is incredibly cheap and abundant,
you can literally make it from sea water as all it is are isotopes of
hydrogen. But even if we had large quantities of antimatter, it's
questionable how useful it would be as a weapon on its own. It's
incredibly difficult to contain as if it touches any normal matter, it
will annihilate. Containing microscopic quantities is not a problem, but
macroscopic quantities are. Even if you could contain it, it would be
incredibly unstable. Fusion and fission weapons fail safely, if you
damage a nuclear weapon the nuclear weapon doesn't detonate. An
antimatter weapon would detonate as soon as containment fails. From a
cost-benefit point of view, pure antimatter weapons do not make sense.

Q: Can you use conventional explosives to catalyze nuclear fusion?
A: No. https://en.wikipedia.org/wiki/Lawson_...
ΑΝΑΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 29/12/2015
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Nuclear Fusion 500 Terawatt Laser at the National Ignition Facility

                  



Nuclear Fusion 500 Terawatt Laser at the National Ignition Facility



Δημοσιεύτηκε στις 16 Ιουλ 2012
The
world's most powerful laser system at the National Ignition Facility at
Lawrence Livermore Labs can deliver an ultrashort laser pulse, 5x10^-11
seconds long, which delivers more than 500 trillion watts (terawatts or
TW) of peak power and 1.85 megajoules (MJ) of ultraviolet laser light
to its target.
In context, 500 terawatts is 1,000 times more power
than the United States uses at any instant in time, and 1.85 megajoules
of energy is about 100 times what any other laser regularly produces
today.

The shot validated NIF's most challenging laser
performance specifications set in the late 1990s when scientists were
planning the world's most energetic laser facility. Combining extreme
levels of energy and peak power on a target in the NIF is a critical
requirement for achieving one of physics' grand challenges -- igniting
hydrogen fusion fuel in the laboratory and producing more energy than
that supplied to the target.

The first step in achieving an
experimental fusion reaction is to induce inertial confinement of a
mixture of Deuterium and Tritium (isotopes of hydrogen) at high enough
densities so that their is a self-sustaining reaction. such a reaction
requires a large cross-section of individual nuclei which can only occur
in a high density plasma.

Various methods of achieving this
have included using the Z-Pinch Process to create high energy X-rays to
induce the confinement in fuel pellets,a so-called Z-Machine. Another
fusion method involves using a uniform plasma confined in a collapsing
magnetic field, called a Tokamak or a Toroidal Nuclear Fusion Reactor.
A
lot of experimental results have come from using high energy laser
facilities such as The National Ignition Facility, not only for fusion
physics but also in the test of nuclear weapons eliminating the need for
ground or sea tests of thermonuclear weapons; all the tests can be done
in a laser ignition facility creating minimum effects to the
environment.

For commercial Nuclear Fusion, the Tokamak Design is
the best design for achieving a self-sustaining fusion reaction by
having the toroidal field create a "bottle" of fusion plasma. Such a
reactor would have to be very large to achieve critical mass for
self-sustaining fusion and by far the International Experimental Reactor
(ITER) in France is the best facility for testing the viability of an
energy generating reactor.

Extracting the energy from the
reaction is a different matter and probably will involve the invention
of a high temperature superconducting heat exchanger or confined
superfluid technology to become an efficient source of power.

So
far the best method of heat extraction from a proposed Nuclear Fusion
Reactor Core would be an oxide alloy of a metal with a high
cross-section for gamma rays and a high melting point for absorbed
infrared; hence an alloy of Tungsten dipped into the fusion reactor
plasma is the best form of fusion heat exchanger available with current
technology.

The exploration of other fusion reactions which
utilise fuels easier to access is also another major problem in
developing an efficient fusion reaction, reactions with Helium-3 and
even a man-made Carbon-Nitrogen-Oxygen, CNO, cycle have been proposed.
Even
the use of low-energy muons to catalyse the reaction have been
proposed, though will be probably a long way off until an cost-efficient
muon generator is developed.

In NIF's laser fusion, the lasers
fired within a few trillionths of a second of each other onto a
2-millimeter-diameter target. The total energy matched the amount
requested by shot managers to within better than 1 percent.

The
interesting thing about laser fusion is that, if you make the laser
pulses short enough - on the order of a few hundred attoseconds say, you
could in principle make a laser that would skip electronic transitions
and just manipulate the nuclei of the atoms. This would mean there would
be no blast from the laser itself, just from the nuclear reactions.
This would give the highest efficiency possible of inducing fusion and
the highest level of control, since all of the radiation emitted would
be from the laser pulse.
1999 Nobel Prize in Chemistry was warded for
using femtosecond lasers to observe and control chemical reactions of
individual molecules. Imagine what progress could be done using even
shorter laser pulses to control the nuclear reactions. In the future it
may even be possible to perform subatomic physics with lasers and go
beyond the Schwinger Limit and create any high energy particle we want
from the vacuum. This would replace large accelerators for particle
physics and could allow mass production of some unstable particles for
scientific use.
ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 29/12/2015










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Putting The Multiverse To The Test

                          

Putting The Multiverse To The Test



Δημοσιεύτηκε στις 20 Ιουλ 2014
Perimeter
Associate Faculty member Matthew Johnson explains the related concepts
of inflation, eternal inflation, and the multiverse. The multiverse
hypothesis, he argues, is more than metaphysics -- the idea that there
might be other universes can be scientifically tested.

For the FQXi "Show Me the Physics" Video Contest: #FQXiVideoContest2014

For more information: http://ow.ly/zf1VQ
ANAΡΤΗΣΗ ΑΠΟ ΤΟ  ΥOUTUBE 29/12/2015










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Κυριακή 27 Δεκεμβρίου 2015

"Quantum Singularity" Hologram - Particle to Micro Black Hole

                 

"Quantum Singularity" Hologram - Particle to Micro Black Hole





Δημοσιεύτηκε στις 19 Δεκ 2015
An
interesting hologram illusion showing a quantum particle collapsing in
on itself and forming a micro black hole - a very eye-catching display!
Compatible with smartphones and tablets. working with an upside or
downside facing "hologram" projector unit.
ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 27/12/2015




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What Happened This Year @NASA December 21, 2015

                      

What Happened This Year @NASA December 21, 2015

Δημοσιεύτηκε στις 21 Δεκ 2015
In
2015, NASA explored the expanse of our solar system and beyond, and the
complex processes of our home planet, while also advancing the
technologies for our journey to Mars, and new aviation systems as the
agency reached new milestones aboard the International Space Station.
Here’s a look at some of the top NASA stories of the year!
ANAΡΤΗΣΗ ΑΠΟ ΤΟ ΥΟUTUBE 27/12/2015











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Σάββατο 26 Δεκεμβρίου 2015

NASA TV Public

            



NASA TV Public



Ξεκίνησε στις 2015-12-20 21:29:33-08:00

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Παρασκευή 25 Δεκεμβρίου 2015

The quandary of the quark

                







The quandary of the quark

Δημοσιεύτηκε στις 10 Δεκ 2013

Rosalind
Franklin Prize Lecture by Professor Christine Davies, The University of
Glasgow. Professor Davies will describe how the properties of the quark
are now being revealed, and the implications that this will have for
our understanding of the physics of fundamental particles.

Filmed at 6.30pm -- 6.30pm on 06 December 2005 at The Royal Society, London
For more information visit http://royalsociety.org/events/2005/q...


ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 26/12/2015
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Quarks and leptons for beginners

               



Quarks and leptons for beginners





Δημοσιεύτηκε στις 28 Μαρ 2014
An
explanation of the range of particles in the families of quarks and
leptons and an introduction to the way quarks exist together to make up
other particles such as hadrons.
Free notes can be copied from here:
http://www.fizzics.org/Pages/Atoms-an...
A prequel video Bosons and Fermions for beginners is here
https://youtu.be/xNrTry27lC4
ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 26/12/2015
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Higgs, Graviton, Weak Bosons, Photon, Gluon, Nuetron, Nuetrino, Proton, ...

                       

Higgs, Graviton, Weak Bosons, Photon, Gluon, Nuetron, Nuetrino, Proton, ...





Δημοσιεύτηκε στις 20 Ιουλ 2014
It
is the Gauge Boson, The Force Carrier - For Electromagnetism, It has no
mass, no electric charge, no weak charge, no color charge, It is the
epitome of almost nothing at all, but yet everything we do in our
everyday lives, From moving a mouse to running in the park requires its
mediation. It is just one of the mant remarkable objects described in
this series - Is it Force or is it Matter?

HD and 3D

Twitter - https://twitter.com/STARGAZERNATION
On Tumblr: http://stargazernation.tumblr.com/
Blogspot - http://stargazernation.blogspot.co.uk/
On Pinterest: http://www.pinterest.com/Stargazernat...







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Πέμπτη 24 Δεκεμβρίου 2015

Blood pressure drugs rethink urged

Blood pressure drugs rethink urged

By Smitha Mundasad Health reporter
  • 24 December 2015
  • From the section Health
 blood pressure - file picture
Image copyright Thinkstock
More lives could be saved if doctors considered giving blood pressure drugs to all patients at high risk of heart disease - even if their blood pressures are normal, a study suggests.
The report calls for a move away from current guidelines which recommend pills only be prescribed if blood pressure is above a certain threshold.
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Weight loss surgery 'cuts risk' of diabetes and heart attacks

Weight loss surgery 'cuts risk' of diabetes and heart attacks

By Michelle Roberts Health editor, BBC News online
  • 23 December 2015
  • From the section Health
Insulin injection


Image copyright SPL

Weight-loss surgery can cut the risk of diabetes and heart attacks as well as keep fat off, a UK study suggests.
It is the largest comprehensive investigation of bariatric surgery - spanning around four years in nearly 8,000 patients.
The health benefits of the surgery are clear and substantial for people who are severely overweight, the authors told PLoS Medicine.
They say 1.4m people in England could benefit.
Currently, around 8,000 people a year receive the treatment on the NHS.
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Nature: Οι δέκα σημαντικότερες εξελίξεις στην Επιστήμη το 2015

Nature: Οι δέκα σημαντικότερες εξελίξεις στην Επιστήμη το 2015

O απολογισμός της χρονιάς έγινε και οι πρωταγωνιστές του χώρου ανέβηκαν στο βάθρο
ΔΗΜΟΣΙΕΥΣΗ:  17/12/2015 17:56
Nature: Οι δέκα σημαντικότερες εξελίξεις στην Επιστήμη το 2015
H Συμφωνία του Παρισιού για το κλίμα αναγνωρίζεται από το Nature ως η σημαντικότερη εξέλιξη του 2015


Λονδίνο 
Στον παραδοσιακό, ετήσιο απολογισμό του, το κορυφαίο περιοδικό Nature παρουσιάζει τις δέκα σημαντικότερες εξελίξεις στην Επιστήμη για την χρονιά που φεύγει και τιμά τα πρόσωπα που αναδείχτηκαν πρωταγωνιστές στο χώρο τους.
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Appearances of the Refsdal supernova

               





Appearances of the Refsdal supernova

Δημοσιεύτηκε στις 16 Δεκ 2015
This
video shows the three appearances of the Refsdal supernova in the
galaxy cluster MACS J1149.5+2223. Calculations showed that the first
image of the supernova appeared in 1998 — an event not observed with a
telescope. The second image produced an almost perfect Einstein Cross,
which was observed in November 2014 (heic1505). The latest appearance
was observed by the NASA/ESA Hubble Space telescope on 11 December 2015,
as correctly predicted by seven different models.

The positions
of all three events are highlighted in this video with animated
supernovae, even though the Einstein Cross event is also visible in the
original image.

More information and download options: http://www.spacetelescope.org/videos/...

Credit:
ESA/Hubble , Music: Johan B Monell
ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 24/12/2015
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MACS J1149.5+2223

               



MACS J1149.5+2223



Δημοσιεύτηκε στις 16 Δεκ 2015
Many
stars end their lives with a with a bang, but only a few of these
stellar explosions have been caught in the act. When they are, spotting
them successfully has been down to pure luck — until now. On 11 December
2015 astronomers not only imaged a supernova in action, but saw it when
and where they had predicted it would be. The supernova, nicknamed
Refsdal, has been spotted in the galaxy cluster MACS J1149.5+2223. While
the light from the cluster has taken about five billion years to reach
us, the supernova itself exploded much earlier, nearly 10 billion years
ago. Refsdal’s story began in November 2014 when scientists spotted four
separate images of the supernova in a rare arrangement known as an
Einstein Cross around a galaxy within MACS J1149.5+2223. The cosmic
optical illusion was due to the mass of a single galaxy within the
cluster warping and magnifying the light from the distant stellar
explosion in a process known as gravitational lensing. These multiple
images of the galaxy presented a rare opportunity. As the matter in the
cluster — both dark and visible — is distributed unevenly, the light
creating each of these images takes a different path with a different
length. Therefore the images of the host galaxy of the supernova are
visible at different times. Using other lensed galaxies within the
cluster and combining them with the discovery of the Einstein Cross
event in 2014, astronomers were able to make precise predictions for the
reappearance of the supernova. Their calculations also indicated that
the supernova appeared once before in a third image of the host galaxy
in 1998 — an event not observed by any telescope. To make these
predictions they had to use some very sophisticated modelling
techniques. Since the end of October 2015 Hubble has been periodically
peering at MACS J1149.5+2223, hoping to observe the unique rerun of the
distant explosion and prove the models correct. On 11 December Refsdal
finally made its predicted, but nonetheless showstopping, reappearance.
The detection of Refsdal’s reappearance served as a unique opportunity
for astronomers to test their models of how mass — especially that of
mysterious dark matter — is distributed within this galaxy cluster.
Astronomers are now eager to see what other surprises the ongoing Hubble
Frontier Fields programme will bring to light.
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Η έκρηξη σουπερνόβα σε επανάληψη

Η έκρηξη σουπερνόβα σε επανάληψη

Ξανά και ξανά είδαν οι επιστήμονες το ίδιο σουπερνόβα σαν να έπαιζαν με την ροή του χρόνου
ΔΗΜΟΣΙΕΥΣΗ:  17/12/2015 14:40
Η έκρηξη σουπερνόβα σε επανάληψη


Βοστόνη, Μασαχουσέτη 
Φανταστείτε να βλέπατε το ίδιο συμβάν να επαναλαμβάνεται μπροστά στα μάτια σας ξανά και ξανά, σαν να παίζει κανείς με τη ροή του χρόνου. Κι όμως, αυτό ακριβώς κατάφερε μια ομάδα αστρονόμων, η οποία προέβλεψε πού και πότε θα μπορούσε να ξαναδεί την έκρηξη του ίδιου σουπερνόβα στον ουρανό.
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Από «ξηρό πάγο» τα ρυάκια του Άρη;

Από «ξηρό πάγο» τα ρυάκια του Άρη;

Από παγωμένο διοξείδιο του άνθρακα ίσως έχουν δημιουργηθεί τα φημισμένα ρυάκια του κόκκινου πλανήτη, σύμφωνα με γάλλους επιστήμονες
ΔΗΜΟΣΙΕΥΣΗ:  22/12/2015 13:10
Από «ξηρό πάγο» τα ρυάκια του Άρη;
Οι γάλλοι επιστήμονες υποστηρίζουν ότι οι διαδικασίες ξηρού πάγου ίσως έχουν παίξει σημαντικότερο ρόλο ως προς την εξέλιξη της αρειανής επιφάνειας από ό,τι προηγουμένως πιστευόταν


 
Τα διάσημα πλέον ρυάκια που αυλακώνουν την επιφάνεια του 'Αρη, δεν έχουν κατ' ανάγκη δημιουργηθεί από τρεχούμενο νερό, αλλά μπορεί να προέρχονται από «ξηρό πάγο», δηλαδή από παγωμένο διοξείδιο του άνθρακα, σύμφωνα με μια εναλλακτική εξήγηση γάλλων επιστημόνων.
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Αθέατοι κομήτες «απειλούν τη Γη»

Αθέατοι κομήτες «απειλούν τη Γη»

Είναι πιο επικίνδυνοι για τον πλανήτη από ό,τι οι αστεροειδείς σύμφωνα με βρετανούς αστρονόμους
ΔΗΜΟΣΙΕΥΣΗ:  23/12/2015 16:03
Αθέατοι κομήτες «απειλούν τη Γη»
Η Φοίβη, ένα μικρό φεγγάρι του Κρόνου, πιστεύεται ότι είναι «κένταυρος» που αιχμαλωτίστηκε από το βαρυτικό πεδίο του πλανήτη (Φωτογραφία: NASA/JPL-Caltech/Space Science Institute )


Λονδίνο 
Μεγάλοι κομήτες που κινούνται σε ασταθείς τροχιές στη μεθόριο του Ηλιακού Συστήματος, και είναι συνήθως αόρατοι, απειλούν τη Γη περισσότεροι από ό,τι οι αστεροειδείς, στους οποίους εστιάζονται μέχρι σήμερα τα προγράμματα πλανητικής προστασίας.
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«Αντίο, Εγκέλαδε»!

«Αντίο, Εγκέλαδε»!

Το διαστημικό σκάφος «Cassini», που εξερευνά το σύστημα του Κρόνου, πέρασε το Σάββατο για τελευταία φορά κοντά από τον Εγκέλαδο, τον δεύτερο μετά τον Τιτάνα πιο ενδιαφέροντα δορυφόρο του Αρχοντα του Δαχτυλιδιών
ΔΗΜΟΣΙΕΥΣΗ:  22/12/2015 05:00
«Αντίο, Εγκέλαδε»!
Την τελευταία του επίσκεψη στον Εγκέλαδο έκανε το «Cassini» στις 19 Δεκεμβρίου.

 
Το διαστημικό σκάφος «Cassini» από το 2004 εξερευνά το σύστημα του Κρόνου. Το 2005 το «Cassini» έφτασε στον Εγκέλαδο, έναν μικρό παγωμένο δορυφόρο του πλανήτη. Το «Cassini» ανακάλυψε ότι από το νότιο ημισφαίριο του δορυφόρου πίδακες υλικού ξεπηδούσαν με ορμή στο Διάστημα. Εκτοτε το «Cassini» συνέχισε να κάνει τακτικές επισκέψεις στον Εγκέλαδο αποκαλύπτοντας την παρουσία γκέιζερ που λειτουργούν με τρόπο παρόμοιο με τα γκέιζερ της Γης.
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Ξανάρχισε η παραγωγή πλουτωνίου στις ΗΠΑ


 

Ξανάρχισε η παραγωγή πλουτωνίου στις ΗΠΑ

Προορίζεται για πυρηνικές μπαταρίες της NASA που πρόκειται να συνοδεύσουν μελλοντικές διαστημικές αποστολές
ΔΗΜΟΣΙΕΥΣΗ:  23/12/2015 18:12
Ξανάρχισε η παραγωγή πλουτωνίου στις ΗΠΑ
Το πλουτώνιο-238 κυριολεκτικά λάμπει λόγω της θερμότητας που εκπέμπει ασταμάτητα


Ουάσινγκτον 
Έπειτα από προειδοποίηση της NASA για έλλειψη καυσίμων που απειλεί σημαντικές διαστημικές αποστολές, το αμερικανικό υπουργείο Ενέργειας ετοιμάζεται να παραδώσει την πρώτη ποσότητα πλουτωνίου-238 που παράγεται στις ΗΠΑ εδώ και 26 χρόνια.

Σε αποστολές που φτάνουν σε μεγάλες αποστάσεις από τον Ήλιο, εκεί όπου οι ηλιακοί συλλέκτες δεν επαρκούν, η μόνη ικανοποιητική πηγή ενέργειας είναι οι λεγόμενες «θερμοηλεκτρικές γεννήτριες ραδιοϊσοτόπων», ή RTG.
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Calculate + Observe: Fundamental Physics in the 21st Century: Nima Arkan...

            

Calculate + Observe: Fundamental Physics in the 21st Century: Nima Arkan...

Δημοσιεύτηκε στις 3 Ιουλ 2015
ANAΡΤΗΣΗ ΑΠΟ ΤΟ  ΥOUTUBE 24/12/2015




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Calculate + Observe: Fundamental Physics in the 21st Century: Nima Arkan...

            

Calculate + Observe: Fundamental Physics in the 21st Century: Nima Arkan...

Δημοσιεύτηκε στις 3 Ιουλ 2015
ANAΡΤΗΣΗ ΑΠΟ ΤΟ  ΥOUTUBE 24/12/2015




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The Edges of the Universe: Black Holes, Horizons and Strings: Andrew Str...

                 





The Edges of the Universe: Black Holes, Horizons and Strings: Andrew Str...

Δημοσιεύτηκε στις 3 Ιουλ 2015
ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 24/12/2015




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The Edges of the Universe: Black Holes, Horizons and Strings: Andrew Str...

                 





The Edges of the Universe: Black Holes, Horizons and Strings: Andrew Str...

Δημοσιεύτηκε στις 3 Ιουλ 2015
ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 24/12/2015




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What Every Physicist Should Know About String Theory: Edward Witten

               



What Every Physicist  Should Know About String Theory: Edward Witten



Δημοσιεύτηκε στις 1 Ιουλ 2015
ΑΝΑΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 24/12/2015
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Q&A - Under the Sea - With Helen Scales

                



Q&A - Under the Sea - With Helen Scales

Δημοσιεύτηκε στις 23 Δεκ 2015
Why
haven't octopuses evolved shells? Helen Scales answers questions from
the audience following her talk. Watch the main event here: https://www.youtube.com/watch?v=n796F...

Subscribe for regular science videos: http://bit.ly/RiSubscRibe

From
shell-stealing octopuses to snails that suck sharks’ blood, molluscs
are a weird bunch. Join marine biologist Helen Scales to find out how
hermit crabs like to party and butterflies learnt to swim. This
interactive talk dives into the spiralling world of seashells and the
bizarre animals that make them.

Helen Scales is a marine
biologist, writer and broadcaster who manages to combine scuba diving,
exploration and storytelling in one job,along with a passion for
protecting the oceans. She spends as much time as possible by the sea,
or preferably in it.

She writes books and articles and make radio
documentaries, searching for stories about the oceans and the natural
world, of the wonders of science and of people.
ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 24/12/2015


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Under the Sea - With Helen Scales

                 



Under the Sea - With Helen Scales



Δημοσιεύτηκε στις 23 Δεκ 2015
A
dive into the spiralling world of seashells and the bizarre animals
that make them. Helen Scales explains how hermit crabs like to party and
butterflies learnt to swim.
Watch the Q&A: https://www.youtube.com/watch?v=GqBHj...
Subscribe for regular science videos: http://bit.ly/RiSubscRibe

From
shell-stealing octopuses to snails that suck sharks’ blood, molluscs
are a weird bunch. Join marine biologist Helen Scales to find out how
hermit crabs like to party and butterflies learnt to swim. This
interactive talk dives into the spiralling world of seashells and the
bizarre animals that make them.

Helen Scales is a marine
biologist, writer and broadcaster who manages to combine scuba diving,
exploration and storytelling in one job,along with a passion for
protecting the oceans. She spends as much time as possible by the sea,
or preferably in it.

She writes books and articles and make radio
documentaries, searching for stories about the oceans and the natural
world, of the wonders of science and of people.

Subscribe for regular science videos: http://bit.ly/RiSubscRibe

Watch more science videos on the Ri Channel http://richannel.org
The Ri is on Twitter: http://twitter.com/ri_science
and Facebook: http://www.facebook.com/royalinstitution
and Tumblr: http://ri-science.tumblr.com/
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ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 24/12/2015


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Postcard from Baikonur: The World’s First Spaceport​

               



Postcard from Baikonur: The World’s First Spaceport​





Δημοσιεύτηκε στις 23 Δεκ 2015
A look at the history and habitat of the inhospitable home of space travel: Baikonur Cosmodrome.
Part of A Place Called Space, our 2015 advent calendar: http://rigb.org/advent
Subscribe for regular science videos: http://bit.ly/RiSubscRibe

In
a hostile natural environment environment, and over 400 km away from
the original ‘Baikonur’ in a place first called Tyuratam, Baikonur
Cosmodrome has a special place in space travel history. It has been the
launch site of hundreds of missions off our planet, from Sputnik, Laika
and Gagarin and to Tim Peake.

As Tim Peake set sail for the ISS,
2003 Christmas Lecturer Monica Grady was there to watch the launch. We
take a look at the history of the enigmatic town that is the home of
space travel.

‘A Place Called Space’ is the 2015 Royal
Institution advent calendar. Every day in the run up to Christmas we'll
be releasing an original piece of content exploring the human experience
and cultural significance of space travel. With hand-drawn animations,
experiments in zero gravity, interviews with astronauts and creative
data visualisations, the calendar will fire you into space every
morning.

'A Place Called Space' channels the voices of seasoned
astronauts and expert scientists through the eyes of a team of talented
animators, film-makers and artists, bringing you a thought-provoking gem
to kick-start each day.
Check it out at http://rigb.org/advent

With special thanks to our lead supporter, Wellcome Trust http://www.wellcome.ac.uk/

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Watch more science videos on the Ri Channel http://richannel.org
The Ri is on Twitter: http://twitter.com/ri_science
and Facebook: http://www.facebook.com/royalinstitution
and Tumblr: http://ri-science.tumblr.com/
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ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 24/12/2015






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What is String Theory? Ashoke Sen

                  



What is String Theory? Ashoke Sen



Δημοσιεύτηκε στις 3 Ιουλ 2015
ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 24/12/2015







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Τρίτη 22 Δεκεμβρίου 2015

Michio Kaku - Interplanetary space technology

                  

Michio Kaku - Interplanetary space technology



Δημοσιεύτηκε στις 2 Δεκ 2015
Michio Kaku - Interplanetary space technology will blow your mind [science docuentary 2015]
Thanks For watching!
You can see more of Dr. Michio Kaku at: https://www.facebook.com/michiokaku
https://twitter.com/michiokaku
ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 22/12/2015






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Michio Kaku - Seriously Now In Depth

                 



Michio Kaku - Seriously Now In Depth





Δημοσιεύτηκε στις 13 Οκτ 2015
Michio Kaku - Seriously Now In Depth
Thanks For watching!
You can see more of Dr. Michio Kaku at: https://www.facebook.com/michiokaku
https://twitter.com/michiokaku
ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 22/12/2015


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Δευτέρα 21 Δεκεμβρίου 2015

A Fossil from the Big Bang - Professor Joseph SIlk

                   

A Fossil from the Big Bang - Professor Joseph SIlk





Δημοσιεύτηκε στις 18 Δεκ 2015
Professor
Joseph Silk describes what we have learned about the earliest moments
of the Universe from the Cosmic Microwave Background.
You can enjoy the full lecture on our website: http://www.gresham.ac.uk/lectures-and...
Gresham
College has been giving free public lectures since 1597. This tradition
continues today with all of our five or so public lectures a week being
made available for free download from our website. There are currently
over 1,800 lectures free to access or download from the website.
Website: http://www.gresham.ac.uk
Twitter: http://twitter.com/GreshamCollege
Facebook: https://www.facebook.com/greshamcollege
Instagram: http://www.instagram/greshamcollege
ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 22/12/2015




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What Every Physicist Should Know About String Theory: Edward Witten

              

What Every Physicist  Should Know About String Theory: Edward Witten





Δημοσιεύτηκε στις 1 Ιουλ 2015
ΑΝΑΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 22/12/2015


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Ending the Epidemic: Science Advances on AIDS

                    

Ending the Epidemic: Science Advances on AIDS



Δημοσιεύτηκε στις 3 Δεκ 2015
This
program, Ending the Epidemic: Science Advances on AIDS, brings together
leading researchers on the forefront of scientific efforts to
understand and attack the virus that causes AIDS.

Moderator
Richard Besser is joined by pathologist Susan Zolla-Pazner, biologist
David Baltimore, activist Peter Staley, and researcher Robert Grant for a
conversation about the early 1980s when AIDS was an unknown killer, the
challenges activists and researchers faced trying to convince the
federal government to fund the science necessary to rein in the
epidemic, and what the future holds as the work towards a cure
continues.
Learn more about this program: http://www.worldsciencefestival.com/p...

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Visit our Website: http://www.worldsciencefestival.com/
Like us on Facebook: https://www.facebook.com/worldscience...
Follow us on twitter: https://twitter.com/WorldSciFest

Participants: Susan Zolla-Pazner, David Baltimore, Jean Ashton, Peter Staley, Robert Grant
Original Program date: May 31, 2013

AIDS: A Timeline. 00:04

Richard Besser's Introduction. 5:02

Participant Introductions. 6:07

What was it like in the early years? 8:03

The non scientific approach to HIV. 15:20

Public stigma and who gets funding. 20:33

What impact did the protests have on the scientific community? 24:45

The Voices of Aids video part 1. 32:47

Finding a vaccine for Aids, why is it so hard? 37:12

What happens when a clinical trial fails? 44:24

Could drug therapy be used to wipe out HIV? 55:13

What does the funding look like for an Aids Drug? 1:01:59

The Voices of Aids video part 2. 1:07:12

Is an end feasible?1:13:46
ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 22/12/2015






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Time Is of the Essence… or Is It?

                  





Time Is of the Essence… or Is It?





Δημοσιεύτηκε στις 6 Αυγ 2015
What
is time? Isaac Newton described it as absolute, but Einstein proved
that time is relative, and, shockingly, that time and space are
intricately interwoven. Now recent work in string theory and quantum
gravity suggests that space and time may not be fundamental. If this is
true, what new picture of reality will emerge?

Subscribe to our YouTube Channel for all the latest from WSF.
Visit our Website: http://www.worldsciencefestival.com/
Like us on Facebook: https://www.facebook.com/worldscience...
Follow us on twitter: https://twitter.com/WorldSciFest

PARTICIPANTS: David Z. Albert, Vijay Balasubramanian, Carlo Rovelli, Lee Smolin
Original Program Date: May 31, 2015

Jim Holt's introduction 00:15

Participant Introductions 02:34

What intellectual changes happened between Newton and Einstein? 04:22

How does simultaneity break down in special relativity? 09:55

Lee's 5 things to know about Special Relativity. 14:50

Does knowing what time is have any practical purpose. 19:28

Why didn't Einstein have the last word on time? 24:15

What is loop quantum theory? 29:46

Albert has different theories that isn't loop theory or string theory. 35:30

VJ metaphor about Love to explain time. 40:49

Lee and Carlo disagree over the reality of time. 42:16

Is time fundamental, and space is emergent? 51:55

Are doing we science or metaphysics? 01:01:45

David disagrees with Lee's viewpoint on time. 01:03:03

VJ and Carlo answers if this is metaphysics or physics. 01:06:23

Carlo's studies with black holes. 01:14:42
ANAΡΤΗΣΗ ΑΠΟ ΤΟ YOUTUBE 22/12/2015








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