What ways can extraterrestrials contact us?

Mankind has yet to meet a single form of life outside of our planet. If we ignore the tales of “Zone 51” and “meetings of eyewitnesses with UFOs and their pilots”, we have not yet received any extraterrestrial signals, even remotely trying to resemble the attempt of some intelligent civilization to establish interstellar or intergalactic communication with us. In general, there are no Ewoks and E.T.

Considering the amazing level of technology development we have achieved in the last 100 years, it would be safe to assume that any other highly developed civilization that has mastered space flights and appeared even hundreds of years ahead of ours could now have even more advanced technologies.

Mankind has come up with many ways of transmitting messages through space. Some are used now, time for others will come. If one day super-advanced aliens want to talk with us, then they will face a real choice.

Old good radio waves

This is what first comes to people’s mind when they talk about communication with aliens. Receiving and transmitting messages using this method became the object of interest in many science fiction books and films such as “Contact” and “Independence Day.” In the end, we have been working with radio waves for almost a hundred years now and have achieved quite a good level of efficiency in their use. Many serious scientists and organizations, such as SETI, still use radio waves as the main tool for searching for extraterrestrial civilizations.

With the help of the same radio waves in the late 70’s, the famous “WOW!” Signal was discovered – an unexpected and sharp emission of radiation from the star cluster that was next to us, which no one could explain for many years. Until recently. Although, according to the latest information, some astronomers still doubt that the real source of this signal was determined.

Be that as it may, the method of radio detection has several critical drawbacks. And the first of them is that the further you are from the source of radio waves, the weaker they are. In this case, the radio waves sent by us into space in the last hundred years actually dissipate in just a few light years, becoming completely elusive.

The solution to this problem may be the use of larger transmitting radio trays, but in this case we will face many complex engineering problems. One of them is the construction of a really giant dish, down to the size of the Earth itself. Theoretically any super-developed space civilization could already solve this problem due to the high level of development of its technologies, but for some reason I want to believe that it could come to a more efficient and less resource-consuming method from the list below.

Lasers

Where radio waves are lost and useless, lasers can become a more effective means of communication at distant cosmic distances. Their plus in integrity and density. A sent laser message from a distant-distant galaxy upon arrival to us will remain distinctly.

In addition, the direction of the laser messages is beneficial. For the purpose of delivering a message, you can select even a single target, thereby increasing the effectiveness of such a message. In this regard, lasers are noticeably superior to radio waves. Sufficiently developed civilizations could send messages via laser transmission to other systems located hundreds of light-years away. And one of these messages could be caught here, on Earth.

However, there is a question: what frequency is the laser signal used for transmission?

If civilization is sufficiently developed, then it could use gamma rays for this. A similar type of radiation can be transmitted to really giant distances. Of course, this will require enormous energy costs, but if we assume that developed civilization does not have shortages in these very resources, then problems should not arise.

For us, the potentially more realistic under current conditions is the use of infrared or microwave lasers. At least simply because they require less energy. And, by the way, this method of sending messages is already slowly beginning to adapt.

star Light

You may have heard of the telescope Kepler, NASA’s space observatory, which searches for exoplanets by observing the change in stellar brightness that occurs as a result of the planet’s transit passage past the star.

And now let’s imagine that some advanced cosmic civilization has found a way to place an artificially created giant rectangular or triangular object into the orbit of its star, or maybe even some 1258-gon (an object with 1258 sides). In this case, we just need to figure out how this object will be displayed in the telescope data, which in principle will be feasible in practice, although it will be necessary to tinker.

What is even more interesting is that extraterrestrial civilization does not even need to be super-advanced in order to have such an opportunity. Even in a couple of hundred years we will be capable of such an adventure. All that is needed is to make the object very thin, to be delivered into space and put in orbit.

Dyson’s sphere

The method will be very similar to the previous one, with the only exception being that only a really very technologically advanced civilization will be capable of doing this. And the main goal will not be explained by the simple desire to contact us. Rather, the main task here will be to collect the energy that the star produces.

The idea is this: why put ordinary pieces of iron in orbit, if you can take out the same billions of solar panels to collect stellar energy? It sounds crazy, we understand. But considering our current technological level, mankind will be able to reach this level of technology in a few hundred, and in a less optimistic case – a thousand years.

Having the ability to manually change the starlight, an advanced civilization could send us intelligent looking messages. And it would be much easier for us to catch and understand such messages than to sit and decipher the effects caused by an object of a complex geometric shape located on the orbit, as a point above.

The collected star energy could also be used to power other communication equipment and technologies described in this article. Any civilization that will be able to create such structures will automatically be higher than us in development. And if we are somehow the first to find such activity, sending a response to such a message will be far from the best idea for us.

Unusual phenomena

If we imagine that somewhere there is a civilization that surpasses us for several million years in technological development, then why not imagine that such a civilization will be able to manipulate the movement of cosmic objects inside at least its galaxy?

Let’s say, to attract our attention, she could control the behavior of a nearby star or other objects. Say, first accelerate objects to near-light speed, and then slow down. Do it again and again. In the end, someone let him notice.

Or you can very quickly change the properties of a star, for example its brightness, and thus send encrypted messages, say, prime numbers or digits of the Pi number. Of course, such opportunities will definitely require colossal energy costs, and the technologies themselves, allowing to do this, now can only be imagined except in science fiction.

Nevertheless, astronomers of the Earth every night continue to peer into the depths of the cosmos in the hope of finding something extraordinary that could definitely draw our attention. The above features for us, of course, would seem god-like.

Gravitational waves

More recently, humanity has confirmed the existence of gravitational waves (rapid changes in the curvature of space-time). In 2015, scientists from the Laser Interferometric Gravitational-Wave Observatory (LIGO) conducted an experiment and announced the first real-time observation of the ripple of space-time, which was predicted by Einstein.

A highly developed civilization with the help of neutron stars and black holes (the main sources of gravitational waves) could send us strange, but clearly sensible signals. A little “pohimichit” with the frequency and amplitude of these waves – and with the help of them you can transfer the encoded information.

All this, of course, will require the presence of technological superiority in development. But the good news is that even our current sensors are able to capture gravitational waves launched from a distance of billions of light years. Therefore, any civilization that decides to use them as a means of conveying messages, immediately “appears on our radar.”

In fact, these space-time distortions are so small that we are talking about distances smaller than the diameter of any proton. But if the aliens really want to attract our attention, they could increase the scale of these waves, so that we could get a clearer message from them. Although the option that they could use these waves in such a way that they will be able to kill all life, in theory, too, is possible.

Bombing with high-charged particles

The Earth is exposed to a colossal volume of radiation every day. But if aliens know the way how to even more change its volume, then, most likely, with the help of this radiation they can send and signals that we can detect. All that is needed is to send an elevated just a couple of percent of the total amount of high-charged particles, and our scientists will definitely notice this. And the very change in the number of particles can be used as the encoding for messages.

Of course, you can come up with a more ecological way. But who among the highly developed civilizations will take care of some kind of security for several billions of upright monkeys?

In general, this method of communication is not yet known to our science. In addition, it is not known how to use this method to send more or less directed messages. In fact, from our point of view, this method does not seem the most suitable and effective for interstellar communication. But if the aliens have already mastered it, then why not?

Destroying something big in space

If civilization is technologically advanced enough, then this is really possible. The destruction of large objects in ways that definitely attract our attention, and then send the message by other methods – obviously will not stay away from our eyes and ears. For example, aliens can launch a huge swarm of nanorobots that disintegrate large objects and turn them into elementary particles, or use black holes as a kind of intergalactic eraser erasing everything in its path from reality. It’s fun, right?

It would be more reasonable, of course, to change the rate of disintegration of some cosmic object like a red dwarf (a star capable of burning trillions of years), quickly “quenching” it. Our scientists have never seen the death of a red dwarf star. Probably because the Universe itself exists less than the life cycle of such stars is potentially equal. Now we would be surprised!

Molehills

In fact, we do not know whether such objects are physically possible. But if it turns out that wormholes are not only our hypotheses, but also quite real reality, we still do not know how (natural or artificial) they can be created.

But just from this moment begins the most interesting. Perhaps the aliens have already found a way to put a wormhole near us in the manner of Interstellar and use it as a kind of portal for the transmission of both physical objects and radio messages.

Maybe someday a mole hole will open next to us, and a whole fleet of ships will appear from it, wanting to make the first contact. Or want to harvest …

Change in the laws of physics

When we look into space, we think that the laws of physics act on the entire Universe, they are constant and never change. It seems to us that everything is really so, but what if we are wrong?

What if the incredibly technologically advanced aliens have found a way to manipulate physics in a way that greatly simplifies the use of those methods that were described above?

When you are subject to the laws of physics – you are able to control everything. If our tiny, though developed monkey brains are not yet able to understand many things that occur even in those parts of the universe to which our gaze has reached, what can we say about technologies that can not simply ignore but actually change the laws of physics?

Just imagine that somewhere there may be technologies that can not simply destroy large objects, but literally take them beyond the bounds of being. And instead of just destroying us in the fiery hyena, these technologies can deprive us of the possibility of existence as such.