Visit Your Local PBS Station PBS Home PBS Home Programs A-Z TV Schedules Watch Video Support PBS Shop PBS Search PBS
 
 
TYCHO OTTESEN BRAHE
TYCHO OTTESEN BRAHE
Scania, Denmark (1546 - 1601)
Tycho Brahe was a Danish nobleman famed for his accurate and comprehensive astronomical and planetary observations. Hailing from Scania, then part of Denmark, now part of modern-day Sweden, Brahe was well known in his lifetime as an astronomer and alchemist.
 

Disfrute estos perspicaces y educacionales videoclips obtenidos de mŠs de 70 horas de entrevistas con las mŠs notables figuras en astronomŪa tomadas durante la filmaciůn del documental 400 AŮos del Telescopio.

Busque en el catŠlogo IR A     VER TODO     Mostrar 5 10 25 videos.

Encontrar videos por nombre

Robert Iliffe

Newton's recreational activities
Robert Iliffe - University of Sussex

I donít think there were punts until the 19th century, but he did pay an annual sub for something called ďbowls and bargesĒ though we donít know what they are.

PLAY VIDEO | VIEW TRANSCRIPT

Robert Iliffe

Newton's work with light
Robert Iliffe - University of Sussex

Newton seems to be very interested in light in about the second or third year of his time at Cambridge. He does experiments with his eyes which famously involve him putting objects underneath his eyeball to try and deform the shape of his eye. But he also starts looking through prisms, and one of the things he notices one day looking through a prism at a piece of thread thatís colored red at the top and blue at the bottom, is that when you look through a prism at this thread, the two parts of the thread are disaggregated Ė theyíre separated from each other. And that observation is the basis of some of his great discoveries in light.

PLAY VIDEO | VIEW TRANSCRIPT

Robert Iliffe

Newton publishes his work on light in 1672
Robert Iliffe - University of Sussex

When Newton publishes his work on light and colors in early 1672, he argues something that nobody, even the ancient Greeks and certainly not his contemporaries had believed possible, which is that white light is composed of all these different rays.

PLAY VIDEO | VIEW TRANSCRIPT

George Jacoby

Light spectra
George Jacoby - WIYN Observatory

A spectrum is the light from a star that has been broken down into its component colors.

PLAY VIDEO | VIEW TRANSCRIPT

George Jacoby

Spectrograph
George Jacoby - WIYN Observatory

The most powerful tool an astronomer can use is a spectrograph. A spectrograph breaks the light from star or galaxy, or from anything else into its component colors.

PLAY VIDEO | VIEW TRANSCRIPT

John Joyce

Lord Rosse's Birr telescope
John Joyce - Birr Historical Science Center

Iím standing in the observation car of the great telescope of Birr, called the Leviathan of Birr. It was the largest telescope in the world for 75 years. From 1845 until 1919 it was the worldís largest telescope, and it was built by the third Earl of Rosse.

PLAY VIDEO | VIEW TRANSCRIPT

John Joyce

Construction of the Birr telescope
John Joyce - Birr Historical Science Center

Lord Rosse had to spend four years working on the mirror. And it was only when he finally had a mirror that he thought suitable for a telescope he began the construction of this great telescope.

PLAY VIDEO | VIEW TRANSCRIPT

John Joyce

Lord Rosse's background
John Joyce - Birr Historical Science Center

The extraordinary thing about the Parsons is that in the nineteenth century - and this is a key to their interest in science - they were not sent away to primary school as such. They were tutored at home.

PLAY VIDEO | VIEW TRANSCRIPT

John Joyce

Lord Rosse's inspiration
John Joyce - Birr Historical Science Center

The reason why Lord Rosse built this telescope, was that two astronomers in particular, Sir William Herschel and Messier, in the late 18th century and early 19th century, had mapped approximately 7,000 areas in the northern hemisphere sky where there appeared to be some glowing illumination.

PLAY VIDEO | VIEW TRANSCRIPT

John Joyce

Specifications of Lord Rosse's Birr telescope
John Joyce - Birr Historical Science Center

When this telescope was built in 1845, it was by far the largest telescope in the world. It remained the largest in the world for seventy-five years. It wasnít until the Wilson telescope on Mount Wilson in 1919 that a larger telescope was built.

PLAY VIDEO | VIEW TRANSCRIPT

Lawrence Krauss

Einstein's blunder
Lawrence Krauss - Arizona State University

Shortly after Einstein had developed his general theory of relativity, there was a problem. Itís the same problem that Newtonís law of gravity has, and any physics student knows that gravity sucks. It always pulls, it never pushes.

PLAY VIDEO | VIEW TRANSCRIPT

Lawrence Krauss

Empty space has energy
Lawrence Krauss - Arizona State University

Now, if you ask how much energy empty space could have, if you asked a four-year-old how much energy empty space should have, the four-year-old would say Ďnoneí. A good answer except the four-year-old hasnít taken quantum mechanics. And the point is that when you allow quantum mechanics to work together with relativity, empty space isnít empty at all.

PLAY VIDEO | VIEW TRANSCRIPT

Lawrence Krauss

Energy density and our existence
Lawrence Krauss - Arizona State University

The fact that the energy of empty space is almost equal to the energy density of everything else in the universe today is, from a fundamental physics perspective, completely inexplicable. We donít understand it. And that has caused some people to think of an extreme solution. A solution which, if itís right, is equally depressing, at least to many physicists like myself.

PLAY VIDEO | VIEW TRANSCRIPT

Lawrence Krauss

Expanding dark energy in an expanding universe
Lawrence Krauss - Arizona State University

The weird thing is that, if empty space is expanding exponentially as it does due to this repulsion produced by dark energy, and if empty space maintains a constant amount of energy per unit volume, and the volume is increasing, then it appears that youíre violating the law of conservation of energy Ė the total energy of the universe seems to be growing exponentially.

PLAY VIDEO | VIEW TRANSCRIPT

Lawrence Krauss

Further observations on dark energy
Lawrence Krauss - Arizona State University

The discovery of dark energy was amazing. Now the question that really matters is, what is the dark energy? Is it a cosmological constant, like Einstein predicted, or is it some weird energy of empty space thatís changing in time and then may go away? The reason we care is that - first of all from a fundamental physics perspective - itís vitally important to know if empty space fundamentally has energy or if this is just some transient that is going to go away.

PLAY VIDEO | VIEW TRANSCRIPT

Lawrence Krauss

How I came to my conclusions on dark energy
Lawrence Krauss - Arizona State University

When dark energy was first discovered Ė experimentally, observationally Ė it was discovered by looking at distant exploding stars and measuring, using them to determine the distance to distant galaxies and then measuring their speed and seeing that the expansion of the universe is speeding up.

PLAY VIDEO | VIEW TRANSCRIPT

Lawrence Krauss

The enigma of dark energy
Lawrence Krauss - Arizona State University

One of the greatest revolutions in cosmology in the 20th century, if not in the entire history of cosmology, has been the discovery of what we call dark energy.

PLAY VIDEO | VIEW TRANSCRIPT

Lawrence Krauss

Is our view of the universe right or wrong?
Lawrence Krauss - Arizona State University

The amazing thing is, our picture of the universe has changed a lot. So you could ask, 'could everything we know today be wrong?' And the answer is, potentially, yes.

PLAY VIDEO | VIEW TRANSCRIPT

Lawrence Krauss

IYA Greeting
Lawrence Krauss - Arizona State University

Well, welcome to 2009, and the 400th anniversary of the invention of the telescope, which represented for me what science is all about.

PLAY VIDEO | VIEW TRANSCRIPT

Lawrence Krauss

The large scale universe
Lawrence Krauss - Arizona State University

In the far, far future, when dark energy dominates the universe completely, all the galaxies that we now see will have moved so far away that we canít see them Ė theyíll be moving faster than the speed of light away from us and the rest of the universe will literally disappear and we will live in an island universe.

PLAY VIDEO | VIEW TRANSCRIPT

Lawrence Krauss

Why I became a cosmologist
Lawrence Krauss - Arizona State University

So my interest initially was in elementary particle physics, the fundamental structure of matter. And what I ultimately realized was that the universe might be the only laboratory that could ultimately tell us about the fundamental structure of matter. And the bridge at that time was dark matter.

PLAY VIDEO | VIEW TRANSCRIPT

Ed Krupp

Artificial lights and moving to cities
Ed Krupp - Griffith Observatory

People still sense a bond to the sky and itís easy to see it. All you have to do is to go out into a dark sky with someone again, let the stars come out, and theyíre astonished.

PLAY VIDEO | VIEW TRANSCRIPT

Ed Krupp

Light and shadow at Chichen Itza
Ed Krupp - Griffith Observatory

Over the last couple of decades, an extraordinary amount of worldwide interest has been directed at Chichen Itza in northern Yucatan in Mexico, a late Maya site where the Castillo, or the temple of Kukulcan, the feathered serpent god, seems to develop a pattern of light and shadow on the balustrade of its north stairway in the last hour or so before sunset.

PLAY VIDEO | VIEW TRANSCRIPT

Ed Krupp

The Copernican Revolution
Ed Krupp - Griffith Observatory

In a sense that transformation of perspective has already occurred. It occurred when we first went into space with the very first satellite, and has continued through our further efforts at exploring space both with instruments and of course with ourselves out there on the moon or in the International Space Station, and whatever is yet to come. That has precipitated major changes in the way that we look at the universe and ourselves.

PLAY VIDEO | VIEW TRANSCRIPT

Ed Krupp

Galileo and the telescope
Ed Krupp - Griffith Observatory

When Galileo first pointed a telescope at the sky and saw craters on the moon, and moons around Jupiter, and phases of Venus, it changed everything.

PLAY VIDEO | VIEW TRANSCRIPT

« 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 »

La PelŪcula | Video | Para Maestros | GuŪa de Programaciůn | Noticias | Programa Planetario
BoletŪn | Calendario IYA | Recursos | Glosario | ContŠctenos | Mapa del Sitio

© 2009 Interstellar Studios. All rights reserved.