Tag: light

38 How old is the oldest light visible from Earth? 2018-04-10T00:40:13.947

35 How do we have photos of galaxies so far away? 2017-09-10T15:53:07.167

33 Why doesn't the moon twinkle? 2016-03-09T09:27:18.143

32 What happens to the 99.9 % of the sun-rays that do not fall on any planets or any other celestial body? 2016-08-20T14:28:05.863

29 Why does the Moon appear gray when passing between the Sun and the Earth? 2016-07-26T12:38:43.577

29 If dark matter bends light, how do we know the stuff in the sky is where we think it is? 2017-01-17T15:59:13.737

28 Is the Sun visible from Proxima Centauri to human eyes? 2016-08-24T19:57:02.193

26 How did Ole Christensen Romer measure the speed of light? 2018-02-20T12:07:37.050

25 Why can't light escape from a black hole? 2013-09-24T19:14:05.603

22 Why can't we see distant galaxies with the naked eye? 2015-01-15T11:21:33.647

21 Is the light we see from stars extremely old? 2013-10-15T04:25:01.693

21 Why can't moon light (reflected sun light) turn the sky blue? 2016-03-10T08:01:49.427

18 What would the effects be on Earth if Jupiter was turned into a star? 2014-08-06T14:42:22.303

17 By putting a mirror in space, would we be able to see into the past? 2014-01-14T20:21:30.870

16 What is Gravitational Lensing? 2013-09-25T00:26:24.657

16 How can a supermassive black hole cause so much energy to enlighten its matter when its massive gravity prevents light to escape? 2016-07-18T13:40:02.400

15 Is the surface of TrES-2b actually dark? 2013-09-29T21:26:48.603

14 What is the difference between our time and space time? 2014-01-15T03:29:04.210

14 Are we still going to have rainbows if Sun is replaced by another star? 2015-12-08T15:29:22.300

13 How do scientists determine the age of stars? 2013-11-17T08:52:00.143

13 How did New Horizons take such well-lit pictures of Pluto? 2015-07-27T03:47:47.003

11 Is there a place in the known universe that there would be no visible light from other stars/galaxies? 2017-01-14T00:56:34.957

10 Can Doppler shift make colors of two stars at same distance different? 2013-12-29T07:06:46.027

10 Why is the speed of light 299,792,458 meters/sec? 2014-02-13T06:53:37.757

10 Exact measurement of a light year 2016-08-29T02:14:11.133

10 Can you see the starting and the ending of a light beam passing in the distance? 2016-12-20T17:22:21.787

9 How does light affect the universe? 2014-01-07T10:31:30.340

9 Why is twilight longer in summer than winter and shortest at the equinox 2014-05-11T11:28:11.923

9 Could light be dark matter? 2014-07-02T11:56:05.587

9 Are there stars that don't emit visible light? 2014-08-28T15:48:17.800

9 How bright is the full Earth during the lunar midnight? 2014-12-04T11:56:37.180

8 Does Sun have a reflection on Earth? 2015-06-19T16:09:47.593

8 How can I calculate the time between sunset and actual darkness? 2017-06-21T12:33:22.333

8 Is the age of the universe relative to an observer's location in that universe? 2017-09-13T00:24:46.303

8 Why do stars twinkle but the Sun doesn't (I'm asking this because the Sun is also a star) 2018-02-06T05:56:03.627

7 Does the Perseid peak cause enough light pollution to be a problem? 2013-10-01T14:01:08.270

7 Are we still in the Solar Maximus stage? Will this winter 2013/14 be a good aurora-viewing season? 2013-10-24T22:17:07.163

7 How would light from a blue or red star affect the way we see? 2014-02-24T18:59:23.883

7 How is it known that Pillars of Creation are destroyed? 2014-12-10T21:05:51.757

7 Why do some artificial satellites decrease and increase in brightness multiple times? 2015-07-25T01:47:22.633

7 Star like light moving in the sky, what could it be? 2015-08-25T00:56:27.563

7 Is Darkness Faster Than Light? 2015-12-20T04:28:55.367

6 When we say a galaxy is 200 million light years away, does this account for the expansion of space in the time it took it's light to reach us? 2014-01-09T20:45:06.780

6 Does gravity slow or speed light up? 2014-01-10T01:11:12.637

6 Did time pass more slowly in the past? 2014-01-14T10:39:20.787

6 Is it possible to have two objects moving by sum speed of light (c) in the opposite direction? 2014-06-03T14:30:38.953

6 Why are (Type II) supernovae so bright? 2014-09-18T13:42:56.453

6 What's in the center of a Galaxy? 2015-06-03T02:53:22.400

6 How does gravity interact with a photon? 2015-06-23T16:41:17.217

6 How to calculate the limiting magnitude of Hubble? 2015-06-29T01:10:33.690

6 What would the night sky look like if the interstellar medium didn't exist to absorb or block light? 2016-05-08T23:45:30.720

6 What color is earthshine? 2016-07-04T11:56:48.737

6 Is there an example of a star that is already dead, but can still be seen on earth? 2017-08-29T09:31:31.667

6 How much do starlight and artificial light illuminate the Moon? 2018-05-17T17:13:18.913

5 What is the farthest point of light that is emitted by a torch? 2014-07-09T14:01:57.987

5 How massive does a planet need to be to create gravitational lensing? 2014-07-21T21:09:06.443

5 Is remote measurement of isotope ratios possible, or must a sample be aquired 2016-07-22T04:48:36.160

5 Can information leave the observable universe? 2016-08-02T02:49:23.520

5 What's the difference of the oldest light and newest light? 2018-04-27T15:27:42.817

5 Are there any examples where the transverse doppler effect is applied in astronomy? 2018-11-18T10:00:03.990

4 Pictures of large galaxies 2014-01-13T23:50:49.733

4 Time dilation on an object circling earth 2014-01-25T18:42:30.900

4 Why is the outline of a crescent moon brighter? 2014-02-04T10:48:53.410

4 Perception of an objects history passing as an observer moves toward it 2014-07-24T07:29:52.387

4 How can light reach us from 14 billion light years away? 2014-09-18T22:48:59.523

4 Could dark matter be considered a medium? 2014-10-14T15:55:05.073

4 How bright are the outer planets, when at close range? 2014-11-05T10:42:02.840

4 Speed of light through the ISM and Wavelength 2015-07-14T22:02:59.480

4 Is a black hole a perfect sphere? 2015-11-05T23:36:33.030

4 Would I actually be able to see Ceres without shining a really bright torch onto it? 2016-01-30T03:02:55.850

4 Which planets have abundant amounts of photoluminiscent matter? 2016-01-31T04:36:51.590

4 Why don't we see more supernovae in our galaxy? 2016-06-04T16:19:35.063

4 Why the light curve goes down when the planet is behind the star? 2016-06-26T14:02:29.067

4 Darkness in Outer Space 2016-10-17T13:33:01.087

4 Light From Sirius 2016-11-21T00:35:09.430

4 Constructing a periscope/telescope - trouble with lenses 2017-02-22T23:12:49.387

4 How bright would it be on the "face" of Titan 2017-12-28T04:22:42.577

4 What would a terraformed Mars look like from Earth? 2018-02-16T07:03:45.450

4 Can light be trapped in orbit? 2018-03-19T19:58:20.893

4 Does Time Exist for Photons? 2018-08-03T13:51:39.010

4 How does V838 Monocerotis look today? Any subsequent light echo images, or is the party over? 2018-11-02T00:51:11.920

3 Why are distant galaxies not visible in the observable Universe? 2014-02-03T11:50:23.463

3 How is the magnitude of a star measured? 2014-02-07T09:08:43.483

3 Is light bending around my finger? 2014-02-22T20:07:02.240

3 Does near light-speed travel doppler-shift the light from the target into gamma rays? 2014-07-19T14:04:23.610

3 how did James Bradley discover light aberration? 2014-07-27T04:02:24.047

3 Is there light on the surface of Venus? 2014-10-22T07:31:05.270

3 speed of light measurement 2014-11-27T09:44:11.610

3 Could someone see anything while being inside black hole? 2015-03-28T05:09:07.017

3 How to differentiate between images of a gravitationally lensed object 2015-04-15T11:20:01.620

3 What is the average color of the universe? 2015-07-28T18:00:55.510

3 How much illumination do the background stars provide? 2015-08-06T17:53:28.653

3 Is the ratio between earth's distance from the sun and the speed of light just a coincidence? 2015-08-07T04:19:32.950

3 How does light so travel so fast?. 2015-09-25T11:57:14.933

3 What's the difference between the apparent horizon and event horizon of a black hole? 2015-11-23T04:19:58.680

3 Why isn't everything yellow(ish)? 2016-01-06T11:45:04.163

3 Gravitational Waves and the Big bang 2016-03-11T08:28:18.960

3 Is there a type of star that emits relatively monochromatic visible light? 2016-08-24T23:14:19.217

3 Total mass of light? 2017-05-06T17:37:50.897