New controversial theory: Past, present, future exist simultaneously
Our experience of time may be blinding us to its true nature, say scientists.
- Time may not be passing at all, says the Block Universe Theory.
- Time travel may be possible.
- Your perception of time is likely relative to you and limited.
We seem to perceive time as passing in one direction. After all, we can't just just forward to the future or revisit our past if we felt like it. Every minute of every day appears to move us ahead, pulling us through our lives towards an inexorable demise. At least that's what the conventional experience of time tells us. But what if your present, past, and future all existed already? Time, from that point of view, would not flow.
The block universe theory says that our universe may be looked at as a giant four-dimensional block of spacetime, containing all the things that ever happen, explained Dr. Kristie Miller, the joint director for the Centre for Time at the University of Sydney.
In the block universe, there is no "now" or present. All moments that exist are just relative to each other within the three spacial dimensions and one time dimension. Your sense of the present is just reflecting where in the block universe you are at that instance. The "past" is just a slice of the universe at an earlier location while the "future" is at a later location.
So, is time just an elaborate mind trick? And more importantly - is time travel possible?
Dr. Miller's answer to that is "yes". Of course, just hypothetically, since we'd need to figure out first how to travel at "some reasonable percentage of the speed of light". Going to the past would entail using wormholes, like "short cuts through space-time".
Block Universe diagram.Credit: ABC Science
Now, if you did manage to get back in time, you won't be able to change it. This is because your past is always simultaneously someone else's future. So if you travel to the past, you're just making that future the way it is. So don't worry about "grandfather paradoxes" - your time machine has already been incorporated into the scheme of things.
'If I travel to the past, I am part of the past," said Miller. "Importantly, I was always part of the past."
What's more - maybe the past has already been altered by time travelers. How would we be able to tell if it hasn't? "For all we know, the reason the past is the way it is, is in part due to the presence of time travelers," added Miller.
By that logic, what you do tomorrow will make it the way it is, with you fulfilling a certain destiny writ in time, which is in itself more of an illusion than a fundamental property of nature.
Certainly, with such claims, the block universe theory has its detractors. One big criticism is that the future shouldn't exist yet. Physicist Lee Smolin wrote that "The future is not now real and there can be no definite facts of the matter about the future." Furthermore, as he added at a 2017 conference, what is real is just "the process by which future events are generated out of present events."
Another negative of this idea is if the block universe is static, what is the point of anything? Can you have progress? Answering that is the "evolving block universe" model which sees the block of the universal space-time growing rather than staying the same. The surface of such a volume would represent the present moment. It's when "the indefiniteness of the future changes to the definiteness of the past," as described it cosmologist George Ellis. Under that model, the changing part would be the future.
While the debates are going to continue, the block universe theory is one of the most promising approaches that can reconcile the cosmological view of time with our everyday experience. What may be certain - time is much more than what it appears to be. Unraveling its mysteries is integral to understanding the human experience.
Researchers documented the most common negative side effects of smoking weed, and who might be most susceptible.
- A team of researchers identified a total of 26 possible adverse reactions to cannabis use.
- Coughing fits, anxiety, and paranoia are among the top three most common adverse reactions to smoking weed.
- It was the people who smoke on a less frequent basis who were more likely to have had the bad experiences.
The most common adverse effects of pot<p>As it turns out, coughing fits are among the top three most common adverse reactions to cannabis use, along with anxiety and paranoia, according to a new study published in the <em>Journal</em><a href="https://jcannabisresearch.biomedcentral.com/articles/10.1186/s42238-019-0013-x" target="_blank"><em> of Cannabis Research</em></a>. </p><p>Now that weed is legal in the state, a team of researchers at Washington State University sought to document potential negative reactions to cannabis in order to paint a detailed picture of the effects of smoking weed for newbies. The authors surveyed more than 1,500 college students on the specific type and frequency of adverse reactions they had experienced while using pot. Additionally, the students in the study were surveyed about their demographics, personality traits, reasons for using cannabis and their use patterns. </p><p>Despite marijuana's <a href="https://bigthink.com/sex-relationships/marijuana-sex" target="_self">numerous benefits</a>, the team identified a total of <a href="https://jcannabisresearch.biomedcentral.com/articles/10.1186/s42238-019-0013-x/tables/2" target="_blank">26 possible adverse reactions to</a> the drug. More than half of the study participants reported having coughing fits along with anxiety and/or paranoia while using cannabis. The most frequently occuring of these were the coughing fits, along with chest/lung discomfort and body humming. A subset of the study group reported these reactions occurring around 30–40% of the time they were using pot. On the flip side, the three <em>least</em>-commonly reported reactions to cannabis use were fainting, visual hallucinations and cold sweats. </p><p>"There's been surprisingly little research on the prevalence or frequency of various adverse reactions to cannabis and almost no research trying to predict who is more likely to experience these types of adverse reactions," <a href="https://news.wsu.edu/2020/03/30/new-research-sheds-light-potentially-negative-effects-cannabis/" target="_blank">said Carrie Cuttler</a>, assistant professor of psychology and an author on the paper, according to WSU News. "With the legalization of cannabis in Washington and 10 other states, we thought it would be important to document some of this information so that more novice users would have a better sense of what types of adverse reactions they may experience if they use cannabis."</p><p>The most distressing of the 26 negative reactions were panic attacks, fainting, and vomiting. Yet, the survey data suggested that cannabis users generally do not find even acute adverse reactions to cannabis to be severely distressing.</p>
What causes a bad reaction?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjkwOTEwOC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNTQ5MDQ2Mn0.S2Pkbh3VAgB4Gk5tkavamMv0_4t76dg65yGWpCHG17U/img.jpg?width=1245&coordinates=0%2C1872%2C0%2C1252&height=700" id="dee45" class="rm-shortcode" data-rm-shortcode-id="df6e30ecae156ba0012f4773a374800c" data-rm-shortcode-name="rebelmouse-image" />
But most city dwellers weren't seeing the science — they were seeing something out of Blade Runner.
On Sept. 9, many West Coast residents looked out their windows and witnessed a post-apocalyptic landscape: silhouetted cars, buildings and people bathed in an overpowering orange light that looked like a jacked-up sunset.
A study finds 1.8 billion trees and shrubs in the Sahara desert.
- AI analysis of satellite images sees trees and shrubs where human eyes can't.
- At the western edge of the Sahara is more significant vegetation than previously suspected.
- Machine learning trained to recognize trees completed the detailed study in hours.
Why this matters<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU2MDQ1OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzOTkyODg5NX0.O3S2DRTyAxh-JZqxGKj9KkC6ndZAloEh4hKhpcyeFDQ/img.jpg?width=980" id="3770d" class="rm-shortcode" data-rm-shortcode-id="3c27b79d4c0600fb6ebb82e650cabec0" data-rm-shortcode-name="rebelmouse-image" />
Area in which trees were located
Credit: University of Copenhagen<p>As important as trees are in fighting climate change, scientists need to know what trees there are, and where, and the study's finding represents a significant addition to the global tree inventory.</p><p>The vegetation Brandt and his colleagues have identified is in the Western Sahara, a region of about 1.3 million square kilometers that includes the desert, <a href="https://en.wikipedia.org/wiki/Sahel" target="_blank">the Sahel</a>, and the <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/subhumid-zones" target="_blank" rel="noopener noreferrer">sub-humid zones</a> of West Africa.</p><p>These trees and shrubs have been left out of previous tabulations of carbon-processing worldwide forests. Says Brandt, "Trees outside of forested areas are usually not included in climate models, and we know very little about their carbon stocks. They are basically a white spot on maps and an unknown component in the global carbon cycle."</p><p>In addition to being valuable climate-change information, the research can help facilitate strategic development of the region in which the vegetation grows due to a greater understanding of local ecosystems.</p>
Trained for trees<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU2MDQ3MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNTk5NTI3NH0.fR-n1I2DHBIRPLvXv4g0PVM8ciZwSLWorBUUw2wc-Vk/img.jpg?width=980" id="e02c0" class="rm-shortcode" data-rm-shortcode-id="79955b13661dca8b6e19007935129af1" data-rm-shortcode-name="rebelmouse-image" />
Credit: Martin Brandt/University of Copenhagen<p>There's been an assumption that there's hardly enough vegetation outside of forested areas to be worth counting in areas such as this one. As a result the study represents the first time a significant number of trees — likely in the hundreds of millions when shrubs are subtracted from the overall figure — have been catalogued in the drylands region.</p><p>Members of the university's Department of Computer Science trained a machine-learning module to recognize trees by feeding it thousands of pictures of them. This training left the AI be capable of spotting trees in the tiny details of satellite images supplied by NASA. The task took the AI just hours — it would take a human years to perform an equivalent analysis.</p><p>"This technology has enormous potential when it comes to documenting changes on a global scale and ultimately, in contributing towards global climate goals," says co-author Christian Igel. "It is a motivation for us to develop this type of beneficial artificial intelligence."</p><p>"Indeed," says Brandt says, "I think it marks the beginning of a new scientific era."</p>
Looking ahead and beyond<p>The researchers hope to further refine their AI to provide a more detailed accounting of the trees it identifies in satellite photos.</p><p>The study's senior author, Rasmus Fensholt, says, "we are also interested in using satellites to determine tree species, as tree types are significant in relation to their value to local populations who use wood resources as part of their livelihoods. Trees and their fruit are consumed by both livestock and humans, and when preserved in the fields, trees have a positive effect on crop yields because they improve the balance of water and nutrients."</p><p>Ahead is an expansion of the team's tree hunt to a larger area of Africa, with the long-term goal being the creation of a more comprehensive and accurate global database of trees that grow beyond the boundaries of forests.</p>
Younger Americans support expanding the Supreme Court and serious political reforms, says new poll.