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| | ==Explanation== | | ==Explanation== |
| − | [[Megan]], [[Cueball]], and [[Ponytail]] are observing the results from a {{w|gravitational wave detector}} (see [[#Gravitational waves|details below]]). This comic came out on the day that the first direct observation of gravitational waves was [http://www.nature.com/news/einstein-s-gravitational-waves-found-at-last-1.19361 publicly announced] on 2016-02-11. The {{w|Gravitational wave observation|actual event}} was recorded five months before on 2015-09-14, but it was not reported publicly before they were sure it was a real signal. It seems that [[Randall]] knew in advance about this announcement because this comic was [[:Category:Thursday comics|published on a Thursday]], not following the normal publish schedule, to coincide with the [https://www.theguardian.com/science/2016/feb/11/gravitational-waves-discovery-hailed-as-breakthrough-of-the-century announcement], and there were no other comics released Friday that week. (The altered schedule could be viewed as a meta-reference to the {{w|Time warp (science fiction)|warping}} of {{w|spacetime}}.) That scientists knew there might be an announcement on the way, and more details for the interested can be seen in these two videos from ''Space Time'': ''[https://www.youtube.com/watch?v=1Tstyqz2g7o Have Gravitational Waves Been Discovered?!?]'' and ''[https://www.youtube.com/watch?v=gw-i_VKd6Wo LIGO's First Detection of Gravitational Waves!]'' (See also their follow up [https://www.youtube.com/watch?v=eJ2RNBAFLj0 The Future of Gravitational Waves]).
| + | {{incomplete|I've added some detailed explanation. Someone please proofread / review it. Might need some copy-editing.}} |
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| − | This is the second time within a month that a new astronomical announcement (of something discovered months before the actual announcement) has resulted in a related comic. The first being [[1633: Possible Undiscovered Planets]].
| + | A {{w|gravitational wave detector}} is a device used to measure {{w|gravitational waves}}, small distortions of {{w|spacetime}} that were first predicted by Albert Einstein in 1916. Gravitational waves are ripples in the spacetime fabric itself. This comic came out the day after gravitational waves were publicly announced. |
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| − | From the patterns in the {{w|gravitational waves}} detected by this instrument, it might be possible to guess the nature of the event (e.g. two bodies with dissimilar masses circling a fixed point, two bodies with equal mass circling each other, collision of two massive bodies, etc.). It might also be possible to triangulate the location of the event. Based on these two facts (the location and nature of the event) we might be able to determine which astronomical bodies caused this event (and the status of those bodies afterwards). Thus, it provides an additional medium to observe the universe in addition to {{w|telescopes}} observing all kinds of {{w|electromagnetic radiation}}. This new medium might enable us to observe properties that we couldn't observe with the rest of our observation instruments.
| + | The wikipedia article on {{w|gravitational waves}} describes them well. In simpler/layman's terms, imagine moving a stone through water while it is partly submerged. It'll cause waves on surface of water as it moves through it. These waves will spread away from the center of disturbance and as they move, they will cause the water molecules to oscilate around their mean positions. Similar waves are created in space-time fabric when two "heavy" celestial bodies interact with each other. If you concentrate on an area of water-surface (analogous to spacetime fabric) far away from the point of disturbance, you can observe that if the wave causes compression in one direction, it'll cause expansion of the fabric in other. See [http://www.einstein-online.info/spotlights/gw_waves this page] for nice animations (as well as {{w|gravitational waves}} wiki page). |
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| − | However, the scientists in this comic appear to be receiving more than the expected signals from {{w|black hole}} collisions, they also receive gravitational {{w|Messaging spam|spam messages}}, such as invitations from {{w|Linkedin}}, a {{w|Mortgage loan|mortgage}} offer, and an announcement of a social meet-up, rather than observing astronomical events (see [[#Explanation of observed events|table below]]).
| + | Note that anything with a mass will cause a gravitational wave. Just as waves created by small stones are tiny in comparison to waves created by huge rocks in water, the waves from humans moving around will be tiny compared to the waves created by celestial bodies. Also, the bigger the body, the stronger the wave and the farther away the it will travel. That is why we can only detect gravity waves from heavy bodies like black holes / neutron stars but not from us moving around. |
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| − | There is also a joke on the social meet-up's use of the word ''local group'' because the '{{w|Local Group}}' is also the technical name for the group of galaxies containing the {{w|Milky Way}}.
| + | Now consider spacetime fabric as a thin rubber sheet. If you mark any two points on this sheet and stretch/compress it along the axis joining those two points, the relative positions of these points with respect to their neighboring points do not change, but the distance between them changes. {{w|LIGO}} (Laser Interferometer Gravitational-Wave Observatory) is a large-scale physics experiment designed to detect this compression/expansion. Two facts need to be remembered to easily understand the experiment. First, speed of light (c) is a constant and velocity of an object is distance divided by time taken to travel that distance. Second, gravitational waves cause opposite effects (compression and expansion) in directions perpendicular to each other. Putting these two together, at {{w|LIGO}}, an experiment is setup, where two perpendicular long tunnels are constructed with apparatus to emit and detect laser beams. The beam from laser is split into those two tunnels, then after going through tunnel and back again (a few times) brought together. Tunnel lengths are set up in such way, that in absence of gravity waves, interference between two combined beams cancels them out. When the gravitational wave passes through earth, it is expected that the two tunnel lengths will differ due to the expansion/compression effect described above. The interference will be incomplete, and light would not cancel out. This observation can be concluded as "detection of the gravitational wave passing through". |
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| − | It is not clear if these so-called "events" are causing gravitational waves to be generated or if something, perhaps an alien civilization, is encoding spam messages in gravitational waves. It is plausible that aliens are using gravity waves to encode their messages, as we do something similar with electromagnetic waves to encode and send our messages. However, it would take an extremely advanced civilization to achieve gravity wave encoding. It requires the controlling of orbits and oscillations of super-massive bodies like the Sun, or more likely bodies ten times more massive than it. For example, the first event detected, both in this comic and in real life, was a merger of two black holes of roughly 30 solar masses each.
| + | Megan, Cueball, and Ponytail are observing the results from a gravitational wave detector. From the patterns in the gravitational waves detected by this instrument, it might be possible to guess the nature of the event. e.g. Two bodies with dissimilar masses circling a fixed point, two bodies with equal mass circling each other, collision of two massive bodies, etc. It might also be possible to triangulate the location of event. Based on these two facts (location and nature of event) we might be able to determine which astronomical bodies caused this event (and well-being of those bodies afterwards). Thus, it provides an additional medium of observation of universe in addition to our telescopes. And this new medium might enable us to observe properties that we couldn't observe with our rest of the observation instruments. |
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| − | The title text makes the speculation, that something is sending spam encoded in gravity waves, seem more plausible, as it follows up with a joke that the message senders have gone to such a length that they caused the most energetic event recorded ever (perhaps on the scale of a few {{w|supernovae}} or black hole collisions). One of the scientists is so impressed with this effort that he suggests that they actually post a reply, but one of the other person declines with a "''Nah''"! (As you should always do with spam, else you will just encourage the sender by making it clear that there actually is a receiver on this address.) Randall may have been referring to the fact that the detected event had a power output equal to 50 times that of the entire visible universe.
| + | However, in case of our heroes in this comic, they seem to be able to tell the events that have less to do with astronomical bodies and more with spam messages like invitations from {{w|Linkedin}}, a job networking site, a mortgage offer, and a social meetup. There is also a joke because the '{{w|Local Group}}' is also the technical name for the group of galaxies containing the Milky Way. It is not clear if these so called "events" are causing gravitational waves to be generated or if someone (alien civilization?) is encoding spam messages in gravitational waves. It is plausible that aliens are using gravity waves to encode their messages, since we do something similar with electromagnetic waves to encode and send our messages. Although this it would take an extremely advanced civilization to achieve gravity wave encoding, since it would require them to control orbits and oscillations of super-massive bodies (think at-least on the scale of the Sun, or typically several hundred times bigger than that). The second conclusion (someone is sending spam encoded in gravity waves) seems more plausible since the title text follows this up with a joke that the message senders have gone such a lengths that they caused the most energetic event recorded ever (maybe they blew up few supernovae). One of the receivers is quite impressed with this and suggests that they have to reply to the spam just because the sender has made such an effort to send the message. The other person is not so impressed. |
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| − | In [[1365: Inflation]] gravitational waves are also mentioned.
| + | == Explanation of observed events == |
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| − | ===Gravitational waves===
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| − | A gravitational wave detector is a device used to measure gravitational waves, small distortions of spacetime that were first predicted by {{w|Albert Einstein}} in 1916. Gravitational waves are ripples in the spacetime fabric itself.
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| − | In layman terms, a gravitational wave is like moving a stone through water while partly submerged. It will cause waves on the surface of the water as it moves through it. These waves will spread away from the center of disturbance and as they move, they will cause the water molecules to oscillate around their mean positions. Similar waves are created in the space-time fabric when two celestial bodies interact with each other. If you concentrate on an area of the fabric far away from the point of disturbance, it can be observed that if the wave causes compression in one direction, it'll cause expansion of the fabric in the other. See [http://www.einstein-online.info/spotlights/gw_waves this page] for nice animations.
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| − | Note that anything with a mass will cause a gravitational wave. Just as waves created by small stones are tiny in comparison to waves created by huge rocks in water, the waves from humans moving around will be tiny compared to the waves created by celestial bodies. Also, the bigger the body, the stronger the wave and the farther away it can be detected. That is why we can only detect gravity waves from heavy bodies like black holes or neutron stars but not from [https://arxiv.org/abs/gr-qc/9810016 us moving around] further than around 10m from the test masses. (the LIGO Hanford observatory has also had problems with [https://arxiv.org/abs/gr-qc/0007050 tumbleweeds hitting the building] and had to build a fence).
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| − | Now, let's consider spacetime fabric as a thin rubber sheet. If you mark any two points on this sheet and stretch or compress it along the axis joining those two points, the relative positions of these points with respect to their neighboring points do not change, but the distance between them changes.
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| − | {{w|LIGO}} (Laser Interferometer Gravitational-Wave Observatory) is a large-scale physics experiment designed to detect this compression/expansion, and it was LIGO who discovered the signal that caused this comic. (For a very detailed description of what the team at LIGO did and the history behind see this 90 minutes feature [https://www.youtube.com/watch?v=xj6vV3T4ok8 Gravitational Waves: A New Era of Astronomy Begins] from the 2016 World Science Festival).
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| − | Two facts need to be remembered to easily understand the experiment. First, the {{w|speed of light}} (c) is constant and the speed of an object is the distance moved divided by the time taken to travel that far. Second, gravitational waves cause opposite effects (compression and expansion) in directions perpendicular to each other. At LIGO, an experiment is set up where two perpendicular long tunnels are constructed with apparatus to emit and detect laser beams. The beam from a laser is split into these two tunnels. After going through the tunnel and back again a few times the beams are brought back together. The lengths of the tunnels are set up in such a way that, in the absence of gravity waves, destructive interference between the two combined beams causes them to cancel one another out, resulting in the detector observing zero light intensity. When the gravitational wave passes through earth, one of the tunnel is expected to expand while the other is expected to compress. Due to the difference in lengths, the destructive interference is incomplete and the detectors will be able to detect the presence of light. This observation can be concluded as "detection of the gravitational wave passing through".
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| − | ==Explanation of observed events==
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| | {| class="wikitable" | | {| class="wikitable" |
| − | | | '''Event''' | + | | | <b >Event</b> |
| − | | | '''Explanation''' | + | | | <b >Explanation</b> |
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| | | | Black hole merger in Carina (30 M<sub>☉</sub>, 30 M<sub>☉</sub>) | | | | Black hole merger in Carina (30 M<sub>☉</sub>, 30 M<sub>☉</sub>) |
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| − | Possibly legitimate result from the gravitational wave detector. M<sub>☉</sub> means 1 {{w|Solar Mass}} (1.98892×10<sup>30</sup> kg). So the statement means that {{w|Binary black hole|two black holes}}, each one 30 times more massive than our Sun were observed {{w|Stellar collision|merging}} in the {{w|Carina (constellation)|Carina constellation}}. This observation is similar to the one actually reported in the announcement on the day of this comic, were the two black holes had masses of 36 and 29 solar masses (with an uncertainty that meant they could have had masses as close as 32 and 30 solar masses vs the 30+30 in this event). Also the {{w|Gravitational wave observation#Location of the event|location of the event}} matches with Carina. Although at present time it is not possible to pinpoint the location of the event (that will need more detectors spread out across Earth) they still manage to find out that it most likely originated in the {{w|Southern Celestial Hemisphere}}, which is also where the Carina constellation is located. | + | Possibly legitimate result from the gravitational wave detector. M<sub>☉</sub> is a symbol depicting 1 {{w|Solar Mass}} (1.98892×10<sup>30</sup> kg). So the statement means that two blackholes, each weighing 30 times our Sun were observed merging in {{w|Carina (constellation)|Carina}}. |
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| | | | Zorlax the Mighty would like to connect on Linkedin | | | | Zorlax the Mighty would like to connect on Linkedin |
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| − | A typical LinkedIn request. As this may be a message encoded in gravitational waves, it either means that LinkedIn has now grown outside the Earth, or that the Zorlax person would like to contact Earth. Zorlax is likely a reference to a kid's television gameshow, based on time travel, [https://www.youtube.com/watch?v=PdGGL0OrmFs Zorlax and the Time Travellers]. The first sentence in the movie is: ''Four billions of years ago in the Earths core, destined to be the master of time he is the Mighty Zorlax''. It is likely someone with the power over time would be able to create gravitational waves at his own leisure. | + | A typical LinkedIn request. Not sure who is Zorlax (the mighty one), but according to title text, he set the record for the most energetic physical event ever observed. He might be looking for a job and this might be him demonstrating (showing-off) his mighty powers instead of simply attaching a resume or filling up his profile. Also, this either means that LinkedIn has now grown outside the Earth, or the Zorlax guy wants to have a job on Earth. |
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| | | | Black hole merger in Orion (20 M<sub>☉</sub>, 50 M<sub>☉</sub>) | | | | Black hole merger in Orion (20 M<sub>☉</sub>, 50 M<sub>☉</sub>) |
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| − | Again, a possibly legitimate observation from the gravitational wave detector. It detected a black hole merger of two bodies in the {{w|Orion (constellation)|Orion constellation}}. One of them is 20 times more massive than Sun, the other is 50 times more massive than the Sun. As Orion is located at the {{w|celestial equator}} and since the masses are far from the one announced on the day of this comic, this would then represent a possible 2nd event to be measured later. | + | Again a possibly legitimate observation from the gravitational wave detector. It detected blackhole merger of two bodies. One of them is 20 times heavier than Sun, the other is 50 times heavier than the Sun. Both of them are located in {{w|Orion (constellation)|Orion}}. |
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| | | | Mortgage offer from Triangulum Galaxy | | | | Mortgage offer from Triangulum Galaxy |
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| − | {{w|Triangulum Galaxy}}, also known as Pinwheel Galaxy, is a {{w|spiral galaxy}} approximately 3 million light-years from Earth. It is the third largest galaxy in the Local Group after the {{w|Andromeda Galaxy}} and the Milky Way, these three being the only spiral galaxies in the group. This is presumably an offer to extend a loan, with a house on Earth serving as collateral. However, unless we develop {{w|wormholes}} or {{w|faster-than-light}} travel technologies, it will be difficult to submit an application, even if the offer is legitimate. | + | {{w|Triangulum Galaxy}}, also known as Pinwheel Galaxy is a spiral galaxy approximately 3 million light-years from Earth. It is not clear if the offer is for a house on Earth or if the advertisers want us to buy house in the Triangulum Galaxy. Either way, unless we humans develop a {{w|Wormhole}} or {{w|Faster-than-light}} travel, we may not be able to take up the offer, even if it is legit. |
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| | | | Zorlax the Mighty would like to connect on Linkedin | | | | Zorlax the Mighty would like to connect on Linkedin |
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| − | Same person who sent us LinkedIn invite moments ago. This repeated request may imply that Zorlax is desperate, or may be a jab at LinkedIn's persistence in spamming users with unaccepted connections to view and/or accept them. According to the title text, this was the most energetic physical event ever observed; it may be that Zorlax is demonstrating his capabilities in the hopes that the request would be accepted. | + | Same guy who sent us LinkedIn invite moments ago. The dude seems desperate. |
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| | | | Meet lonely singles in the local group tonight! | | | | Meet lonely singles in the local group tonight! |
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| − | The space advertisers are using space-GeoIP technology on a galactic scale to send spam. A Local Group is the technical term for the group of nearby galaxies that also includes the Milky Way, our own galaxy. There are more than 54 galaxies and few other celestial objects in our local group. This Local Group along with several others form the {{w|Virgo Supercluster}}. It would seem that the advertiser is targeting ads to everyone in the Virgo Supercluster. However, finding "lonely singles" in the 54 galaxies within our local group might be easier said than done for humans here on Earth. Another joke is that human race has been trying to find not just "lonely singles" but any lifeforms beyond Earth for the past few decades and hasn't been able to find them successfully. It seems that gravitational wave detector in the cartoon helped with this mission as well. This kind of spam was previously featured in [[713: GeoIP]]. | + | The space advertisers are using space-GeoIP technology on a galactic scale to send spam. {{w|Local Group}} is the technical term for group of close-by galaxies that also includes {{w|Milky Way}} (our galaxy). There are more than 54 galaxies and few other celestial objects in the local group. {{w|Local Group}} along with several other local groups form {{w|Virgo Supercluster}}. So, it seems that the advertiser might be targetting ads to everyone in the Virgo Supercluster. However, finding "lonely singles" in 54 galaxies within our local group might be easier said than done for humans here on Earth. This kind of spam was previously joked with in [[713: GeoIP]]. |
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| | + | == Trivia == |
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| | + | This comic was published on a Thursday, not following the normal publish schedule, to coincide with the [https://www.theguardian.com/science/2016/feb/11/gravitational-waves-discovery-hailed-as-breakthrough-of-the-century announcement of the discovery of a clear gravitational wave signal] on February 11, 2016. Gravitational waves were detected through the collision of 2 black holes. |
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| | ==Transcript== | | ==Transcript== |
| − | :[Cueball, with arms up, is standing behind Megan who has her hands at her mouth, and who in turn is standing behind Ponytail, who is sitting in front of a large computer console with a screen, a keyboard, and several items on the side (presumably lights and labels). Three wires lead away from the console out of the image to the right.] | + | |
| | + | :[Cueball, Megan, and Ponytail are in a room in front of a computer machine] |
| | :Megan: The gravitational wave detector works! For the first time, we can listen in on the signals carried by ripples in the fabric of space itself! | | :Megan: The gravitational wave detector works! For the first time, we can listen in on the signals carried by ripples in the fabric of space itself! |
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| − | :[Larger panel with the same setting in the middle, but both Cueball and Megan have taken their arms down. More of the wires from the console can be seen to the right. The computer lists six events:]
| + | :Computer: EVENT: Black hole merger in Carina (30 M<sub>☉</sub>, 30 M<sub>☉</sub>) |
| − | :Computer: '''''Event:''''' Black hole merger in Carina (30 M<sub>☉</sub>, 30 M<sub>☉</sub>) | + | :Computer: EVENT: Zorlax the Mighty would like to connect on Linkedin |
| − | :Computer: '''''Event:''''' Zorlax the Mighty would like to connect on Linkedin | + | :Computer: EVENT: Black hole merger in Orion (20 M<sub>☉</sub>, 50 M<sub>☉</sub>) |
| − | :Computer: '''''Event:''''' Black hole merger in Orion (20 M<sub>☉</sub>, 50 M<sub>☉</sub>) | + | :Computer: EVENT: Mortgage offer from Triangulum Galaxy |
| − | :Computer: '''''Event:''''' Mortgage offer from Triangulum Galaxy | + | :Computer: EVENT: Zorlax the Mighty would like to connect on Linkedin |
| − | :Computer: '''''Event:''''' Zorlax the Mighty would like to connect on Linkedin | + | :Computer: EVENT: Meet lonely singles in the local group tonight! |
| − | :Computer: '''''Event:''''' Meet lonely singles in the local group tonight! | |
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| | {{comic discussion}} | | {{comic discussion}} |
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| | [[Category:Comics featuring Cueball]] | | [[Category:Comics featuring Cueball]] |
| | [[Category:Comics featuring Megan]] | | [[Category:Comics featuring Megan]] |
| | [[Category:Comics featuring Ponytail]] | | [[Category:Comics featuring Ponytail]] |
| | [[Category:Astronomy]] | | [[Category:Astronomy]] |
| − | [[Category:Space]]
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| − | [[Category:Social networking]]
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| − | [[Category:Physics]]
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