It's useless science Friday in my head - Welcome to the show.

[Strychnine]

the resolution just isn't possible yet

No, really. Not possible.

Light dims over distance according to the inverse square law: "The energy twice as far from the source is spread over four times the area"




Dimmer light = fewer photons at the viewer, so think about it like this:




I did some math for you. To see dinosaurs you would need to go a minimum of 65 million light years away. Compare the light intensity of the Earth from the surface of the Moon to what you would get on this faraway planet...




At that distance you'll have 0.000000000000000000000000000039125 times fewer protons to capture. That's so far beyond any needle in a haystack situation just to get ONE photon...
Beyond the Earth just reflects light, it doesn't produce it, and it's fairly close to a really bright source of light, so good luck even seeing anything that's not the Sun when you point your impossibly large telescope this way.


FWIW, this is how Hubble sees an entire galaxy from 60 million light years away. It measures 45,000 light years across and is really just a fuzzy glow.

[Grimpala]

..

From what I gather it would never be possible due to the scattering/diffusion of the light particles as they traveled away.

The 1.3 billion year old signals weren't light, they were gravitational, something that can be physically detected, whereas the light would be too diffuse to assemble a discernible picture of dinosaurs.

[Grimpala]

You'll never travel anywhere near an appreciable fraction of the speed of light because of Special Relativity and that pesky exponent in E=mc^2. So really you'd have to work out that whole wormhole situation to travel any light-year scale distance quickly. Say you do warp space and jump from one point to another you still can't trick the optics.

It's basically the same as asking, "If someone were on a planet 65+ million light years away could they see dinosaurs if they looked at Earth?" and the answer really has to be no. Light reflected from earth (or anything for that matter) is diluted over distance (following the inverse-square law) so by the time you got that far away the lens of your telescope (however large you may decide to build it) could never gather enough photons from Earth to make out anything more than a dot of dim light - the resolution just isn't possible.

Roger

[Craizie]

You'll never travel anywhere near an appreciable fraction of the speed of light because of Special Relativity and that pesky exponent in E=mc^2. So really you'd have to work out that whole wormhole situation to travel any light-year scale distance quickly. Say you do warp space and jump from one point to another you still can't trick the optics.

It's basically the same as asking, "If someone were on a planet 65+ million light years away could they see dinosaurs if they looked at Earth?" and the answer really has to be no. Light reflected from earth (or anything for that matter) is diluted over distance (following the inverse-square law) so by the time you got that far away the lens of your telescope (however large you may decide to build it) could never gather enough photons from Earth to make out anything more than a dot of dim light - the resolution just isn't possible yet.

..

[Strychnine]

Not quite as big a deal as detection of Gravity Waves, but...

In the Bernie Sanders' spirit of giving away free shit, download yourself some cool NASA/JPL retro sci-fi space travel posters.

http://www.jpl.nasa.gov/news/news.php?feature=5052

I love those. Someone on Reddit had them printed, framed, and hung in his living room.

[Strychnine]

Theoretical question.

Say we develop super high speed space travel. Could we in theory head out into space a determined distance and then turn around and observe the earth from this great distance in order to see the past?

Granted we would have to travel faster than light to get far enough ahead to do this, but in theory I could work, correct?

You'll never travel anywhere near an appreciable fraction of the speed of light because of Special Relativity and that pesky exponent in E=mc^2. So really you'd have to work out that whole wormhole situation to travel any light-year scale distance quickly. Say you do warp space and jump from one point to another you still can't trick the optics.

It's basically the same as asking, "If someone were on a planet 65+ million light years away could they see dinosaurs if they looked at Earth?" and the answer really has to be no. Light reflected from earth (or anything for that matter) is diluted over distance (following the inverse-square law) so by the time you got that far away the lens of your telescope (however large you may decide to build it) could never gather enough photons from Earth to make out anything more than a dot of dim light - the resolution just isn't possible.

[helosailor]

in theory.

Theoretically.

[Baron Von Crowder]

You sure?

in theory.

[Grimpala]

Only if you do it on a treadmill.


And, in theory, yes...it would work, theoretically.

You sure?

[helosailor]

Theoretical question.

Say we develop super high speed space travel. Could we in theory head out into space a determined distance and then turn around and observe the earth from this great distance in order to see the past?

Granted we would have to travel faster than light to get far enough ahead to do this, but in theory I could work, correct?

Only if you do it on a treadmill.


And, in theory, yes...it would work, theoretically.

[Grimpala]

http://www.sciencedaily.com/releases...0211103935.htm

Theoretical question.

Say we develop super high speed space travel. Could we in theory head out into space a determined distance and then turn around and observe the earth from this great distance in order to see the past?

Granted we would have to travel faster than light to get far enough ahead to do this, but in theory I could work, correct?

[46Tbird]

Not quite as big a deal as detection of Gravity Waves, but...

In the Bernie Sanders' spirit of giving away free shit, download yourself some cool NASA/JPL retro sci-fi space travel posters.

http://www.jpl.nasa.gov/news/news.php?feature=5052

[Strychnine]

Gravitational waves detected 100 years after Einstein's prediction

LIGO opens new window on the universe with observation of gravitational waves from colliding black holes


The plots show signals of gravitational waves detected by the twin LIGO observatories. The signals came from two merging black holes 1.3 billion light-years away. The top two plots show data received at each detector, along with waveforms predicted by general relativity. The X-axis plots time, the Y-axis strain--the fractional amount by which distances are distorted. The LIGO data match the predictions very closely. The final plot compares data from both facilities, confirming the detection.



For the first time, scientists have observed ripples in the fabric of spacetime called gravitational waves, arriving at Earth from a cataclysmic event in the distant universe. This confirms a major prediction of Albert Einstein's 1915 general theory of relativity and opens an unprecedented new window onto the cosmos.

Gravitational waves carry information about their dramatic origins and about the nature of gravity that cannot otherwise be obtained. Physicists have concluded that the detected gravitational waves were produced during the final fraction of a second of the merger of two black holes to produce a single, more massive spinning black hole. This collision of two black holes had been predicted but never observed.

The gravitational waves were detected on September 14, 2015 at 5:51 a.m. Eastern Daylight Time (09:51 UTC) by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington, USA. The LIGO Observatories are funded by the National Science Foundation (NSF), and were conceived, built, and are operated by Caltech and MIT. The discovery, accepted for publication in the journal Physical Review Letters, was made by the LIGO Scientific Collaboration (which includes the GEO Collaboration and the Australian Consortium for Interferometric Gravitational Astronomy) and the Virgo Collaboration using data from the two LIGO detectors.

Based on the observed signals, LIGO scientists estimate that the black holes for this event were about 29 and 36 times the mass of the sun, and the event took place 1.3 billion years ago. About 3 times the mass of the sun was converted into gravitational waves in a fraction of a second -- with a peak power output about 50 times that of the whole visible universe. By looking at the time of arrival of the signals -- the detector in Livingston recorded the event 7 milliseconds before the detector in Hanford -- scientists can say that the source was located in the Southern Hemisphere.

According to general relativity, a pair of black holes orbiting around each other lose energy through the emission of gravitational waves, causing them to gradually approach each other over billions of years, and then much more quickly in the final minutes. During the final fraction of a second, the two black holes collide into each other at nearly one-half the speed of light and form a single more massive black hole, converting a portion of the combined black holes' mass to energy, according to Einstein's formula E=mc2. This energy is emitted as a final strong burst of gravitational waves. It is these gravitational waves that LIGO has observed.

The existence of gravitational waves was first demonstrated in the 1970s and 80s by Joseph Taylor, Jr., and colleagues. Taylor and Russell Hulse discovered in 1974 a binary system composed of a pulsar in orbit around a neutron star. Taylor and Joel M. Weisberg in 1982 found that the orbit of the pulsar was slowly shrinking over time because of the release of energy in the form of gravitational waves. For discovering the pulsar and showing that it would make possible this particular gravitational wave measurement, Hulse and Taylor were awarded the Nobel Prize in Physics in 1993.

The new LIGO discovery is the first observation of gravitational waves themselves, made by measuring the tiny disturbances the waves make to space and time as they pass through Earth.

"Our observation of gravitational waves accomplishes an ambitious goal set out over 5 decades ago to directly detect this elusive phenomenon and better understand the universe, and, fittingly, fulfills Einstein's legacy on the 100th anniversary of his general theory of relativity," says Caltech's David H. Reitze, executive director of the LIGO Laboratory.

http://www.sciencedaily.com/releases/2016/02/160211103935.htm

[cobrajet69]

Decomposition of uranium in a cloud chamber

Not what I would have expected to see, assuming I would ever get to witness such an event.
Pretty cool none-the-less.



David

[Strychnine]

Decomposition of uranium in a cloud chamber

The chamber is filled with a supersaturated vapor of water or alcohol. If a charged particle (such as an electron or in this gif's case, an alpha particle, aka a helium nucleus) flies through it and charges the vapor molecules. These charged molecules act as a condensation site and the supersaturated vapor quickly condenses on those ions which we see as mist. Different particles leave different trails based on their size, speed, and field strength.